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                                                                   Exhibit 10.22

                              BEDFORD BUSINESS PARK
                                4-18 CROSBY DRIVE
                             BEDFORD, MASSACHUSETTS

                         Lease Dated February 22, 2007

     THIS INSTRUMENT IS AN INDENTURE OF LEASE in which the Landlord and the
Tenant are the parties hereinafter named, and which relates to space in a
certain complex (the "Complex") known as Bedford Business Park, and with an
address at, 4-18 Crosby Drive, Bedford, Massachusetts.

     The parties to this Indenture of Lease hereby agree with each other as
follows:

                                    ARTICLE I

                                 Reference Data

1.1  Subjects Referred To

     Each reference in this Lease to any of the following subjects shall be
     construed to incorporate the data stated for that subject in this Article:

<TABLE>
<S>                              <C>
Landlord:                        Boston Properties Limited Partnership, a
                                 Delaware limited partnership

Landlord's Original Address:     c/o Boston Properties, Inc.
                                 111 Huntington Avenue, Suite 300
                                 Boston, Massachusetts 02199-7610

Landlord's Construction          Ben Lavery/Richard Monopoli
Representative:

Tenant:                          iRobot Corporation, a Delaware corporation

Tenant's Original Address:       63 South Avenue
                                 Burlington, Massachusetts 01803

Tenant's Construction            Tom Isley/Mark A. Urbanek, P.E.
Representative:

Commencement Date:               As defined in Sections 2.4 and 3.4.
</TABLE>

<PAGE>

<TABLE>
<S>                              <C>
Term (Sometimes Called           One hundred forty-four (144) calendar months
Original Term):                  (plus the partial month, if any, immediately
                                 following the Commencement Date), unless
                                 extended or sooner terminated as provided in
                                 this Lease.

Extension Option:                Two (2) periods of five (5) years each, as
                                 provided in and on the terms set forth in
                                 Section 8.20 hereof.

The Site:                        That certain parcel of land known as and
                                 numbered 4-18 Crosby Drive, Bedford, Middlesex
                                 County, Massachusetts, being more particularly
                                 described in Exhibit A attached hereto

Building C:                      The building in the "Complex" (as hereinafter
                                 defined in this Section 1.1) presently known as
                                 Building C and appropriately labeled on Exhibit
                                 A-1 attached hereto and incorporated herein by
                                 reference.

Building D:                      The building in the Complex presently known as
                                 Building D and appropriately labeled on Exhibit
                                 A-1 attached hereto and incorporated herein by
                                 reference.

Building E:                      The building in the Complex presently known as
                                 Building E and appropriately labeled on Exhibit
                                 A-1 attached hereto and incorporated herein by
                                 reference.

The Building:                    Building C, Building D or Building E, as may
                                 apply to the context.

The Buildings:                   Building C, Building D and Building E,
                                 collectively.

The Additional Buildings:        The other buildings in the Complex and
                                 presently numbered Buildings A, B, F, G and H,
                                 as shown on Exhibit A-1 attached hereto and
                                 incorporated herein by reference.

The Complex:                     The Buildings and the Additional Buildings
                                 together with all parking areas and the Site.
</TABLE>


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<TABLE>
<S>                              <C>
Premises (Sometimes also         The entirety of Buildings C, D and E in
Referred to as "Tenant's         accordance with the floor plans annexed hereto
Space"):                         as Exhibit D and incorporated herein by
                                 reference (subject to the exclusions described
                                 in Section 2.1 below).

Number of Parking Privileges:    Three (3) parking privileges for each 1,000
                                 square feet of rentable floor area leased by
                                 Tenant, subject to and in accordance with the
                                 provisions of Section 2.2.1 below.

Annual Fixed Rent:               (a) During the period commencing on the
                                 Commencement Date and ending on the last day of
                                 the thirty-sixth (36th) full calendar month
                                 immediately following the Commencement Date, at
                                 the annual rate of $2,008,488.48 (being the
                                 product of (i) $12.73 and (ii) the "Rentable
                                 Floor Area of the Premises" (hereinafter
                                 defined in this Section 1.1)).

                                 (b) During the period commencing on the first
                                 day of the thirty-seventh (37th) full calendar
                                 month immediately following the Commencement
                                 Date and ending on the last day of the Original
                                 Term, at the annual rate of $2,087,376.48
                                 (being the product of (i) $13.23 and (ii) the
                                 Rentable Floor Area of the Premises).

                                 (c) During each extension option period (if
                                 exercised), as determined pursuant to Section
                                 8.20.

Additional Rent:                 All charges and other sums payable by Tenant to
                                 Landlord as set forth in this Lease, in
                                 addition to Annual Fixed Rent.

Rentable Floor Area of           51,123 square feet.
Building C:

Rentable Floor Area of           54,507 square feet.
Building D:
</TABLE>


                                        3

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<TABLE>
<S>                              <C>
Rentable Floor Area of           52,126 square feet.
Building E:

Rentable Floor Area of the       157,776 square feet, being the sum of (i) the
Premises (Sometimes also         Rentable Floor Area of Building C, (ii) the
Called "Rentable Floor Area      Rentable Floor Area of Building D and (iii) the
of Tenant's Space"):             Rentable Floor Area of Building E.

Total Rentable Floor Area of     157,776 square feet.
the Buildings:

Total Rentable Floor Area Of     315,928 square feet.
The Additional Buildings:

Total Rentable Floor Area of     473,704 square feet.
the Complex:

Permitted Uses:                  Collectively, the Permitted Use of the
                                 Buildings and the Permitted Use of the
                                 Additional Land Areas (as that term is defined
                                 in Section 8.27 below).

Permitted Use of the             Research, design, engineering, prototyping and
Buildings:                       development of the products and equipment from
                                 time to time of Tenant, light manufacturing
                                 (including installation and operation of
                                 machine shops) and testing of such products and
                                 equipment, and general administrative and
                                 executive office uses, as each of the same may
                                 from time to time be permitted by the Zoning
                                 By-Law for the Town of Bedford.

Permitted Use of Additional      Testing of Tenant's products and equipment
Land Areas:                      (including testing robot-controlled vehicles),
                                 as the same may from time to time be permitted
                                 by the Zoning By-Law for the Town of Bedford.

Initial Minimum Limits of        $6,000,000.00 combined single limit per
Tenant's Commercial General      occurrence, which can be achieved through a
Liability Insurance:             combination of primary and umbrella liability
                                 coverage.

Broker:                          Richards, Barry, Joyce & Partners
                                 53 State Street
                                 Boston, Massachusetts 02109
</TABLE>


                                        4

<PAGE>

<TABLE>
<S>                              <C>
Security Deposit:                $2,000,000.00, to be held and disposed of
                                 (including any reductions in the amount
                                 thereof) pursuant to the provisions of Section
                                 8.21 of this Lease.
</TABLE>

1.2  Exhibits

     There are incorporated as part of this Lease:

Exhibit A   -- Description of Site

Exhibit A-1 -- Site Plan of Complex

Exhibit A-2 -- Tenant's Visitor Parking Area

Exhibit B-1 -- Landlord's Base Building Work

Exhibit B-2 -- Preliminary Schematic Plans for Tenant Improvement Work

Exhibit C   -- Landlord's Services

Exhibit D   -- Floor Plans

Exhibit E   -- Form of Commencement Date Agreement

Exhibit F-1 -- Form of Lien Waivers

Exhibit F-2 -- Construction Rules and Regulations

Exhibit G   -- Broker Determination of Prevailing Market Rent

Exhibit H   -- Form of Letter of Credit

Exhibit I-1 -- Land Recreation Area A

Exhibit I-2 -- Land Recreation Area B

Exhibit J   -- MHD Lease

Exhibit K   -- Lease Audit Confidentiality Agreement

Exhibit L   -- Notice of Lease

Exhibit M   -- Current Lender's Standard Form SNDA


                                        5
<PAGE>

Exhibit N -- Form of Landlord's Lien Waiver

Exhibit O -- Existing Leases

1.3  Table of Articles and Sections

<TABLE>
<S>                                                                          <C>
ARTICLE I ................................................................     1
   Reference Data ........................................................     1
      1.1  Subjects Referred To ..........................................     1
      1.2  Exhibits ......................................................     5
      1.3  Table of Articles and Sections ................................     6

ARTICLE II ...............................................................     8
   Building, Premises, Term and Rent .....................................     8
      2.1  The Premises ..................................................     8
      2.2  Rights to Use Site Facilities .................................     9
      2.3  Landlord's Reservations .......................................    12
      2.4  Habendum ......................................................    13
      2.5  Fixed Rent Payments ...........................................    13
      2.6  Operating Expenses ............................................    14
      2.7  Real Estate Taxes .............................................    21
      2.8  Tenant Electricity ............................................    24

ARTICLE III ..............................................................    24
   Condition of Premises; Alterations ....................................    24
      3.1  Base Building Work ............................................    24
      3.2  Tenant Improvement Work .......................................    26
      3.3  Tenant Allowances .............................................    28
      3.4  Substantial Completion ........................................    31
      3.5  Force Majeure and Other Delays ................................    34
      3.6  Quality and Performance of Work ...............................    36
      3.7  Arbitration ...................................................    39
      3.8  Escrow of Funds ...............................................    39

ARTICLE IV ...............................................................    40
   Landlord's Covenants; Interruptions and Delays ........................    40
      4.1  Landlord Covenants ............................................    40
      4.2  Interruptions and Delays in Services and Repairs, Etc .........    41
      4.3  Landlord's Insurance ..........................................    43
      4.4  Landlord's Indemnity ..........................................    44
      4.5  Compliance with Laws ..........................................    44
      4.6  Leasing Restrictions ..........................................    44

ARTICLE V ................................................................    45
</TABLE>


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<TABLE>
<S>                                                                          <C>
   Tenant's Covenants ....................................................    45
      5.1  Payments ......................................................    46
      5.2  Repair and Yield Up ...........................................    46
      5.3  Use ...........................................................    46
      5.4  Obstructions; Items Visible From Exterior; Rules and
           Regulations ...................................................    48
      5.5  Safety Appliances .............................................    48
      5.6  Assignment; Sublease ..........................................    49
      5.7  Indemnity; Insurance ..........................................    57
      5.8  Personal Property at Tenant's Risk ............................    58
      5.9  Right of Entry ................................................    59
      5.10 Floor Load; Prevention of Vibration and Noise .................    60
      5.11 Personal Property Taxes .......................................    60
      5.12 Compliance with Laws ..........................................    60
      5.13 Payment of Litigation Expenses ................................    60
      5.14 Alterations ...................................................    61
      5.15 Vendors .......................................................    64
      5.16 Patriot Act ...................................................    65
      5.17 Signage .......................................................    66

ARTICLE VI ...............................................................    69
   Casualty and Taking ...................................................    69
      6.0  Landlord's Restoration Estimate ...............................    69
      6.1  Damage Resulting from Casualty ................................    69
      6.2  Uninsured Casualty ............................................    71
      6.3  Rights of Termination for Taking ..............................    71
      6.4  Award .........................................................    73
      6.5  Damage to Parking Areas and Land Recreation Area A ............    73
      6.6  Allocation of Proceeds Following Termination ..................    74

ARTICLE VII ..............................................................    75
   Default ...............................................................    75
      7.1  Tenant's Default ..............................................    75
      7.2  Landlord's Default ............................................    79

ARTICLE VIII .............................................................    80
   Miscellaneous Provisions ..............................................    80
      8.1  Extra Hazardous Use ...........................................    80
      8.2  Waiver ........................................................    80
      8.3  Cumulative Remedies ...........................................    80
      8.4  Quiet Enjoyment ...............................................    81
      8.5  Notice to Mortgagee and Ground Lessor .........................    82
      8.6  Assignment of Rents ...........................................    82
      8.7  Surrender .....................................................    82
      8.8  Brokerage .....................................................    83
      8.9  Invalidity of Particular Provisions ...........................    83
</TABLE>


                                        7

<PAGE>

<TABLE>
<S>                                                                          <C>
      8.10 Provisions Binding, Etc .......................................    83
      8.11 Recording; Confidentiality ....................................    84
      8.12 Notices .......................................................    84
      8.13 When Lease Becomes Binding ....................................    85
      8.14 Section Headings ..............................................    85
      8.15 Rights of Mortgagee ...........................................    85
      8.16 Status Reports and Financial Statements .......................    86
      8.17 Self-Help .....................................................    87
      8.18 Holding Over ..................................................    88
      8.19 Non-Subrogation ...............................................    89
      8.20 Extension Option ..............................................    89
      8.21 Security Deposit ..............................................    90
      8.22 Late Payment ..................................................    93
      8.23 Tenant's Payments .............................................    94
      8.24 Waiver of Trial By Jury .......................................    94
      8.25 Governing Law .................................................    94
      8.26 Tenant's Equipment ............................................    94
      8.27 Land Recreation Space .........................................    97
      8.28 Tenant's Expansion Rights: Buildings F, G and H ...............   100
      8.29 Tenant's Expansion Rights: Buildings A and B ..................   105
      8.30 Waiver of Landlord's Lien .....................................   107
      8.31 Arbitration ...................................................   107
      8.32 Temporary Space ...............................................   108
</TABLE>

                                   ARTICLE II

                        Building, Premises, Term and Rent

2.1  The Premises

     Landlord hereby demises and leases to Tenant, and Tenant hereby hires and
     accepts from Landlord, Tenant's Space in the Building excluding the roof
     and exterior faces of exterior walls, elevator wells and pipes, ducts,
     conduits, wires and appurtenant fixtures serving exclusively or in common
     other parts of the Buildings or the Complex. Notwithstanding the foregoing,
     for so long as Tenant leases the entire rentable square footage of any of
     the Buildings (or the entire rentable floor area of any of the Additional
     Buildings in the event Tenant shall exercise any expansion rights under
     Sections 8.28 or 8.29 below), Tenant shall have the exclusive right to use
     the loading areas, fan rooms, janitorial, electrical, telephone and
     telecommunications closets, conduits, risers, plenum spaces and elevators
     exclusively serving such Building or Buildings (or Additional Building(s)
     if applicable), subject, however, to Landlord's right to control access to
     such spaces. In the event that Tenant leases less than the entirety of a
     Building or Additional Building, Tenant's rights to use the foregoing areas
     shall be in common with the rights of other occupants of such Building or
     Additional Building.


                                        8
<PAGE>

     Tenant's Space with such exclusions is hereinafter referred to as the
     "Premises." The term "Buildings" means the Buildings identified in Section
     1.1, and which are the subject of this Lease; the term "Additional
     Buildings" means the Additional Buildings identified in Section 1.1; the
     term "Site" means all, and also any part of the Land described in Exhibit
     A, plus any additions or reductions thereto resulting from the acquisition
     of adjacent property by Landlord or from the change of any abutting street
     line and all parking areas and structures. The term "Complex" means the
     Buildings, the Additional Buildings and the Site.

     Landlord shall use commercially reasonable efforts to cause the Town of
     Bedford to modify the existing numerical/alphabetical address system for
     the Complex in a manner reasonable acceptable to Tenant prior to the
     Commencement Date; provided, however, that Landlord shall not be deemed to
     be in default of its obligations hereunder in the event that the Town of
     Bedford fails to authorize such modifications, so long as Landlord has used
     commercially reasonable efforts as aforesaid. If the existing address
     system is thus modified, Landlord and Tenant shall within a reasonable time
     thereafter execute a letter agreement confirming the new building
     designations within the Complex.

2.2  Rights to Use Site Facilities

     Subject to Landlord's right to change or alter any of the following in
     Landlord's discretion as expressly herein provided, Tenant shall have, as
     appurtenant to the Premises, the non-exclusive right to use in common with
     others, subject to reasonable rules of general applicability to tenants of
     the Complex from time to time made by Landlord of which Tenant is given
     notice (a) any common lobbies, corridors, stairways, restrooms, elevators,
     loading platforms, janitor's closets, electrical and telephone closets of
     the Buildings and the pipes, ducts, conduits, wires and appurtenant meters
     and equipment serving the Buildings or the Premises, (b) common walkways
     and driveways necessary for access to the Buildings and parking areas
     serving the Complex and (c) the cafeteria and fitness center located or to
     be located in Building A of the Complex and the common corridors in
     Buildings A, B and G providing access thereto (the foregoing collectively
     referred to as the "Common Areas"). So long as Tenant leases the entirety
     of Building E, Tenant shall have the exclusive right, at no additional
     charge, to use the loading areas and bays in or at Building E.
     Notwithstanding anything to the contrary herein, Landlord has no obligation
     to allow any particular telecommunication service provider to have access
     to the Premises except as may be required by applicable law and except that
     Landlord agrees to permit Verizon to have telecommunications access to the
     Premises and the Complex at no additional charge for the purpose of
     providing telecommunications service to Tenant. Except as otherwise
     expressly provided above, if Landlord permits such access, Landlord may
     condition such access upon the payment to Landlord by the service provider
     of fees assessed by Landlord in its reasonable discretion. Notwithstanding
     the foregoing, Landlord will not unreasonably withhold, condition or delay
     its approval of any telecommunications provider designated by Tenant to
     service the Premises, so long as such provider is not utilizing the Site to
     provide service to third parties other than Tenant. Landlord hereby
     represents and warrants to Tenant that Verizon presently provides
     telecommunications services to the Complex.


                                       9

<PAGE>

     2.2.1 Tenant's Parking

          (A) In addition, Tenant shall have the right, at no additional charge
          to Tenant, to use the Number of Parking Spaces (referred to in Section
          1.1) in the parking areas of the Complex for the parking of
          automobiles, in common with use by other tenants from time to time of
          the Complex, provided, however, that Landlord shall not be obligated
          to furnish stalls or spaces on the Site specifically designated for
          Tenant's use. Notwithstanding the foregoing, for so long as Tenant
          shall be directly leasing Buildings C and D in their entirety, Tenant
          shall have the exclusive right to use the area designated as "Tenant's
          Visitor Parking Area" on Exhibit A-2 attached hereto for parking by
          Tenant and its visitors (it being understood and agreed that in the
          event Tenant shall cease to directly lease Buildings C and D in their
          entirety, the number of spaces which Tenant shall be entitled to use
          shall be reduced proportionately based upon the square footage Tenant
          continues to directly lease in Buildings C and D). Landlord will use
          reasonable efforts, by the use of signs and markings, to designate the
          spaces as being intended for the use of Tenant's visitors, but shall
          not be obligated to police the use of such spaces, which Tenant
          recognizes are to be operated on a self-parking basis. Tenant's
          visitor parking shall not be subject to or affected by any Managed
          Parking Program instituted by Landlord under this Section 2.2.1.

          In the event that the Rentable Floor Area of the Premises increases or
          decreases at any time during the Lease Term, the Number of Parking
          Spaces provided to Tenant hereunder shall be increased or reduced
          proportionately based upon the ratio set forth in Section 1.1.

          (B) In the event that during the Lease Term, Landlord executes leases
          for premises within the Complex (including this Lease) that result in
          the commitment of more than One Thousand One Hundred (1,100) parking
          spaces in the aggregate, Landlord shall, at its sole cost and expense,
          commence the process of obtaining the necessary permits and approvals
          to construct a structured parking facility on the Site. In the event
          that during the Lease Term, Landlord executes leases for premises
          within the Complex (including this Lease) that result in the
          commitment of more than One Thousand Two Hundred Thirty (1,230)
          parking spaces in the aggregate and such commitments result in the
          existence of a "Parking Shortage" (as hereinafter defined), Landlord
          shall, at its sole cost and expense, use commercially reasonable best
          efforts to at Landlord's election either (x) endeavor to negotiate
          with adjacent landowners for the right to use land adjacent to the
          Site as a satellite parking area serving the Complex or (y) endeavor
          to construct a structured parking facility on the Site (either of the
          options described in subsections (x) or (y) being hereinafter referred
          to as the "Alternative Parking"). During Landlord's pursuit of the
          Alternative Parking, Landlord shall, at its sole cost and expense,
          institute a managed parking program for the parking areas on the Site
          (the "Managed Parking Program"). Tenant acknowledges and agrees that
          there may be a temporary disruption in parking in


                                       10

<PAGE>

          connection with the conversion to a Managed Parking Program and/or the
          construction of a new parking facility, and Tenant shall reasonably
          cooperate with Landlord at no cost to Tenant during such conversion
          and/or construction (Landlord hereby agreeing to use commercially
          reasonable efforts to minimize such disruption). Tenant further
          acknowledges that, despite its use of commercially reasonable best
          efforts, Landlord may be unable to obtain rights to use additional
          land or to secure the permits and approvals to construct a new parking
          facility, and accordingly that in no event shall Landlord be in
          default of its obligations hereunder so long as (x) Landlord has used
          commercially reasonable best efforts as aforesaid and (y) Landlord has
          implemented the Managed Parking Program in order to address the
          Parking Shortage.

          For the purposes hereof, a "Parking Shortage" shall be defined as an
          overuse of the parking areas of the Site such that Tenant is unable to
          utilize the Number of Parking Spaces provided to Tenant hereunder, as
          determined in accordance with the following procedure:

          (i)  In the event that Landlord receives four (4) complaints from
               tenants of the Complex over a period of two (2) weeks indicating
               that they are unable to find parking spaces at the Complex,
               Landlord shall perform and complete a parking survey of the
               Complex within two (2) weeks of its receipt of the last such
               complaint.

          (ii) If the parking survey indicates that less than ninety-eight
               percent (98%) of the total number of parking spaces on the Site
               are available for tenant parking over a period of two (2) weeks,
               then Landlord shall attempt to ascertain whether the cause of the
               problem is a particular tenant's overuse of the number of parking
               spaces provided to such tenant under the terms of its lease and
               shall take reasonable measures to enforce the terms of such lease
               and rectify the situation.

          (iii) In the event that the overuse cannot be readily addressed by
               Landlord, then a Parking Shortage shall be deemed to exist and
               shall trigger Landlord's obligations under this Section 2.2.1 to
               implement the Managed Parking Program and endeavor to obtain the
               Alternative Parking.

          Notwithstanding anything contained herein to the contrary, it is
          expressly understood and agreed that Landlord shall be under no
          obligation whatsoever (under this subsection (B) or otherwise) to
          address a Parking Shortage at the Site to the extent such Parking
          Shortage is caused by the use of parking spaces by any subtenant of
          Tenant's in a ratio greater than three (3) parking privileges for each
          1,000 square feet of rentable floor area of the subleased premises. In
          addition, under no circumstances shall Landlord be required to
          endeavor to obtain the Alternative Parking in the event of a Parking
          Shortage that occurs during the last three (3) years of the Lease Term
          unless and until Tenant shall validly exercise its then-current
          extension option under Section 8.20 below (it being understood and


                                       11

<PAGE>

          agreed in connection with the foregoing that (x) Landlord shall have
          no obligation to endeavor to obtain the Alternative Parking in the
          event that Tenant shall have no further rights to extend the Lease
          Term and (y) Landlord shall nonetheless be required to implement the
          Managed Parking Program to address the Parking Shortage irrespective
          of the amount of time remaining in the Lease Term).

          (C) Subject to the provisions of Section 8.27 below and for so long as
          Tenant has the exclusive right to use the Additional Land Areas (as
          defined in said Section 8.27), in no event shall the Additional Land
          Areas be used by Landlord to provide additional parking facilities or
          parking spaces for the Site or to satisfy the Number of Parking Spaces
          to which Tenant is entitled hereunder unless (a) Tenant shall request
          the same, (b) such spaces are approved by applicable government
          authorities and (c) such spaces are designated for Tenant's exclusive
          use.

          (D) Tenant covenants and agrees that it and all persons claiming by,
          through and under it, shall at all times abide by all reasonable rules
          and regulations promulgated by Landlord with respect to the use of the
          parking areas on the Site (including, without limitation, those
          relating to the Managed Parking Program, if implemented) provided such
          rules and regulations are not inconsistent with Tenant's rights under
          this Lease and are of general applicability to the occupants of the
          Complex. The parking privileges granted herein are non-transferable
          except to an assignee or subtenant permitted or consented to pursuant
          to Section 5.6 through Section 5.6.5 or to a permitted occupant under
          Section 5.6.6 below. Further, except to the extent of Landlord's gross
          negligence or willful misconduct, Landlord assumes no responsibility
          whatsoever for loss or damage due to fire, theft or otherwise to any
          automobile(s) parked on the Site or to any personal property therein,
          however caused, and Tenant covenants and agrees, upon request from
          Landlord from time to time, to notify its officers, employees, agents
          and invitees of such limitation of liability. Tenant acknowledges and
          agrees that a license only is hereby granted, and no bailment is
          intended or shall be created.

2.3  Landlord's Reservations

     Landlord reserves the right from time to time, without unreasonable
     interference with Tenant's use and upon reasonable prior notice to Tenant
     (except in the event of an emergency): (a) to install, use, maintain,
     repair, replace and relocate for service to the Premises and other parts of
     the Buildings or either, pipes, ducts, conduits, wires and appurtenant
     fixtures, wherever located in the Premises or Buildings, and (b) to alter
     or relocate any other common facility, provided that substitutions are
     substantially equivalent or better. Installations, replacements and
     relocations referred to in clause (a) above shall be located to the extent
     practicable in the central core area of the Buildings, above ceiling
     surfaces, below floor surfaces or within perimeter walls of the Premises.
     Landlord shall use commercially reasonable efforts to schedule any such
     work contemplated by this Section 2.3 during Tenant's non-business hours.


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<PAGE>

2.4  Habendum

     Tenant shall have and hold the Premises for a period commencing on the
     earlier of (a) the Substantial Completion Date (as determined in accordance
     with Section 3.4(D) below), or (b) that date on which Tenant commences
     occupancy of any portion of the Premises for the Permitted Uses, and
     continuing for the Term unless sooner terminated as provided in Article VI
     or Article VII or unless extended as provided in Section 8.20.

     As soon as may be convenient after the date has been determined on which
     the Term commences as aforesaid, Landlord and Tenant agree to join with
     each other in the execution of a written Declaration, in the form of
     Exhibit E, in which the date on which the Term commences as aforesaid and
     the Term of this Lease shall be stated. If Tenant fails to execute or state
     objections to such Declaration within thirty (30) days after such
     Declaration is submitted by Landlord to Tenant, the Commencement Date and
     Lease Term shall be as originally set forth in the Declaration delivered by
     Landlord.

2.5  Fixed Rent Payments

     Tenant agrees to pay to Landlord, or as directed by Landlord, at the
     place(s) specified below, or at such other place as Landlord shall from
     time to time designate by notice, (1) on the Commencement Date (defined in
     Section 1.1 hereof) and thereafter monthly, in advance, on the first day of
     each and every calendar month during the Original Term, a sum equal to one
     twelfth (1/12th) of the then-applicable Annual Fixed Rent for the Premises
     and (2) on the first day of each and every calendar month during each
     extension option period (if exercised), a sum equal to one twelfth (1/12th)
     of the annual fixed rent as determined in Section 8.20 for the extension
     option period. Until notice of some other designation is given, Annual
     Fixed Rent and all other charges for which provision is herein made shall
     be paid by remittance to or for the order of Boston Properties Limited
     Partnership either (i) by mail to P.O. Box 3557, Boston, Massachusetts
     02241-3557, (ii) by wire transfer to Bank of America in Dallas, Texas, Bank
     Routing # 0260-0959-3 or (iii) by ACH transfer to Bank of America in
     Dallas, Texas, Bank Routing Number 111 000 112, and in case of (ii) or
     (iii) referencing Account Number 3756454460, Account Name of Boston
     Properties, LP, Tenant's name and the Property address. All remittances
     received by Boston Properties Limited Partnership or by any subsequently
     designated recipient, shall be treated as payment to Landlord.

     Annual Fixed Rent and Additional Rent for any partial month shall be paid
     by Tenant to Landlord at such rate on a pro rata basis, and, if the
     Commencement Date is a day other than the first day of a calendar month,
     the first payment of Annual Fixed Rent and Additional Rent which Tenant
     shall make to Landlord shall be a payment equal to a proportionate part of
     such monthly Annual Fixed Rent for the partial month from the Commencement
     Date to the first day of the succeeding calendar month.

     The Annual Fixed Rent and all other charges for which provision is herein
     made shall be paid by Tenant to Landlord, without offset, deduction or
     abatement except as otherwise


                                       13

<PAGE>

     specifically set forth in this Lease.

2.6  Operating Expenses

     "Landlord's Operating Expenses" means the cost of operation of the
     Buildings and the Site which shall exclude costs of special services
     rendered to tenants (including Tenant) for which a separate charge is made,
     but shall include, without limitation, the following: premiums for
     insurance carried with respect to the Buildings and the Site (including,
     without limitation, liability insurance, insurance against loss in case of
     fire or casualty and insurance of monthly installments of fixed rent and
     any Additional Rent which may be due under this Lease for not more than 12
     months in the case of both fixed rent and Additional Rent and if there be
     any first mortgage of the Property, including such insurance as may be
     required by the holder of such first mortgage), subject in all events to
     the provisions of Section 4.3 below; compensation and all fringe benefits,
     worker's compensation insurance premiums and payroll taxes paid to, for or
     with respect to all persons engaged in the operating, maintaining or
     cleaning of the Buildings or Site (but in the case of persons who are also
     providing services to other properties outside of the Complex, excluding
     any portion of such compensation which is not reasonably allocable to
     services performed for the Complex); water, sewer, gas, electric and oil
     charges (excluding utility charges (i) separately payable by Tenant under
     Section 2.8 below, (ii) separately chargeable to tenants for additional or
     special services, or (iii) for the supply of applicable utilities to
     leaseable areas of the Complex to the extent Tenant's entire use of any
     such utility is separately metered and/or submetered and Tenant pays
     separately therefor); cost of building supplies and equipment; cost of
     maintenance, cleaning and repairs (other than repairs not properly
     chargeable against income or reimbursed from contractors under guarantees);
     cost of snow removal and care of landscaping; payments under service
     contracts with independent contractors; management fees at reasonable rates
     for self-managed buildings consistent with the type of occupancy and the
     service rendered, not to exceed three percent (3%) of the "gross rents" for
     the Premises ("gross rents" for the purposes hereof being defined as all
     annual fixed rent, Landlord's Operating Expenses and Landlord's Tax
     Expenses, as defined in Section 2.7 below, scheduled for the Premises),
     which such management fees shall for the purposes of this Section 2.6 be
     deemed to be part of Landlord's Operating Expenses allocable to the
     Buildings rather than to the Site; the fair market rental value of the
     space in the Complex or at another property owned by Landlord or an
     affiliate of Landlord and used as the management office, provided that if
     the management office services more than one building or properties, the
     rent for such management office shall be equitably prorated and apportioned
     between the Complex and the other building or properties; cost of
     operating, cleaning and maintaining the shared cafeteria and fitness center
     facilities to be constructed in the Complex as part of Landlord's Base
     Building Work under Section 3.0 below (net of any revenue collected from
     the operation of such cafeteria and fitness center); costs of maintaining
     and insuring Land Recreation Area A and Land Recreation Area B (as those
     terms are defined in Section 8.26 below) and any real estate taxes required
     to be paid by Landlord as tenant under the MHD Lease (as that term is
     defined in said Section 8.26) (all of which such costs shall for the
     purposes of this Section 2.6 be deemed to be part of Landlord's Operating
     Expenses allocable to the Buildings rather


                                       14

<PAGE>

     than to the Site); and all other reasonable and necessary expenses paid in
     connection with the operation, cleaning and maintenance of the Buildings
     and the Site and properly chargeable against income in accordance with
     generally acceptable accounting practices consistently applied, provided,
     however, that if during the Term of this Lease, Landlord shall make a
     capital expenditure (i) to reduce Landlord's Operating Expenses if Landlord
     shall have reasonably determined that the annual reduction in Landlord's
     Operating Expenses shall exceed the annual charge-off therefor or (ii) to
     comply with applicable laws, rules, regulations, requirements, statutes,
     ordinances, by-laws and court decisions of all public authorities which
     first became applicable to the Complex after the Commencement Date (the
     foregoing categories of capital expenditures in (i) and (ii) being referred
     to as "Permitted Capital Expenditures"), Landlord may include in the
     calculation of Landlord's Operating Expenses for the year in which it was
     made and in Landlord's Operating Expenses for each succeeding year wholly
     or partly falling in the Term until fully amortized, the annual charge off
     of such Permitted Capital Expenditures. Annual charge off shall be
     determined by dividing the original capital expenditure plus an interest
     factor, reasonably determined by Landlord as being the interest rate then
     being charged for long term mortgages by institutional lenders on like
     properties within the locality in which the Complex is located, by the
     number of years of useful life of the improvement made with the capital
     expenditure; and the useful life shall be determined reasonably by Landlord
     in accordance with generally accepted accounting principles and practices
     in effect at the time of making such expenditure.

     Notwithstanding anything in this Lease to the contrary, the following shall
     be excluded from Landlord's Operating Expenses Allocable to the Premises:

     (i)  All capital expenditures and depreciation, except as otherwise
          explicitly provided in this Section 2.6;

     (ii) Interest on indebtedness, debt amortization, ground rent, and
          refinancing costs for any mortgage or ground lease of the Buildings or
          the Complex;

     (iii) Legal, auditing, consulting and professional fees and other costs
          (other than those legal, auditing, consulting and professional fees
          and other costs incurred in connection with the normal and routine
          maintenance and operation of the Complex), including, without
          limitation, those: (i) paid or incurred in connection with financings,
          refinancings or sales of any Landlord's interest in the Buildings or
          the Complex; (ii) relating to any special reporting required by
          securities laws; (iii) relating to negotiations or disputes with, or
          leasing to, tenants or prospective tenants; (iv) relating to
          litigation (including costs of settlement judgments and payments in
          lieu thereof); (v) the interpretation of leases or other occupancy
          agreements; (vi) the enforcement of the provisions of any lease or
          other occupancy agreement affecting the Complex including without
          limitation this Lease; (vii) the initial construction of the
          improvements on the Property; (viii) the review, approval or other
          actions in connection with the sublease or assignment of tenant leases
          (provided, however, that Tenant shall nonetheless be responsible under
          Section 5.6.5(B) for any such costs relative to its own requests for
          consent


                                       15

<PAGE>

          to a sublease or assignment); (ix) any action against a present or
          former tenant or occupant under a lease or other occupancy agreement,
          including, without limitation, eviction, distraint, levy and
          collection actions; and (x) costs incurred as a result of the
          violation by Landlord or any tenant of the terms and conditions of any
          lease;

     (iv) The cost of any item or service to the extent reimbursed or
          reimbursable to Landlord by insurance required to be maintained under
          the Lease or by any third party;

     (v)  The cost of repairs or replacements incurred by reason of fire or
          other casualty or condemnation other than costs not in excess of a
          commercially reasonable deductible (currently $25,000.00) on any
          insurance maintained by Landlord which provides a recovery for such
          repair or replacement;

     (vi) Any advertising, promotional or marketing expenses for the Buildings;

     (vii) The cost of any service or materials provided by any party related to
          Landlord (other than the management fee), to the extent such costs
          exceed the reasonable cost for such service or materials absent such
          relationship in buildings similar to the Buildings in the vicinity of
          the Buildings;

     (viii) Payments for rented equipment, the cost of which equipment would
          constitute a capital expenditure if the equipment were purchased to
          the extent that such payments exceed the amount which could have been
          included in Landlord's Operating Expenses had Landlord purchased such
          equipment rather than leasing such equipment;

     (ix) Penalties, damages, and interest for late payment or violations of any
          obligations of Landlord, including, without limitation, taxes, Legal
          Requirements, insurance, equipment leases and other past due amounts;

     (x)  Contributions to charitable or political organizations, and any
          entertainment, dining or travel expenses of Landlord's employees for
          any purpose;

     (xi) The cost of testing, remediation or removal of "Hazardous Materials"
          (as defined in Section 5.3) in the Buildings or on the Site required
          by "Hazardous Materials Laws" (as defined in Section 5.3);

     (xii) Wages, salaries, or other compensation (including benefits) paid to
          any executive employees above the grade of Building manager;

     (xiii) The net (i.e. net of the reasonable costs of collection) amount
          recovered by Landlord under any warranty or service agreement from any
          contractor or service provider shall be credited against Landlord's
          Operating Expenses;


                                       16

<PAGE>

     (xii) Costs in connection with leasing space in the Complex or to retain
          existing tenants, including brokerage commissions, lease concessions,
          lease assumptions, rental abatements, construction allowances granted
          to specific tenants and alteration work performed by Landlord to
          prepare space for tenants, including any utilities or services
          incurred in connection with performing such work;

     (xiii) The cost of any work or service performed or rendered exclusively
          for any tenant, including Tenant, or for which Tenant pays directly to
          any third party (i.e. costs of cleaning tenant spaces if Tenant
          provides its own janitorial services for the Premises) and costs
          incurred in connection with the making of repairs which are the
          obligations of another tenant of the Complex;

     (xiv) The cost of acquisition of any sculpture, paintings or other objects
          of art;

     (xv) Any amounts billed or billable to Tenant or any other tenant for any
          services furnished to Tenant or any other tenant by Landlord or
          Landlord's agents or contractors for which a separate charge is made,
          including, without limitation, the supply of overtime
          air-conditioning, ventilation and heating, and above-standard cleaning
          services;

     (xvi) Any costs of maintenance, repairs or replacements required because of
          the negligent or willful act or omission of Landlord, its officers,
          directors, servants, agents, employees or contractors;

     (xvii) Any expenses to design and construct (including permitting fees,
          costs of insurance and bonds, and costs of equipment and materials)
          the Base Building Work, and any costs to correct any defects, latent
          or patent, in any of the equipment or improvements which are a part of
          the Base Building Work (except to the extent caused by Tenant's use of
          the Premises for other than general office use);

     (xviii) Reserves for bad debts or for future improvements, repairs or
          additions;

     (xix) Any above-standard cleaning (which shall include trash collection and
          removal), including, but not limited to construction cleanup or
          special cleanings associated with parties/events and specific tenant
          requirements in excess of service provided to Tenant;

     (xx) The costs of new services or substantial increases in existing
          services to the extent such new or increased level of services are
          required solely as the result of the presence of a particular occupant
          at the Complex, such as for example, the cost of providing additional
          security services due to threats against a particular occupant;

     (xxi) Costs in connection with acquiring additional land or development
          rights or of constructing any additional buildings within the Complex;
          and


                                       17

<PAGE>

     (xxii) Costs of installing any new shared building amenities within the
          Complex after the Commencement Date and the cost to renovate the
          existing cafeteria and to construct the new fitness facility in
          Building A.

     "Operating Expenses Allocable to the Premises" shall mean the same
     proportion of Landlord's Operating Expenses for and pertaining to the
     Complex as the Rentable Floor Area of the Premises bears to the Total
     Rentable Floor Area of the Complex; provided, however, that to the extent
     that any components of Landlord's Operating Expenses relate to services
     that are provided solely to a single Building or Buildings, "Operating
     Expenses Allocable to the Premises" for any such services shall mean the
     same proportion of Landlord's Operating Expenses for and pertaining solely
     to such services as the rentable floor area of that portion of the Premises
     located within such Building or Buildings to which the services are being
     exclusively provided bears to the total rentable floor area of such
     Building or Buildings (it being understood and agreed that to the extent
     any components of Landlord's Operating Expenses relate to services that are
     provided solely to a single Additional Building or Buildings in which
     Tenant does not lease any space, the cost of such services would not be
     included within Landlord's Operating Expenses billable to Tenant under this
     Lease).

     For each calendar year falling within the Term, Tenant shall pay to
     Landlord, as Additional Rent, the Operating Expenses Allocable to the
     Premises for such corresponding full calendar year, and for each fraction
     of a calendar year falling within the Term at the beginning or end thereof,
     Tenant shall pay to Landlord, as Additional Rent, the product of (i) such
     applicable fraction of a calendar year and (ii) the Operating Expenses
     Allocable to the Premises for the calendar year in which said fraction
     occurs.

     Not later than one hundred and twenty (120) days after the end of the first
     calendar year or fraction thereof ending December 31 and of each succeeding
     calendar year during the Term or fraction thereof at the end of the Term,
     Landlord shall render Tenant a statement in reasonable detail and according
     to usual accounting practices certified by a representative of Landlord,
     showing for the preceding calendar year or fraction thereof, as the case
     may be, Landlord's Operating Expenses and Operating Expenses Allocable to
     the Premises. Said statement to be rendered to Tenant shall also show for
     the preceding year or fraction thereof as the case may be the amounts of
     operating expenses already paid by Tenant as Additional Rent, and the
     amount of operating expenses remaining due from, or overpaid by, Tenant for
     the year or other period covered by the statement. Within thirty (30) days
     after the date of delivery of such statement, Tenant shall pay to Landlord
     the balance of the amounts, if any, required to be paid pursuant to the
     above provisions of this Section 2.6 with respect to the preceding year or
     fraction thereof, or Landlord shall credit any amounts due from it to
     Tenant pursuant to the above provisions of this Section 2.6 against (i)
     monthly installments of fixed rent next thereafter coming due or (ii) any
     sums then due from Tenant to Landlord under this Lease (or refund such
     portion of the overpayment as aforesaid if the Term has ended and Tenant
     has no further obligation to Landlord).

     In addition, Tenant shall make payments monthly on account of Operating
     Expenses


                                       18

<PAGE>

     Allocable to the Premises anticipated for the then current year at the time
     and in the fashion herein provided for the payment of fixed rent. The
     amount to be paid to Landlord shall be an amount reasonably estimated
     annually by Landlord to be sufficient to cover, in the aggregate, a sum
     equal to Operating Expenses Allocable to the Premises for each calendar
     year during the Term. Notwithstanding the foregoing, in determining the
     amount of Landlord's Operating Expenses for any calendar year or portion
     thereof falling within the Lease Term, if less than ninety-five percent
     (95%) of the Total Rentable Floor Area of the Buildings with respect to
     Landlord's Operating Expenses for and pertaining to the Buildings and/or
     less than ninety-five percent (95%) of the Total Rentable Floor Area of the
     Complex with respect to Landlord's Operating Expenses for and pertaining to
     the Site shall have been occupied by tenants at any time during the period
     in question, then, at Landlord's election, those components of Landlord's
     Operating Expenses that vary based on occupancy for such period shall be
     adjusted to equal the amount such components of Landlord's Operating
     Expenses would have been for such period had occupancy been ninety-five
     percent (95%) throughout such period.

     2.6.1 Tenant's Audit Right

          Subject to the provisions of this paragraph, Tenant shall have the
          right, at Tenant's cost and expense, to examine all documentation and
          calculations prepared in the determination of Operating Expenses
          Allocable to the Premises and Landlord's Tax Expenses Allocable to the
          Premises (as defined in Section 2.7 below) (collectively, the "Total
          Expenses"):

          (1)  Such documentation and calculation shall be made available to
               Tenant at the offices where Landlord keeps such records during
               normal business hours within a reasonable time after Landlord
               receives a written request from Tenant to make such examination.

          (2)  Having previously made such examination in respect of any period
               for which Landlord has given Tenant a statement of the actual
               amount of Landlord's Operating Expenses or Landlord's Tax
               Expenses, Tenant may not thereafter make a subsequent examination
               of Landlord's Operating Expenses or Landlord's Tax Expenses, as
               the case may be, for that same period.

          (3)  Any request for examination in respect of any calendar year may
               be made no more than one (1) year after Landlord advises Tenant
               of the actual amount of Landlord's Operating Expenses or
               Landlord's Tax Expenses, as the case may be, in respect of such
               calendar year or fiscal year and provides to Tenant the
               applicable year-end statement required under Section 2.6 or
               Section 2.7.

          (4)  Such examination may be made only by Tenant's employees, internal
               accounting department, outside accountants or other professional
               auditing


                                       19

<PAGE>

               company, provided any such outside accountants and/or auditing
               company are not being paid by Tenant on a contingent fee basis.

          (5)  As a condition to performing any such examination, Tenant and its
               examiners shall be required to execute and deliver to Landlord an
               agreement, in form attached hereto as Exhibit K, agreeing to keep
               confidential any information which it discovers about Landlord or
               the Buildings in connection with such examination; provided,
               however, that Tenant may disclose such information (i) to
               Tenant's employees, counsel and advisors who have the need to
               know such information in order to provide Tenant with advice in
               connection with such audit, (ii) actual or proposed successors,
               assigns, subtenants, lenders or purchasers of Tenant and (iii) to
               the extent required by applicable law or reporting requirements
               or by administrative, governmental or judicial proceeding.

          (6)  If, after the audit by Tenant of Landlord's books and records
               pursuant to this Section 2.6.1 with respect to any calendar year
               or fiscal year, as applicable, it is finally determined that: (i)
               Tenant has made an overpayment on account of Operating Expenses
               Allocable to the Premises or Landlord's Tax Expenses Allocable to
               the Premises, as the case may be, Landlord shall credit such
               overpayment against the next installment(s) of Annual Fixed Rent
               thereafter payable by Tenant, except that if such overpayment is
               determined after the termination or expiration of the term of
               this Lease, Landlord shall promptly refund to Tenant the amount
               of such overpayment less any amounts then due from Tenant to
               Landlord; and (ii) Tenant has made an underpayment on account of
               Operating Expenses Allocable to the Premises or Landlord's Tax
               Expenses Allocable to the Premises, as the case may be, Tenant
               shall, within thirty (30) days of such determination, pay such
               underpayment to Landlord.

          (7)  If, Tenant performs any such audit, it is determined that
               Landlord has overcharged Tenant on account of Operating Expenses
               Allocable to the Premises or Landlord's Tax Expenses Allocable to
               the Premises, as the case may be, by more than five percent (5%)
               in the aggregate, then Landlord shall reimburse Tenant for the
               reasonable out-of-pocket costs incurred by Tenant in performing
               such audit not to exceed Five Thousand and 00/100 Dollars
               ($5,000.00).

          (8)  Any disputes under this Section 2.6.1 relating to amounts in
               excess of One Hundred Thousand and 00/100 Dollars ($100,000.00)
               may be resolved by arbitration under Section 8.31 below.

     2.6.2 Tenant's Right to Provide Specified Services

          So long as there shall be no lease of space in any of the Buildings
          then in effect between Landlord and a third party, Tenant shall have
          the right to require


                                       20

<PAGE>

          Landlord to terminate all of the "Specified Services" (hereinafter
          defined), which termination shall take effect on the sixtieth (60th)
          day following the date of Landlord's receipt of such termination
          notice (the "Service Termination Date"). Commencing at 12:01 AM on the
          Service Termination Date and continuing for the balance of the Lease
          Term as it may be extended, Tenant shall perform or cause to be
          performed by contractors first reasonably approved by Landlord the
          Specified Services (hereinafter called "Tenant's Performance of the
          Specified Services") and the costs of the Specified Services shall no
          longer be included in Operating Expenses Allocable to the Premises.
          Tenant's Performance of the Specified Services shall be done in a
          manner consistent with the requirements of Exhibit C hereof and
          otherwise consistent with the operation of the Buildings and Site, as
          applicable, in a similar manner as operated by Landlord and in
          conformity with applicable Legal Requirements and the requirements of
          the insurers of the Complex. Tenant's indemnity as set forth in
          Section 5.7 shall include any and all loss, cost, expense and damage
          (including, without limitation, any damage to the Buildings, the Site
          or the Complex) arising or claimed to have arisen from Tenant or any
          other person, firm or entity providing or failing to provide the
          Specified Services. The "Specified Services" shall consist of, and be
          limited to, all of the interior cleaning and janitorial services for
          the Buildings (including replacement of all bulbs and ballasts). In
          any event, Landlord shall continue to provide all other services
          required to be provided by Landlord under this Lease with the
          exception of the Specified Services following Tenant's election to
          perform said Specified Services.

          No later than ninety (90) days after the Service Termination Date,
          Landlord shall render Tenant a statement in reasonable detail and
          according to usual accounting practices certified by a representative
          of Landlord, showing for the "Subject Period" (hereinafter defined)
          Landlord's Operating Expenses respecting the Terminated Services. Such
          statement to be rendered to Tenant also shall show for the Subject
          Period, the amounts already paid by Tenant on account of Tenant's
          payments respecting the Terminated Services and the amount of payments
          remaining due from, or overpaid by, Tenant respecting the Terminated
          Services. If such statement shows a balance remaining due to Landlord,
          Tenant shall pay same to Landlord on or before the thirtieth (30th)
          day following receipt by Tenant of said statement. Any balance shown
          as due to Tenant shall be credited against Annual Fixed Rent next due,
          or refunded to Tenant if the Lease Term has then expired and Tenant
          has no further obligation to Landlord. The "Subject Period" is the
          period beginning on January 1st of the calendar year in which the
          Termination Date occurs and ending on the Service Termination Date.

          The termination right of Tenant set forth in this Section 2.6.3 shall
          only apply to the Specified Services.

2.7  Real Estate Taxes

     For each Tax Year falling within the Term, Tenant shall pay to Landlord, as
     Additional


                                       21

<PAGE>

     Rent, the Landlord's Tax Expenses Allocable to the Premises for such
     corresponding Tax Year, and for each fraction of a Tax Year falling within
     the Term at the beginning or end thereof, Tenant shall pay to Landlord, as
     Additional Rent, the product of (i) such applicable fraction of a Tax Year
     and (ii) the Landlord's Tax Expenses Allocable to the Premises for the Tax
     Year in which said fraction occurs. Not later than ninety (90) days after
     Landlord's Tax Expenses Allocable to the Premises are determined for the
     first such Tax Year or fraction thereof and for each succeeding Tax Year or
     fraction thereof during the Term, Landlord shall render Tenant a statement
     in reasonable detail certified by a representative of Landlord showing for
     the preceding year or fraction thereof, as the case may be, real estate
     taxes on the Buildings and the Site and abatements and refunds of any taxes
     and assessments. Expenditures for legal fees and for other expenses
     incurred in seeking the tax refund or abatement may be charged against the
     tax refund or abatement before the adjustments are made for the Tax Year.
     Said statement to be rendered to Tenant shall also show for the preceding
     Tax Year or fraction thereof as the case may be the amounts of real estate
     taxes already paid by Tenant as Additional Rent, and the amount of real
     estate taxes remaining due from, or overpaid by, Tenant for the year or
     other period covered by the statement. Within thirty (30) days after the
     date of delivery of the foregoing statement, Tenant shall pay to Landlord
     the balance of the amounts, if any, required to be paid pursuant to the
     above provisions of this Section 2.7 with respect to the preceding Tax Year
     or fraction thereof, or Landlord shall credit any amounts due from it to
     Tenant pursuant to the provisions of this Section 2.7 against (x) monthly
     installments of fixed rent next thereafter coming due or (y) any sums then
     due from Tenant to Landlord under this Lease (or refund such portion of the
     over-payment as aforesaid if the Term has ended and Tenant has no further
     obligation to Landlord). In the event Landlord succeeds in obtaining a
     reduction of such real estate taxes, rates or assessments with respect to a
     real estate tax fiscal year as to which Tenant contributed Tenant's share
     of Landlord's Tax Expenses, then, Tenant shall be entitled to receive its
     proportionate share of the net amount of any refund received or reduction
     obtained by Landlord to the extent allocable to the Term of this Lease.
     Tenant's entitlement to such refund amount shall survive the expiration of
     the Term.

     Landlord will, upon the written request of Tenant, who together with other
     tenants lease at least fifty (50%) of the Total Rentable Floor Area of the
     Complex, at Landlord's election either (i) apply for an abatement of real
     estate taxes or (ii) allow such tenants to apply for abatements in their
     own name, or in Landlord's name, at their own cost (subject to such
     tenants' right to recover such costs on a first dollar basis from the
     abatement proceeds, if any). If such tenants apply for an abatement of real
     estate taxes, then Landlord shall have the right to be involved in each
     step of the abatement process, including, without limitation, Landlord's
     right to approve all filings in connection with such abatement proceedings
     (such approval not to be unreasonably withheld) and the right to attend all
     meetings between Tenant and its representatives and the representatives of
     the Town of Bedford.

     In addition, payments by Tenant on account of Landlord's Tax Expenses
     Allocable to the Premises anticipated for the then current year shall be
     made monthly at the time and in the fashion herein provided for the payment
     of fixed rent. The amount so to be paid to


                                       22

<PAGE>

     Landlord shall be an amount reasonably estimated by Landlord to be
     sufficient to provide Landlord, in the aggregate, a sum equal to Landlord's
     Tax Expenses Allocable to the Premises, at least ten (10) days before the
     day on which such payments by Landlord would become delinquent.

     To the extent that real estate taxes shall be payable to the taxing
     authority in installments with respect to periods less than a Tax Year, the
     foregoing statement shall be rendered and payments made on account of such
     installments.

     Terms used herein are defined as follows:

          (i)  "Tax Year" means the twelve-month period beginning July 1 each
               year during the Term or if the appropriate governmental tax
               fiscal period shall begin on any date other than July 1, such
               other date.

          (ii) "Landlord's Tax Expenses Allocable to the Premises" shall mean
               the same proportion of Landlord's Tax Expenses as the Rentable
               Floor Area of the Premises bears to the Total Rentable Floor Area
               of the Complex.

          (iii) "Landlord's Tax Expenses" with respect to any Tax Year means the
               aggregate real estate taxes on the Complex with respect to that
               Tax Year, reduced by any abatement receipts with respect to that
               Tax Year.

          (iv) "Real estate taxes" means all taxes and special assessments of
               every kind and nature and user fees and other like fees assessed
               by any governmental authority on the Buildings or Site which the
               Landlord shall become obligated to pay because of or in
               connection with the ownership, leasing and operation of the Site,
               the Building and the Property and reasonable expenses of and fees
               for any formal or informal proceedings for negotiation or
               abatement of taxes (collectively, "Abatement Expenses"). The
               amount of special taxes or special assessments to be included
               shall be limited to the amount of the installment (plus any
               interest, other than penalty interest, payable thereon) of such
               special tax or special assessment required to be paid during the
               year in respect of which such taxes are being determined. There
               shall be excluded from such taxes (1) any income, estate,
               succession, inheritance and transfer taxes, (2) any increased
               real estate taxes attributable to any leasehold improvements made
               by other tenants of the Complex and (3) any tax penalties
               incurred as a result of Landlord's failure to make payments
               and/or to file any tax or informational returns when due.
               Notwithstanding the foregoing, if at any time during the Term the
               present system of ad valorem taxation of real property shall be
               changed so that in lieu of the whole or any part of the ad
               valorem tax on real property there shall be assessed on Landlord
               a capital levy or other tax on the gross rents received with
               respect to the Site or Buildings or Property, or a federal,
               state, county, municipal, or other local income, franchise,
               excise or similar tax, assessment, levy or charge


                                       23

<PAGE>

               distinct from any now in effect in the jurisdiction in which the
               Property is located is assessed and which is measured solely by,
               or based (in whole or in part) upon, any such gross rents, then
               any and all of such taxes, assessments, levies or charges, to the
               extent so measured or based, shall be deemed to be included
               within the term "real estate taxes" but only to the extent that
               the same would be payable if the Site and Buildings were the only
               property of Landlord. Landlord represents that the Complex
               constitutes one tax parcel which does not currently include any
               real estate or improvements other than the Site, the Buildings
               and the Additional Buildings.

2.8  Tenant Electricity

     Landlord shall, at Landlord's sole cost and expense, install and deliver
     possession of the Premises to Tenant with separate meters installed to
     measure the electrical consumption in each of the Buildings comprising the
     Premises. Effective as of the Commencement Date and continuing throughout
     the Term, for so long as Tenant shall be directly leasing any of the
     Buildings in their entirety, Tenant covenants and agrees to make
     application to the appropriate utility company or utility provider for
     electrical service to any such Building or Buildings being directly leased
     in its or their entirety by Tenant and to make any deposit (including but
     not limited to, such letters of credit) as such utility company or provider
     shall require. Tenant covenants and agrees to pay, punctually as and when
     due, all electricity charges and rates for and relating to the Buildings
     and from time-to-time if requested by Landlord to provide Landlord with
     evidence of payment to, and good standing with, such utility company or
     provider as Landlord may reasonably require. Tenant further covenants and
     agrees to defend, save harmless and, indemnify Landlord against all
     liability, cost and damage arising out of or in any way connected to the
     payment, nonpayment or late payment of any and all charges or deposits to
     such utility company or provider. The provisions of this Section 2.8 shall
     survive the expiration or termination of this Lease for a period of twelve
     (12) full calendar months.

                                   ARTICLE III

                       Condition of Premises; Alterations

3.1  Base Building Work

     (A) Definition of Base Building Work. The "Base Building Work" shall be all
     labor, materials and other work necessary to design, permit and perform the
     renovation of the Buildings and other portions of the Complex, as described
     in the Base Building Plans and Specifications described in subsection (B)
     below and shown in Exhibit B-1 attached hereto.

     (B) Plans and Specifications. Attached hereto as Exhibit B-1 is a
     description of the scope of the Base Building Work, and as further
     reflected in the schematic plans and outline specifications dated January
     25, 2007 describing certain renovations to Buildings


                                       24

<PAGE>

     A, B, C, D, E and G of the Complex (the "Base Building Plans and
     Specifications") prepared on behalf of Landlord by Landlord's architect,
     ADD, Inc. ("Landlord's Architect"). Tenant hereby acknowledges its approval
     of the Base Building Plans and Specifications.

     (C) Finish Allowances. It is acknowledged and agreed that Exhibit B-1
     contemplates that Landlord shall be renovating the lobby of Building D as
     part of the Base Building Work. In connection therewith, Landlord shall
     submit its final construction documents showing the Building D lobby area
     to Tenant and, to the extent that Tenant desires to use different finishes
     on the lobby floors than the finishes shown on such final construction
     documents, Tenant shall submit to Landlord a list in reasonable specificity
     (including schematic plans and details where appropriate) of the finishes
     selected by Tenant for the lobby floors within fifteen (15) days after
     Tenant's receipt of the final construction documents from Landlord (such
     submission by Tenant being hereinafter referred to as "Tenant's Finish
     Selection Notice"). As soon as reasonably practicable but no later than
     fifteen (15) business days (unless Landlord has previously advised Tenant
     that a longer time period is reasonably necessary due to the nature and
     scope of Tenant's Finish Selection Notice or the fact that the information
     provided by Tenant in Tenant's Finish Selection Notice is insufficient for
     the purpose of enabling Landlord to make the determination set forth
     herein) after Landlord's receipt of Tenant's Finish Selection Notice,
     Landlord shall advise Tenant of any pricing, budgetary, scheduling or other
     matters, issues and/or problems reflected in or on Tenant's Finish
     Selection Notice which are inconsistent with the design, cost and
     construction schedule for the Base Building Work. In its response to
     Tenant's Finish Selection Notice, Landlord shall provide Tenant with
     available documentation from Landlord's general contractor substantiating
     the determination that an item or items will impact the current pricing of
     or schedule for the Base Building Work. Landlord shall have the right to
     approve all matters reflected in or on Tenant's Finish Selection Notice
     (which such approval shall not be unreasonably withheld, conditioned or
     delayed) and Landlord shall not be obligated to approve any portion of
     Tenant's Finish Selection Notice which (i) is likely to increase the cost
     of the Base Building Work for which Tenant does not agree to pay, (ii)
     extends or increases Landlord's estimated time to substantially complete
     the Base Building Work unless Tenant agrees that any delay caused by such
     portion of Tenant's Finish Selection Notice shall constitute a Tenant Delay
     (as defined in Section 3.5(C) below) for the purposes of this Article III.
     Such portion of Tenant's Finish Selection Notice as is approved by Landlord
     in accordance with the foregoing is hereinafter called the "Approved Tenant
     Lobby Finishes."

     In connection with the foregoing, it is specifically understood and agreed
     that the cost of any portions of the Approved Tenant Lobby Finishes that
     exceed the allowances set forth on Exhibit B-1 relative thereto shall, at
     Tenant's option, either be (x) paid in full by Tenant prior to the
     commencement by Landlord of the Base Building Work or (y) paid by Tenant
     using the Tenant Allowance, subject to and in accordance with the
     provisions of Section 4.3 below. To the extent that the cost of the
     Approved Tenant Lobby Finishes are less than the allowances set forth on
     Exhibit B-1 relative thereto, Tenant shall not be entitled to any credit
     nor shall Tenant be entitled to apply any such savings against the


                                       25

<PAGE>

     other costs of the Tenant Improvement Work.

     (D) Performance of Base Building Work. Landlord, at its sole cost and
     expense, shall promptly and with all due diligence perform the Base
     Building Work in a good and workmanlike manner and as set forth in the Base
     Building Plans and Specifications, and, in connection therewith, Landlord
     shall obtain all necessary governmental permits and approvals necessary for
     the construction of the Base Building Work.

3.2  Tenant Improvement Work

     (A) Definition of Tenant Improvement Work. Tenant shall perform all work
     set forth in the Approved Tenant Improvement Construction Documents (as
     defined below) necessary to prepare the Premises for Tenant's use and
     occupancy (such work being hereinafter called the "Tenant Improvement
     Work"). It is expressly understood and agreed that Tenant shall be liable,
     at its sole cost and expense, for the payment of all costs of the Tenant
     Improvement Work (subject to the provisions of Section 3.3 below).

     (B) Tenant Improvement Construction Documents. On or before June 1, 2007,
     Tenant shall cause its architect to prepare construction documents for the
     Tenant Improvement Work based on the preliminary schematic plans attached
     to this Lease as Exhibit B-2 (such construction drawings being hereinafter
     called the "Tenant Improvement Construction Documents") and shall submit
     the same to Landlord for its approval as set forth herein. Landlord shall
     review the Tenant Improvement Construction Documents and within fifteen
     (15) business days after receipt thereof Landlord shall provide Tenant with
     written notice of either (i) its approval of the Tenant Improvement
     Construction Documents or (ii) the need for additional information in order
     to review and approve the same. In its approval of the Tenant Improvement
     Construction Documents, Landlord shall specify those alterations, additions
     and improvements that must be removed by Tenant at the expiration or
     earlier termination of the Term. Landlord's failure to so respond within
     said fifteen (15) business day period shall be deemed to constitute
     Landlord's approval of the Tenant Improvement Construction Documents and
     determination that the alterations, additions and improvements shown
     thereon do not need to be removed by Tenant at the expiration or earlier
     termination of the Term. Notwithstanding the foregoing, it is understood
     and agreed that Tenant may apply for a building permit from the appropriate
     municipal officials prior to Landlord's final approval of the Tenant
     Improvement Construction Documents; provided that if Landlord shall
     disapprove any element of the Tenant Improvement Construction Documents,
     Tenant shall promptly revise the Tenant Improvement Construction Documents
     accordingly and (if required) resubmit the same to the municipal
     authorities. The Tenant Improvement Construction Documents, once approved
     or deemed approved, shall be referred to as the "Approved Tenant
     Improvement Construction Documents."

     (C) Performance of Tenant Improvement Work. Upon the completion of the
     Approved Tenant Improvement Construction Documents, Tenant may enter the
     Premises (subject to and in accordance with the terms and provisions of
     Sections 3.4(A) and 3.6(A) below) to perform the Tenant Improvement Work as
     set forth in the Approved Tenant


                                       26

<PAGE>

     Improvement Construction Documents, and, in connection therewith, Tenant
     shall obtain all necessary governmental permits and approvals and submit
     any notifications required in connection with any Legal Requirements
     necessary for the construction of the Tenant Improvement Work (the
     "Tenant's Permits"). All of the Tenant Improvement Work shall be performed
     in accordance with the Approved Tenant Improvement Construction Documents
     and in accordance with applicable Legal Requirements and Insurance
     Requirements. Tenant shall have the Tenant Improvement Work performed by
     contractors, reasonably approved by Landlord (Landlord hereby approving J.
     Calnan & Associates, Inc. as Tenant's general contractor), which
     contractors shall provide to Landlord such insurance as Landlord may
     reasonably require (consistent with the size and scope of the Tenant
     Improvement Work project). Notwithstanding anything contained herein to the
     contrary, it is understood and agreed that Tenant may retain contractors
     and subcontractors that use union or non-union labor in connection with the
     construction of the Tenant Improvement Work. In addition, during such time
     as Tenant is performing the Tenant Improvement Work under this Article III,
     Tenant, at Tenant's expense, or Tenant's general contractor shall also
     maintain builder's risk insurance for the full insurable value of such
     Tenant Improvement Work. It shall be Tenant's obligation to obtain a
     certificate of occupancy for the Tenant Improvement Work (except that
     Tenant shall not be in default hereunder to the extent that Tenant is
     unable to obtain the same due to the status of completion of the Base
     Building Work), and Tenant shall not occupy the Premises for the conduct of
     business until and unless such certificate of occupancy has been authorized
     for issuance by the applicable governmental authority (Tenant hereby
     agreeing to deliver a copy of the final certificate of occupancy for the
     Tenant Improvement Work to Landlord promptly after the issuance thereof).
     Tenant shall also prepare and submit to Landlord within two (2) months
     after the Tenant Improvement Work is substantially complete a set of
     as-built plans in both print and electronic forms showing the work
     performed by Tenant to the Premises including, without limitation, a
     schematic plan of any wiring or cabling installed by Tenant or Tenant's
     contractor for Tenant's computer, telephone and other communication
     systems.

     (D) Change Orders. Tenant shall have the right, in accordance herewith, to
     submit for Landlord's approval change proposals subsequent to the
     completion of the Approved Tenant Improvement Construction Documents (each,
     a "Tenant Improvement Work Change Proposal"). Landlord agrees to respond to
     any such Tenant Improvement Work Change Proposal within such time as is
     reasonably necessary, but no more than five (5) business days, after the
     submission thereof by Tenant (unless Landlord has previously advised Tenant
     that a longer time period is reasonably necessary due to the nature and
     scope of the Tenant Improvement Work Change Proposal, together with
     Landlord's good faith estimate as to the amount of additional time that
     will be necessary, or the fact that the information provided by Tenant in
     the Tenant Improvement Work Change Proposal is insufficient for the
     purposes of enabling Landlord to make the determination set forth herein),
     advising Tenant of any items which Landlord in good faith reasonably
     believes are inconsistent with the design, cost and construction schedule
     for the Base Building Work, as well as specifying (subject to the terms of
     Section 5.2 below) whether any alterations, additions or improvements shown
     in the Tenant Improvement Work Change Proposal must be removed by Tenant
     upon the expiration or earlier termination of the


                                       27

<PAGE>

     Term ("Landlord's Tenant Improvement Work Change Order Response") (it being
     understood and agreed that Landlord's failure to respond within said five
     (5) business day period shall be deemed to constitute Landlord's approval
     of the Tenant Improvement Work Change Proposal and determination that none
     of the items shown thereon are to be removed by Tenant at the expiration or
     earlier termination of the Term). Tenant shall have the right to then
     proceed with or withdraw such Tenant Improvement Work Change Proposal
     within five (5) business days after receipt of Landlord's Tenant
     Improvement Work Change Order Response. If Tenant fails to respond to
     Landlord's Tenant Improvement Work Change Order Response within such five
     (5) business day period, such Tenant Improvement Work Change Proposal shall
     be deemed withdrawn. If Tenant proceeds with such Tenant Improvement Work
     Change Proposal, then such Tenant Improvement Work Change Proposal shall be
     deemed to be a part of the Approved Tenant Improvement Construction
     Documents for the purposes of this Article III.

3.3  Tenant Allowances

     (A) Landlord shall provide to Tenant an allowance equal to the product of
     (i) $28.00 and (ii) the Total Rentable Floor Area of the Premises (the
     "Tenant Improvement Allowance"). The Tenant Improvement Allowance shall be
     used and applied by Tenant solely on account of the cost of the Tenant
     Improvement Work. For the purposes hereof, the costs to which the Tenant
     Improvement Allowance may be applied hereunder shall include the cost of
     leasehold improvements but not the cost of any of Tenant's personal
     property, trade fixtures or trade equipment or any so-called soft costs;
     provided, however, that a portion of the Tenant Improvement Allowance in an
     amount not to exceed the product of (x) $5.00 and (y) the Rentable Floor
     Area of the Premises may be applied towards the costs incurred by Tenant
     (as evidenced by paid invoices or receipts submitted by Tenant to Landlord)
     in preparing architectural and engineering plans in connection with the
     Tenant Improvement Work and in installing wiring and cabling for Tenant's
     telecommunications equipment in the Premises.

     In addition, Landlord shall provide to Tenant (i) an allowance of Two
     Hundred Fifty Thousand and 00/100 Dollars ($250,000.00) (the "Restroom
     Allowance") to be used solely towards the costs of upgrades (including,
     without limitation, upgrades necessary to comply with the applicable
     provisions of the Americans With Disabilities Act (the "ADA")) to the
     existing restrooms in the Premises and the construction of a new restroom
     on the first floor of Building C (the "Restroom Work") as part of the
     Tenant Improvement Work and (ii) an allowance of Fifty Thousand and 00/100
     Dollars ($50,000.00) (the "Water Fountain and Fire Alarm Allowance") to be
     used solely towards the costs of installing ADA-compliant water fountains
     and fire alarm strobes in the Premises (the "Water Fountain and Fire Alarm
     Work") as part of the Tenant Improvement Work. In connection therewith, it
     is understood and agreed that (x) the Restroom Allowance may be applied
     solely towards the cost of the Restroom Work and the Water Fountain and
     Fire Alarm Allowance may be applied solely towards the cost of the Water
     Fountain and Fire Alarm Work, and (y) to the extent Tenant does not fully
     utilize the Restroom Allowance and/or the Water Fountain and Fire Alarm
     Allowance, as the case may be, Tenant shall not be entitled to apply any
     unused portions of the


                                       28

<PAGE>

     applicable allowance towards the costs of any other portion of the Tenant
     Improvement Work nor shall Tenant be entitled to any credit on account
     thereof; provided, however, that notwithstanding the foregoing, Tenant
     shall be entitled to apply any unused portions of the Water Fountain and
     Fire Alarm Allowance towards the cost of the Restroom Work.

     The Tenant Improvement Allowance, the Restroom Allowance and the Water
     Fountain and Fire Alarm Allowance are hereinafter referred to collectively
     as the "Tenant Allowances."

     (B) Landlord shall pay within thirty (30) days after receipt of a complete
     requisition (as hereinafter defined) submitted by Tenant to Landlord the
     requested portion(s) of the Tenant Allowances as set forth on such
     requisition either to Tenant or, at Tenant's election, directly to the
     contractors, vendors and other service providers performing the Tenant
     Improvement Work as Tenant may designate or request, until the entirety of
     Tenant Allowances have been applied towards the appropriate components of
     the Tenant Improvement Work as set forth in subsection (A) above. For the
     purposes hereof, a "requisition" shall mean written documentation, together
     with (i) an AIA requisition form with respect to work performed pursuant to
     Tenant's construction contract with its general contractor, (ii) invoices
     from Tenant's service providers, showing in reasonable detail the cost of
     the item in question or of the improvements installed to date in the
     Premises, (iii) lien waivers in the form attached hereto as Exhibit F-1
     (provided that Tenant shall not be required to deliver any lien waivers
     with respect to any items of work covered by Tenant's first requisition for
     the Tenant Allowances to the extent Tenant had not paid the service
     provider(s) at issue prior to the date of such requisition, but Tenant
     shall deliver the lien waivers and evidence of payment in full of the items
     of work covered by such first requisition within twenty-one (21) days
     following the disbursement of the Tenant Allowances with respect to such
     first requisition) and (iv) certifications from Tenant that the amount of
     the requisition in question does not exceed the cost of the items, services
     and work covered by such certification. In the event that any portions of
     the Tenant Allowances reflected on a particular requisition are to be
     funded directly to Tenant, as Tenant may designate or request, such
     requisition shall be accompanied by evidence reasonably satisfactory to
     Landlord that the items, services and work covered by such requisition have
     been fully paid by Tenant. Landlord shall have the right, upon reasonable
     advance notice to Tenant, to inspect Tenant's books and records relating to
     each requisition in order to verify the amount thereof. Tenant shall submit
     requisition(s) no more often than monthly.

     Notwithstanding anything contained herein to the contrary:

          (i)  Landlord shall have no obligation to advance funds on account of
               the Tenant Allowances unless and until Landlord has received the
               requisition in question, together with the certifications
               required above.

          (ii) Except with respect to work and/or materials previously paid by
               Tenant (as evidenced by paid invoices and written lien waivers
               provided to


                                       29

<PAGE>

               Landlord), Tenant shall have the right to have portions of the
               Tenant Allowances paid directly to Tenant's contractors,
               consultants, service providers and vendors.

          (iii) Tenant shall not be entitled to any portion of the Tenant
               Allowances, and Landlord shall have no obligation to pay the
               Tenant Allowances, in respect of any requisition submitted after
               the date which is two (2) years from the Commencement Date (it
               being understood and agreed that irrespective of said time
               period, Tenant shall not be entitled to any payment or credit on
               account of any unused portions of the Tenant Allowances nor shall
               there be any application of the same toward Annual Fixed Rent or
               Additional Rent owed by Tenant under this Lease).

          (iv) Landlord shall have no obligation to fund any portion of the
               Tenant Allowances to the extent that (a) at the time of the
               requisition Tenant is in default under this Lease beyond the
               expiration of any notice and cure period (it being understood and
               agreed that if Tenant cures a default prior to the expiration of
               the applicable cure period, or if Tenant cures a default
               thereafter and Landlord has not terminated this Lease, Tenant
               shall be entitled to such payment from Landlord) or (b) there are
               any liens (unless bonded to the reasonable satisfaction of
               Landlord) filed against Tenant's interest in this Lease or
               against the Building or the Site arising solely out of the Tenant
               Improvement Work (specifically excluding the Base Building Work)
               or any litigation in which Tenant is a party relating to the
               Tenant Improvement Work.

          (v)  For each requisition submitted by Tenant hereunder, Landlord
               shall only be required to disburse a portion of the applicable
               Tenant Allowance towards the total costs set forth on each such
               requisition in an amount equal to the same proportion as the
               total component of the Tenant Allowance at issue bears to the
               total costs of the Tenant Improvement Work towards which such
               component of the Tenant Allowances may be applied (with Tenant
               being fully and solely responsible for the remainder of the
               amount shown in the requisition). By way of example, if the total
               Tenant Improvement Allowance equals $4,200,000.00 and the total
               costs of the Tenant Improvement Work equal $6,300,000.00, then
               the ratio of the total Tenant Improvement Allowance to the total
               costs of the Tenant Improvement Work would be 2:3 and if Tenant
               submitted a requisition for $300,000.00, Landlord would be
               required to disburse $200,000.00 of the Tenant Improvement
               Allowance on account of such requisition and Tenant would be
               responsible for the remaining $100,000.00.

          (vi) In no event shall Landlord be deemed to have assumed any
               obligations, in whole or in part, of Tenant to any contractors,
               subcontractors, suppliers, workers or materialmen on account of
               the Tenant Improvement Work (specifically excluding the Base
               Building Work).


                                       30
<PAGE>

3.4  Substantial Completion

     (A) Delivery Dates. It is understood and agreed that Landlord shall deliver
     the Premises to Tenant in phases in accordance with the following schedule
     so that Tenant may commence its construction of the Tenant Improvement
     Work:

<TABLE>
<CAPTION>
Phase                            Delivery Conditions                   Estimated Delivery Date
-----                            -------------------                   -----------------------
<S>                                                                    <C>
Building C    -    all replacement exterior glass has been installed   September 14, 2007

              -    new windows have been installed on the first
                   floor level

              -    roof replacement work has been completed

Building D    -    all replacement exterior glass has been installed   September 28, 2007

              -    the perimeter wall of the elevator shaft for the
                   new elevator has been substantially completed

              -    asbestos abatement work to remove the vinyl
                   asbestos floor tile and mastic has been
                   substantially completed

              -    new electrical panel has been installed

Building E    -    all replacement exterior glass has been installed   October 12, 2007

              -    modifications to freight elevator door have been
                   completed
</TABLE>

     For the purposes hereof, the "Delivery Date" for each Building shall be
     deemed to have occurred on the date on which all of the applicable Delivery
     Conditions for such Building have been satisfied. Landlord shall use
     commercially reasonable efforts to cause the Delivery Date for each
     Building to occur on or before the respective dates set forth above for
     such Building (it being understood and agreed that the failure by Landlord
     to satisfy the applicable Delivery Conditions for any Building on or before
     the applicable Delivery Date for such Building as set forth above shall
     constitute a Landlord Delay under Section 3.5(A) below, except to the
     extent that such failure is the result of Tenant Delays or, subject to the
     limitations set forth in Section 3.5(B) below, Landlord's Force Majeure).

     Notwithstanding the foregoing, upon the completion of the Approved Tenant
     Improvement Construction Documents, Tenant shall have the right to enter
     portions of the Premises prior to the date on which the applicable Delivery
     Conditions related to such portion of the Premises have been satisfied in
     order to perform specific components of the Tenant Improvement Work as set
     forth below, provided that such work can be performed safely and without
     unreasonable interference with the Base Building Work then being undertaken
     by Landlord in such portions of the Premises:


                                       31

<PAGE>

<TABLE>
<CAPTION>
Portion of Premises                   Permissible Items of Tenant Improvement Work
-------------------                   --------------------------------------------
<S>                                   <C>
Buildings C, D and E - Second Floor   -    mechanical, electrical and plumbing
                                           coordination process

                                      -    electrical makesafe/temporary lighting

                                      -    mechanical, electrical and plumbing
                                           cut/cap/drop

                                      -    demolition

                                      -    metal stud framing/door frames
                                           (excluding the last fifteen
                                           (15) feet of any wall where
                                           it meets a window frame)

                                      -    rough overhead mechanical, electrical
                                           and plumbing work

                                      -    in wall rough (excluding the last
                                           fifteen (15) feet of any wall
                                           where it meets a window frame)

Buildings C, D and E - First Floor    -    mechanical, electrical and plumbing
                                           coordination process

                                      -    electrical makesafe/temporary lighting

                                      -    mechanical, electrical and plumbing
                                           cut/cap/drop
</TABLE>

     Notwithstanding the foregoing, Tenant shall not have the right to enter the
     second (2nd) floor of Building D prior to the completion of Landlord's
     asbestos abatement work in that portion of the Premises, which is estimated
     to be finished on or about June 15, 2007.

     Further, Tenant shall have the right to request Landlord's permission to
     enter portions of the Premises prior to the date on which the applicable
     Delivery Conditions related to such portion of the Premises have been
     satisfied in order to perform other components of the Tenant Improvement
     Work provided that the same can be performed safely and without
     unreasonable interference with the Base Building Work then being undertaken
     by Landlord, and Landlord shall evaluate any such requests in good faith
     and advise Tenant within five (5) business days after any request on a
     case-by-case basis whether or not such items of work may be performed by
     Tenant without Tenant's having been deemed to have begun its construction
     of the Tenant Improvement Work for the purpose of triggering the applicable
     Delivery Date hereunder.

     Landlord shall provide Tenant with at least ten (10) days' advance notice
     of the date upon which Landlord estimates that the Delivery Conditions
     related to each of the Delivery Dates will be completed and the applicable
     Delivery Date will occur.

     From and after the Delivery Date for a Building, Tenant shall have free and
     unimpeded access to such Building for purposes of performing the Tenant
     Improvement Work; provided, however, that Landlord shall continue to have
     access to such Building to perform the remaining portions of the Base
     Building Work therein, so long as such work can be performed safely and
     without unreasonable interference to the Tenant


                                       32

<PAGE>

     Improvement Work then being undertaken by Tenant.

     (B) Base Building Work. The Base Building Work shall be deemed to be
     substantially completed on the date on which the work described in the Base
     Building Plans and Specifications has been completed except for so-called
     "punch-list" items of work and adjustment of equipment and fixtures which
     can be completed after occupancy has been taken without causing substantial
     interference with Tenant's use and enjoyment of the Premises or the right
     to legally occupy the entire Premises.

     (C) Delays in Completion of the Base Building Work. Landlord shall exercise
     commercially reasonable efforts to complete the Base Building Work within
     the Premises on or before March 31, 2008 and to complete the remainder of
     the Base Building Work outside of the Premises on or before May 1, 2008 (in
     both cases, subject to Tenant Delays and, subject to the limitations set
     forth in Section 3.5(B) below, Landlord's Force Majeure). Notwithstanding
     anything contained in this Lease to the contrary, if Landlord shall fail to
     substantially complete the Base Building Work on or before June 1, 2008
     (which date shall be extended automatically for such periods of time as
     Landlord is prevented in delivering the same by reason of Landlord's Force
     Majeure or any Tenant Delay), the Annual Fixed Rent and payments on account
     of Operating Expenses Allocable to the Premises and Landlord's Tax Expenses
     Allocable to the Premises shall be abated by one (1) day for each day from
     and after June 1, 2008 (as so extended) to the date of substantial
     completion of the Base Building Work.

     If Landlord shall fail to substantially complete the Base Building Work by
     August 1, 2008 (which date shall be extended automatically for such periods
     of time as Landlord is prevented in delivering the same by reason of
     Landlord's Force Majeure or any Tenant Delay), Tenant shall have the right
     to terminate this Lease effective as of the thirtieth (30th) day after
     receipt by Landlord of a notice from Tenant given on or after August 1,
     2008 (as so extended) indicating Tenant's desire to so terminate and upon
     the giving of such notice, the Term of this Lease shall cease and come to
     an end without further liability or obligation on the part of either party
     as of the expiration of the aforesaid thirty (30) day period, unless the
     Base Building Work shall in fact be substantially completed as determined
     pursuant to Section 3.4(B) above on or before the expiration of such thirty
     (30) day period.

     The foregoing abatement and termination rights shall be Tenant's sole and
     exclusive remedies at law or in equity or otherwise for the failure of
     Landlord to substantially complete the Base Building Work within the time
     periods set forth above.

     (D) Tenant Improvement Work. The Premises shall be deemed to be
     substantially completed, notwithstanding that the Tenant Improvement Work
     may not be complete and notwithstanding that a certificate of occupancy for
     the Tenant Improvement Work may not then have been approved for issuance or
     actually issued, on the date (the "Substantial Completion Date") which is
     the later to occur of (x) that date which is Two Hundred Ten (210) days
     after the Building C Delivery Date and (y) May 1, 2008, subject in the case
     of (x) and (y) to Tenant's Force Majeure (subject to the limitations of
     Section 3.5(D)


                                       33

<PAGE>

     below) and Landlord Delays; provided, however, that under no circumstances
     shall the Substantial Completion Date be deemed to have occurred hereunder
     until such time as the Base Building Work has been substantially completed
     (or deemed substantially completed) in accordance with the terms and
     conditions of Section 3.4(B) above.

3.5  Force Majeure and Other Delays

     (A) Landlord Delays. A "Landlord Delay" shall be defined as any delay in
     the design, permitting or performance of the Tenant Improvement Work and/or
     the authorization for issuance of a certificate of occupancy to the extent
     that such delay is actually caused by any act or, where there is a duty to
     act under this Lease, any failure to act by Landlord or Landlord's
     contractors, architects, engineers, or anyone else engaged by or on behalf
     of Landlord in connection with the construction of the Base Building Work
     as set forth in this Article III (including, without limitation, any
     failure by Landlord to meet any of the Delivery Conditions for any of the
     Buildings by the applicable date set forth in Section 3.4(A) above, except
     to the extent such failure is the result of Tenant Delays or, subject to
     the limitations of subsection (B) below, Landlord's Force Majeure) and
     disclosed to Landlord as hereinafter provided. Notwithstanding the
     foregoing, in no event shall any delays in the completion of the Tenant
     Improvement Work caused by Landlord's use of non-union labor constitute a
     Landlord Delay hereunder.

     Notwithstanding the foregoing, no event shall be deemed a Landlord Delay
     unless and until Tenant has given Landlord written notice (the "Landlord
     Delay Notice") advising Landlord: (x) that a Landlord Delay is occurring
     and setting forth Tenant's good faith estimate as to the likely length of
     such Landlord Delay; (y) of the basis on which Tenant has determined that a
     Landlord Delay is occurring; and (z) the actions which Tenant believes that
     Landlord must take to eliminate such Landlord Delay; provided, however, no
     Landlord Delay Notice shall be required with respect to any failure of
     Landlord to satisfy the Delivery Conditions for a Building as of the
     Delivery Date applicable to such Building set forth in Section 3.4(A)
     above. No event shall be deemed to be a Landlord Delay unless and until
     Landlord has failed to rectify the situation causing the Landlord Delay
     within forty-eight (48) hours after Landlord's receipt of the Landlord
     Delay Notice (which for the purposes of determining receipt may be
     delivered by hand to Landlord's Construction Representative, with copies to
     follow to Landlord at the notice address set forth in Section 1.1 of this
     Lease within five (5) days thereafter); provided, however, that if Landlord
     shall fail to eliminate the Landlord Delay within the aforesaid 48-hour
     period, then the 48-hour cure period shall be included in the period of
     time charged to Landlord pursuant to such Landlord Delay Notice (it being
     understood and agreed that if Landlord shall in fact eliminate the delay
     within the 48-hour cure period, no Landlord Delay shall be deemed to have
     occurred for the purposes of this Article III). In addition, any delay to
     the extent caused by (i) Tenant Delay (as defined in subsection (C) below)
     or (ii) subject to the limitations set forth in subsection (B) below,
     Landlord's Force Majeure (as defined in said subsection (B)) shall not
     constitute Landlord Delay.

     (B) Landlord's Force Majeure. For the purposes of this Article III,
     "Landlord's Force Majeure" shall mean delays due to unusual scarcity of or
     inability to obtain labor or


                                       34

<PAGE>

     materials (to the extent that such scarcity or inability is the result of
     conditions not prevalent in the market, and otherwise unforeseen, as of the
     date of this Lease), unusual or unforeseen labor difficulties (with the
     exception of strikes or other labor difficulties caused by or resulting
     from the use by either Landlord or Tenant of non-union labor at the Site),
     casualty or other causes beyond Landlord's reasonable control. Landlord
     shall provide Tenant with written notice within forty-eight (48) hours
     after the occurrence of any Landlord's Force Majeure event hereunder
     (together with Landlord's good faith estimate of the projected duration of
     such Landlord's Force Majeure event), and shall also notify Tenant as soon
     as such Landlord's Force Majeure event has ended. In no event shall any
     Landlord's Force Majeure under this Section 3.5(B) exceed a total of ninety
     (90) days in the aggregate. In addition, it is expressly understood and
     agreed that any casualty or Taking (as defined in Article VI below) that
     occurs prior to the Commencement Date of this Lease shall be deemed to be
     an event of Landlord's Force Majeure and/or Tenant's Force Majeure (as
     applicable) and shall be governed by the provisions of this Article III
     related thereto and not by the provisions of said Article VI.

     (C) Tenant Delays. A "Tenant Delay" shall be defined as any delay in the
     design, permitting or performance of the Base Building Work to the extent
     that such delay is actually caused by any act or, where there is a duty to
     act under this Lease, any failure to act by Tenant or Tenant's contractors,
     architects, engineers, or anyone else engaged by or on behalf of Tenant in
     connection with the construction of the Tenant Improvement Work as set
     forth in this Article III (including, without limitation, any delays
     resulting from the Approved Tenant Finishes under Section 3.1(C) above) and
     disclosed to Tenant as hereinafter provided. Notwithstanding the foregoing,
     in no event shall any delays in the completion of the Base Building Work
     caused by Tenant's use of non-union labor constitute a Tenant Delay
     hereunder.

     Notwithstanding the foregoing, no event shall be deemed a Tenant Delay
     unless and until Landlord has given Tenant written notice (the "Tenant
     Delay Notice") advising Tenant: (x) that a Tenant Delay is occurring and
     setting forth Landlord's good faith estimate as to the likely length of
     such Tenant Delay; (y) of the basis on which Landlord has determined that a
     Tenant Delay is occurring; and (z) the actions which Landlord believes that
     Tenant must take to eliminate such Tenant Delay. No event shall be deemed
     to be a Tenant Delay unless and until Tenant has failed to rectify the
     situation causing the Tenant Delay within forty-eight (48) hours after
     Tenant's receipt of the Tenant Delay Notice (which for the purposes of
     determining receipt may be delivered by hand to Tenant's Construction
     Representative, with copies to follow to Tenant at the notice address set
     forth in Section 1.2 of this Lease within five (5) days thereafter);
     provided, however, that if Tenant shall fail to eliminate the delay within
     the aforesaid 48-hour period, then the 48-hour cure period shall be
     included in the period of time charged to Tenant pursuant to such Tenant
     Delay Notice (it being understood and agreed that if Tenant shall in fact
     eliminate the Tenant Delay within the 48-hour cure period, no Tenant Delay
     shall be deemed to have occurred for the purposes of this Article III). In
     addition, any delay to the extent caused by (i) Landlord Delay or (ii)
     subject to the limitations of subsection (D) below, Tenant's Force Majeure
     (as defined in said subsection (D)) shall not constitute Tenant Delay.


                                       35

<PAGE>

     Tenant covenants that no Tenant Delay shall delay commencement of the Term
     or the obligation to pay Annual Fixed Rent or Additional Rent. The Delivery
     Dates and/or the date of substantial completion of the Base Building Work,
     as applicable, shall be deemed to have occurred as of the date when such
     Delivery Dates and/or date of substantial completion of the Base Building
     Work, as applicable, would have occurred but for any Tenant Delays, as
     determined by Landlord in the exercise of its good faith business judgment
     (it being understood and agreed that the foregoing shall not be construed
     so as to relieve Landlord of its obligation to actually complete the Base
     Building Work, notwithstanding the fact that substantial completion may
     have been deemed to have occurred prior to actual completion as the result
     of Tenant Delays).

     (D)Tenant's Force Majeure. For the purposes of this Article III, "Tenant's
     Force Majeure" shall mean delays due to unusual scarcity of or inability to
     obtain labor or materials (to the extent that such scarcity or inability is
     the result of conditions not prevalent in the market, and otherwise
     unforeseen, as of the date of this Lease), unusual or unforeseen labor
     difficulties (with the exception of strikes or other labor difficulties
     caused by or resulting from the use by either Landlord or Tenant of
     non-union labor at the Site), casualty or other causes beyond Tenant's
     reasonable control. Tenant shall provide Landlord with written notice
     within forty-eight (48) hours after the occurrence of any Tenant's Force
     Majeure event hereunder (together with Tenant's good faith estimate of the
     projected duration of such Tenant's Force Majeure event), and shall also
     notify Landlord as soon as such Tenant's Force Majeure event has ended. In
     no event shall any Tenant's Force Majeure under this Section 3.5(D) exceed
     a total of ninety (90) days in the aggregate. In addition, it is expressly
     understood and agreed that any casualty or Taking (as defined in Article VI
     below) that occurs prior to the Commencement Date of this Lease shall be
     deemed to be an event of Landlord's Force Majeure and/or Tenant's Force
     Majeure (as applicable) and shall be governed by the provisions of this
     Article III related thereto and not by the provisions of said Article VI.

3.6  Quality and Performance of Work

     (A)Quality; Cooperation. All construction work required or permitted by
     this Lease shall be done in a good and workmanlike manner and in compliance
     with all applicable laws, ordinances, rules, regulations, statutes,
     by-laws, court decisions, and orders and requirements of all public
     authorities ("Legal Requirements") and all Insurance Requirements. Landlord
     and Tenant acknowledge and agree that, notwithstanding the phasing of the
     Delivery Dates as set forth in Section 3.4 above, components of the Base
     Building Work and Tenant Improvement Work will be performed simultaneously,
     and accordingly agree to work cooperatively in order to coordinate the
     performance of the Base Building Work and the Tenant Improvement Work so
     that neither party unreasonably interferes with or delays the efforts of
     the other to complete its respective portion of the work within the time
     periods set forth herein; provided, however, that notwithstanding anything
     contained in Section 3.4(A) to the contrary, (i) prior to the occurrence of
     a Delivery Date for a particular Building, Landlord's performance of the
     Base Building Work in such Building shall have priority in terms of access,
     scheduling


                                       36

<PAGE>

     and other aspects requiring coordination between Landlord and Tenant and
     (ii) from and after the occurrence of a Delivery Date for a particular
     Building, Tenant's performance of the Tenant Improvement Work in such
     Building shall have priority in terms of access, scheduling and other
     aspects requiring coordination between Landlord and Tenant. Each party may
     inspect the work of the other at reasonable times and shall promptly give
     notice of observed defects. Each party authorizes the other to rely upon
     the approval and other actions on the party's behalf by any Construction
     Representative of the party named in Section 1.1 or any person hereafter
     designated in substitution or addition by notice to the party relying.

     In connection with the foregoing, Landlord and Tenant (together with their
     respective contractors and representatives, as appropriate) agree to hold
     periodic job meetings to discuss the performance and scheduling of the Base
     Building Work and the Tenant Improvement Work. In addition, from time to
     time during the performance of the Base Building Work and the Tenant
     Improvement Work under this Article III, either party may request
     construction information from the other party's Construction Representative
     to the extent reasonably necessary in connection with the performance by
     the requesting party of the work for which it is responsible hereunder.

     In the event of any casualty during the performance of the Base Building
     Work and the Tenant Improvement Work under this Article III, it is
     understood and agreed that each party shall be solely responsible for the
     restoration of their respective components of work.

     (B) Correction of Defects.

     (i)Landlord warrants to Tenant that: (a) the materials and equipment
     furnished in the performance of the Base Building Work will be of good
     quality (except to the extent used by any of the Tenant Parties, as
     hereinafter defined, in the performance of the Tenant Improvement Work);
     (b) the Base Building Work will be free from defects not inherent in the
     quality described in the Base Building Plans and Specifications; and (c)
     the Base Building Work and all components thereof shall be weather-tight
     (except to the extent resulting from particular components of the Tenant
     Improvement Work, such as rooftop penetrations) and otherwise in good
     working order and condition and shall comply with all Legal Requirements as
     of the completion of the Base Building Work. Any portion of the Base
     Building Work not conforming to the foregoing requirements may be
     considered defective. Landlord's warranty hereunder shall not apply to the
     extent of damage or defect caused by (1) the negligent acts or omissions or
     the willful misconduct of Tenant, its employees, agents, contractors,
     sublessees or permitted occupants under Section 5.6.6 below (hereinafter,
     the "Tenant Parties"), (2) improper operation by any of the Tenant Parties,
     or (3) normal wear and tear and normal usage.

     (ii) The warranty contained in the foregoing subsection (i) shall commence
     on the date on which Landlord has completed the Base Building Work under
     Section 3.4(B) above (the "Completion Date") and shall expire on the day
     immediately preceding the first (1st) anniversary of the Completion Date,
     provided that Tenant is required to deliver


                                       37

<PAGE>

     notice to Landlord of any defects within three hundred twenty (320) days of
     the Completion Date (the "Warranty Notice Period") in order to permit
     Landlord to take action to enforce Landlord's warranty rights with respect
     to the Base Building Work. In the event that the Completion Date is delayed
     as the result of any Tenant Delay, the Warranty Notice Period shall
     commence on the date that the Base Building Work would have been completed
     but for the Tenant Delay.

     (iii)Landlord agrees that it shall, without cost to Tenant, correct any
     portion of the Base Building Work which during the Warranty Period is found
     not to be in accordance with the warranties set forth in subsection (i)
     above. All defective items shall, subject to Tenant Delays and provided
     that Tenant has afforded Landlord with reasonable access to the Premises
     subject to the terms and provisions of Section 5.9 below in order to
     undertake the work described herein, be completed by Landlord within a
     reasonable period of time to be mutually agreed upon by Landlord and Tenant
     given the nature of the defect at issue after Landlord's receipt of a
     written notice from Tenant setting forth in reasonable detail the nature of
     the defect and Tenant's assessment of why it believes such defect is
     covered by the warranties set forth herein (Landlord hereby agreeing to use
     reasonable efforts to minimize interference with Tenant's use and enjoyment
     of the Premises, consistent with the fact that Landlord is undertaking to
     remedy the defective work).

     (iv) Except to the extent to which Tenant shall have given notice to
     Landlord within the Warranty Notice Period of the respects in which the
     Base Building Work is not in conformance with the warranties set forth in
     subsection (i) above, Tenant shall be deemed conclusively to have approved
     Landlord's construction of the Base Building Work and shall have no claim
     that Landlord has failed to perform any of its obligations under this
     Article III. Notwithstanding the foregoing, Landlord agrees that upon and
     after the expiration of the Warranty Notice Period, Landlord shall, at
     Tenant's request and at Tenant's sole cost and expense, enforce and
     exercise on behalf of Tenant any and all construction and manufacturers'
     warranties and guaranties with respect to the Base Building Work to the
     extent still in force and effect at the time of Tenant's request.

     (D) Time of Essence. Time is of the essence with respect to all of the time
     periods set forth in this Article III. Where no specific time period is
     specified herein for any review, approval, consent, or similar action
     required to be performed by Landlord under this Article III, Landlord shall
     respond to any request from Tenant, and/or Tenant's Construction
     Representative for approvals or information in connection with the work
     contemplated by this Article III within five (5) business days after
     Landlord's receipt of such request. Where no specific time period is
     specified herein for any review, approval, consent, or similar action
     required to be performed by Tenant under this Article III, Tenant shall
     respond to any request from Landlord and/or Landlord's Construction
     Representative for approvals or information in connection with the work
     contemplated by this Article III within five (5) business days after
     Tenant's receipt of such request.


                                       38

<PAGE>

3.7  Arbitration

     Any disputes relating to provisions or obligations in this Article III or
     arising from the performance of the parties under this Article III shall be
     resolved by arbitration, under the Construction Industry Rules of the
     American Arbitration Association (the "AAA"), and subject to the provisions
     of Mass. General Laws, c. 251, with hearings conducted as expeditiously as
     practicable and with no undue delay, and in no event later than sixty (60)
     days after the date of demand, in Boston, Massachusetts. Prior written
     notice of application by either party for arbitration shall be given to the
     other at least ten (10) days before filing of any demand for arbitration
     hereunder. Any award of an arbitrator rendered hereunder shall be subject
     to confirmation and entry of judgment thereon in any court of competent
     jurisdiction sitting in Suffolk or Middlesex Counties, Massachusetts, and
     the parties hereby consent to the jurisdiction of such court. The costs and
     administration expenses of each arbitration hereunder and their
     apportionment between the parties shall be borne equally by the parties,
     and each party shall be responsible for its own attorneys' fees and expert
     witness fees. In connection with the foregoing, it is expressly understood
     and agreed that the parties shall continue to perform their respective
     obligations under this Lease during the pending of any such arbitration
     proceeding hereunder (with any adjustments or reallocations to be made on
     account of such continued performance as determined by the arbitrator in
     his or her award).

3.8  Escrow of Funds

     In the event that the Landlord originally named herein transfers, sells,
     assigns or otherwise conveys its interest in the Complex (a "Landlord
     Transfer") prior to the earlier of (i) the date that the Tenant Allowances
     have been fully disbursed by Landlord, and (ii) that date which is thirty
     (30) days from the first anniversary of the Commencement Date (the later of
     (i) and (ii) being referred to as the "Outside TI Date"), then prior to or
     at the time of such Landlord Transfer, the Landlord originally named herein
     shall, at its election, (a) deposit into an escrow account in form and
     substance, and with an escrow agent, reasonably satisfactory to Landlord
     and Tenant, cash in the amount of the undisbursed portions of the Tenant
     Allowances, such escrow account to be used to fund the remaining allowance
     obligations of Landlord under this Lease, or (b) provide Tenant with a
     letter of credit, in form and substance, and from an issuing bank,
     reasonably satisfactory to Tenant in the amount of the undisbursed portions
     of the Tenant Allowances, such letter of credit to be held by Tenant as
     security for the remaining allowance obligations of Landlord under this
     Lease. Any funds remaining in the escrow account, or the letter of credit,
     as the case may be, shall be returned to the Landlord named herein promptly
     after the later of (i) the Outside TI Date and (ii) the repayment of all
     reimbursable amounts of the Tenant Allowances properly and timely requested
     by Tenant in accordance with the provisions of this Lease.


                                       39

<PAGE>

                                   ARTICLE IV

                 Landlord's Covenants; Interruptions and Delays

4.1  Landlord Covenants

     Landlord covenants and agrees to the following during the Term:

     4.1.1 Services Furnished by Landlord

          To furnish services, utilities, facilities and supplies set forth in
          Exhibit C attached hereto to the Premises and the Complex in a manner
          equal to that customarily provided by landlords in comparable,
          first-class office/research and development multi-building complexes
          in the Boston Northwest Suburban Market subject to reimbursement in
          accordance with, and as limited by, the provisions of Section 2.6.

     4.1.2 Additional Services Available to Tenant

          To furnish, at Tenant's expense, reasonable additional Building
          operation services which are usual and customary in comparable,
          first-class office/research and development complexes in the Boston
          Northwest Suburban Market upon reasonable advance request of Tenant at
          reasonable and equitable rates from time to time established by
          Landlord. Tenant agrees to pay to Landlord, as Additional Rent, the
          cost of any such additional Building services requested by Tenant and
          for the cost of any additions, alterations, improvements or other work
          performed by Landlord in the Premises at the request of Tenant within
          thirty (30) days after being billed therefor.

     4.1.3 Roof, Exterior Wall, Floor Slab and Common Facility Repairs

          Except for damage caused by fire and casualty and by eminent domain,
          and except as otherwise provided in Article VI and subject to
          reimbursement in accordance with, and as limited by, the provisions of
          Section 2.6, (i) to make such repairs and/or replacements (as
          appropriate) to all structural and non-structural portions and
          components of the roof systems (including roof membranes) and the
          mechanical, electrical, plumbing, sprinkler, fire/life safety and the
          heating, ventilating and air conditioning ("HVAC") systems serving the
          Premises (but exclusive of any specialty installations installed or
          requested by Tenant that exclusively serve the Premises which shall be
          maintained at Tenant's sole cost and expense), the Common Areas and
          the Structural Elements (as hereafter defined) as may be necessary to
          keep them in good and operable condition consistent with the level of
          maintenance and repair customary for comparable, first-class
          office/research and development properties in the Boston Northwest
          Suburban Market, and (ii) to maintain the Complex (exclusive of
          Tenant's responsibilities under this Lease) in a first class manner
          comparable to the


                                       40

<PAGE>

          maintenance of similar first-class office/research and development
          complexes in the Boston Northwest Suburban Market. The term
          "Structural Elements" shall mean the structural components of the
          Buildings, including without limitation the roofs, foundations,
          exterior structural walls, floor/ceiling slabs, exterior glass and
          mullions, columns, beams, shafts, elevator cabs and other load-bearing
          elements of the Buildings.

          Within six (6) months following the substantial completion of the Base
          Building Work (but not as a condition of substantial completion),
          Landlord agrees to perform, at its sole cost and expense, an infrared
          scan of the roofs of Buildings C, D and E and to provide Tenant with a
          copy of the results of such scan. In the event that such scan revels
          that the roof systems are not weather-tight (except to the extent
          resulting from particular components of the Tenant Improvement Work),
          Landlord agrees, at Landlord's sole cost and expense and without
          inclusion in Landlord's Operating Expenses, to promptly and diligently
          repair any such problem areas in accordance with good and sound
          construction standards in the commercial roofing industry.

4.2  Interruptions and Delays in Services and Repairs, Etc.

     (A)Except as specifically provided in Section 4.2(C) below, Landlord shall
     not be liable to Tenant for any compensation or reduction of rent by reason
     of inconvenience or annoyance or for loss of business arising from the
     necessity of Landlord or its agents entering the Premises in accordance
     with, and as limited by, the provisions of Section 5.9 below for any of the
     purposes in this Lease authorized, or for repairing the Premises or any
     portion of the Buildings however the necessity may occur. In case Landlord
     is prevented or delayed from making any repairs, alterations or
     improvements, or furnishing any services or performing any other covenant
     or duty to be performed on Landlord's part, by reason of any cause
     reasonably beyond Landlord's control, Landlord shall not be liable to
     Tenant therefor, nor, except as expressly otherwise provided in Section
     4.2(C) or in Article VI, shall Tenant be entitled to any abatement or
     reduction of rent by reason thereof, or right to terminate this Lease, nor
     shall the same give rise to a claim in Tenant's favor that such failure
     constitutes actual or constructive, total or partial, eviction from the
     Premises.

     (B) Landlord reserves the right to stop any service or utility system, when
     necessary by reason of accident or emergency, or until necessary repairs
     have been completed; provided, however, that in each instance of stoppage,
     Landlord shall exercise reasonable diligence to eliminate the cause
     thereof. Except in case of emergency repairs, Landlord will give Tenant
     reasonable advance notice of any contemplated stoppage and will use
     reasonable efforts to avoid unnecessary inconvenience to Tenant by reason
     thereof, including, without limitation, scheduling such stoppage during
     Tenant's non-business hours to the extent commercially practicable under
     the circumstances.

     (C) Notwithstanding anything to the contrary in this Lease contained, if
     due to (i) any repairs, alterations, replacements, or improvements made by
     Landlord, (ii) Landlord's


                                       41

<PAGE>

     failure to make any repairs, alterations, or improvements required to be
     made by Landlord hereunder, or to provide any service required to be
     provided by Landlord hereunder, or to remediate any Hazardous Materials (as
     that term is defined in Section 5.3 below) required to be remediated by
     Landlord hereunder, or (iii) failure of electric supply, water and/or sewer
     service, or HVAC service to the Premises, any portion of the Premises
     becomes untenantable so that for the Premises Untenantability Cure Period,
     as hereinafter defined, the continued operation in the ordinary course of
     Tenant's business is materially adversely affected (including, without
     limitation, as the result of the Premises being rendered inaccessible as
     the result of any of the circumstances described in subsections (i), (ii)
     or (iii) above), then, provided that Tenant ceases to use the affected
     portion of the Premises during the entirety of the Premises Untenantability
     Cure Period by reason of such untenantability, and that such
     untenantability and Landlord's inability to cure such condition is not
     caused by the fault or neglect of Tenant or Tenant's agents, employees or
     contractors, Annual Fixed Rent, Operating Expenses Allocable to the
     Premises and Landlord's Tax Expenses Allocable to the Premises shall from
     and after the expiration of the Premises Untenantability Cure Period be
     abated in proportion to such untenantability and its impact on the
     continued operation in the ordinary course of Tenant's business until the
     day such condition is completely corrected. For the purposes hereof, the
     "Premises Untenantability Cure Period" shall be defined as five (5)
     consecutive business days after Landlord's receipt of written notice from
     Tenant of the condition causing untenantability in the Premises, provided
     however, that the Premises Untenantability Cure Period shall be ten (10)
     consecutive business days after Landlord's receipt of written notice from
     Tenant of such condition causing untenantability in the Premises if either
     the condition was caused by causes beyond Landlord's control or Landlord is
     unable to cure such condition as the result of causes beyond Landlord's
     control.

     In addition, if due to (a) any repairs, alterations, replacements, or
     improvements made by Landlord, (b) Landlord's failure to make any repairs,
     alterations, or improvements required to be made by Landlord hereunder or
     to provide any service required to be provided by Landlord hereunder, (c)
     Landlord's Failure to remediate any Hazardous Materials required to be
     remediated by Landlord under this Lease, or (d) the failure of electric
     supply, water and/or sewer service, or HVAC service to the Premises, the
     operation of Tenant's business in the Premises in the normal course is
     materially adversely affected (including, without limitation, as the result
     of the Premises being rendered inaccessible as the result of any of the
     circumstances described in clauses (a), (b), (c) or (d) above) for a period
     of five (5) consecutive months after Landlord's receipt of written notice
     of such condition from Tenant, then, provided that Tenant ceases to use the
     affected portion of the Premises for the period of such untenantability and
     such untenantability and Landlord's inability to cure such condition is not
     caused by the fault or neglect of Tenant, or Tenant's agents, employees or
     contractors, then Tenant may terminate this Lease by giving Landlord
     written notice as follows:

     (i)  Said notice shall be given after said five (5) month period.


                                       42

<PAGE>

     (ii) Said notice shall set forth an effective date which is not earlier
          than thirty (30) days after Landlord receives said notice.

     (iii) If said condition is remedied on or before the date thirty (30) days
          after the receipt of such notice, said notice shall have no further
          force and effect.

     (iv) If said condition is not remedied on or before the date thirty (30)
          days after the receipt of such notice for any reason other then
          Tenant's fault, as aforesaid, the Lease shall terminate as of said
          effective date, and the Annual Fixed Rent and Additional Rent due
          under the Lease shall be apportioned (to the extent not abated) as of
          said effective date.

     The remedies set forth in this Section 4.2(C) shall be Tenant's sole
     remedies for the events described herein. The provisions of this subsection
     shall not apply in the event of untenantability caused by fire or other
     casualty, or taking (which shall be subject to the terms and conditions of
     Article VI below).

4.3  Landlord's Insurance

     Landlord shall carry at all times during the Term of this Lease (i)
     commercial general liability insurance with respect to the Buildings in an
     amount not less than $10,000,000.00 combined single limit per occurrence,
     (ii) insurance against loss or damage with respect to the Complex covered
     by the so-called "all risk" type insurance coverage with customary
     exceptions in an amount equal to one hundred percent (100%) of the
     replacement value of all improvements within the Complex and (iii) loss of
     "rental value" insurance in an amount equal to not less than the Annual
     Fixed Rent and payments on account of Operating Expenses Allocable to the
     Premises and Landlord's Tax Expenses Allocable to the Premises payable by
     Tenant under this Lease for not less than a one (1) year period (with a
     customary deductible). Landlord may also maintain such other insurance as
     may from time to time be required by a mortgagee holding a mortgage lien on
     the Buildings. Further, Landlord may also maintain such insurance against
     loss of annual fixed rent and additional rent and such other risks and
     perils as Landlord deems proper. Any and all such insurance (x) may be
     maintained under a blanket policy affecting other properties of Landlord
     and/or its affiliated business organizations, (y) may be written with
     deductibles as reasonably determined by Landlord (which such deductible is
     currently $25,000.00) and (z) shall be subject to reimbursement in
     accordance with Section 2.6.

     Nothing contained herein shall be construed so as to require Landlord to
     maintain terrorism or environmental pollution liability insurance (it being
     acknowledged, however, that Landlord does in fact maintain such coverages
     as of the date of this Lease); provided, however, that in the event the
     Landlord originally named herein shall sell, transfer, assign, convey or
     ground lease its interest in the Complex to an unaffiliated third party,
     such new owner and any subsequent party succeeding to the original
     Landlord's interest as Landlord under this Lease shall not be entitled to
     charge to Tenant at any time during the Term as part of Operating Expenses
     Allocable to the Premises any costs of terrorism


                                       43

<PAGE>

     or environmental pollution liability insurance in excess of one hundred ten
     percent (110%) of the costs being paid by Tenant on account of such
     coverages during the last full calendar year immediately prior to the
     conveyance by the original named Landlord.

4.4  Landlord's Indemnity

     Subject to the limitations of Section 8.4 below and to the provisions of
     Section 8.19 below, to the maximum extent this agreement is effective
     according to law and to the extent not resulting from any act, omission,
     fault, negligence or misconduct of Tenant or its contractors, agents,
     licensees, invitees, servants or employees, Landlord agrees to defend with
     counsel first approved by Tenant (counsel appointed by Landlord's insurance
     carrier shall be deemed approved by Tenant and for any other circumstances
     such approval shall not be unreasonably withheld or delayed) indemnify and
     save harmless Tenant and Tenant's beneficiaries, partners, subsidiaries,
     officers, directors, agents, trustees and employees (collectively, the
     "Tenant Parties") from and against any claim arising from any injury to any
     person occurring in the Premises, in the Buildings or on the Site after the
     date that possession of the Premises is first delivered to Tenant and until
     the expiration or earlier termination of the Lease Term, to the extent such
     injury results from the negligence or willful misconduct of Landlord or
     Landlord's agents, employees or contractors provided, however that in no
     event shall the aforesaid indemnity render Landlord responsible or liable
     for any loss or damage to fixtures or personal property of Tenant and
     Landlord shall in no event be liable for any indirect or consequential
     damages; and provided, further, that the provisions of this Section 4.4
     shall not be applicable to the holder of any mortgage now or hereafter on
     the Site or the Buildings (whether or not such holder shall be a mortgagee
     in possession of or shall have exercised any rights under a conditional,
     collateral or other assignment of leases and/or rents respecting, the Site
     and/or Buildings) except to the extent otherwise agreed by such holder in
     any Subordination, Non-Disturbance and Attornment Agreement by and between
     Tenant and such holder.

4.5  Compliance with Laws

     To the best of Landlord's actual knowledge, the Buildings were constructed
     in accordance with the provisions of the Zoning Bylaw for the Town of
     Bedford and other laws, ordinances, rules and regulations applicable to the
     Buildings as of the construction thereof.

4.6  Leasing Restrictions

     Provided that, on the condition that and only so long as (i) Tenant
     directly leases from Landlord at least 75,000 square feet of rentable floor
     area and its Government and Industrial Division is still in occupancy of
     portions of the Premises, (ii) no Event of Default of Tenant exists, (iii)
     this Lease is still in full force and effect, and (iv) Tenant has neither
     assigned this Lease nor sublet the Premises in its entirety (except for an
     assignment or sublease under Section 5.6.1 above or a permitted occupancy
     under Section 5.6.6 below), (a) Landlord shall not hereafter directly enter
     into a lease of other


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<PAGE>

     space in the Complex with any of the "Named Companies" (as hereinafter
     defined), and (b) Landlord agrees to include in all "Future Leases" (as
     hereinafter defined) the same clause as is contained in Section 5.6.2(i)
     below (the "Assignment and Subletting Restriction Clause") which would
     allow Landlord to withhold its consent (and Landlord shall so withhold its
     consent) to a proposed assignment or sublease that would be in violation of
     the restrictions of this Section 4.6. Landlord shall use commercially
     reasonable efforts to enforce the terms of the Assignment and Subletting
     Restriction Clauses in its Future Leases, but in no event shall Landlord be
     liable to Tenant (x) for the failure of other occupants of the Complex to
     comply with the Assignment and Subletting Restriction Clause so long as
     Landlord has withheld its consent and used commercially reasonable efforts
     to enforce the same as aforesaid or (y) to the extent that a court of
     competent jurisdiction determines that the Assignment and Subletting
     Restriction Clause is invalid and/or unenforceable.

     Notwithstanding the foregoing, the provisions of this Section 4.6 shall not
     apply to the Existing Leases set forth in Exhibit O hereto or to any
     business operations or other activities of the holders of the tenant(s)
     interest(s) in the Existing Leases or, to the extent such Existing Leases
     do not contain the Assignment and Subletting Restriction Clause, of the
     subtenants or assignees under the Existing Leases.

     For the purposes hereof:

          (i)  The "Named Companies" are Samsung, LG, Yujin, Foster-Miller,
               Qinetiq, Allen-Vanguard, Northrop Grummann's Remotec division,
               General Dynamics Robotic Systems, and any successor-in-interest
               to the foregoing entities and/or divisions, as the case may be,
               who is engaged in whole or in part in the business of developing
               or manufacturing robotic devices. Landlord agrees during the term
               to reasonably consider requests by tenant to include additional
               or substitute entities to the list of Named Companies provided
               that Tenant can demonstrate to Landlord's reasonable satisfaction
               that such proposed entities are direct and substantial
               competitors of Tenant (provided that in no event shall there be
               more than eight (8) Named Companies at any time).

          (ii) A "Future Lease" shall be a lease entered into after the date of
               this Lease for space in the Complex between Landlord, as
               landlord, and a person or entity (other than Tenant), as tenant,
               but excluding, to the extent herein provided, the Existing Leases
               and the implementation of the provisions of the Existing Leases.

                                    ARTICLE V

                               Tenant's Covenants

     Tenant covenants and agrees to the following during the Term and such
     further time as


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<PAGE>

     Tenant occupies any part of the Premises:

5.1  Payments

     To pay when due all fixed rent and Additional Rent and all charges for
     utility services rendered to the Premises (except as otherwise provided in
     Exhibit C) and, as further Additional Rent, all charges for additional
     services rendered pursuant to Section 4.1.2.

5.2  Repair and Yield Up

     Except as otherwise provided in Article VI and Section 4.1.3 to keep the
     Premises in good order, repair and condition, excepting only reasonable
     wear and tear and damage by fire or taking under the power of eminent
     domain, and all interior glass in windows (except glass in exterior walls
     unless the damage thereto is attributable to Tenant's negligence or misuse)
     and doors of the Premises whole and in good condition with glass of the
     same type and quality as that injured or broken, and at the expiration or
     termination of this Lease peaceably to yield up the Premises with all
     construction, work, improvements, and all alterations and additions thereto
     in good order, repair and condition, reasonable wear and tear and damage by
     fire or taking under the power of eminent domain only excepted, first
     removing all goods and effects of Tenant and (x) to the extent specified by
     Landlord by notice to Tenant given at least sixty (60) days prior to such
     expiration or termination, the wiring for Tenant's computer, telephone and
     other communication systems and equipment whether located in the Premises
     or in any other portion of the Buildings (including all risers) and (y) to
     the extent specified for removal by Landlord at the time Landlord approves
     of the same under Article III above or Section 5.14 below, all alterations
     and additions made by Tenant, and repairing any damage caused by such
     removal and restoring the Premises and leaving them clean and neat. Tenant
     shall not permit or commit any waste, and Tenant shall be responsible for
     the cost of repairs which may be made necessary by reason of damage to the
     Buildings or to the Site or to the Additional Buildings caused by Tenant,
     Tenant's agents, contractors, employees, sublessees, licensees,
     concessionaires or invitees.

5.3  Use

     To use and occupy the Premises for the Permitted Uses only, and not to
     injure or deface the Premises, Buildings, the Additional Buildings, the
     Site or any other part of the Complex nor to permit in the Premises or on
     the Site any auction sale or inflammable fluids or chemicals, or nuisance,
     or the emission from the Premises of any objectionable noise or odor, nor
     to operate in the Premises in such a way as to result in the leakage of
     fluid, and not to use or devote the Premises or any part thereof for any
     purpose other than the Permitted Uses, nor any use thereof which is
     inconsistent with the maintenance of the Buildings as office/research and
     development buildings of the first class in the quality of its maintenance,
     use and occupancy, or which is improper, offensive, contrary to law or
     ordinance or liable to invalidate or increase the premiums for any
     insurance on the Buildings (Landlord hereby representing that to the best
     of its actual knowledge as of the date of this Lease, the Permitted Uses
     will not invalidate or increase the insurance


                                       46

<PAGE>

     premiums for the Complex) or its contents or liable to render necessary any
     alteration or addition to the Buildings. Further, except as otherwise set
     forth in this Lease (i) Tenant shall not, nor shall Tenant permit its
     employees, invitees, agents, independent contractors, contractors,
     assignees or subtenants to, keep, maintain, store or dispose of (into the
     sewage or waste disposal system or otherwise) or engage in any activity
     which might produce or generate any substance which is or may hereafter be
     classified as a hazardous material, waste or substance (collectively
     "Hazardous Materials"), under federal, state or local laws, rules and
     regulations, including, without limitation, 42 U.S.C. Section 6901 et seq.,
     42 U.S.C. Section 9601 et seq., 42 U.S.C. Section 2601 et seq., 49 U.S.C.
     Section 1802 et seq. and Massachusetts General Laws, Chapter 21E and the
     rules and regulations promulgated under any of the foregoing, as such laws,
     rules and regulations may be amended from time to time (collectively
     "Hazardous Materials Laws"), (ii) Tenant shall immediately notify Landlord
     of any incident in, on or about the Premises, the Buildings or the Site
     that would require the filing of a notice under any Hazardous Materials
     Laws, (iii) Tenant shall comply and shall cause its employees, invitees,
     agents, independent contractors, contractors, assignees and subtenants to
     comply with each of the foregoing and (iv) Landlord shall have the right,
     at Landlord's sole cost and expense, to make such inspections (including
     testing) as Landlord shall elect from time to time to determine that Tenant
     is complying with the foregoing (provided that Landlord shall promptly
     restore any portions of the Premises that may have been disturbed by such
     inspections).

     Notwithstanding the foregoing, Tenant may use Hazardous Materials and other
     substances typically used by Tenant for the conduct of the Permitted Uses,
     including, without limitation, diesel fuel in such amounts as are
     appropriate for the testing of Tenant's existing and prototype products,
     provided that Tenant uses, stores and disposes of such Hazardous Materials
     and other substances in the manner which they are normally used, and in
     compliance with all Hazardous Materials Laws and other applicable laws,
     ordinances, bylaws, rules and regulations, and Tenant obtains and complies
     with all permits required by Hazardous Materials Laws or any other laws,
     ordinances, bylaws, rules or regulations prior to the use or presence of
     any such substances in the Premises.

     Landlord represents and warrants to Tenant that, except as set forth in
     those certain reports entitled (x) "Report on Phase I Environmental Site
     Assessment Update, 2 to 14 Crosby Drive, Bedford, Massachusetts" prepared
     by Haley & Aldrich, Inc. and dated March 21, 1997 and (y) "Phase IV
     Inspection and Monitoring Report No. 3, 4D Crosby Drive, Bedford,
     Massachusetts" prepared by Sanborn, Head & Associates, Inc and dated May
     17, 2006 (copies of which have been provided to Tenant), to the best of
     Landlord's actual knowledge as of the date of this Lease there are no
     Hazardous Materials in the Buildings or on the Site which are or would be
     required to be removed or otherwise abated in accordance with applicable
     Hazardous Materials Laws. Subject to the limitations of Section 8.4 hereof,
     Landlord shall use reasonable efforts to remove or abate, as required by
     applicable Hazardous Materials Laws, Hazardous Materials on the Site or in
     the Common Areas, the Structural Elements or the base building systems of
     the Complex, provided that the foregoing shall not apply to (i)
     requirements of Hazardous Materials Laws resulting from the use of, or
     additions, alterations or improvements in the


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<PAGE>

     Premises, or (ii) Hazardous Materials which are in the Buildings or on the
     Site because of the action or inaction of any tenant or occupant in the
     Complex, including Tenant, or any employee, agent or contractor thereof, or
     (iii) any tenant space in the Complex, including the Premises, and any
     additions, alterations and improvements therein. In connection with the
     foregoing, Landlord hereby agrees to use best efforts to enforce the terms
     of its leases with other tenants of the Complex in the event of a violation
     of Hazardous Materials Laws resulting from the action or inaction of any
     tenant or occupant of the Complex or any employee, agent or contractor
     thereof; provided, however, that in no event shall Landlord be liable to
     Tenant for any violation of Hazardous Materials Laws by any tenant or
     occupant of the Complex. Subject to the limitations of Section 8.4 hereof,
     Landlord agrees to defend with counsel first approved by Tenant (counsel
     appointed by Landlord's insurance carrier shall be deemed approved by
     Tenant and for any other circumstances such approval shall not be
     unreasonably withheld or delayed), indemnify and save Tenant harmless from
     liability, loss and damage to persons or property and from any claims,
     actions, proceedings and expenses in connection therewith resulting from
     the failure of Landlord to fulfill its obligations under this Section 5.3;
     provided, however, that in no event shall the foregoing indemnity render
     Landlord liable for any loss or damage to Tenant's Property and Landlord
     shall in no event be liable for indirect or consequential damages.

5.4  Obstructions; Items Visible From Exterior; Rules and Regulations

     Not to obstruct in any manner any portion of the Additional Buildings not
     hereby leased or any portions of the Site used by Tenant in common with
     others; not without prior consent of Landlord, except as otherwise
     expressly set forth in this Lease, to permit the painting or placing of any
     signs, awnings, aerials or flagpoles, visible from outside the Premises;
     and to comply with all reasonable Rules and Regulations of general
     applicability to tenants of the Complex now or hereafter made by Landlord,
     of which Tenant has been given notice and which are not inconsistent with
     any of Tenant's rights under this Lease, for the care and use of the
     Buildings and Site and their facilities and approaches. Landlord agrees to
     enforce such Rules and Regulations in a uniform and non-discriminatory
     manner, but in no event shall Landlord be liable to Tenant for the failure
     of other occupants of the Complex to conform to such Rules and Regulations.

5.5  Safety Appliances

     Subject to Landlord's obligations under this Lease, to keep the Premises
     equipped with all safety appliances (including, without limitation, the
     sprinkler and fire suppression systems serving the Premises) required by
     any public authority because of any use made by Tenant other than normal
     office use, and to procure all licenses and permits so required because of
     such use and, if requested by Landlord, to do any work so required because
     of such use, it being understood that the foregoing provisions shall not be
     construed to broaden in any way the Permitted Uses.


                                       48
<PAGE>

5.6  Assignment; Sublease

     Except as otherwise expressly provided herein, Tenant covenants and agrees
     that it shall not assign, mortgage, pledge, hypothecate or otherwise
     transfer this Lease and/or Tenant's interest in this Lease or sublet (which
     term, without limitation, shall include granting of concessions, licenses
     or the like) the whole or any part of the Premises without first obtaining
     Landlord's prior written consent, which consent will be governed by the
     terms and provisions of Section 5.6.2 below if Landlord does not exercise
     its rights under Section 5.6.1.1 below. Any assignment, mortgage, pledge,
     hypothecation, transfer or subletting not expressly permitted in or
     consented to by Landlord under Sections 5.6.1-5.6.7 shall be void, ab
     initio; shall be of no force and effect; and shall confer no rights on or
     in favor of third parties. In addition, Landlord shall be entitled to seek
     specific performance of or other equitable relief with respect to the
     provisions hereof.

     5.6.1 Notwithstanding the foregoing provisions of Section 5.6 above and the
          provisions of Sections 5.6.1.1, 5.6.2 and 5.6.4 below, but subject to
          the provisions of the first paragraph of Sections 5.6.3 (the first
          paragraph only) and 5.6.5 below, Tenant shall have the right to assign
          this Lease or to sublet the Premises in whole or in part, without
          Landlord's consent, to any other entity (the "Successor Entity") (i)
          which controls or is controlled by Tenant or Tenant's parent
          corporation, or (ii) which is under common control with Tenant, or
          (iii) which purchases all or substantially all of the assets of
          Tenant, or (iv) which purchases all or substantially all of the stock
          of (or other membership interests in) Tenant or (v) which merges or
          combines with Tenant; provided, that to the extent Tenant does not
          remain in existence after an assignment to or other transaction with a
          Successor Entity, the Successor Entity has a net worth (on a pro forma
          basis using generally accepted accounting principles consistently
          applied after giving effect to the merger, consolidation or purchase
          of assets, stock or other membership interests) reasonably sufficient
          to perform the obligations of the tenant under this Lease. Except in
          cases of statutory merger, in which case the surviving entity in the
          merger shall be liable as the Tenant under this Lease, Tenant shall
          continue to remain fully liable under this Lease, on a joint and
          several basis with the Successor Entity and, following such sublease
          or assignment, Tenant or such Successor Entity, as the case may be,
          shall continue to comply with all of its obligations under this Lease,
          including with respect to the Permitted Uses of the Premises. If any
          affiliate, parent or subsidiary entity of Tenant to which this Lease
          is assigned or the Premises sublet (in whole or in part) without
          Landlord's consent pursuant to this Section 5.6.1 shall cease to be
          such an affiliate, parent or subsidiary entity, such cessation shall
          be considered an assignment or subletting requiring Landlord's
          consent. Landlord agrees that the offer and sale by Tenant (or any
          stockholder of Tenant) of any stock or other membership interests
          pursuant to an effective registration statement filed pursuant to the
          Securities Act of 1933 or pursuant to and in accordance with the
          securities laws of the United States or any foreign country governing
          publicly traded companies and not in violation of U.S. law, shall not
          constitute an assignment of this Lease, and shall


                                       49

<PAGE>

          not require the consent or approval of Landlord. To the extent Tenant
          remains in existence after the assignment or sublease to a Successor
          Entity, the continued economic viability of Tenant and the amount of
          the Security Deposit then being held under this Lease shall be taken
          into account when evaluating the ability of the assignee or subtenant
          to perform the obligations of the tenant under this Lease as set forth
          above.

          5.6.1.1 Notwithstanding the provisions of Section 5.6 above, in the
               event Tenant desires to assign this Lease or to sublet the
               Premises and this Section 5.6.1.1 is applicable to the proposed
               transfer, Tenant shall give Landlord a Proposed Transfer Notice
               (as defined in Section 5.6.3 hereof) and in the event of (x) a
               proposed assignment of this Lease or (y) a proposed sublease of
               fifty percent (50%) or more of the Rentable Floor Area of the
               Premises or (z) a proposed sublease of less than fifty percent
               (50%) of the Rentable Floor Area of the Premises for all or
               substantially all of the then-remaining Lease Term (which for the
               purposes hereof shall be defined as any sublease expiring within
               the last eighteen (18) months of the Term of this Lease), then
               Landlord shall have the right at its sole option, to be exercised
               within fifteen (15) business days after receipt of Tenant's
               Proposed Transfer Notice (the "Acceptance Period"), to terminate
               this Lease as of a date specified in a notice to Tenant, which
               date shall not be earlier than the proposed possession date under
               Tenant's proposed sublease or assignment, as applicable;
               provided, however, that (i) upon the termination date as set
               forth in Landlord's notice, all obligations relating to the
               period after such termination date (but not those relating to the
               period before such termination date) shall cease and promptly
               upon being billed therefor by Landlord, Tenant shall make final
               payment of all Annual Fixed Rent and Additional Rent due from
               Tenant through the termination date and (ii) Landlord shall, at
               Landlord's sole cost and expense, remove or close off and secure,
               in compliance with applicable laws, any internal stairways,
               doors, or corridors which connect the terminated portion of the
               Premises from the remainder of the Premises and shall, if
               applicable, install any separate utility meters, corridors and/or
               demising walls required to separate and demise the terminated
               portion of the Premises from the remaining portion of the
               Premises. In the event Landlord exercises its option to terminate
               this Lease as to the portion or, if applicable, the entire
               Premises as and to the extent permitted under this Section
               5.6.1.1, then Tenant may rescind its request for Landlord's
               consent to such transfer by notice to Landlord within ten (10)
               business days following receipt of Landlord's election to
               terminate whereupon Landlord's election to terminate this Lease
               as to the applicable portion of the Premises proposed to be
               transferred shall be null and void.

               Notwithstanding the foregoing, in the event that Tenant shall
               only propose to sublease a portion of the Premises, Landlord
               shall only have the right to so terminate this Lease with respect
               to the portion of the Premises and for


                                       50

<PAGE>

               the proposed term of the sublease therefor (if such sublease was
               for less than all or substantially all of the remainder of the
               Term) for which Landlord's rights under this Section 5.6.1.1 are
               or would be triggered (the "Terminated Portion of the Premises")
               and from and after such termination date the Rentable Floor Area
               of the Premises shall be reduced to the rentable floor area of
               the remainder of the Premises and the definition of Rentable
               Floor Area of the Premises shall be so amended and after such
               termination all (and until the proposed expiration date of the
               proposed sublease if such sublease was for less than all or
               substantially all of the remainder of the Term) references in
               this Lease to the "Premises" or the "Rentable Floor Area of the
               Premises" shall be deemed to be references to the remainder of
               the Premises and accordingly Tenant's payments for Annual Fixed
               Rent and its share of operating costs, real estate taxes and
               electricity shall be reduced on a pro rata basis to reflect the
               size of the remainder of the Premises. In the case of an
               assignment or partial subletting where Landlord has exercised its
               termination right pursuant to this Section 5.6.1.1, Tenant shall
               pay to Landlord, as Additional Rent, within thirty (30) days
               after demand therefor, the reasonable costs which Tenant had
               agreed to pay or perform in connection with Tenant's proposed
               sublease to separately physically demise that portion of the
               Premises which are being terminated from the remainder of the
               Premises.

               In the event that Landlord shall exercise its termination right
               hereunder and thereafter relets the portion of the Premises thus
               recaptured from Tenant (the "Recapture Premises") for all or part
               of the then-remaining Lease Term (exclusive of any extension
               options not exercised as of the date of the recapture), Landlord
               shall pay to Tenant, within fifteen (15) days after receipt by
               Landlord, an amount equal to fifty percent (50%) of the excess of
               (i) the fixed rent, additional rent and all other charges and
               sums actually received by Landlord pursuant to such reletting,
               after deducting (x) Landlord's architectural, legal and brokerage
               fees in connection with such reletting and (y) any construction
               expenses incurred by Landlord in connection with such reletting
               and the fair market rental value of the Recapture Premises for
               any period after the recapture and prior to such reletting, over
               (ii) the Annual Fixed Rent, Additional Rent and other charges
               that would have been payable by Tenant for the Recapture Premises
               over the portion of the term of the reletting that falls within
               the then-remaining Lease Term (exclusive of any extension options
               not exercised as of the date of the recapture). Landlord shall
               certify the amounts set forth in subsections (i) and (ii) above
               to Tenant from time to time (but not more often than monthly)
               upon written request. Notwithstanding anything contained herein
               to the contrary, Tenant not be entitled to any sums due under
               this Section 5.6.1.1 until Landlord has fully recovered or been
               credited its costs in connection with the reletting at issue and
               the amount of any excess costs of Landlord may be carried over


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<PAGE>

               to a subsequent year(s) and deducted from the reletting revenues
               for such year(s) until a profit is received. In addition, the
               terms and provisions of this subparagraph shall not apply (and
               Tenant shall not be entitled to received any sums hereunder) in
               the event that the reletting is to a tenant with a significantly
               different use than the Permitted Uses and/or who is making
               significant alterations, additions or improvements to the
               Premises.

               In the event that Landlord shall not exercise its termination
               rights as aforesaid, or shall fail to give any or timely notice
               pursuant to this Section 5.6.1.1 the provisions of Sections 5.6.2
               - 5.6.5 shall be applicable. This Section 5.6.1.1 shall not be
               applicable to an assignment or sublease pursuant to Section 5.6.1
               or an occupancy permitted pursuant to Section 5.6.6.

     5.6.2 Notwithstanding the provisions of Section 5.6 above, but subject to
          the provisions of this Section 5.6.2 and the provisions of Sections
          5.6.3, 5.6.4 and 5.6.5 below, in the event that Landlord shall not
          have exercised the termination right as set forth in Section 5.6.1.1,
          or shall have failed to give any or timely notice under Section
          5.6.1.1, then for a period of one hundred twenty (120) days (i) after
          the receipt of Landlord's notice stating that Landlord does not elect
          the termination right, or (ii) after the expiration of the Acceptance
          Period, in the event Landlord shall not give any or timely notice
          under Section 5.6.1.1 as the case may be, Tenant shall have the right
          to assign this Lease or sublet the Premises in accordance with the
          Proposed Transfer Notice provided that, in each instance, Tenant first
          obtains the express prior written consent of Landlord, which consent
          shall not be unreasonably withheld, conditioned or delayed. It is
          understood and agreed that Landlord's consent shall be deemed given
          hereunder in the event that Landlord shall fail to respond to a
          Proposed Transfer Notice meeting all of the requirements of Section
          5.6.3 below within fifteen (15) business days after receipt of a
          request therefor from Tenant.

          Without limiting the foregoing standard, Landlord shall not be deemed
          to be unreasonably withholding its consent to such a proposed
          assignment or subleasing if:

               (a)  the proposed assignee or subtenant is a tenant elsewhere in
                    the Complex or is or has been in active negotiation with
                    Landlord for premises elsewhere in the Complex within the
                    six (6) month period prior to the proposed effective date of
                    the assignment or sublease (provided, however, that Landlord
                    may not withhold its consent on this basis if Landlord is
                    unable to satisfy such existing or proposed tenant's need as
                    to size of premises and/or length of term in the Complex),
                    or

               (b)  the proposed assignee or subtenant is not of a character
                    consistent with the operation of a first-class
                    office/research and development


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<PAGE>

                    building (by way of example Landlord shall not be deemed to
                    be unreasonably withholding its consent to an assignment or
                    subleasing to any governmental or quasi-governmental agency,
                    unless such agency is currently in occupancy of any portion
                    of the Complex at the time of Tenant's proposed request for
                    consent), or

               (c)  the proposed assignee does not possess adequate financial
                    capability to perform the Tenant obligations as and when due
                    or required or the proposed subtenant does not possess
                    adequate financial capability to perform the obligations of
                    the subtenant under the sublease as and when due or required
                    (taking into account in both cases the continued liability
                    of Tenant notwithstanding such transfer), or

               (d)  the assignee or subtenant proposes to use the Premises (or
                    part thereof) for a purpose other than the purpose for which
                    the Premises may be used as stated in Section 1.1 hereof, or

               (e)  the character of the business to be conducted or the
                    proposed use of the Premises by the proposed subtenant or
                    assignee shall (i) be likely to materially increase
                    Landlord's Operating Expenses beyond that which Landlord now
                    incurs for use by Tenant (unless Tenant or the proposed
                    assignee or subtenant agrees to pay the excess costs
                    attributable thereto); (ii) be likely to materially increase
                    the burden on elevators or other Building systems or
                    equipment over the burden prior to such proposed subletting
                    or assignment (unless Tenant or the proposed assignee or
                    subtenant agrees to pay the excess costs attributable
                    thereto); or (iii) violate or be likely to violate any
                    provisions or restrictions contained herein relating to the
                    use or occupancy of the Premises, or

               (f)  there shall be an existing Event of Default (defined in
                    Section 7.1) or there have been three (3) or more Event of
                    Default occurrences of a material nature during the Term, or

               (g)  if any proposed assignment or sublease shall potentially
                    have any adverse effect on the real estate investment trust
                    qualification requirements applicable to Landlord and its
                    affiliates, or

               (h)  the holder of any mortgage or ground lease on property which
                    includes the Premises does not approve of the proposed
                    assignment or sublease (where such holder has approval
                    rights pursuant to the terms of the mortgage or ground
                    lease), or

               (i)  due to the identity or business of a proposed assignee or
                    subtenant, such approval would cause Landlord to be in
                    violation of any


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<PAGE>

                    covenant or restriction contained in another lease or other
                    agreement affecting space elsewhere in the Complex.

     5.6.3 Tenant shall give Landlord notice (the "Proposed Transfer Notice") of
          any proposed sublease or assignment, and said notice shall specify the
          provisions of the proposed assignment or subletting (or a draft of the
          proposed assignment or sublease document in close-to-final form),
          including (a) the name and address of the proposed assignee or
          subtenant, (b) in the case of a proposed assignment or subletting
          pursuant to Section 5.6.2, such information as to the proposed
          assignee's or proposed subtenant's net worth and financial capability
          and standing as may reasonably be required for Landlord to make the
          determination referred to in Section 5.6.2 above (provided, however,
          that Landlord shall hold such information confidential having the
          right to release same to its officers, accountants, attorneys and
          mortgage lenders on a confidential basis), (c) in the case of a
          proposed assignment or subletting pursuant to Section 5.6.2, all other
          information necessary to make the determination referred to in Section
          5.6.2 above and (d) in the case of a proposed assignment or subletting
          pursuant to Section 5.6.1 above, such information as may be reasonably
          required by Landlord to determine that such proposed assignment or
          subletting complies with the requirements of said Section 5.6.1. In
          the event that Tenant's Proposed Transfer Notice does not contain the
          information required hereunder, Landlord shall provide Tenant with
          written notice setting forth the additional information to be provided
          by Tenant within five (5) business days after Landlord's receipt of
          such Proposed Transfer Notice.

          If Landlord shall consent to the proposed assignment or subletting, as
          the case may be, then, in such event, Tenant may thereafter sublease
          or assign pursuant to Tenant's notice, as given hereunder; provided,
          however, that if such assignment or sublease shall not be executed and
          delivered to Landlord within one hundred twenty (120) days after the
          date of Landlord's consent, the consent shall be deemed null and void
          and the provisions of Section 5.6.1.1 shall be applicable.

     5.6.4 In addition, in the case of any assignment or subleasing as to which
          Landlord may consent (other than an assignment or subletting permitted
          under Section 5.6.1 hereof or an occupancy permitted pursuant to
          Section 5.6.6 hereof) such consent shall be upon the express and
          further condition, covenant and agreement, and Tenant hereby covenants
          and agrees that, in addition to the Annual Fixed Rent, Additional Rent
          and other charges to be paid pursuant to this Lease, fifty percent
          (50%) of the "Assignment/Sublease Profits" (hereinafter defined
          actually received by Tenant), if any, shall be paid to Landlord. The
          "Assignment/Sublease Profits" shall be the excess, if any, of (a) the
          "Assignment/Sublease Net Revenues" as hereinafter defined over (b) the
          Annual Fixed Rent and Additional Rent and other charges provided in
          this Lease (provided, however, that for the purpose of calculating the
          Assignment/Sublease Profits in the case of a sublease, appropriate
          proportions in the applicable Annual Fixed Rent, Additional Rent and
          other charges under this Lease shall be made based on the percentage
          of the Premises


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<PAGE>

          subleased and on the terms of the sublease). The "Assignment/Sublease
          Net Revenues" shall be the fixed rent, additional rent and all other
          charges and sums actually received by Tenant either initially or over
          the term of the sublease or assignment plus all other profits and
          increases actually received by Tenant as a result of such subletting
          or assignment, exclusive of amounts paid to Tenant for the purchase or
          lease of personal property or equipment of Tenant (except to the
          extent such amounts exceed the fair market value or rental value of
          the same), after deducting the reasonable costs of Tenant incurred in
          such subleasing or assignment (the definition of which shall be
          limited to rent concessions, architectural fees, attorneys' fees,
          moving expenses, brokerage commissions and alteration allowances
          associated with the subleasing or assignment at issue, in each case
          actually paid), as set forth in a statement certified by an
          appropriate officer of Tenant and delivered to Landlord within thirty
          (30) days of the full execution of the sublease or assignment
          document. Notwithstanding anything contained herein to the contrary,
          Landlord shall not be entitled to any sums due under this Section
          5.6.4 until Tenant has fully recovered or been credited its costs in
          connection with the transfer at issue and the amount of any excess
          costs of Tenant may be carried over to a subsequent year(s) and
          deducted from the Assignment/Sublease Net Revenues for such year(s)
          until a profit is received.

          All payments of the Assignment/Sublease Profits due Landlord shall be
          made within fifteen (15) days of receipt of same by Tenant.

     5.6.5 (A) It shall be a condition of the validity of any assignment or
          subletting of right under Section 5.6.1 above, or consented to under
          Section 5.6.2 above, that both Tenant and the assignee or sublessee
          enter into a separate written instrument directly with Landlord in a
          form and containing terms and provisions reasonably required by
          Landlord, including, without limitation, the agreement of the assignee
          or sublessee to be bound directly to Landlord for all the obligations
          of the Tenant hereunder, including, without limitation, the obligation
          (a) to pay the rent and other amounts provided for under this Lease
          (but in the case of a partial subletting pursuant to Section 5.6.1,
          such subtenant shall agree on a pro rata basis to be so bound) and (b)
          to comply with the provisions of Sections 5.6 through 5.6.5 hereof.
          Such assignment or subletting shall not relieve the Tenant named
          herein of any of the obligations of the Tenant hereunder and Tenant
          shall remain fully and primarily liable therefor and the liability of
          Tenant and such assignee (or subtenant, as the case may be) shall be
          joint and several. Further, and notwithstanding the foregoing, the
          provisions hereof shall not constitute a recognition of the sublease
          or the subtenant thereunder, and at Landlord's option, upon the
          termination or expiration of the Lease (whether such termination is
          based upon a cause beyond Tenant's control, a default of Tenant, the
          agreement of Tenant and Landlord or any other reason), the sublease
          shall be terminated.

          (B) Tenant shall pay to Landlord as a fee for Landlord's review of any
          proposed assignment or sublease requested by Tenant and the
          preparation of any associated documentation, within thirty (30) days
          after receipt of an invoice from


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<PAGE>

          Landlord, as Additional Rent, an amount equal to the sum of (i)
          $150.00 per hour for in-house staff and/or (ii) reasonable out of
          pocket legal fees or other expenses incurred by Landlord in connection
          with such request (any such legal fees under subsections (i) or (ii)
          above in no event to exceed $5,000.00 in connection with any given
          request for consent).

          (C) If this Lease is assigned, or if the Premises or any part thereof
          be sublet or occupied by anyone other than Tenant, Landlord may upon
          prior notice to Tenant, at any time and from time to time, collect
          rent and other charges from the assignee, sublessee or occupant and
          apply the net amount collected to the rent and other charges herein
          reserved, but no such assignment, subletting, occupancy or collection
          shall be deemed a waiver of this covenant, or a waiver of the
          provisions of Sections 5.6 through 5.6.5 hereof, or the acceptance of
          the assignee, sublessee or occupant as a tenant or a release of Tenant
          from the further performance by Tenant of covenants on the part of
          Tenant herein contained, the Tenant herein named to remain primarily
          liable under this Lease.

          (D) The consent by Landlord to an assignment or subletting under any
          of the provisions of Sections 5.6.1 or 5.6.3 shall in no way be
          construed to relieve Tenant from obtaining the express consent in
          writing of Landlord to any further assignment or subletting.

          (E) On or after the occurrence of an "Event of Default" (defined in
          Section 7.1), Landlord shall be entitled to one hundred percent (100%)
          of any Assignment/Sublease Profits.

          (F) Without limiting Tenant's obligations under Section 5.14, Tenant
          shall be responsible, at Tenant's sole cost and expense, for
          performing all work necessary to comply with Legal Requirements and
          Insurance Requirements in connection with any assignment or subletting
          hereunder including, without limitation, any work in connection with
          such assignment or subletting.

          (G) In addition to the other requirements set forth in this Lease and
          notwithstanding any other provision of this Lease, partial sublettings
          of the Premises shall only be permitted under the following terms and
          conditions: (i) the configuration of both the subleased premises and
          the remainder of the Premises must comply with applicable Legal
          Requirements and be approved by Landlord, including, without
          limitation, all requirements concerning access and egress; (ii) in the
          event the subleased premises are separately physically demised from
          the remainder of the Premises, Tenant shall pay all costs (if any) of
          physically demising the subleased premises (including, without
          limitation, construction and design costs); and (iii) there shall be
          no more than three (3) subleases in effect in any single Building at
          any given time.

     5.6.6 Tenant shall have the right, without the consent of Landlord (but
          upon reasonable prior notice to Landlord), to permit the use or
          occupancy of space in the Premises


                                       56

<PAGE>

          by any affiliate, subsidiary or other related entity of Tenant or,
          with respect to a portion of the Premises that is not separately
          demised and consists of not more than 25,000 rentable square feet of
          the Premises in the aggregate for periods of less than one (1) year at
          a time, by persons who have an ongoing contractual or other business
          relationship with Tenant providing for cooperative or collaborative
          research and development such that such occupants have a reasonable
          need to work in proximity with Tenant (such persons who shall be
          permitted to occupy portions of the Premises pursuant to this Section
          5.6.6 being referred to individually as a "Permitted Occupant", or
          collectively as the "Permitted Occupants"); provided that (x) the
          Permitted Occupants shall use the Premises in conformity with all
          applicable provisions of this Lease, (y) such occupancy will terminate
          automatically upon the expiration or earlier termination of this Lease
          and (z) Tenant shall remain fully liable for the acts or omissions of
          the Permitted Occupants in the Premises, within the Complex and/or on
          the Additional Land Areas (as defined in Section 8.27 below).

     5.6.7 At the written request of Tenant, Landlord will approve or disapprove
          of a proposed transferee prior to receiving a final, executed copy of
          the proposed assignment, sublease and other contractual documents,
          provided that (i) Landlord has been provided with sufficient
          information to make such decision, and (ii) any approval by Landlord
          of a proposed transferee shall be conditioned upon Landlord's
          subsequent approval of the actual signed assignment, sublease or other
          contractual documents that are entered into to effectuate the proposed
          Transfer. Notwithstanding the foregoing, Landlord's approval shall be
          null and void and deemed withdrawn if Tenant does not, within one
          hundred twenty (120) days of Tenant's initial request for Landlord's
          approval, enter into an assignment or sublease upon substantially the
          same economic and other material terms as were set forth in the
          documentation previously delivered to Landlord.

5.7  Indemnity; Insurance

     (A) Indemnity. Subject to the limitations of Section 8.4 below and to the
     provisions of Section 8.19 below, to the maximum extent this agreement is
     effective according to law and to the extent not resulting from the
     negligence or willful misconduct of Landlord or its employees, agents or
     contractors, Tenant agrees to defend with counsel first approved by
     Landlord (counsel appointed by Tenant's insurance carrier shall be deemed
     approved by Landlord and for any other circumstances such approval shall
     not be unreasonably withheld or delayed), save harmless, and indemnify
     Landlord and Landlord's managing agent, beneficiaries, partners,
     subsidiaries, officers, directors, agents, trustees and employees
     (collectively, the "Landlord Parties") from any liability for injury, loss,
     accident or damage to any person or property, and from any claims, actions,
     proceedings and expenses and costs in connection therewith (including
     without limitation reasonable counsel fees) (i) arising from or claimed to
     have arisen from (a) the omission, fault, willful act, negligence or other
     misconduct of Tenant or Tenant's contractors, licensees, invitees, agents,
     servants, independent contractors or employees or (b) any use made or thing
     done or occurring on the Premises not due to the omission,


                                       57

<PAGE>

     fault, willful act, negligence or other misconduct of Landlord, or (ii)
     resulting from the failure of Tenant to perform and discharge its covenants
     and obligations under this Lease.

     (B) Insurance. To maintain in full force from the date upon which Tenant
     first enters the Premises for any reason, throughout the Term of this
     Lease, and thereafter, so long as Tenant is in occupancy of any part of the
     Premises, commercial general liability insurance or comprehensive general
     liability insurance written on an occurrence basis with a broad form
     comprehensive liability endorsement under which Tenant is the named insured
     and Landlord and Landlord's managing agent (and such persons as are in
     privity of estate with Landlord and Landlord's managing agent as may be set
     out in notice from time to time) are named as additional insureds with
     limits which shall, at the commencement of the Term, be at least equal to
     those stated in Section 1.1 and from time to time during the Term shall be
     for such higher limits, if any, as Landlord may reasonably require provided
     such higher limits are customarily carried by tenants leasing premises in
     comparable, first-class office/research and development complexes in the
     Boston Northwest Suburban Market, and worker's compensation insurance with
     statutory limits covering all of Tenant's employees working in the
     Premises. Tenant shall deposit with Landlord on or before the earlier of
     the date Tenant enters the Premises or the Commencement Date and concurrent
     with all renewals thereof, certificates for any insurance Tenant is
     required to maintain under this Lease, in a form reasonably acceptable to
     Landlord and bearing the endorsement that the insurer will endeavor to
     provide Landlord with thirty (30) days' written notice prior to
     cancellation of the policies. In addition, in the event Tenant hosts a
     function in the Premises, Tenant agrees to obtain and maintain, and cause
     any persons or parties providing services for such function to obtain, the
     appropriate insurance coverages as determined by Landlord (including liquor
     liability, if applicable) and, upon request, provide Landlord with evidence
     of the same. All insurance required to be maintained by Tenant pursuant to
     this Lease shall be maintained with responsible companies qualified to do
     business, and in good standing, in the Commonwealth of Massachusetts and
     which have a rating of at least "A-" and are within a financial size
     category of not less than "Class VIII" in the most current Best's Key
     Rating Guide or such similar rating as may be reasonably selected by
     Landlord if such Guide is no longer published.

5.8  Personal Property at Tenant's Risk

     That all of the furnishings, fixtures, equipment, effects and property of
     every kind, nature and description of Tenant and of all persons claiming
     by, through or under Tenant which, during the continuance of this Lease or
     any occupancy of the Premises by Tenant or anyone claiming under Tenant,
     may be on the Premises or elsewhere in the Buildings or on the Site, shall
     be at the sole risk and hazard of Tenant, and if the whole or any part
     thereof shall be destroyed or damaged by fire, water or otherwise, or by
     the leakage or bursting of water pipes, steam pipes, or other pipes, by
     theft or from any other cause, no part of said loss or damage is to be
     charged to or be borne by Landlord, except to the extent caused by the
     gross negligence or willful misconduct of Landlord and except that Landlord
     shall in no event be indemnified or held harmless or exonerated from any


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     liability to Tenant or to any other person, for any injury, loss, damage or
     liability to the extent such indemnity, hold harmless or exoneration is
     prohibited by law. Further, Tenant, at Tenant's expense, shall maintain at
     all times during the Term of this Lease business interruption insurance and
     insurance against loss or damage covered by so-called "all risk" type
     insurance coverage with respect to Tenant's fixtures, equipment, goods,
     wares and merchandise, tenant improvements made by or paid for by Tenant
     which are removable by Tenant at the end of the Term of this Lease, and
     other property of Tenant (including, without limitation, the Tenant's
     Equipment as that term is defined in Section 8.26 below) (collectively
     "Tenant's Property"). Such insurance shall be in an amount at least equal
     to the full replacement cost of Tenant's Property. Tenant shall maintain
     all of its equipment, furniture and furnishings in good order and repair.
     In addition, during such time as Tenant is performing work in or to the
     Premises, Tenant, at Tenant's expense, shall also maintain builder's risk
     insurance for the full insurable value of such work.

5.9  Right of Entry

     To permit Landlord and its agents at reasonable times and upon reasonable
     prior notice (except in the event of an emergency) (i) to examine the
     Premises and if Landlord shall be entitled and shall so elect, to make any
     repairs or replacements Landlord may deem necessary; (ii) to remove, at
     Tenant's expense, any alterations, additions, signs, curtains, blinds,
     shades, awnings, aerials, flagpoles, or the like not consented to in
     writing; and (iii) to show the Premises to prospective tenants during the
     twelve (12) months preceding expiration of the Term and to prospective
     purchasers and mortgagees at all reasonable times. Landlord agrees to use
     commercially reasonable efforts to conduct any such entry under this
     Section 5.9 in such a manner and at such times so as to minimize any
     unreasonable interference with Tenant's business operations in the
     Premises, consistent with the reasons for such entry (Landlord hereby
     agreeing to use commercially reasonable efforts to schedule any such access
     hereunder during Tenant's normal business hours and in the presence of a
     representative of Tenant when feasible, except in the event of an
     emergency).

     Notwithstanding anything to the contrary set forth above, Tenant may
     designate certain areas of the Premises as "Secured Areas" should Tenant
     require such areas for the purpose of securing certain valuable property or
     confidential information. Landlord may not enter such Secured Areas except
     in the case of an emergency or in the event of a Landlord inspection (it
     being understood and agreed that prior to commencing any non-emergency
     inspection of the Secured Areas, Landlord shall be required to demonstrate
     reasonable grounds therefor), in which latter case Landlord shall provide
     Tenant with two (2) business days' prior written notice of the specific
     date and time of such Landlord inspection. If Tenant does designate any
     such Secured Areas as aforesaid, Landlord shall have no responsibility
     under this Lease for the provision of any services (other than utility
     services for which Landlord is responsible under this Lease) to such
     Secured Areas (including, without limitation, the non-utility services
     described in Section 4.1 above).


                                       59

<PAGE>

5.10 Floor Load; Prevention of Vibration and Noise

     Not to place a load on any floor of the Premises above the ground floor
     exceeding an average rate of 100 pounds of live load per square foot of
     floor area (partitions shall be considered as part of the live load); and
     not to move any safe, vault or other heavy equipment in, about or out of
     the Premises except in such manner and at such time as Landlord shall in
     each instance authorize; Tenant's business machines and mechanical
     equipment which cause vibration or noise that may be transmitted to the
     Building structure or to any other space in the Buildings shall be so
     installed, maintained and used by Tenant so as to eliminate such vibration
     or noise.

5.11 Personal Property Taxes

     To pay promptly when due all taxes which may be imposed upon Tenant's
     Property in the Premises to whomever assessed.

5.12 Compliance with Laws

     To comply with all applicable Legal Requirements now or hereafter in force
     which shall impose a duty on Landlord or Tenant relating to or as a result
     of the use or occupancy of the Premises; provided that Tenant shall not be
     required to make any alterations, additions, upgrades or improvements (i)
     to the Premises, unless the same are required by Legal Requirements that
     first become applicable to the Complex after the completion of the Base
     Building Work and the Tenant Improvement Work as a result of or in
     connection with Tenant's use or occupancy of the Premises for a use other
     than general office use, (ii) to the Common Areas, the Structural Elements
     (as defined in Section 4.1.3) or any of the base building systems serving
     the Complex unless the same are required by Legal Requirements that first
     become applicable to the Complex after the completion of the Base Building
     Work and the Tenant Improvement Work as a result of or in connection with
     Tenant's use or occupancy of the Premises for a use other than general
     office use or (iii) to the Premises or any component of the Buildings or
     the Complex, in order to bring the Buildings and/or the Complex into
     compliance with Legal Requirements of general applicability to the
     Buildings and/or the Complex that first become applicable to the Complex
     after the completion of the Base Building Work and the Tenant Improvement
     Work except to the extent that the non-compliance is triggered by either
     (x) any alterations, additions or improvements being done by or on behalf
     of Tenant in the Buildings or on the Site (other than the Tenant
     Improvement Work) or (y) by Tenant's specific and unique use of the
     Buildings and/or the Site for other than general office use. Tenant shall
     promptly pay all fines, penalties and damages that may arise out of or be
     imposed because of its failure to comply with the provisions of this
     Section 5.12.

5.13 Payment of Litigation Expenses

     As Additional Rent, to pay all reasonable costs, counsel and other fees
     incurred by Landlord in connection with the successful enforcement by
     Landlord of any obligations


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<PAGE>

     of Tenant under this Lease or in connection with any bankruptcy case
     involving Tenant or any guarantor (Landlord hereby similarly agreeing to
     pay all reasonable costs, counsel and other fees incurred by Tenant in
     connection with the successful enforcement by Tenant of any obligations of
     Landlord under this Lease or in connection with any bankruptcy case
     involving Landlord).

5.14 Alterations

     Tenant shall not make alterations and additions to the Premises (including,
     without limitation, the Additional Land Areas as that term is defined in
     Section 8.27 below) except in accordance with plans and specifications
     therefor first approved by Landlord, which approval shall not be
     unreasonably withheld or delayed. However, Landlord's determination of
     matters relating to aesthetic issues relating to alterations, additions or
     improvements which are visible outside the Premises shall be in Landlord's
     sole discretion. Without limiting such standard Landlord shall not be
     deemed unreasonable for withholding approval of any alterations or
     additions (including, without limitation, any alterations or additions to
     be performed by Tenant under Article III) which (a) in Landlord's opinion
     might adversely affect any structural or exterior element of the Buildings,
     any area or element outside of the Premises, or any facility or base
     building mechanical or electrical system serving any area of the Buildings
     outside of the Premises, or (b) involve or affect the exterior design,
     size, height, or other exterior dimensions of the Buildings or (c) will
     require unusual expense to readapt the Premises to normal office use on
     Lease termination or expiration or increase the cost of construction or of
     insurance or taxes on the Buildings or of the services called for by
     Section 4.1 unless Tenant first gives assurance acceptable to Landlord for
     payment of such increased cost and that such readaptation will be made
     prior to such termination or expiration without expense to Landlord, (d)
     enlarge the Rentable Floor Area of the Premises, or (e) except with respect
     to the Tenant Improvement Work, are inconsistent, in Landlord's judgment,
     with alterations satisfying Landlord's standards for new alterations in the
     Buildings. Landlord's review and approval of any such plans and
     specifications and consent to perform work described therein shall not be
     deemed an agreement by Landlord that such plans, specifications and work
     conform with applicable Legal Requirements and requirements of insurers of
     the Buildings and the other requirements of this Lease with respect to
     Tenant's insurance obligations (herein called "Insurance Requirements") nor
     deemed a waiver of Tenant's obligations under this Lease with respect to
     applicable Legal Requirements and Insurance Requirements nor impose any
     liability or obligation upon Landlord with respect to the completeness,
     design sufficiency or compliance of such plans, specifications and work
     with applicable Legal Requirements and Insurance Requirements nor give
     right to any other parties. Further, Tenant acknowledges that Tenant is
     acting for its own benefit and account, and that Tenant shall not be acting
     as Landlord's agent in performing any work in the Premises, accordingly, no
     contractor, subcontractor or supplier shall have a right to lien Landlord's
     interest in the Property in connection with any such work. Within thirty
     (30) days after receipt of an invoice from Landlord, Tenant shall pay to
     Landlord as a fee for Landlord's review of any work or plans (excluding any
     review respecting initial improvements performed pursuant to Article III
     hereof but including any review of plans or work relating to any assignment
     or


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     subletting), as Additional Rent, an amount equal to the sum of: (i) $
     150.00 per hour for time spent by Landlord's in-house personnel, plus (ii)
     third party expenses incurred by Landlord to review Tenant's plans and
     Tenant's work (provided such third party expenses are reasonable and within
     market rates, and are accompanied by receipts and invoices). All
     alterations and additions shall be part of the Building unless and until
     Landlord shall timely specify the same for removal at the time Landlord
     approves of such alteration or additions under this Section 5.14 or under
     Section 3.2(B) above with respect to the Tenant Improvement Work (it being
     understood and agreed that the removal of any alterations or additions that
     do no require Landlord's approval shall be subject to the terms of Section
     5.14.1 below). All of Tenant's alterations and additions and installation
     of furnishings shall be coordinated with any work being performed by
     Landlord and, except as otherwise expressly permitted under Article III
     above with respect to the Tenant Improvement Work, in such manner as to
     maintain harmonious labor relations and not to damage the Buildings or Site
     or interfere with construction or operation of the Buildings and other
     improvements to the Site and, except for installation of furnishings, shall
     be performed by Landlord's general contractor or by contractors or workers
     first approved by Landlord, which approval will not be unreasonably
     withheld, conditioned or delayed. Except for work by Landlord's general
     contractor, Tenant, before its work is started, shall secure all licenses
     and permits necessary therefor; deliver to Landlord a statement of the
     names of all its contractors and subcontractors and the estimated cost of
     all labor and material to be furnished by them and security satisfactory to
     Landlord protecting Landlord against liens arising out of the furnishing of
     such labor and material (it being understood and agreed that no such
     security shall be required to be posted for contracts of less than
     $50,000.00); and cause each contractor to carry worker's compensation
     insurance in statutory amounts covering all the contractor's and
     subcontractor's employees and commercial general liability insurance or
     comprehensive general liability insurance with a broad form comprehensive
     liability endorsement with such limits as Landlord may reasonably require,
     but in no event less than $2,000,000.00 combined single limit per
     occurrence on a per location basis (all such insurance to be written in
     companies approved by Landlord and naming and insuring Landlord and
     Landlord's managing agent as additional insureds and insuring Tenant as
     well as the contractors), and to deliver to Landlord certificates of all
     such insurance. Tenant shall also prepare and submit to Landlord a set of
     as-built plans, in both print and electronic forms, showing such work
     performed by Tenant to the Premises promptly after any such alterations,
     improvements or installations are substantially complete and a set of
     schematic plans, in both print and electronic forms, promptly after any
     wiring or cabling for Tenant's computer, telephone and other communications
     systems is installed by Tenant or Tenant's contractor; provided, however,
     that if the work is not of a nature where as-built plans would customarily
     be prepared, Tenant shall only be required to prepare and submit the type
     of plans that would customarily be prepared in connection with such work.
     Without limiting any of Tenant's obligations hereunder, Tenant shall be
     responsible, as Additional Rent, for the costs of any alterations,
     additions or improvements in or to the Building that are required in order
     to comply with Legal Requirements as a result of any work performed by
     Tenant (expressly including the Tenant Improvement Work being performed by
     Tenant under Article III above). Landlord shall have the right to provide
     such rules and regulations relative to the


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     performance of any alterations, additions, improvements and installations
     by Tenant hereunder and Tenant shall abide by all such reasonable rules and
     regulations and shall cause all of its contractors to so abide including,
     without limitation, payment for the costs of using Building services (a
     copy of Landlord's current rules and regulations for construction being
     attached hereto as Exhibit F-2). Tenant agrees to pay promptly when due the
     entire cost of any work done on the Premises by Tenant, its agents,
     employees, or independent contractors, and not to cause or permit any liens
     for labor or materials performed or furnished in connection therewith to
     attach to the Premises or the Buildings or the Site and promptly (in no
     event to exceed thirty (30) days) to discharge any such liens which may so
     attach. Tenant shall pay, as Additional Rent, 100% of any real estate taxes
     on the Complex which shall, at any time after commencement of the Term,
     result from any alteration, addition or improvement to the Premises made by
     Tenant. Tenant acknowledges and agrees that Landlord shall be the owner of
     any additions, alterations and improvements in the Premises or the
     Buildings to the extent paid for by Landlord.

     5.14.1 Permitted Alterations

          Notwithstanding the terms of Section 5.14, Tenant shall have the
          right, without obtaining the prior consent of Landlord but upon notice
          to Landlord given ten (10) days prior to the commencement of any work
          (which notice shall specify the nature of the work in reasonable
          detail), to make alterations, additions or improvements to the
          Premises where:

          (i) the same are within the interior of the Buildings (or the interior
          of the Premises from time to time leased by Tenant, if any in the
          Additional Buildings), and do not affect the exterior of the Buildings
          (including no signs on windows);

          (ii) the same do not affect the Structural Elements or the base
          building mechanical, electrical, plumbing, heating, ventilating,
          air-conditioning and fire protection systems of the Buildings;

          (iii) the cost of any individual alteration, addition or improvement
          shall not exceed $25,000.00 and the aggregate cost of said
          alterations, additions or improvements made by Tenant during the Lease
          Term shall not exceed $250,000.00 in cost; and

          (iv) Tenant shall comply with the provisions of this Lease and if such
          work increases the cost of insurance or taxes or of services, Tenant
          shall pay for any such increase in cost;

          provided, however, that Tenant shall, within fifteen (15) days after
          the making of such changes, send to Landlord plans and specifications
          describing the same in reasonable detail and provided further that
          Landlord, by notice to Tenant given within thirty (30) days after
          Landlord's receipt of such plans and specifications, may require
          Tenant to restore the Premises to its condition prior to such
          alteration, addition or improvement at the expiration or earlier
          termination of the Lease Term.


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<PAGE>

          In addition, Tenant shall have the right, without obtaining the prior
          consent of Landlord to from time to time modify the topography of the
          Additional Land Areas (as defined in Section 8.27 below) and erect
          temporary structures thereon in order to simulate user environments.
          This may include, without limitation, bringing sand, dirt, pavement,
          rubble and rocks to the Additional Land Areas, as well as creating
          water features, stairs, levels and obstacles on the Additional Land
          Areas; provided, however, that under no circumstances may Tenant
          excavate or otherwise dig up any portions of the Additional Land Areas
          without Landlord's prior written consent (which Landlord may condition
          on Tenant's expressly acknowledging that it is solely responsible for
          any Hazardous Materials that are disturbed by Tenant's activities).
          Tenant's obligation to restore the Additional Land Areas upon the
          expiration or earlier termination of this Lease shall be as set forth
          in Section 8.27.

     5.14.2 Tenant's Security System

          Tenant may install a security system within the Premises, provided
          such system and its installation (i) shall be subject to Landlord's
          prior written approval, which shall not be unreasonably withheld,
          conditioned or delayed (provided Landlord may deny consent to any
          system which is not compatible with the Complex's overall security and
          fire safety and life safety systems), (ii) shall be in accordance with
          all applicable Legal Requirements, and (iii) shall be performed at
          Tenant's sole expense, and shall otherwise be installed in accordance
          with the provisions governing alterations under this Lease. Tenant
          shall have the right, at Tenant's sole cost and expense, to hire and
          have a security guard stationed at the security desk in the lobby of
          any Building directly leased by Tenant in its entirety at such times
          as Tenant shall elect in Tenant's reasonable discretion. Neither party
          shall have any liability to the other party on account of the failure
          or neglect of any security guard hired by Tenant to stop or prevent
          any theft, damage, crime or other intentional wrongdoing of any person
          in, on or at the Complex.

5.15 Vendors

     Any vendors engaged by Tenant to perform services in or to the Premises
     including, without limitation, janitorial contractors and moving
     contractors shall be coordinated with any work being performed by or for
     Landlord and, except as expressly provided in Article III above with
     respect to the Tenant Improvement Work, in such manner as to maintain
     harmonious labor relations and not to damage the Buildings or the Property
     or interfere with Building construction or operation and shall be performed
     by vendors first approved by Landlord, which approval will not be
     unreasonably withheld, conditioned of delayed.


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<PAGE>

5.16 Patriot Act

     (A) As an inducement to Landlord to enter into this Lease, Tenant hereby
     represents and warrants that: (i) Tenant is not, nor is it owned or
     controlled directly or indirectly by, any person, group, entity or nation
     named on any list issued by the Office of Foreign Assets Control of the
     United States Department of the Treasury ("OFAC") pursuant to Executive
     Order 13224 or any similar list or any law, order, rule or regulation or
     any Executive Order of the President of the United States as a terrorist,
     "Specially Designated National and Blocked Person" or other banned or
     blocked person (any such person, group, entity or nation being hereinafter
     referred to as a "Prohibited Person"); (ii) Tenant is not (nor is it owned,
     controlled, directly or indirectly, by any person, group, entity or nation
     which is) acting directly or indirectly for or on behalf of any Prohibited
     Person; and (iii) from and after the effective date of the above-referenced
     Executive Order, Tenant (and any person, group, entity or nation which owns
     or controls Tenant, directly or indirectly) has not conducted nor will
     knowingly conduct business or has not engaged nor will knowingly engage in
     any transaction or dealing with any Prohibited Person in violation of the
     U.S. Patriot Act or any OFAC rule or regulation, including without
     limitation any assignment of this Lease or any subletting of all or any
     portion of the Premises or the making or receiving of any contribution or
     funds, goods or services to or for the benefit of a Prohibited Person in
     violation of the U.S. Patriot Act or any OFAC rule or regulation. In
     connection with the foregoing, it is expressly understood and agreed that
     (x) any breach by Tenant of the foregoing representations and warranties
     shall be deemed an Event of Default by Tenant under Section 7.1 (a) (iv) of
     this Lease and shall be covered by the indemnity provisions of Section 5.7
     above, and (y) the representations and warranties contained in this
     subsection shall be continuing in nature and shall survive the expiration
     or earlier termination of this Lease. Notwithstanding anything contained
     herein to the contrary, for the purposes of this subsection (A) the phrase
     "owned or controlled directly or indirectly by any person, group, entity or
     nation" and all similar such phrases shall not include any holder of a
     direct or indirect interest in a publicly traded company whose shares are
     listed and traded on a nationally recognized stock exchange.

     (B) As an inducement to Tenant to enter into this Lease, Landlord hereby
     represents and warrants that: (i) Landlord is not, nor is it owned or
     controlled directly or indirectly by, any person, group, entity or nation
     named on any list issued by the Office of Foreign Assets Control of the
     United States Department of the Treasury ("OFAC") pursuant to Executive
     Order 13224 or any similar list or by any law, order, rule or regulation or
     any Executive Order of the President of the United States as a terrorist,
     "Specially Designated National and Blocked Person" or other banned or
     blocked person (any such person, group, entity or nation being hereinafter
     referred to as a "Prohibited Person"); (ii) Landlord is not (nor is it
     owned or controlled, directly or indirectly, by any person, group, entity
     or nation which is) acting directly or indirectly for or on behalf of any
     Prohibited Person; and (iii) from and after the effective date of the
     above-referenced Executive Order, Landlord (and any person, group, or
     entity which Landlord controls, directly or indirectly) has not conducted
     nor will knowingly conduct business nor has engaged nor will knowingly
     engage in any transaction or dealing with any Prohibited


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<PAGE>

     Person in violation of the U.S. Patriot Act or any OFAC rule or regulation,
     including without limitation, the making or receiving of any contribution
     of funds, good or services to or for the benefit of a Prohibited Person in
     violation of the U.S. Patriot Act or any OFAC rule or regulation. In
     connection with the foregoing, is expressly understood and agreed that (x)
     any breach by Landlord of the foregoing representatives and warranties
     shall be covered by the indemnity provisions of Section 4.4 above and (y)
     the representations and warranties contained in this subsection shall be
     continuing in nature and shall survive the expiration or earlier
     termination of this Lease. Notwithstanding anything contained herein to the
     contrary, for the purposes of this subsection (B) the phrase "owned or
     controlled directly or indirectly by any person, group, entity or nation"
     and all similar such phrases shall not include (1) any shareholder of
     Boston Properties, Inc., (2) any holder of a direct or indirect interest in
     a publicly traded company whose shares are listed and traded on a
     nationally recognized stock exchange or (3) any limited partner, unit
     holder or shareholder owning an interest of five percent (5%) or less in
     Boston Properties Limited Partnership or the holder of any direct or
     indirect interest in Boston Properties Limited Partnership.

5.17 Signage

     (A) For so long as Tenant directly leases from Landlord a minimum of one
     (1) full floor in any of the Buildings, Tenant may, at its sole cost and
     expense (subject to the payment of the Signage Allowance described in
     subsection (D) below), install and maintain signage containing Tenant's
     name and corporate logo in one (1) area to be reasonably agreed upon by the
     parties in the main lobby of any such Building where Tenant satisfies the
     minimum leasing requirement described above. In addition, the design,
     proportions and color of such signage shall be subject to the prior
     approval of Landlord, which approval will not be unreasonably withheld,
     conditioned or delayed. Tenant's rights to lobby signage in each of the
     Buildings under this subsection (A) shall be exclusive for so long as
     Tenant leases the entire rentable floor area of the applicable Building in
     its entirety, including in any Additional Buildings leased in their
     entirety by Tenant and, if not leasing the entirety, Tenant's shall have
     the non-exclusive right to building-standard lobby and elevator directory
     signage and suite entry signage.

     (B) (1) In the event at the time Tenant exercises its right under this
     Section 5.17(B)(1), (i) Tenant leases from Landlord a minimum of 100,000
     square feet of rentable floor area in the Complex (including the entirety
     of Building D) and (ii) Tenant has neither assigned this Lease nor sublet
     more than thirty-three percent (33%) of the Rentable Floor Area of the
     Premises (except for an assignment or subletting permitted pursuant to
     Section 5.6.1 or an occupancy permitted under Section 5.6.6), Tenant shall
     be permitted, at Tenant's sole cost and expense (subject to the payment of
     the Signage Allowance described in subsection (D) below), to erect one (1)
     sign on the exterior facade above the roofline of Building D (the "Route 3
     Impact Signage"), which such signage shall contain Tenant's name and logo
     and shall be in a location first reasonably approved by Landlord. Tenant's
     right to erect the Route 3 Impact Signage shall be exclusive for so long as
     Tenant meets the occupancy requirements of this Section 5.17(B)(1).


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     (2) In the event that Tenant shall cease to meet the occupancy requirements
     set forth in subsection (1) above with respect to the Route 3 Impact
     Signage but shall directly lease from Landlord any of the Buildings or
     Additional Buildings in their entirety, in lieu of the Route 3 Impact
     Signage, Tenant shall be permitted, at its sole cost and expense, to erect
     one (1) sign on a panel to be located on the exterior facade of any of the
     Buildings or Additional Buildings leased by Tenant in their entirety (the
     "Panel Signage"), which signage shall contain Tenant's name and logo and
     shall be in a location first reasonably approved by Landlord. Tenant's
     right to erect the Panel Signage shall be exclusive with respect to any
     Building or Additional Building directly leased by Tenant in its entirety.

     (3) In addition to the Route 3 Impact Signage or the Panel Signage, as the
     case may be, and for so long as Tenant shall directly lease from Landlord
     the entirety of Building D, Tenant shall be permitted, at its sole cost and
     expense (subject to the payment of the Signage Allowance described in
     subsection (D) below), to erect one (1) monument sign at the entrance to
     Building D (the "Monument Signage"), which signage shall contain Tenant's
     name and logo and shall be in a location first reasonably approved by
     Landlord. Tenant's right to erect the Monument Signage shall be exclusive
     for so long as Tenant directly leases Building D in its entirety.

     (4) The design, proportions and color of all such signage described in this
     subsection (B) shall be subject to the prior approval (which approval shall
     not be unreasonably withheld, conditioned or delayed) of Landlord and shall
     be further subject to the requirements of the Zoning By-Law of the Town of
     Bedford and any other applicable laws and to Tenant obtaining all necessary
     permits and approvals therefor. Tenant acknowledges and agrees that, except
     as otherwise provided in this subsection (B) Tenant's right to corporate
     signage on the Site pursuant to this subsection (B) is not on an exclusive
     basis and that Landlord may grant other tenants in the Complex the right to
     maintain signage on the Site; provided, however, that Landlord shall never
     permit or grant any other tenant or occupant of the Complex the right to
     install any exterior signage on any of the Buildings or Additional
     Buildings which are leased entirely to Tenant or to install any exclusive
     monument signage at the entrance to any of the Buildings or Additional
     Buildings which are leased entirely to Tenant.

     (C) In the event that at any time during the Lease Term Tenant ceases to
     meet the applicable occupancy thresholds described in subsections (A) and
     (B) above, Tenant shall, upon Landlord's written request and at Tenant's
     sole cost and expense, remove all or any portion of the Tenant's signage
     described in this Section 5.17 and designated by Landlord for removal and
     restore any areas of the Buildings affected by the installation and
     subsequent removal of Tenant's signage. Notwithstanding the foregoing, in
     the event that Tenant ceases to meet the occupancy threshold under
     subsection (B)(1) above and Landlord requires that the Route 3 Impact
     Signage be removed from Building D, Landlord shall perform such removal and
     restoration work at Landlord's sole cost and expense. In addition, Tenant
     shall be required at its sole cost and expense to remove all of the
     Tenant's signage described in this Section 5.17 and restore any areas of
     the Buildings affected by the installation and subsequent removal of
     Tenant's signage upon


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<PAGE>

     the expiration or earlier termination of the Lease Term.

     (D) Landlord shall provide to Tenant a special allowance of Fifteen
     Thousand and 00/100 Dollars ($15,000.00) (the "Signage Allowance"). The
     Signage Allowance shall be used and applied by Tenant solely on account of
     the purchase and installation of the exterior signage described in
     subsections (A) and (B) above (the "Signage Work"). Provided that the
     Tenant (i) has completed all of such Signage Work in accordance with the
     terms of this Lease, has paid for all of such Signage Work in full, (ii)
     has delivered to Landlord lien waivers from all persons who might have a
     lien as a result of such work, in the recordable forms attached hereto as
     Exhibit F, (iii) has delivered to Landlord its certificate specifying the
     cost of such Signage Work and all contractors, subcontractors and supplies
     involved with Signage Work, together with evidence of such cost in the form
     of paid invoices, receipts and the like, (iv) has satisfied the
     requirements of (i) through (iii) above and made request for such payment
     on or before the Commencement Date, (v) there exists no Event of Default
     under this Lease, and (vi) there are no liens (unless bonded to the
     reasonable satisfaction of Landlord) against Tenant's interest in this
     Lease or against the Buildings or the Site arising out of Signage Work or
     any litigation in which Tenant is a party relating to the Signage Work,
     then within thirty (30) days after the satisfaction of the foregoing
     conditions, Landlord shall pay to Tenant the lesser of the amount of such
     costs so certified or the amount of the Signage Allowance. Notwithstanding
     the foregoing, Landlord shall be under no obligation to apply any portion
     of the Signage Allowance for any purposes other than as provided in this
     subsection (D), nor shall Landlord be deemed to have assumed any
     obligations, in whole or in part, of Tenant to any contractors,
     subcontractors, suppliers, workers or materialmen. Further, in no event
     shall Landlord be required to make application of any portion of the
     Signage Allowance on account of any supervisory fees, overhead, management
     fees or other payments to Tenant, or any partner or affiliate of Tenant. In
     the event that such cost of Signage Work is less than the Signage
     Allowance, Tenant shall not be entitled to any payment or credit nor shall
     there be any application of the same toward Annual Fixed Rent or Additional
     Rent owed by Tenant under this Lease. Landlord shall use reasonable efforts
     to cooperate with Tenant in obtaining the proper governmental approvals and
     permits for Tenant's signage rights under any provisions of this Section
     5.17 which require Tenant to seek the necessary governmental approvals and
     permits for such signage; provided, however that Landlord shall be put to
     no cost or expense in connection therewith.

     (E) Landlord presently maintains monument signs at the Complex identifying
     the tenants or occupants thereof and Tenant shall have the non-exclusive
     right to a listing on each such monument sign (other than those that relate
     solely to buildings within the Complex in which Tenant does not lease any
     space), subject to the terms and provisions of this Section 5.17 and
     subject to Landlord's approval of the final details of such listing, which
     approval will not be unreasonably withheld, conditioned or delayed.

     (F) Landlord shall not grant any other tenant or occupant of the Complex
     the right to erect exterior or interior signage on or in any Building or
     Additional Building directly leased by Tenant in its entirety.


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                                   ARTICLE VI

                               Casualty and Taking

6.0  Landlord's Restoration Estimate

     In case during the Lease Term the Buildings or Site (which for the purposes
     of this Article VI shall expressly include the parking areas of the Complex
     and Land Recreation Area A, as that term is defined in Section 8.27 below)
     are damaged by fire or other casualty, Landlord shall within sixty (60)
     days after the occurrence thereof notify Tenant in writing of Landlord's
     reasonable estimate of the length of time necessary to repair or restore
     such fire or casualty damage from the time that repair work would commence
     ("Landlord's Restoration Estimate").

6.1  Damage Resulting from Casualty

     In case during the Lease Term, the Premises or the Site are damaged by fire
     or other casualty and, if according to Landlord's Restoration Estimate,
     such fire or casualty damage cannot, in the ordinary course, reasonably be
     expected to be repaired within two hundred forty (240) days from the time
     that repair work would commence, either party may, at its election,
     terminate this Lease by notice given to the other within thirty (30) days
     after the date of Landlord's Restoration Estimate, specifying the effective
     date of termination; provided, however, that (x) Landlord shall only be
     permitted to terminate this Lease on account of such damage if Landlord
     terminates the leases of all other tenants in the Complex similarly
     affected by the casualty (where Landlord has a termination right
     thereunder) and (y) in the event of damage to a single Building which would
     in and of itself trigger any termination right under this Section 6.1, this
     Lease may be terminated by either party (to the extent such party has a
     termination right hereunder) with respect solely to such damaged Building
     but not with respect to the other Buildings not similarly affected by the
     casualty (provided, however, that if Tenant reasonably determines that
     Tenant is unable to continue to operate its business economically and
     efficiently within the undamaged portion of the Premises, Tenant may
     terminate this Lease as to the entire Premises so long as the casualty is
     of such a magnitude as to trigger a termination right hereunder). The
     effective date of termination specified by either party hereunder shall not
     be less than thirty (30) days nor more than forty-five (45) days after the
     date of notice of such termination.

     In case during the last eighteen (18) months of the Lease Term, the
     Premises are damaged by fire or casualty and such fire or casualty damage
     cannot, in the ordinary course, reasonably be expected to be repaired
     within one hundred fifty (150) days (and/or as to special work or work
     which requires long lead time then if such work cannot reasonably be
     expected to be repaired within such additional time as is reasonable under
     the circumstances given the nature of the work) from the time that repair
     work would commence, Tenant may, at its election, terminate this Lease by
     notice given to Landlord within sixty (60) days after the date of such fire
     or other casualty, specifying the effective date of termination. The
     effective date of termination specified by Tenant shall be not


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     less than thirty (30) days nor more than forty-five (45) days after the
     date of notice of such termination.

     Unless terminated pursuant to the foregoing provisions, this Lease shall
     remain in full force and effect following any such damage subject, however,
     to the following provisions.

     If the Buildings or the Site or any part thereof are damaged by fire or
     other casualty and this Lease is not so terminated, or Landlord or Tenant
     have no right to terminate this Lease, and in any such case the holder of
     any mortgage which includes the Buildings as a part of the mortgaged
     premises or any ground lessor of any ground lease which includes the Site
     as part of the demised premises allows the net insurance proceeds to be
     applied to the restoration of the Buildings (and/or the Site), Landlord
     promptly after such damage and the determination of the net amount of
     insurance proceeds available shall use due diligence to restore the
     Premises and the Buildings in the event of damage thereto (excluding
     Tenant's Property) into substantially the same condition as existed prior
     to the damage and a just proportion of the Annual Fixed Rent, Operating
     Expenses Allocable to the Premises and Landlord's Tax Expenses Allocable to
     the Premises according to the nature and extent of the injury to the
     Premises shall be abated until the earlier to occur of (i) the date the
     Premises is substantially restored to the extent required under this Lease
     and Tenant has had a period of time (in no event to exceed thirty (30) days
     after Landlord has completed its restoration obligations as aforesaid) to
     install its furniture, fixtures and equipment, which Tenant agrees to
     undertake in a reasonably expeditious manner, and (iii) the date Tenant
     commences business operations in the Premises. Notwithstanding anything
     herein contained to the contrary, Landlord shall not be obligated to expend
     for such repair and restoration any amount in excess of the net insurance
     proceeds (provided, however, that if Landlord elects not to expend any sums
     in excess of the net insurance proceeds, Tenant shall have the right to
     terminate this Lease as set forth in the immediately following sentence).
     If such net insurance proceeds are not allowed by such mortgagee or ground
     lessor to be applied to, or are otherwise insufficient for, the restoration
     of the Buildings (and/or the Site) and if Landlord does not otherwise elect
     to spend the additional funds necessary to fully restore the Buildings
     (and/or the Site), then Landlord shall give notice ("Landlord's Proceeds
     Notice") to Tenant within thirty (30) days after the final determination by
     such mortgagee or ground lessor as to the disbursement of proceeds that
     Landlord does not elect to fund the amount of deficiency and Tenant shall
     thereafter have the right to terminate this Lease by providing Landlord
     with a notice of termination within thirty (30) days after Tenant's receipt
     of Landlord's Proceeds Notice (the effective date of which termination
     shall not be less than sixty (60) days after the date of notice of such
     termination).

     Unless such restoration is (x) commenced within six (6) months from the
     date of the casualty or taking (except to the extent such restoration work
     could be completed within the one (1) year period described in subsection
     (y) below, notwithstanding the fact that it did not commence within six (6)
     months from the date of the casualty or taking), such period to be subject,
     however, to extension where the delay in commencement of such work is due
     to Force Majeure, as defined hereinbelow (but in no event beyond ten (10)


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     months from the date of the casualty or taking) and (y) completed within
     one (1) year from the date of the casualty or taking, such one (1) year
     period to be subject, however, to extension where the delay in completion
     of such work is due to Force Majeure, as defined hereinbelow, (but in no
     event beyond eighteen (18) months from the date of the casualty or taking),
     Tenant, as its sole and exclusive remedy, shall have the right to terminate
     this Lease at any time after the expiration of such six-month or one-year
     (as extended) period, as the case may be, until the restoration is
     substantially completed, such termination to take effect as of the
     thirtieth (30th) day after the date of receipt by Landlord of Tenant's
     notice, with the same force and effect as if such date were the date
     originally established as the expiration date hereof unless, within thirty
     (30) days after Landlord's receipt of Tenant's notice, such restoration is
     commenced or substantially completed, as the case may be, in which case
     Tenant's notice of termination shall be of no force and effect and this
     Lease and the Lease Term shall continue in full force and effect. When used
     in this Article VI, "Force Majeure" shall mean any prevention, delay or
     stoppage due to governmental regulation, strikes, lockouts, acts of God,
     acts of war, terrorists acts, civil commotions, unusual scarcity of or
     inability to obtain labor or materials, labor difficulties, casualty or
     other causes reasonably beyond Landlord's control or attributable to
     Tenant's action or inaction; provided, however, that (1) in no event shall
     Landlord's financial inability constitute a cause beyond Landlord's
     reasonable control and (2) in order for Landlord to claim the benefit of
     any delay due to Force Majeure, Landlord shall be required to use
     reasonable efforts to minimize the extent and duration of such delay and to
     notify Tenant of the existence and nature of the cause of such delay within
     a reasonable time after the delay first commences.

6.2  Uninsured Casualty

     Notwithstanding anything to the contrary contained in this Lease, if the
     Buildings or the Premises shall be substantially damaged by fire or
     casualty as the result of a risk not covered by the forms of casualty
     insurance at the time maintained by Landlord and such fire or casualty
     damage cannot, in the ordinary course, reasonably be expected to be
     repaired within ninety (90) days from the time that repair work would
     commence, either party may, at its election, terminate the Term of this
     Lease by notice to the other party given within sixty (60) days after such
     loss; provided, however that Landlord may not terminate this Lease on
     account of an uninsured casualty and shall restore the Premises, the Common
     Areas and the Complex in accordance with the terms of this Lease, if and to
     the extent such damage would have been covered by the insurance coverages
     required to be carried by Landlord under this Lease. If either party shall
     give such notice, then this Lease shall terminate as of the date of such
     notice with the same force and effect as if such date were the date
     originally established as the expiration date hereof.

6.3  Rights of Termination for Taking

     If (i) the entire Premises, or such portion thereof as to render the
     balance (if reconstructed to the maximum extent practicable in the
     circumstances) unsuitable for Tenant's purposes, or (ii) twenty-five
     percent (25%) or more of the parking areas serving the Complex shall be
     taken by condemnation or right of eminent domain, Landlord or Tenant


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     shall have the right to terminate this Lease by notice to the other of its
     desire to do so, provided that such notice is given not later than thirty
     (30) days after Tenant has been deprived of possession. In the event of a
     taking of a single Building which would in and of itself trigger any
     termination right under this Section 6.3, this Lease may be terminated by
     either party (to the extent such party has a termination right hereunder)
     solely with respect to the Building that was the subject of the taking but
     not with respect to the other Buildings not similarly affected by the
     taking (provided, however, that if Tenant reasonably determines that Tenant
     is unable to continue to operate its business economically and efficiently
     with the undamaged portion of the Premises, Tenant may terminate this Lease
     as to the entire Premises so long as the taking is of such a magnitude as
     to trigger a termination right hereunder). In addition, Tenant may
     terminate this Lease if fifty percent (50%) or more of Land Recreation Area
     A shall be taken and the remaining portion of Land Area Recreation A is
     insufficient for the Permitted Uses of the Additional Land Areas, as
     determined by Tenant in its reasonable discretion (taking into account the
     continued availability of Land Recreation Area B for such purposes). If
     either party shall give such notice, then this Lease shall terminate as of
     the date of such notice with the same force and effect as if such date were
     the date originally established as the expiration date hereof. For the
     purposes hereof, the work "taking" shall mean and refer to the acquisition
     or taking of property (or any right, title or interest therein) by any
     governmental or quasi-governmental authority acting under power of
     condemnation or eminent domain, and shall encompass contested as well as
     uncontested takings as long as initiated by the applicable governmental or
     quasi-governmental authority and any conveyances in lieu of an initiated
     taking.

     Should any part of the Premises be so taken or condemned during the Lease
     Term hereof, and should this Lease not be terminated in accordance with the
     foregoing provisions, and the holder of any mortgage which includes the
     Premises as part of the mortgaged premises or any ground lessor of any
     ground lease which includes the Site as part of the demised premises allows
     the net condemnation proceeds to be applied to the restoration of the
     Buildings, Landlord agrees that after the determination of the net amount
     of condemnation proceeds available to Landlord, Landlord shall use due
     diligence to put what may remain of the Premises into proper condition for
     use and occupation as nearly like the condition of the Premises prior to
     such taking as shall be practicable (excluding Tenant's Property).
     Notwithstanding the foregoing, Landlord shall not be obligated to expend
     for such repair and restoration any amount in excess of the net
     condemnation proceeds made available to it (provided, however, that if
     Landlord elects not to expend any sums in excess of the net condemnation
     proceeds, Tenant shall have the right to terminate this Lease as set forth
     in the immediately following sentence). If such net condemnation proceeds
     are not allowed by such mortgagee or ground lessor to be applied to, or are
     otherwise insufficient for, the restoration of the Buildings (and/or the
     Site) and if Landlord does not otherwise elect to spend the additional
     funds necessary to fully restore the Buildings (and/or the Site), then
     Landlord shall give notice ("Landlord's Award Notice") to Tenant within
     thirty (30) days after the final determination by such mortgagee or ground
     lessor as to the disbursement of proceeds that Landlord does not elect to
     fund the amount of the insufficiency and Tenant shall thereafter have the
     right to terminate this Lease by providing Landlord with a notice of
     termination within thirty (30)


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     days after Tenant's receipt of Landlord's Award Notice (the effective date
     of which termination shall not be less than sixty (60) days after the date
     of notice of such termination).

     If the Premises shall be affected by any exercise of the power of eminent
     domain, then the Annual Fixed Rent, Operating Expenses Allocable to the
     Premises and Landlord's Tax Expenses Allocable to the Premises shall be
     justly and equitably abated and reduced according to the nature and extent
     of the loss of use thereof suffered by Tenant; and in case of a taking
     which permanently reduces the Rentable Floor Area of the Premises, a just
     proportion of the Annual Fixed Rent, Tenant's share of operating costs and
     Tenant's share of real estate taxes shall be abated for the remainder of
     the Lease Term.

6.4  Award

     Landlord shall have and hereby reserves to itself any and all rights to
     receive awards made for damages to the Premises, the Building, the
     Additional Buildings, the Complex and the Site and the leasehold hereby
     created, or any one or more of them, accruing by reason of exercise of
     eminent domain or by reason of anything lawfully done in pursuance of
     public or other authority. Tenant hereby grants, releases and assigns to
     Landlord all Tenant's rights to such awards, and covenants to execute and
     deliver such further assignments and assurances thereof as Landlord may
     from time to time request, and if Tenant shall fail to execute and deliver
     the same within fifteen (15) days after notice from Landlord, Tenant hereby
     covenants and agrees that Landlord shall be irrevocably designated and
     appointed as its attorney-in-fact to execute and deliver in Tenant's name
     and behalf all such further assignments thereof which conform with the
     provisions hereof.

     Nothing contained herein shall be construed to prevent Tenant from
     prosecuting in any condemnation proceeding a claim for the value of any of
     Tenant's usual trade fixtures installed in the Premises by Tenant at
     Tenant's expense and for relocation and moving expenses, provided that such
     action and any resulting award shall not affect or diminish the amount of
     compensation otherwise recoverable by Landlord from the taking authority.

6.5  Damage to Parking Areas and Land Recreation Area A

     Notwithstanding anything contained in this Article VI to the contrary,
     Tenant shall have no right to terminate this Lease on account of a casualty
     or taking affecting the parking areas of the Complex unless or until such
     casualty or taking results in a Parking Shortage (as that term is defined
     in Section 2.2.1 above). In addition, if such casualty or taking does
     result in a Parking Shortage, Tenant shall have no right to terminate this
     Lease under this Article VI notwithstanding that Landlord has been unable
     to restore such parking areas and eliminate the Parking Shortage within the
     applicable time periods set forth in this Article VI, if from and after the
     date on which Tenant's termination right would otherwise have been
     exercisable Landlord is able to provide Tenant with Alternative Parking in
     an amount which (together with any parking spaces remaining on


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     the Site after the casualty or taking) would enable Tenant to fully utilize
     the Number of Parking Spaces provided to it under Section 1.1.

     In addition, Tenant shall not have the right to terminate this Lease on
     account of any casualty or taking affecting Land Recreation Area A to the
     extent that Tenant no longer had the exclusive right to use Land Recreation
     Area A under the terms of Section 8.27(A) above at the time of such
     casualty or taking.

6.6  Allocation of Proceeds Following Termination

     In the event that this Lease is terminated (x) by Landlord under Section
     6.1 or 6.3 above or (y) by Tenant under the provisions of the fourth (4th)
     paragraph of Section 6.1 or the second (2nd) paragraph of Section 6.3 above
     (i.e. on account of Landlord's election not to fund an insufficiency in the
     insurance proceeds or condemnation award necessary to fully restore the
     Buildings and/or the Site), Tenant shall be entitled to receive out of the
     Proceeds or Award Balance (as hereinafter defined) the Book Value of the
     Tenant Improvement Work (as hereinafter defined); provided, however, that
     if the sum of the Book Value of the Tenant Improvement Work and the Book
     Value of the Tenant Allowances (as hereinafter defined) exceed the Proceeds
     or Award Balance, then the Book Value of the Tenant Improvement Work and
     the Book Value of the Tenant Allowances shall be proportionately reduced to
     an amount which, when added together, shall equal the Proceeds or Award
     Balance and in such event Tenant shall be entitled to receive out of the
     Proceeds or Award Balance the amount of the Book Value of the Tenant
     Improvement Work as so reduced. To the extent that the sum of the Book
     Value of the Tenant Improvement Work and the Book Value of the Tenant
     Allowances is less than the Proceeds or Award Balance, Landlord shall be
     entitled to the entire residual balance thereof.

     For the purposes hereof:

          (i)  The "Proceeds or Award Balance" shall be the amount, if any, by
               which the net insurance proceeds or net condemnation award (as
               applicable) exceeds the total of (x) the portion of the proceeds
               or award allocable to the Site (i.e. as if the land were
               unimproved), plus (y) the replacement cost of the Buildings and
               the Additional Buildings (exclusive of the Tenant Improvement
               Work), plus (z) all amounts payable to Landlord's mortgagee or
               ground lessor on account of such casualty or taking.

          (ii) The "Book Value of the Tenant Improvement Work" shall be the then
               unamortized portion of all costs of construction of the Tenant
               Improvement Work under Article III above (less the Tenant
               Allowances), calculated on a straight-line basis over the
               Original Lease Term and determined as of the date of the casualty
               or taking.

          (iii) The "Book Value of the Tenant Allowances" shall be the then
               unamortized portion of the Tenant Allowances, calculated on a
               straight-


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               line basis over the Original Lease Term and determined as of the
               date of the casualty or taking.

                                   ARTICLE VII

                                     Default

7.1  Tenant's Default

     (a)  If at any time subsequent to the date of this Lease any one or more of
          the following events (herein sometimes called an "Event of Default")
          shall occur:

          (i)  Tenant shall fail to pay the fixed rent, Additional Rent or other
               charges for which provision is made herein on or before the date
               on which the same become due and payable, and the same continues
               for five (5) business days after written notice from Landlord
               thereof; or

          (ii) Landlord having rightfully given the notice specified in
               subsection (a)(i) above twice in any calendar year, Tenant shall
               thereafter in the same calendar year fail to pay the fixed rent,
               Additional Rent or other charges on or before the date on which
               the same become due and payable; or

          (iii) Tenant shall assign its interest in this Lease or sublet any
               portion of the Premises in violation of the requirements of
               Sections 5.6 through 5.6.5 of this Lease and the same continues
               for fifteen (15) business days after written notice from Landlord
               thereof; or

          (iv) Tenant shall neglect or fail to perform or observe any other
               covenant herein contained on Tenant's part to be performed or
               observed and Tenant shall fail to remedy the same within thirty
               (30) days after notice to Tenant specifying such neglect or
               failure, or if such failure is of such a nature that Tenant
               cannot reasonably remedy the same within such thirty (30) day
               period, Tenant shall fail to commence promptly to remedy the same
               and to prosecute such remedy to completion with diligence and
               continuity; or

          (v)  Tenant's leasehold interest in the Premises shall be taken on
               execution or by other process of law directed against Tenant; or

          (vi) Tenant shall make an assignment for the benefit of creditors or
               shall file a voluntary petition in bankruptcy or shall be
               adjudicated bankrupt or insolvent, or shall file any petition or
               answer seeking


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               any reorganization, arrangement, composition, readjustment,
               liquidation, dissolution or similar relief for itself under any
               present or future Federal, State or other statute, law or
               regulation for the relief of debtors, or shall seek or consent to
               or acquiesce in the appointment of any trustee, receiver or
               liquidator of Tenant or of all or any substantial part of its
               properties, or shall admit in writing its inability to pay its
               debts generally as they become due, in all cases which is not
               dismissed within sixty (60) days after filing; or

          (v)  A petition shall be filed against Tenant in bankruptcy or under
               any other law seeking any reorganization, arrangement,
               composition, readjustment, liquidation, dissolution, or similar
               relief under any present or future Federal, State or other
               statute, law or regulation and shall remain undismissed or
               unstayed for an aggregate of sixty (60) days (whether or not
               consecutive), or if any debtor in possession (whether or not
               Tenant) trustee, receiver or liquidator of Tenant or of all or
               any substantial part of its properties or of the Premises shall
               be appointed without the consent or acquiescence of Tenant and
               such appointment shall remain unvacated or unstayed for an
               aggregate of sixty (60) days (whether or not consecutive) --

          then, and in any of said cases (notwithstanding any license of a
          former breach of covenant or waiver of the benefit hereof or consent
          in a former instance), Landlord lawfully may, immediately or at any
          time thereafter, terminate this Lease by notice to Tenant, specifying
          a date not less than ten (10) days after the giving of such notice on
          which this Lease shall terminate, and this Lease shall come to an end
          on the date specified therein as fully and completely as if such date
          were the date herein originally fixed for the expiration of the Lease
          Term (Tenant hereby waiving any rights of redemption), and Tenant will
          then quit and surrender the Premises to Landlord, but Tenant shall
          remain liable as hereinafter provided.

     (b)  If this Lease shall have been terminated as provided in this Article,
          then Landlord may, without notice, re- enter the Premises, either by
          force, summary proceedings, ejectment or otherwise, and remove and
          dispossess Tenant and all other persons and any and all property from
          the same, as if this Lease had not been made, and Tenant hereby waives
          the service of notice of intention to re-enter or to institute legal
          proceedings to that end.

     (c)  In the event that this Lease is terminated under any of the provisions
          contained in Section 7.1 (a) or shall be otherwise terminated by
          breach of any obligation of Tenant, Tenant covenants and agrees
          forthwith to pay and be liable for, on the days originally fixed
          herein for the payment thereof, amounts equal to the several
          installments of rent and other charges reserved as they would, under
          the terms of this Lease, become due if this Lease had not been
          terminated or if Landlord had not entered or re-entered, as aforesaid,
          and whether the Premises be relet or


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          remain vacant, in whole or in part, or for a period less than the
          remainder of the Term, and for the whole thereof, but in the event the
          Premises be relet by Landlord, Tenant shall be entitled to a credit in
          the net amount of rent and other charges received by Landlord in
          reletting, after deduction of all expenses incurred in reletting the
          Premises (including, without limitation, remodeling costs, brokerage
          fees and the like), and in collecting the rent in connection
          therewith, in the following manner:

               Amounts received by Landlord after reletting shall first be
               applied against such Landlord's expenses, until the same are
               recovered, and until such recovery, Tenant shall pay, as of each
               day when a payment would fall due under this Lease, the amount
               which Tenant is obligated to pay under the terms of this Lease
               (Tenant's liability prior to any such reletting and such recovery
               not in any way to be diminished as a result of the fact that such
               reletting might be for a rent higher than the rent provided for
               in this Lease); when and if such expenses have been completely
               recovered, the amounts received from reletting by Landlord as
               have not previously been applied shall be credited against
               Tenant's obligations as of each day when a payment would fall due
               under this Lease, and only the net amount thereof shall be
               payable by Tenant. Further, amounts received by Landlord from
               such reletting for any period shall be credited only against
               obligations of Tenant allocable to such period, and shall not be
               credited against obligations of Tenant hereunder accruing
               subsequent or prior to such period; nor shall any credit of any
               kind be due for any period after the date when the term of this
               Lease is scheduled to expire according to its terms.

          Landlord agrees to use reasonable efforts to relet the Premises after
          Tenant vacates the same in the event this Lease is terminated based
          upon an Event of Default by Tenant hereunder. The marketing of the
          Premises in a manner similar to the manner in which Landlord markets
          other premises within Landlord's control within the Complex shall be
          deemed to have satisfied Landlord's obligation to use "reasonable
          efforts" hereunder. In no event shall Landlord be required to (i)
          solicit or entertain negotiations with any other prospective tenant
          for the Premises until Landlord obtains full and complete possession
          of the Premises (including, without limitation, the final and
          unappealable legal right to relet the Premises free of any claim of
          Tenant), (ii) relet the Premises before leasing other vacant space in
          the Complex, or (iii) lease the Premises for a rental less than the
          current fair market rent rate then prevailing for similar space in the
          Complex.

     (d)  (i) Landlord may elect, as an alternative, to have Tenant pay
          liquidated damages, which election may be made by notice given to
          Tenant at any time after such termination and whether or not Landlord
          shall have collected any damages as aforesaid, as liquidated final
          damages and in lieu of all other damages beyond the date of such
          notice. Upon such notice, Tenant shall promptly pay to Landlord,


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          as liquidated damages, in addition to any damages collected or due
          from Tenant for any period prior to such notice and all expenses which
          Landlord may have incurred with respect to the collection of such
          damages, such a sum as at the time of the giving of such notice
          represents the amount of the excess, if any, of (x) the discounted
          present value, at a discount rate of six percent (6%) of the total
          rent and other benefits which would have accrued to Landlord under
          this Lease from the date of such notice for what would be the then
          unexpired Lease Term if the Lease terms had been fully complied with
          by Tenant over and above (y) the discounted present value, at a
          discount rate of six percent (6%), of the then cash rental value (in
          advance) of the Premises for the balance of the Lease Term.

          (ii) For the purposes of this Article, if Landlord elects to require
          Tenant to pay damages in accordance with the immediately preceding
          paragraph, the total rent shall be computed by assuming that Tenant's
          share of excess taxes, Tenant's share of excess operating costs and
          Tenant's share of excess electrical costs would be, for the balance of
          the unexpired Term from the date of such notice, the amount thereof
          (if any) for the immediately preceding annual period payable by Tenant
          to Landlord.

     (e)  In case of any Event of Default, re-entry, dispossession by summary
          proceedings or otherwise, Landlord may (i) re-let the Premises or any
          part or parts thereof, either in the name of Landlord or otherwise,
          for a term or terms which may at Landlord's option be equal to or less
          than or exceed the period which would otherwise have constituted the
          balance of the Term of this Lease and may grant concessions,
          abatements or free rent to the extent that Landlord considers
          advisable or necessary to re-let the same and (ii) may make such
          alterations, repairs and decorations in the Premises as Landlord in
          its sole judgment considers advisable or necessary for the purpose of
          reletting the Premises; and the making of such alterations, repairs
          and decorations shall not operate or be construed to release Tenant
          from liability hereunder as aforesaid. Landlord shall in no event be
          liable in any way whatsoever for failure to re-let the Premises, or,
          in the event that the Premises are re-let, for failure to collect the
          rent under re-letting. Tenant hereby expressly waives any and all
          rights of redemption granted by or under any present or future laws in
          the event of Tenant being evicted or dispossessed, or in the event of
          Landlord obtaining possession of the Premises, by reason of the
          violation by Tenant of any of the covenants and conditions of this
          Lease.

     (f)  The specified remedies to which Landlord may resort hereunder are not
          intended to be exclusive of any remedies or means of redress to which
          Landlord may at any time be entitled lawfully, and Landlord may invoke
          any remedy (including the remedy of specific performance) allowed at
          law or in equity as if specific remedies were not herein provided for.
          Further, nothing contained in this Lease shall limit or prejudice the
          right of Landlord to prove for and obtain in proceedings for
          bankruptcy or insolvency by reason of the termination of this Lease,
          an amount equal to the maximum allowed by any statute or rule of law
          in effect at the time when, and governing the proceedings in which,
          the damages are


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          to be proved, whether or not the amount be greater, equal to, or less
          than the amount of the loss or damages referred to above.

     (g)  In lieu of any other damages or indemnity and in lieu of the recovery
          by Landlord of all sums payable under all the foregoing provisions of
          this Section 7.1, Landlord may elect to collect from Tenant, by notice
          to Tenant, at any time after this Lease is terminated under any of the
          provisions contained in this Article VII or otherwise terminated by
          breach of any obligation of Tenant and before full recovery under such
          foregoing provisions, and Tenant shall thereupon pay, as liquidated
          damages, an amount equal to the sum of (x) the Annual Fixed Rent and
          all Additional Rent payable for the lesser of (i) the twelve (12)
          months ended next prior to such termination or (ii) the number of
          months then remaining in the Term of this Lease at the time of such
          termination, plus (y) the amount of Annual Fixed Rent and Additional
          Rent of any kind accrued and unpaid at the time of such election plus
          any and all expenses which the Landlord may have incurred for and with
          respect of the collection of any of such rent.

7.2  Landlord's Default

     Landlord shall in no event be in default in the performance of any of
     Landlord's obligations hereunder unless and until Landlord shall have
     failed to perform such obligations within thirty (30) days after notice by
     Tenant to Landlord properly specifying wherein Landlord has failed to
     perform any such obligation; provided that (i) if the alleged breach is of
     such a nature that it cannot reasonably be cured within such thirty (30)
     day period, then Landlord shall not be in default if Landlord commences a
     cure within such thirty (30) day period and diligently thereafter
     prosecutes such cure to completion, and (ii) in the event of an Emergency
     (as hereinafter defined), such grace or cure period shall be shortened as
     reasonably necessary given the scope and nature of the Emergency, provided
     that such shortened grace or cure period shall only apply to permit the
     exercise of Tenant's self-help rights under Section 8.17 below (as opposed
     to determining whether Tenant shall be entitled to exercise any other
     rights and remedies on account of such failure of performance by Landlord).
     In the event of a default by Landlord after expiration of applicable notice
     and cure periods, Tenant shall be entitled to pursue all rights and
     remedies available at law or in equity except as limited by this Lease, and
     in all events excluding indirect or consequential damages. Tenant shall use
     commercially reasonable efforts to mitigate its damages in the event of any
     default by Landlord hereunder. The term "Emergency" shall mean and refer to
     any situation or circumstance where there is an immediate or imminent risk
     of injury or death to persons or material damage to property unless
     immediate action is taken to address such situation or circumstances, as
     determined by the party invoking such term in good faith. Notwithstanding
     anything contained herein to the contrary, except to the extent expressly
     provided in Section 8.17(B) below, Tenant shall not assert any right to
     deduct the cost of repairs or any monetary claim against Landlord from rent
     thereafter due and payable, but shall look solely to the Landlord for
     satisfaction of such claim.


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                                  ARTICLE VIII

                            Miscellaneous Provisions

8.1  Extra Hazardous Use

     Tenant covenants and agrees that Tenant will not do or permit anything to
     be done in or upon the Premises, or bring in anything or keep anything
     therein, which shall increase the rate of insurance on the Premises or on
     the Buildings above the standard rate applicable to premises being occupied
     for the Permitted Uses; and Tenant further agrees that, in the event that
     Tenant shall do any of the foregoing, Tenant will promptly pay to Landlord,
     on demand, any such increase resulting therefrom, which shall be due and
     payable as Additional Rent thereunder.

8.2  Waiver

     Failure on the part of Landlord or Tenant to complain of any action or
     non-action on the part of the other, no matter how long the same may
     continue, shall never be a waiver by Tenant or Landlord, respectively, of
     any of its rights hereunder. Further, no waiver at any time of any of the
     provisions hereof by Landlord or Tenant shall be construed as a waiver of
     any of the other provisions hereof, and a waiver at any time of any of the
     provisions hereof shall not be construed as a waiver at any subsequent time
     of the same provisions. The consent or approval of Landlord or Tenant to or
     of any action by the other requiring such consent or approval shall not be
     construed to waive or render unnecessary Landlord's or Tenant's consent or
     approval to or of subsequent similar act by the other.

     No payment by Tenant, or acceptance by Landlord, of a lesser amount than
     shall be due from Tenant to Landlord shall be treated otherwise than as a
     payment on account. The acceptance by Landlord of a check for a lesser
     amount with an endorsement or statement thereon, or upon any letter
     accompanying such check, that such lesser amount is payment in full, shall
     be given no effect, and Landlord may accept such check without prejudice to
     any other rights or remedies which Landlord may have against Tenant.

8.3  Cumulative Remedies

     Except as expressly provided in this Lease, the specific remedies to which
     Landlord or Tenant may resort under the terms of this Lease are cumulative
     and are not intended to be exclusive of any other remedies or means of
     redress to which such party may be lawfully entitled in case of any breach
     or threatened breach by the other party of any provisions of this Lease. In
     addition to the other remedies provided in this Lease, Landlord and Tenant
     shall be entitled to the restraint by injunction of the violation or
     attempted or threatened violation of any of the covenants, conditions or
     provisions of this Lease or to a decree compelling specific performance of
     any such covenants, conditions or provisions.


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8.4  Quiet Enjoyment

     This Lease is subject and subordinate to all matters of record as of the
     date of this Lease. So long as an Event of Default by Tenant is not in
     existence under this Lease, Tenant shall lawfully, peaceably and quietly
     have, hold, occupy and enjoy the Premises during the Term (exclusive of any
     period during which Tenant is holding over after the expiration or
     termination of this Lease without the consent of Landlord), without
     interference, disturbance, hindrance or ejection by any person claiming by,
     through or under Landlord, subject, however, to the terms of this Lease;
     the foregoing covenant of quiet enjoyment is in lieu of any other covenant,
     express or implied; and it is understood and agreed that this covenant and
     any and all other covenants of Landlord contained in this Lease shall be
     binding upon Landlord and Landlord's successors, including ground or master
     lessees, only with respect to breaches occurring during Landlord's or
     Landlord's successors' respective ownership of Landlord's interest
     hereunder, as the case may be.

     Further, Tenant specifically agrees to look solely to Landlord's then
     equity interest in the Complex (including the rents and other income,
     insurance proceeds and condemnation awards therefrom) at the time owned, or
     in which Landlord holds an interest as ground lessee, for recovery of any
     judgment from Landlord; it being specifically agreed that neither Landlord
     (original or successor), nor any beneficiary of any trust of which any
     person holding Landlord's interest is trustee, nor any member, manager,
     partner, director or stockholder, nor Landlord's managing agent, shall ever
     be personally liable for any such judgment, or for the payment of any
     monetary obligation to Tenant. The provision contained in the foregoing
     sentence is not intended to, and shall not, limit any right that Tenant
     might otherwise have to obtain injunctive relief against Landlord or
     Landlord's successors in interest, or any action not involving the personal
     liability of Landlord (original or successor), any successor trustee to the
     persons named herein as Landlord, or any beneficiary of any trust of which
     any person holding Landlord's interest is trustee, or of any manager,
     member, partner, director or stockholder of Landlord or of Landlord's
     managing agent to respond in monetary damages from Landlord's assets other
     than Landlord's equity interest aforesaid in the Building, but except as
     expressly provided in this Lease to the contrary, in no event shall Tenant
     have the right to terminate or cancel this Lease or to withhold rent or to
     set-off any claim or damages against rent as a result of any default by
     Landlord or breach by Landlord of its covenants or any warranties or
     promises hereunder, except in the case of a wrongful eviction of Tenant
     from the demised premises (constructive or actual) by Landlord continuing
     after notice to Landlord thereof and a reasonable opportunity for Landlord
     to cure the same.

     In no event shall Landlord or Tenant ever be liable to the other party for
     any indirect or consequential damages suffered from whatever cause;
     provided that the foregoing shall not limit or alter any procedural right
     or remedy of Landlord or Tenant under this Lease nor shall the same apply
     to the obligations of Tenant with respect to any hold over by Tenant after
     the expiration or earlier termination of this Lease.


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8.5  Notice to Mortgagee and Ground Lessor

     After receiving notice (together with an address for notices to be sent)
     from any person, firm or other entity that it holds a mortgage which
     includes the Premises as part of the mortgaged premises, or that it is the
     ground lessor under a lease with Landlord, as ground lessee, which includes
     the Premises as a part of the demised premises, no notice from Tenant to
     Landlord shall be effective unless and until a copy of the same is given to
     such holder or ground lessor, and the curing of any of Landlord's defaults
     by such holder or ground lessor within the time periods permitted for a
     cure by Landlord under this Lease shall be treated as performance by
     Landlord. For the purposes of this Section 8.5 or Section 8.15, the term
     "mortgage" includes a mortgage on a leasehold interest of Landlord (but not
     one on Tenant's leasehold interest).

8.6  Assignment of Rents

     With reference to any assignment by Landlord of Landlord's interest in this
     Lease, or the rents payable hereunder, conditional in nature or otherwise,
     which assignment is made to the holder of a mortgage or ground lease on
     property which includes the Premises, Tenant agrees that the execution
     thereof by Landlord, and the acceptance thereof by the holder of such
     mortgage or the ground lessor, shall never be treated as an assumption by
     such holder or ground lessor of any of the obligations of Landlord
     hereunder, unless such holder, or ground lessor, shall, by notice sent to
     Tenant, specifically otherwise elect, or upon foreclosure of such holder's
     mortgage and the taking of possession of the Premises, or, in the case of a
     ground lessor, the assumption of Landlord's position hereunder by such
     ground lessor.

     In no event shall the acquisition of title to the Buildings and the land on
     which the same is located by a purchaser which, simultaneously therewith,
     leases the entire Buildings or such land back to the seller thereof be
     treated as an assumption by such purchaser-lessor, by operation of law or
     otherwise, of Landlord's obligations hereunder, but Tenant shall look
     solely to such seller-lessee, and its successors from time to time in
     title, for performance of Landlord's obligations hereunder subject to the
     provisions of Section 8.4 hereof. In any such event, this Lease shall be
     subject and subordinate to the lease to such purchaser provided that such
     purchaser agrees to recognize the rights of Tenant under this Lease upon
     the payment of rent and other charges payable by Tenant under this Lease
     and the performance by Tenant of Tenant's obligations hereunder and
     provided that Tenant agrees to attorn to such purchaser. For all purposes,
     such seller-lessee, and its successors in title, shall be the landlord
     hereunder unless and until Landlord's position shall have been assumed by
     such purchaser-lessor by notice sent to Tenant or by termination of the
     lease by such purchaser-lessor.

8.7  Surrender

     No act or thing done by Landlord during the Lease Term shall be deemed an
     acceptance of a surrender of the Premises, and no agreement to accept such
     surrender shall be valid, unless in writing signed by Landlord. No employee
     of Landlord or of Landlord's agents


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     shall have any power to accept the keys of the Premises prior to the
     termination of this Lease. The delivery of keys to any employee of Landlord
     or of Landlord's agents shall not operate as a termination of the Lease or
     a surrender of the Premises.

8.8  Brokerage

     (A) Tenant warrants and represents that Tenant has not dealt with any
     broker in connection with the consummation of this Lease other than the
     broker, person or firm, if any, designated in Section 1.1 hereof; and in
     the event any claim is made against the Landlord relative to dealings by
     Tenant with brokers including the Brokers, if any, designated in Section
     1.1 hereof, Tenant shall defend the claim against Landlord with counsel of
     Tenant's selection first approved by Landlord (which approval will not be
     unreasonably withheld) and save harmless and indemnify Landlord on account
     of loss, cost or damage which may arise by reason of such claim.

     (B) Landlord warrants and represents that Landlord has not dealt with any
     broker in connection with the consummation of this Lease other than the
     broker, person or firm, if any, designated in Section 1.1 hereof; and in
     the event any claim is made against the Tenant relative to dealings by
     Landlord with brokers including the Brokers, if any, designated in Section
     1.1 hereof, Landlord shall defend the claim against Tenant with counsel of
     Landlord's selection and save harmless and indemnify Tenant on account of
     loss, cost or damage which may arise by reason of such claim. Landlord
     agrees that it shall be solely responsible for the payment of brokerage
     commissions to the Broker for the Original Term of this Lease, if any,
     designated in Section 1.1 hereof.

8.9  Invalidity of Particular Provisions

     If any term or provision of this Lease, or the application thereof to any
     person or circumstance shall, to any extent, be invalid or unenforceable,
     the remainder of this Lease, or the application of such term or provision
     to persons or circumstances other than those as to which it is held invalid
     or unenforceable, shall not be affected thereby, and each term and
     provision of this Lease shall be valid and be enforced to the fullest
     extent permitted by law.

8.10 Provisions Binding, Etc

     The obligations of this Lease shall run with the land, and except as herein
     otherwise provided, the terms hereof shall be binding upon and shall inure
     to the benefit of the successors and assigns, respectively, of Landlord and
     Tenant and, if Tenant shall be an individual, upon and to his heirs,
     executors, administrators, successors and assigns. Each term and each
     provision of this Lease to be performed by Tenant shall be construed to be
     both a covenant and a condition. The reference contained to successors and
     assigns of Tenant is not intended to constitute a consent to subletting or
     assignment by Tenant.


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8.11 Recording; Confidentiality

     Landlord and Tenant agree, not to record the within Lease, but
     simultaneously with their execution and delivery of this Lease to execute
     and deliver a Notice of Lease in the form attached hereto as Exhibit L. In
     no event shall such document set forth rent or other charges payable by
     Tenant under this Lease; and any such document shall expressly state that
     it is executed pursuant to the provisions contained in this Lease, and is
     not intended to vary the terms and conditions of this Lease.

     Tenant agrees that this Lease and the terms contained herein will be
     treated as strictly confidential and except as required by law (or except
     with the written consent of Landlord) Tenant shall not disclose the same to
     any third party except for Tenant's employees, brokers, agents, partners,
     lenders, accountants and attorneys and like parties who have been advised
     of the confidentiality provisions contained herein and agree to be bound by
     the same. In the event Tenant is required by law to provide this Lease or
     disclose any of its terms, Tenant shall give Landlord prompt notice of such
     requirement prior to making disclosure so that Landlord may seek an
     appropriate protective order. If failing the entry of a protective order
     Tenant is compelled to make disclosure, Tenant shall only disclose portions
     of the Lease which Tenant is required to disclose and will exercise
     reasonable efforts to obtain assurance that confidential treatment will be
     accorded to the information so disclosed. In connection with the foregoing,
     it is acknowledged and agreed that Tenant will be required by applicable
     governmental regulations to disclose this Lease in its public filings with
     the United States Securities and Exchange Commission.

8.12 Notices

     Whenever, by the terms of this Lease, notice shall or may be given either
     to Landlord or to Tenant, such notice shall be in writing and shall be sent
     by overnight commercial courier or by registered or certified mail postage
     or delivery charges prepaid, as the case may be:

          If intended for Landlord, addressed to Landlord at the address set
          forth in Article I of this Lease, with a copy to Landlord, Attention:
          General Counsel at the same address (or to such other address or
          addresses as may from time to time hereafter be designated by Landlord
          by like notice).

          If intended for Tenant, addressed to Tenant at the address set forth
          in Article I of this Lease except that from and after the Commencement
          Date the address of Tenant shall be the Premises, with a copy to
          Tenant, Attention: General Counsel at the same address (or to such
          other address or addresses as may from time to time hereafter be
          designated by Tenant by like notice).

     Except as otherwise provided herein, all such notices shall be effective
     when received; provided, that (i) if receipt is refused, notice shall be
     effective upon the first occasion that such receipt is refused, (ii) if the
     notice is unable to be delivered due to a change of


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     address of which no notice was given, notice shall be effective upon the
     date such delivery was attempted, (iii) if the notice address is a post
     office box number, notice shall be effective the day after such notice is
     sent as provided hereinabove or (iv) if the notice is to a foreign address,
     notice shall be effective two (2) days after such notice is sent as
     provided hereinabove.

     Where provision is made for the attention of an individual or department,
     the notice shall be effective only if the wrapper in which such notice is
     sent is addressed to the attention of such individual or department.

     Any notice given by an attorney on behalf of Landlord or by Landlord's
     managing agent shall be considered as given by Landlord and shall be fully
     effective. Any notice given by an attorney by or on behalf of Tenant shall
     be considered as given by Tenant and shall be fully effective.

     Time is of the essence with respect to any and all notices and periods for
     giving notice or taking any action thereto under this Lease.

8.13 When Lease Becomes Binding

     Employees or agents of Landlord have no authority to make or agree to make
     a lease or any other agreement or undertaking in connection herewith. The
     submission of this document for examination and negotiation does not
     constitute an offer to lease, or a reservation of, or option for, the
     Premises, and this document shall become effective and binding only upon
     the execution and delivery hereof by both Landlord and Tenant. All
     negotiations, considerations, representations and understandings between
     Landlord and Tenant are incorporated herein and may be modified or altered
     only by written agreement between Landlord and Tenant, and no act or
     omission of any employee or agent of Landlord shall alter, change or modify
     any of the provisions hereof.

8.14 Section Headings

     The titles of the Articles throughout this Lease are for convenience and
     reference only, and the words contained therein shall in no way be held to
     explain, modify, amplify or aid in the interpretation, construction or
     meaning of the provisions of this Lease.

8.15 Rights of Mortgagee

     This Lease shall be subject and subordinate to any mortgage now or
     hereafter on the Site, the Buildings, or the Complex, and to each advance
     made or hereafter to be made under any mortgage, and to all renewals,
     modifications, consolidations, replacements and extensions thereof and all
     substitutions therefor provided, however, that in consideration of and as a
     condition precedent to Tenant's agreement to subordinate this Lease with
     respect to mortgages hereafter placed on the Site shall be the receipt of a
     commercially reasonable non-disturbance agreement from and wherein the
     applicable mortgagee expressly recognizes the rights of Tenant under this
     Lease (including the right to use and


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     occupy the Premises and to lease additional premises at the Complex) upon
     the payment of rent and other charges payable by Tenant under this Lease
     and the performance by Tenant of Tenant's obligations hereunder. In
     confirmation of such subordination and recognition, Tenant shall execute
     and deliver promptly such instruments of subordination and recognition as
     such mortgagee may reasonably request subject to receipt of such
     instruments of recognition from such mortgagee as Tenant may reasonably
     request. Tenant hereby appoints such mortgagee (from time to time) as
     Tenant's attorney-in-fact to execute such subordination upon default of
     Tenant in complying with such mortgagee's (from time to time) request. In
     the event that any mortgagee or its respective successor in title shall
     succeed to the interest of Landlord, then, this Lease shall nevertheless
     continue in full force and effect and, provided Tenant has received the
     non-disturbance agreement required under this Section 8.15, Tenant shall
     and does hereby agree to attorn to such mortgagee or successor and to
     recognize such mortgagee or successor as its landlord. If any holder of a
     mortgage which includes the Premises, executed and recorded prior to the
     date of this Lease, shall so elect, this Lease and the rights of Tenant
     hereunder, shall be superior in right to the rights of such holder, with
     the same force and effect as if this Lease had been executed, delivered and
     recorded, or a statutory notice hereof recorded, prior to the execution,
     delivery and recording of any such mortgage. The election of any such
     holder shall become effective upon either notice from such holder to Tenant
     in the same fashion as notices from Landlord to Tenant are to be given
     hereunder or by the recording in the appropriate registry or recorder's
     office of an instrument in which such holder subordinates its rights under
     such mortgage to this Lease.

     Landlord shall obtain and deliver to Tenant, as a condition of the
     effectiveness of this Lease, a non-disturbance agreement from the current
     mortgagee of the Premises and/or the Complex as of the date of this Lease,
     which said non-disturbance agreement shall be in the form attached hereto
     as Exhibit M (as the same may be modified by such changes as Tenant may
     request and such mortgagee may approve).

     Landlord represents and warrants to Tenant that Landlord is the fee simple
     owner of the Complex and, as of the date hereof, the Complex is not subject
     to any ground lease or overlease.

8.16 Status Reports and Financial Statements

     Recognizing that Landlord may find it necessary to establish to third
     parties, such as accountants, banks, potential or existing mortgagees,
     potential purchasers or the like, the then current status of performance
     hereunder, Tenant, on the request of Landlord made from time to time, will
     within fifteen (15) business days after such request furnish to Landlord,
     or any existing or potential holder of any mortgage encumbering the
     Premises, the Buildings, the Site and/or the Complex or any potential
     purchaser of the Premises, the Buildings, the Site and/or the Complex,
     (each an "Interested Party"), a statement of the status of any matter
     pertaining to this Lease, including, without limitation, acknowledgments
     that (or the extent to which) each party is in compliance with its
     obligations under the terms of this Lease. At Tenant's request, Landlord
     shall similarly


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     within fifteen (15) business days after Tenant's request, furnish to Tenant
     a commercially reasonable statement with similar types of information as
     set forth above, which statement may be relied upon by any actual or
     prospective assignee, subtenant, lender or purchaser of Tenant.

     In addition, Tenant shall deliver to Landlord, or any Interested Party
     designated by Landlord, financial statements of Tenant and any guarantor of
     Tenant's obligations under this Lease, as reasonably requested by Landlord,
     including, but not limited to financial statements for the past three (3)
     years to the extent available and maintained by Tenant, except that so long
     as Tenant's stock is publicly traded on a national exchange that requires
     its financial statements to be publicly disclosed, Tenant shall have no
     obligation to deliver any financial statements to Landlord.

     Landlord shall keep any non-public information provided by Tenant pursuant
     to this Section 8.16 confidential, and shall not disclose the same other
     than (i) to Landlord's officers, employees and consultants (or to any of
     the Interested Parties) or (ii) to the extent required by applicable law or
     by any administrative, governmental or judicial proceeding.

     Any such status statement or financial statement delivered by Tenant
     pursuant to this Section 8.16 may be relied upon by any Interested Party.

8.17 Self-Help

     (A) If an Event of Default of Tenant is in existence and continuing,
     Landlord shall have the right, but shall not be obligated, to enter upon
     the Premises and to perform such obligation notwithstanding the fact that
     no specific provision for such substituted performance by Landlord is made
     in this Lease with respect to such default. In performing such obligation,
     Landlord may make any payment of money or perform any other act as is
     reasonably deemed necessary. All sums so paid by Landlord (together with
     interest at the Default Rate (as defined in Section 8.22 below) and all
     costs and expenses in connection with the performance of any such act by
     Landlord, shall be deemed to be Additional Rent under this Lease and shall
     be payable to Landlord immediately on demand. Landlord may exercise the
     foregoing rights without waiving any other of its rights or releasing
     Tenant from any of its obligations under this Lease.

     (B) In the event that Landlord shall be in default in the performance of
     any of Landlord's obligations under this Lease beyond the expiration of the
     applicable notice and cure periods provided in Section 7.2 above, then if
     Landlord or the holder of any such mortgage (at the option of such
     mortgagee) fails to (i) commence to cure such default within the time
     periods specified in said Section 7.2 and (ii) thereafter prosecute such
     cure to completion with due diligence given the nature thereof, then
     thereafter at any time prior to Landlord's or such mortgagee's commencing
     such cure or subsequent to Landlord or such mortgagee commencing such cure
     if Landlord or such mortgagee has not prosecuted such cure to completion
     with due diligence given the nature of such cure, Tenant may, but need not
     (and without limitation of any other rights and remedies to


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     which Tenant may be entitled under this Lease, at law or in equity on
     account of such default of Landlord), perform such obligation and charge
     the reasonable cost thereof to Landlord; provided, however, that in the
     case of emergency repairs (i) such notice by Tenant to Landlord and such
     mortgagee need not be in writing, and (ii) Tenant may make such emergency
     repairs and charge the reasonable cost thereof to Landlord if either
     Landlord or such mortgagee has not made such emergency repairs within a
     reasonable time after such notice. All sums so paid by Tenant (together
     with interest at the Default Rate) and all costs and expenses in connection
     with the performance of any such act by Tenant shall be payable to Tenant
     immediately on demand. If Landlord fails to reimburse Tenant for the sums
     paid by Tenant within thirty (30) days of Tenant's demand therefor (such
     demand to include reasonable evidence of the costs so incurred by Tenant),
     and Landlord has not, within ten (10) business days of its receipt of
     Tenant's demand, given written notice to Tenant objecting to such demand
     and submitting the same to arbitration under Section 8.31 below (or if
     Landlord has timely disputed Tenant's demand, has submitted such dispute to
     arbitration in accordance with said Section 8.31 and has thereafter failed
     to pay Tenant the amount of any final, unappealable arbitration award
     against Landlord within thirty (30) days after the issuance thereof) then
     subject to the last sentence of this paragraph, Tenant shall have the right
     to offset the amount of such sums demanded by Tenant against the Annual
     Fixed Rent and Additional Rent payable under this Lease until offset in
     full. Notwithstanding the foregoing, Tenant shall have no right to reduce
     any monthly installment of Annual Fixed Rent by more than ten percent (10%)
     of the amount of Annual Fixed Rent which would otherwise have been due and
     payable by Tenant to Landlord, unless the aggregate amount of such
     deductions over the remainder of the Lease Term (as the same may have been
     extended) will be insufficient to fully reimburse Tenant for the amount
     demanded by Tenant, in which event Tenant may effect such offset by making
     deductions from each monthly installment of Annual Fixed Rent in equal
     monthly amounts over the balance of the remainder of the Lease Term.

8.18 Holding Over

     Any holding over by Tenant after the expiration of the term of this Lease
     shall be treated as a tenancy at sufferance and shall be on the terms and
     conditions as set forth in this Lease, as far as applicable except that
     Tenant shall pay as a use and occupancy charge an amount equal to the
     greater of (x) 150% of the Annual Fixed Rent and Additional Rent calculated
     (on a daily basis) at the highest rate payable under the terms of this
     Lease, or (y) the fair market rental value of the Premises, in each case
     for the period measured from the day on which Tenant's hold-over commences
     and terminating on the day on which Tenant vacates the Premises. In
     addition, Tenant shall save Landlord, its agents and employees harmless and
     will exonerate, defend and indemnify Landlord, its agents and employees
     from and against any and all damages which Landlord may suffer on account
     of Tenant's hold-over in the Premises after the expiration or prior
     termination of the term of this Lease. Nothing in the foregoing nor any
     other term or provision of this Lease shall be deemed to permit Tenant to
     retain possession of the Premises or hold over in the Premises after the
     expiration or earlier termination of the Lease Term. All property which
     remains in the Buildings or the Premises after the expiration or
     termination of this


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     Lease shall be conclusively deemed to be abandoned and may either be
     retained by Landlord as its property or sold or otherwise disposed of in
     such manner as Landlord may see fit. If any part thereof shall be sold,
     then Landlord may receive the proceeds of such sale and apply the same, at
     its option against the expenses of the sale, the cost of moving and
     storage, any arrears of rent or other charges payable hereunder by Tenant
     to Landlord and any damages to which Landlord may be entitled under this
     Lease and at law and in equity.

8.19 Non-Subrogation

     Any insurance carried by either party with respect to the Premises or
     property therein or occurrences thereon shall include a clause or
     endorsement denying to the insurer rights of subrogation against the other
     party to the extent rights have been waived by the insured prior to
     occurrence of injury or loss. Each party, notwithstanding any provisions of
     this Lease to the contrary, hereby waives any rights of recovery against
     the other for injury or loss due to hazards covered by such insurance (or
     which would have been covered had such party carried the insurance required
     to be carried by it under the Lease) to the extent of the indemnification
     received under such insurance policy and to the extent of any deductible
     maintained by such party in excess of $25,000.00. In addition, this waiver
     of rights by the parties shall apply to, and be for the benefit of, the
     Landlord Parties and the Tenant Parties, as applicable.

8.20 Extension Option

     (A) On the conditions (which conditions Landlord may waive by written
     notice to Tenant) that both at the time of exercise of the herein described
     applicable option to extend and as of the commencement of the Extended Term
     in question (i) there exists no monetary or other material Event of Default
     (defined in Section 7.1), (ii) this Lease is still in full force and
     effect, and (iii) Tenant has not sublet more than fifty percent (50%) of
     the Rentable Floor Area of the Premises (except for a subletting permitted
     without Landlord's consent under Section 5.6.1 hereof or any occupancy
     permitted under Section 5.6.6 hereof), Tenant shall have the right to
     extend the Term hereof upon all the same terms, conditions, covenants and
     agreements herein contained (except for the Annual Fixed Rent which shall
     be adjusted during the option periods as hereinbelow set forth) for two (2)
     periods of five (5) years each as hereinafter set forth. Each option period
     is sometimes herein referred to as an "Extended Term." Notwithstanding any
     implication to the contrary Landlord has no obligation to make any
     additional payment to Tenant in respect of any construction allowance or
     the like or to perform any work to the Premises as a result of the exercise
     by Tenant of any such option (although the absence of any construction or
     other refurbishment allowance from Landlord for the Extended Term shall be
     a factor considered by all parties in determining the Prevailing Market
     Rent under this Section 8.20 and Exhibit H).

     (B) If Tenant desires to exercise its applicable option to extend the Term,
     then Tenant shall give notice to Landlord, not earlier than sixteen (16)
     months nor later than twelve (12) months prior to the expiration of the
     Lease Term (as it may have been previously


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     extended hereunder) of Tenant's request for Landlord's quotation to Tenant
     of a proposed Annual Fixed Rent for the applicable Extended Term, which
     quotation Landlord shall deliver to Tenant in writing within fifteen (15)
     business days after receipt of Tenant's request. If at the expiration of
     thirty (30) days after the date when Tenant receives Landlord's quotation
     of the proposed Annual Fixed Rent as aforesaid (the "Negotiation Period"),
     Landlord and Tenant have not reached agreement on a determination of an
     Annual Fixed Rent for the applicable Extended Term and executed a written
     instrument extending the Term of this Lease pursuant to such agreement,
     then Tenant shall have the right, for thirty (30) days following the
     expiration of the Negotiation Period, to make a request to Landlord for a
     broker determination (the "Broker Determination") of the Prevailing Market
     Rent (as defined in Exhibit H) for the applicable Extended Term, which
     Broker Determination shall be made in the manner set forth in Exhibit H. If
     Tenant timely shall have requested the Broker Determination, then the
     Annual Fixed Rent for the applicable Extended Term shall be the greater of
     (a) ninety-five percent (95%) of the Prevailing Market Rent (as defined in
     Exhibit H) as determined by the Broker Determination or (b) the Annual
     Fixed Rent in effect during the last twelve (12) month period of the Lease
     Term immediately prior to such Extended Term. If Tenant shall have failed
     to timely request the Broker Determination, then the Annual Fixed Rent for
     the applicable Extended Term shall be as set forth in Landlord's original
     quotation.

     (C) Upon the giving of notice by Tenant to Landlord exercising Tenant's
     option to extend the Lease Term in accordance with the provisions of
     Section 8.20(B) above, then this Lease and the Lease Term hereof shall
     automatically be deemed extended, for the applicable Extended Term, without
     the necessity for the execution of any additional documents, except that
     Landlord and Tenant agree to enter into an instrument in writing setting
     forth the Annual Fixed Rent for the applicable Extended Term as determined
     in the relevant manner set forth in this Section 8.20; and in such event
     all references herein to the Lease Term or the Term of this Lease shall be
     construed as referring to the Lease Term, as so extended, unless the
     context clearly otherwise requires. Notwithstanding anything contained
     herein to the contrary, in no event shall Tenant have the right to exercise
     more than one extension option at a time and further, Tenant shall not have
     the right to exercise its second extension option unless it has duly
     exercised its first extension option, and in no event shall the Lease Term
     hereof be extended for more than ten (10) years after the expiration of the
     Original Term hereof

8.21 Security Deposit

     (A) Concurrently with the execution of this Lease, Tenant shall pay to
     Landlord a security deposit in the amount of Two Million and 00/100 Dollars
     ($2,000,000.00) and Landlord shall hold the same, throughout the Term of
     this Lease (including the Extended Term, if applicable), unless sooner
     returned to Tenant as provided in this Section 8.21 and subject to the
     provisions of subsection (B) below, as security for the performance by
     Tenant of all obligations on the part of Tenant to be performed under this
     Lease. Such deposit shall be in the form of an irrevocable, unconditional,
     negotiable letter of credit (the "Letter of Credit"). The Letter of Credit
     shall (i) be issued by and drawn on a bank


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     reasonably approved by Landlord and at a minimum having a corporate credit
     rating from Standard and Poor's Professional Rating Service of BBB- or a
     comparable minimum rating from Moody's Professional Rating Service, (ii) be
     substantially in the form attached hereto as Exhibit G, (iii) permit one or
     more draws thereunder to be made accompanied only by certification by
     Landlord or Landlord's managing agent that pursuant to the terms of this
     Lease, Landlord is entitled to draw upon such Letter of Credit, (iv) permit
     transfers at any time without charge, and (v) provide that any notices to
     Landlord be sent to the notice address provided for Landlord in this Lease.
     If the credit rating for the issuer of such Letter of Credit falls below
     the standard set forth in (i) above or if the financial condition of such
     issuer changes in any other material adverse way, Landlord shall have the
     right to require that Tenant provide a substitute letter of credit that
     complies in all respects with the requirements of this Section, and
     Tenant's failure to provide the same within ten (10) business days
     following Landlord's written demand therefor shall entitle Landlord to
     immediately draw upon the Letter of Credit and hold the proceeds as a cash
     security deposit under this Lease. Any such Letter of Credit shall be for a
     term of two (2) years (or for one (1) year if the issuer thereof regularly
     and customarily only issues letters of credit for a maximum term of one (1)
     year) and shall in either case provide for automatic one (1) year renewals
     through the date which is ninety (90) days subsequent to the scheduled
     expiration of this Lease (as the same may be extended) or if the issuer
     will not grant automatic renewals, the Letter of Credit shall be renewed by
     Tenant each year and each such renewal shall be delivered to and received
     by Landlord not later than thirty (30) days before the expiration of the
     then current Letter of Credit (herein called a "Renewal Presentation
     Date"). In the event of a failure to so deliver any such renewal Letter of
     Credit on or before the applicable Renewal Presentation Date, Landlord
     shall be entitled to present the then existing Letter of Credit for payment
     and to receive the proceeds thereof, which proceeds shall be held as
     Tenant's security deposit, subject to the terms of this Section 8.21. Any
     failure or refusal of the issuer to honor the Letter of Credit shall be at
     Tenant's sole risk and shall not relieve Tenant of its obligations
     hereunder with regard to the security deposit. Upon the occurrence of any
     Event of Default, Landlord shall have the right from time to time without
     prejudice to any other remedy Landlord may have on account thereof, to draw
     on all or any portion of such deposit held as a Letter of Credit and to
     apply the proceeds of such Letter of Credit or any cash held as such
     deposit, or any part thereof, to Landlord's damages arising from such Event
     of Default on the part of Tenant under the terms of this Lease. If Landlord
     so applies all or any portion of such deposit, Tenant shall within seven
     (7) days after notice from Landlord deposit cash with Landlord in an amount
     sufficient to restore such deposit to the full amount stated in this
     Section 8.21. While Landlord holds any cash deposit Landlord shall have no
     obligation to pay interest on the same and shall have the right to
     commingle the same with Landlord's other funds. Neither the holder of a
     mortgage nor the Landlord in a ground lease on property which includes the
     Premises shall ever be responsible to Tenant for the return or application
     of any such deposit, whether or not it succeeds to the position of Landlord
     hereunder, unless such deposit shall have been received in hand by such
     holder or ground Landlord.

     (B) Landlord shall return the security deposit to Tenant in accordance with
     the schedule set forth below (or if such deposit is in the form of a Letter
     of Credit, Landlord


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     shall either exchange the Letter of Credit for a Letter of Credit delivered
     by Tenant which reduces the amount secured by the Letter of Credit by the
     amount stated below and otherwise in strict conformity with the
     requirements herein or accept and consent to an amendment to the existing
     Letter of Credit which reduces the amount thereof to the amount required
     below) if as of each Scheduled Reduction Date set forth below (i) Tenant
     has met the corresponding Total Stockholder Equity Threshold and Prior
     Twelve Month Total Revenue Threshold, (ii) Tenant is not then in default
     under the terms of this Lease without the benefit of notice or grace
     (provided that such return or reduction shall be made upon the curing of
     any such default), and (iii) there have been no more than four (4) monetary
     and other material Event of Default occurrences during the Term
     (subsections (i), (ii) and (iii) being hereinafter referred to as the
     "Reduction Conditions").

<TABLE>
<CAPTION>
Scheduled Reduction                          Remaining      Total Stockholder      Prior Twelve Month
        Date          Reduction Amount   Security Deposit    Equity Threshold   Total Revenue Threshold
-------------------   ----------------   ----------------   -----------------   -----------------------
<S>                   <C>                <C>                <C>                 <C>
3/1/10                   $250,000.00       $1,750,000.00     $ 99,800,000.00        $250,000,000.00
3/1/11                   $250,000.00       $1,500,000.00     $104,800,000.00        $250,000,000.00
3/1/12                   $250,000.00       $1,250,000.00     $110,000,000.00        $275,000,000.00
3/1/13                   $250,000.00       $1,000,000.00     $115,500,000.00        $275,000,000.00
3/1/14                   $250,000.00       $  750,000.00     $121,300,000.00        $300,000,000.00
3/1/15                   $250,000.00       $  500,000.00     $127,400,000.00        $300,000,000.00
</TABLE>

     If Tenant believes that it has satisfied all of the Reduction Conditions,
     then it shall request such reduction in writing to Landlord, which request
     shall certify to Landlord that all such Reduction Conditions have been
     satisfied and shall be accompanied by appropriate documentation evidencing
     the same. If Landlord determines that all of the Reduction Conditions are
     met, the security deposit shall be so reduced in accordance with this
     Section 8.21(B). No Letter of Credit shall automatically reduce, but any
     reduction in the amount thereof shall require Landlord's prior written
     notice or consent to the issuer of the Letter of Credit of the reduced
     amount. Promptly after Landlord's receipt of Tenant's request for a
     reduction as described above, Landlord shall determine whether such a
     reduction is permitted in accordance with this Section 8.21(B), and if it
     is, Landlord shall notify the issuer of the Letter of Credit of the amount
     to which the Letter of Credit shall be reduced.

     In connection with the foregoing, it is understood and agreed that:

          (i)  The Total Stockholder Equity and Prior Twelve Month Total Revenue
               shall be determined based on the information contained in the
               audited


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<PAGE>

               annual financial statements set forth in Tenant's Form 10-K
               Annual Report filed with the Securities and Exchange Commission
               for the most recent fiscal year immediately preceding the
               Scheduled Reduction Date at issue (it being understood and agreed
               that if Tenant ceases to be a publicly-held company whose shares
               are traded on a national stock exchange, Tenant shall provide
               Landlord with a certified copy of its most recent audited annual
               financials statements at the time it submits its request for
               reduction as set forth above, and the foregoing thresholds or
               their reasonable equivalents shall be determined based on such
               audited annual financial statements).

          (ii) To the extent that Tenant fails to meet the applicable Total
               Stockholder Equity Threshold and/or Prior Twelve Month Total
               Revenue Threshold for a given Scheduled Reduction Date, such
               Scheduled Reduction Date and all of the Scheduled Reduction Dates
               thereafter shall be postponed for one (1) year. By way of
               example, if on March 1, 2010 Tenant does not have $99,800,000.00
               in Total Stockholder Equity and $250,000,000.00 in Prior Twelve
               Month Total Revenue, Tenant shall not be entitled to a return of
               a $250,000.00 portion of the security deposit until March 1, 2011
               (assuming the foregoing thresholds have been met) and on March 1,
               2012 Tenant shall be entitled to a return of another $250,000.00
               portion of the security deposit only if it has $104,800,000.00 in
               Total Stockholder Equity and $250,000,000.00 in Prior Twelve
               Month Total Revenue.

     Any disputes under this Section 8.21(B) as to whether or not the Reduction
     Conditions have been satisfied may be resolved by arbitration under Section
     8.31 below.

     (C) Tenant not then being in default and having performed all of its
     obligations under this Lease, including the payment of all Annual Fixed
     Rent, Landlord shall return the deposit, or so much thereof as shall not
     have theretofore been applied in accordance with the terms of this Section
     8.21, to Tenant on the expiration or earlier termination of the term of
     this Lease (as the same may have been extended) and surrender possession of
     the Premises by Tenant to Landlord in the condition required in the Lease
     at such time.

8.22 Late Payment

     If Landlord shall not have received any payment or installment of Annual
     Fixed Rent or Additional Rent (the "Outstanding Amount") on or before the
     date on which the same first becomes payable under this Lease (the "Due
     Date"), the amount of such payment or installment shall incur a late charge
     equal to the sum of: (a) three percent (3%) of the Outstanding Amount for
     administration and bookkeeping costs associated with the late payment and
     (b) interest on the Outstanding Amount from the Due Date through and
     including the date such payment or installment is received by Landlord, at
     a rate (the "Default Rate") equal to the lesser of (i) the rate announced
     by Bank of America, N.A. (or its successor) from time to time as its prime
     or base rate (or if such rate is no longer available, a comparable rate
     reasonably selected by Landlord), plus two percent (2%), or


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<PAGE>

     (ii) the maximum applicable legal rate, if any. Such interest shall be
     deemed Additional Rent and shall be paid by Tenant to Landlord upon demand.
     Landlord agrees to waive the late charge due hereunder for the first late
     payment by Tenant under this Lease per calendar year provided that Landlord
     receives such payment from Tenant within five (5) business days after the
     Due Date.

8.23 Tenant's Payments

     Each and every payment and expenditure, other than Annual Fixed Rent, shall
     be deemed to be Additional Rent or additional rent hereunder, whether or
     not the provisions requiring payment of such amounts specifically so state,
     and shall be payable, unless otherwise provided in this Lease, within ten
     (10) days after written demand by Landlord, and in the case of the
     non-payment of any such amount, Landlord shall have, in addition to all of
     its other rights and remedies, all the rights and remedies available to
     Landlord hereunder or by law in the case of non-payment of Annual Fixed
     Rent. Unless expressly otherwise provided in this Lease, the performance
     and observance by Tenant of all the terms, covenants and conditions of this
     Lease to be performed and observed by Tenant shall be at Tenant's sole cost
     and expense. If Tenant has not objected to any statement of Additional Rent
     which is rendered by Landlord to Tenant within ninety (90) days after
     Landlord has rendered the same to Tenant (or such longer period of time as
     provided to Tenant under Section 2.6.1 above to the extent that the item of
     Additional Rent in question is covered by Tenant's audit rights as set
     forth in said Section 2.6.1), then the same shall be deemed to be a final
     account between Landlord and Tenant not subject to any further dispute. In
     the event that Tenant shall seek Landlord's consent or approval under this
     Lease, then Tenant shall reimburse Landlord, upon demand, as Additional
     Rent, for all reasonable costs and expenses, including legal and
     architectural costs and expenses, incurred by Landlord in processing such
     request, whether or not such consent or approval shall be given.

8.24 Waiver of Trial By Jury

     Landlord and Tenant each hereby waive any right to trial by jury in any
     action, proceeding or counterclaim brought by either Landlord or Tenant on
     any matters whatsoever arising out of or any way connected with this Lease,
     the relationship of the Landlord and the Tenant, the Tenant's use or
     occupancy of the Premises and/or any claim of injury or damage, including
     but not limited to, any summary process eviction action.

8.25 Governing Law

     This Lease shall be governed exclusively by the provisions hereof and by
     the law of the Commonwealth of Massachusetts without regard to conflict of
     law principles, as the same may from time to time exist.

8.26 Tenant's Equipment

     (A) Subject to the terms and provisions of this Section 8.26, Tenant shall
     be permitted


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     to install (x) telecommunications equipment, television antennas, related
     receiving equipment, related cable connections and other related
     telecommunications equipment (collectively, the "Telecom Equipment") and
     (y) HVAC equipment and any and all related equipment to accommodate
     Tenant's excess HVAC requirements (collectively, the "HVAC Unit") in a
     location or locations on the rooftop of any of the Buildings in which
     Tenant directly leases Premises from Landlord in an area to be mutually
     agreed upon the parties, provided that (i) such installation and the
     operation thereof shall not cause any measurable interference with any
     existing communication equipment in the Complex, and (ii) such installation
     does not adversely affect the structural elements or the visual aesthetic
     of the Buildings as determined by Landlord in its sole discretion. In
     addition, Landlord shall have the option upon notice to Tenant to relocate
     the Telecom Equipment and/or the HVAC Unit to other areas on the rooftop of
     the Buildings at Landlord's sole cost and expense and so long as such
     relocation does not materially adversely affect Tenant's use of the
     Premises. Tenant shall have no right to license, sublease, assign or
     otherwise transfer its rights to install and use Telecom Equipment and the
     HVAC Unit on the Buildings and/or the Site (other than to an assignee or
     subtenant permitted or consented to under this Lease). Landlord hereby
     reserves the right (at its sole discretion) to install and to permit others
     to install, use and maintain telecommunications equipment, antennas and
     similar installations on the rooftop of the Buildings and elsewhere on the
     Site provided that any agreement with a third party granting the right to
     install telecommunications equipment subsequent to the Commencement Date
     hereof shall contain language prohibiting interference with Tenant's
     Telecom Equipment then existing and shall provide Landlord with a
     termination right if such interference is not remedied after a reasonable
     period of time. If measurable interference shall occur, Tenant shall
     provide notice thereof to Landlord and Landlord shall use reasonable
     efforts to cause the same to be remedied, however, if despite such efforts
     the same are not remedied within a period reasonably necessary to cure such
     interference, Landlord shall exercise the termination right set forth in
     its agreement with such interfering party.

     (B) Subject to the provisions of this Section 8.26, Tenant shall have the
     right to install a generator, related connections and a diesel fuel tank or
     similar fuel storage compartment (collectively, the "Generator") in an area
     on the Site to be mutually agreed upon by Landlord and Tenant (it being
     understood and agreed that the Generator may not be installed on the roof
     of any of the Buildings or on Land Recreation Area B, as that term is
     defined in Section 8.27 below).

     (C) Tenant's use of the Telecom Equipment, the HVAC Unit and the Generator
     (collectively, the "Tenant's Equipment") shall be upon all of the
     conditions of the Lease, except as modified below:

     (i)  It is understood and agreed that Tenant shall be responsible, at its
          sole cost and expense, for installing the Tenant's Equipment. In
          addition to complying with the applicable construction provisions of
          this Lease, Tenant shall not install or operate any portion of the
          Tenant's Equipment until Tenant shall have obtained Landlord's prior
          written approval, which approval will not be unreasonably


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<PAGE>

          withheld or delayed, of Tenant's plans and specifications therefor.
          Landlord shall inform Tenant at the time of its review of the plans
          and specifications for the Generator whether Landlord will require the
          same to be removed by Tenant upon the expiration or earlier
          termination of this Lease.

     (ii) Landlord shall have no obligation to provide any services to the
          Tenant's Equipment, provided Tenant shall have the right to connect
          Tenant's Equipment to existing base building utility systems, subject
          to Landlord's right to reasonably approve such connections. Tenant
          shall, at its sole cost and expense and otherwise in accordance with
          the provisions of this Section 8.26, arrange for all utility services
          required for the operation of the Tenant's Equipment.

     (iii) Tenant shall have no right to make any changes, alterations or other
          improvements to the Tenant's Equipment without Landlord's prior
          written consent, which consent shall not be unreasonably withheld or
          delayed; provided, however, that Tenant shall have the right to
          maintain and make repairs to the Tenant's Equipment.

     (iv) Tenant shall be responsible for the cost of repairing any damage to
          the Complex caused by the installation, use and removal of the
          Tenant's Equipment.

     (v)  Except for assignees of this Lease or subtenants of all or a portion
          of the Premises, no other person, firm or entity (including, without
          limitation, other tenants, licensees or occupants of the Complex)
          shall have the right to connect to the Tenant's Equipment other than
          Tenant.

     (vi) To the maximum extent permitted by law, Tenant's use of the Tenant's
          Equipment shall be at the sole risk of Tenant, and Landlord shall have
          no liability to Tenant in the event that the Tenant's Equipment is
          damaged for any reason.

     (vii) Landlord shall have the right, upon no less than ninety (90) days
          notice to Tenant and at Landlord's sole cost and expense, to relocate
          portions of the Tenant's Equipment to another area within the Complex
          reasonably acceptable to Tenant. Landlord and Tenant shall cooperate
          with each other in good faith to schedule such relocation work on
          nights and weekends so as to minimize interference with Tenant's
          business operations. Any such relocation by Landlord shall not
          independently (i.e., in the absence of another cause) be deemed to
          constitute a failure of electric supply under Section 4.2(C) above.

     (viii) In addition to the indemnification provisions set forth in this
          Lease (which shall be applicable to the Tenant's Equipment), Tenant
          shall, to the maximum extent permitted by law, indemnify, defend, and
          hold Landlord, its agents, contractors and employees harmless from any
          and all claims, losses, demands, actions or causes of actions suffered
          by any person, firm, corporation, or other entity arising from the
          installation, use or removal of the Tenant's Equipment.


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<PAGE>

     (C) Tenant shall, at its sole cost and expense, secure the approvals of all
     governmental authorities and all permits required by governmental
     authorities having jurisdiction over such approvals for the Tenant's
     Equipment, and shall provide Landlord with copies of such approvals and
     permits prior to commencing any work with respect thereto. In addition,
     Tenant shall be solely responsible for all costs and expenses in connection
     with the installation, maintenance, use and removal of the Tenant's
     Equipment, except that Tenant will not be obligated to pay Landlord any
     rental for that portion of the Buildings and/or the Site on which the
     Tenant's Equipment is located. In connection therewith, Tenant shall
     provide Landlord with evidence on an annual basis of the existence of a
     maintenance contract for the Generator with a service provider reasonably
     acceptable to Landlord. Tenant shall have access to those portions of the
     Buildings and/or the Site on which the Tenant's Equipment is located for
     the purposes of inspecting, repairing, maintaining and replacing the same,
     subject in all events to Landlord's reasonable rules and regulations
     regarding such access (it being understood and agreed, without limiting the
     generality of the foregoing, that access to the rooftops of the Buildings
     is controlled by Landlord).

8.27 Land Recreation Space

     (A) For so long as (i) Tenant directly leases from Landlord at least
     150,000 square feet of rentable floor area, (ii) there have been no more
     than four (4) monetary or other material Event of Default occurrences
     during the Term, (iii) this Lease is still in full force and effect, and
     (iv) Tenant has not assigned this Lease (except for an assignment under
     Section 5.6.1 above or any occupancy permitted under Section 5.6.6 above),
     Tenant shall have the exclusive right to use the portion of the Site shown
     on Exhibit I-1 attached hereto (such area being hereinafter referred to as
     "Land Recreation Area A") for the Permitted Uses of the Additional Land
     Areas set forth in Section 1.1. Landlord agrees, at its sole cost and
     expense, to construct a fence and gate in the areas shown on Exhibit I-1 to
     segregate Land Recreation Area A from the remainder of the parking area in
     that portion of the Complex.

     Notwithstanding the foregoing, in the event that Tenant shall cease to
     directly lease Building E in its entirety but shall continue to directly
     lease Buildings C and D in their entirety, Tenant shall have the right to
     use only that portion of Land Recreation Area A as shown on Exhibit I-1
     attached hereto as the "Reduced Land Recreation Area A" for the purposes
     described in this Section 8.27 (it being understood and agreed that (x) the
     remainder of Land Recreation Area A may be used by Landlord for any purpose
     so long as Tenant is still provided with access to the Reduced Land
     Recreation Area A and (y) Landlord shall at its sole cost and expense
     construct or relocate a fence and gate to segregate Reduced Land Recreation
     Area A from the remainder of Land Recreation Area A).

     (B) (1) For so long as (i) Tenant directly leases from Landlord at least
     75,000 square feet of rentable floor area, (ii) there have been no more
     than four (4) monetary or other material Event of Default occurrences
     during the Term, (iii) this Lease is still in full force and effect, and
     (iv) Tenant has not assigned this Lease (except for an assignment


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     under Section 5.6.1 above or a permitted occupancy under Section 5.6.6
     above), Tenant shall have the exclusive right to use the area adjacent to
     the Site shown on Exhibit I-2 attached hereto (such area being hereinafter
     referred to as "Land Recreation Area B" and collectively with Land
     Recreation Area A as the "Additional Land Areas") for the Permitted Uses of
     the Additional Land Areas set forth in Section 1.1. Notwithstanding the
     foregoing, in the event that Tenant shall meet the requirements of
     subsections (ii) - (iv) above but shall directly lease from Landlord less
     than 75,000 square feet of rentable floor area, Tenant shall still have the
     right to use Land Recreation Area B on an exclusive basis but Tenant shall
     be required to pay to Landlord, as Additional Rent, its pro rata share of
     the rent payable to MHD under the MHD Lease (as those terms are defined in
     subsection (B)(2) below) in the inverse proportion that the rentable floor
     area of the remainder of the Premises then leased by Tenant bears to the
     Rentable Floor Area of the Premises originally set forth in Section 1.1
     above (e.g., if Tenant is directly leasing 50,000 square feet of rentable
     floor area, then Tenant shall pay two-thirds of the rent associated with
     the MHD Lease).

     (2) In connection with the foregoing, it is understood and agreed that Land
     Recreation Area B is located on property owned by the Massachusetts Highway
     Department ("MHD") and is the subject of a lease (the "MHD Lease") between
     MHD and Landlord, a copy of which is attached hereto as Exhibit J. On or
     before the Commencement Date, Landlord shall, at Landlord's sole cost and
     expense, install a fence around Land Recreation Area B of a type, quality
     and in a location selected by Landlord (it being understood and agreed that
     if Tenant wants to install additional screening, it shall be done at
     Tenant's sole cost and expense and shall be undertaken in accordance with
     the terms and provisions of the MHD Lease). Tenant acknowledges and agrees
     that the MHD Lease provides, among other things, for a term of five (5)
     years with one (1) five (5) year renewal option, and accordingly that the
     term of the MHD Lease will expire prior to the expiration of the Original
     Term of this Lease (Landlord making no representation about its ability to
     negotiate for any further extension of the MHD Lease beyond the original
     5-year term and 5-year extension option period). Tenant shall have the
     right to direct Landlord to exercise or not exercise the renewal option
     available to Landlord under the MHD Lease; provided, however, that if
     Tenant directs Landlord not to exercise the renewal option, Landlord shall
     nonetheless have the right to exercise the same, in which event (x) Tenant
     shall have no right to use Land Recreation Area B under this Section 8.28
     from and after the expiration of the initial lease term under the MHD Lease
     and (y) Tenant shall not be required to pay any costs and expenses
     associated with Land Recreation Area B as part of Landlord's Operating
     Expenses Allocable to the Premises or otherwise (unless and only to the
     extent that Land Recreation Area B is used as a parking area serving the
     tenants of the Complex and the costs of maintaining the same are chargeable
     to the tenants of the Complex as a part of Landlord's Operating Expenses
     under Section 2.6 above). For so long as Tenant shall have the right to use
     Land Recreation Area B and shall actually be using the same in accordance
     with the terms and provisions of this Section 8.27 (B), Landlord covenants
     and agrees: (i) to comply with all of the terms and obligations of
     Landlord, as tenant, under the MHD Lease; (ii) not to act or omit to act in
     any manner that would result in a default of Landlord, as tenant, under the
     MHD Lease; and (iii) not to voluntarily terminate or


                                       98
<PAGE>

     surrender the MHD Lease without Tenant's prior written consent, which
     consent shall be in Tenant's sole and unfettered discretion. Tenant
     covenants and agrees not to use Land Recreation Area B in any manner that
     would be in violation of the terms and provisions of the MHD Lease or would
     cause Landlord to be in default of its obligations thereunder (it being
     understood and agreed that Landlord shall in no way be liable to Tenant for
     any breach of the covenants of Landlord set forth in the immediately
     preceding sentence or in the event that the MHD Lease is terminated as the
     result of any failure by Tenant to comply with the terms and provisions of
     the MHD Lease as applicable to Tenant's use of Land Recreation Area B).

     (3) In the event that Tenant is prevented from using (and in fact ceases to
     use) Land Recreation Area B as the result of either (x) a default by MHD
     under the MHD Lease or (y) a casualty or taking affecting Land Recreation
     Area B, Landlord shall use commercially reasonable efforts to enforce the
     terms of the MHD Lease. To the extent that the foregoing condition
     continues for a period of more than thirty (30) days and that Landlord is
     no longer required to make payments to MHD under the MHD Lease on account
     thereof, Landlord shall pay to Tenant an amount equal to the monthly
     payment Landlord would have otherwise been required to pay under the MHD
     Lease for each month for the period from and after the thirty-first (31st)
     day that Tenant is unable to use Land Recreation Area B as aforesaid until
     the first to occur of such time as (1) the condition causing the same has
     been cured, (2) Landlord has obtained rights to an alternative parcel of
     land to be substituted for Land Recreation Area B (as set forth below) or
     (3) Tenant has terminated this Lease (as set forth below).

     In addition, if Tenant is prevented from using (and in fact ceases to use)
     Land Recreation Area B as the result of the circumstances described in
     subsections (x) or (y) of the immediately preceding paragraph for a period
     of eleven (11) consecutive months after Landlord's receipt of written
     notice of such condition from Tenant, then Tenant may terminate this Lease
     by giving Landlord written notice as follows:

          (i)  Said notice shall be given after said eleven (11) month period.

          (ii) Said notice shall set forth an effective date which is not
               earlier than thirty (30) days after Landlord receives said
               notice.

          (iii) If said condition is remedied on or before the date thirty (30)
               days after the receipt of such notice, said notice shall have no
               further force and effect.

          (iv) If said condition is not remedied on or before the date thirty
               (30) days after the receipt of such notice, this Lease shall
               terminate as of said effective date, and the Annual Fixed Rent
               and Additional Rent due under this Lease shall be apportioned as
               of said effective date.

     Notwithstanding the foregoing, Tenant shall have no right to terminate this
     Lease in the event that Landlord has made available to Tenant another
     parcel of land consisting of one and one-half (1 1/2) acres or more and
     located within a ten (10) mile radius of the


                                       99
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     Complex, which may be used by Tenant for all of the same purposes as Land
     Recreation Area B hereunder (Landlord hereby acknowledging that Landlord
     shall be solely responsible for all costs associated with obtaining the
     rights to such alternative parcel, notwithstanding that such costs may
     exceed what would have been payable under the MHD Lease, provided that
     Tenant shall still be responsible for any costs that Landlord is otherwise
     entitled to pass through to Tenant on account of Land Recreation Area B in
     accordance with Section 2.6 above). In the event any zoning relief or
     changes need to be obtained for such alternate land in order to permit
     Tenant's use of the same for the same purposes as Land Recreation Area B,
     Landlord shall be responsible, at Landlord's sole cost and expense, for
     obtaining any and all of such necessary zoning relief and/or changes.

     The remedies set forth in this Section 8.27(B)(3) shall be Tenant's sole
     remedies for the events described herein.

     (C) Landlord shall deliver possession of the Additional Land Areas in the
     condition required under this Lease to Tenant in the condition required by
     this Lease on or before the Commencement Date. Except as expressly provided
     in subsection (B) above, Tenant shall not be required to pay any rent or
     use and occupancy charge with respect to the Additional Land Areas
     (provided, however, that Tenant shall be required to pay all maintenance
     costs and real estate taxes associated therewith as part of Operating
     Expenses Allocable to the Premises under Section 2.6 above). The Additional
     Land Areas shall be deemed to be a part of the Premises for the purposes of
     the covenants and agreements of Tenant under Article V of this Lease;
     provided, however, that Tenant shall not have the right to assign its
     rights under this Section 8.27 or to sublease all or any portion of the
     Additional Land Areas, other than in connection with an assignment or
     sublease under Section 5.6.1 above or a permitted occupancy under Section
     5.6.6 above. Without limiting the generality of the foregoing, it is
     expressly understood and agreed that the indemnification provisions of
     Section 5.7 of this Lease shall be deemed to include any claims,
     liabilities, damages and expenses, including reasonable attorney's fees,
     relating to, or claimed to relate to, Tenant's use of the Additional Land
     Areas (including, without limitation, any claims that may arise under the
     MHD Lease). In addition, in the event that Tenant shall cease to meet the
     respective requirements set forth in subsections (A) and (B) above,
     Landlord shall have the right to require Tenant to discontinue its use of
     Land Recreation Area A and/or Land Recreation Area B, as applicable, and to
     yield up such area to Landlord in the condition required by Section 5.2
     above (provided, however, that Tenant shall not have any obligation to
     remove any pavement or fences installed by or on behalf of Tenant in either
     of the Additional Land Areas, so long as Tenant delivers such areas to
     Landlord in a level condition).

8.28 Tenant's Expansion Rights: Buildings F, G and H

     (A) On the conditions (which conditions Landlord may waive by written
     notice to Tenant at any time), that as of both the time that any portion of
     the RFO Premises (as hereinafter defined) becomes available for reletting
     (as hereinafter defined) and as of the commencement date of Tenant's
     leasing of such portion of the RFO Premises: (i) Tenant


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<PAGE>

     directly leases from Landlord at least 75,000 square feet of rentable floor
     area, (ii) no monetary or other material Event of Default of Tenant exists
     and there have been no more than two (2) monetary or other material Event
     of Default occurrences during the Lease Term, (iii) this Lease is still in
     full force and effect, and (iv) Tenant has neither assigned this Lease nor
     sublet more than fifty percent (50%) of the Total Rentable Floor Area of
     the Buildings (except for an assignment or sublease under Section 5.6.1
     above or an occupancy permitted pursuant to Section 5.6.6 above), Tenant
     shall have a right of first offer ("Right of First Offer") to lease the RFO
     Premises, as hereinafter defined.

     For the purposes hereof, the "RFO Premises" shall be defined as any and all
     space in Buildings F, G and H of the Complex as and when such space becomes
     available for reletting (as hereinafter defined); provided, however, that
     Landlord shall have the right to reconfigure portions of the RFO Premises
     (e.g. to subdivide an existing space or to combine several spaces to create
     one larger space) prior to offering the same to Tenant hereunder if in
     Landlord's reasonable judgment such reconfiguration is necessary or
     desirable to create a commercially rentable layout.

     (B) When any portion of the RFO Premises becomes available for reletting,
     as hereinafter defined, Landlord shall notify Tenant ("Landlord's RFO
     Premises Notice") of the availability of such space, which notice shall
     contain the size, configuration, location and date of availability of such
     RFO Premises, the Annual Market Rent, and the other business terms upon
     which Landlord is willing to so lease such space. The net effective rental
     rate set forth in Landlord's RFO Premises Notice expressed by the (i)
     Annual Market Rent for the RFO Premises quoted by Landlord, (ii) amount of
     Base Taxes and Base Operating Expenses, (iii) free rent or "build-out"
     period, if any, after the commencement of the lease term, (iv) tenant
     improvement allowance, if any, and (v) length of the lease term, shall
     hereinafter be referred to as "Landlord's Offered Rental Terms."

     For the purposes hereof:

          (1)  The "Annual Market Rent" shall be the annual fair market rent for
               such space as of the date when the same becomes available for
               reletting, based upon the use of such space as first class
               office/research and development space utilizing properties of
               similar character within the Boston Northwest Suburban Market.

          (2)  RFO Premises shall be deemed "available for reletting" when
               Landlord, in its sole judgment, determines that the then current
               tenant of the RFO Premises will vacate the RFO Premises at the
               expiration or earlier termination of such tenant's lease.

     In connection with the foregoing, it is understood and agreed that Tenant's
     rights under this Section 8.28 shall be subject and subordinate to the
     rights of the existing tenants in Buildings F, G and H as of the date of
     this Lease (the "Existing Tenants") as set forth on Exhibit O attached
     hereto (the terms of any leases with the Existing Tenants, including,


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<PAGE>

     but not limited to, the original terms thereof and options to extend the
     terms thereof contained in lease documents executed prior to the date
     hereof are hereinafter individually and collectively called the "Existing
     Leases").

     (C) If Tenant wishes to exercise Tenant's Right of First Offer, Tenant
     shall do so, if at all, by giving Landlord notice ("Tenant's RFO Exercise
     Notice") of Tenant's desire to lease either:

          (i)  the entire amount of space designated in Landlord's RFO Premises
               Notice; or

          (ii) in the case of Building F only, a portion of the space designated
               in Landlord's RFO Premises Notice containing not less than 10,000
               contiguous rentable square feet of floor area of the RFO
               Premises; or

          (iii) in the event that Landlord designates the entirety of Building
               G, a portion thereof consisting of one (1) full floor of the
               Building; or

          (iv) in the event that Landlord designates the entirety of Building H,
               a portion thereof consisting of one (1) full floor of the
               Building.

     within ten (10) business days after receipt of Landlord's RFO Premises
     Notice, time being of the essence. Tenant shall in Tenant's RFO Exercise
     Notice specify whether it shall be leasing the applicable portion of the
     RFO Premises for (1) the lease term specified in Landlord's RFO Premises
     Notice or (2) a lease term that is coterminous with the Term of this Lease
     with respect to the original Premises (it being understood and agreed that
     if less than thirty-six (36) months then remain in the Lease Term at the
     time Tenant delivers the Tenant's RFO Exercise Notice and Tenant desires
     that the lease term with respect to the RFO Premises be coterminous with
     the Lease Term with respect to the original Premises and if such period is
     shorter than the lease term offered in Landlord's RFO Premises Notice,
     Tenant must simultaneously exercise its extension option under Section 8.20
     with its exercise of its rights under this Section 8.28 and that if no such
     extension option is then available to Tenant then the term with respect to
     the RFO Premises shall automatically be as specified in Landlord's RFO
     Premises Notice) (the lease term as determined under subsection (1) or (2)
     being hereinafter referred to as the "Designated RFO Lease Term"). In the
     event that Tenant shall elect to lease less than the entirety of the space
     designated in Landlord's RFO Notice in accordance with subsections (ii),
     (iii) and/or (iv) above, (x) the part of the RFO Premises not accepted by
     Tenant shall be in a commercially rentable configuration, (y) Tenant shall
     pay all costs and expenses associated with subdividing and separately
     physically demising the portion of the RFO Premises accepted by Tenant from
     the remainder of the RFO Premises and (z) Tenant acknowledges that the
     rentable floor area of the portion of the RFO Premises accepted by it and
     other economic terms associated therewith may be reasonably adjusted based
     on the conversion of the Building from a single-tenant to a multi-tenant
     building. In addition to the requirements set forth in the immediately
     preceding sentence, in the


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     event that Landlord has offered the entirety of Building H to Tenant and
     Tenant exercises its rights hereunder only with respect to one (1) full
     floor of Building H in accordance with subsection (iv) above, Landlord
     shall have a period of ninety (90) days from the date of Tenant's RFO
     Exercise Notice to negotiate with prospective third-party tenants for a
     lease of the entirety of Building H and if Landlord shall sign a letter of
     intent with a third-party tenant for the entirety of Building H within said
     ninety (90) day period, then Tenant's RFO Exercise Notice shall be deemed
     null and void and of no further force or effect (it being understood and
     agreed that if Landlord shall not sign a letter of intent with a
     third-party tenant for the entirety of Building H within said ninety (90)
     day period, then Tenant shall proceed to lease the portion of Building H
     designated in Tenant's RFO Exercise Notice in accordance with the terms and
     provisions of this Section 8.28).

     If Tenant shall give a Tenant's RFO Exercise Notice the same shall
     constitute an agreement to enter into an instrument in writing to lease the
     RFO Premises identified in Tenant's RFO Exercise Notice within a reasonable
     time period after receipt of a first draft of such amendment to this Lease
     adding the RFO Premises to the Premises upon all of the same terms and
     conditions in this Lease, except to the extent inconsistent with the
     provisions of this Section and except that (x) the Annual Fixed Rent shall
     be equal to the Annual Market Rent as quoted by Landlord, (y) the lease
     term with respect to the RFO Premises shall be the Designated RFO Lease
     Term, and (z) the lease amendment shall also reflect such other business
     terms as were set forth in Landlord's RFO Premises Notice.

     (D) If Tenant shall not timely exercise its rights under this Section 8.28
     within such period (or if Tenant shall timely exercise such right to lease
     only with respect to a portion of the RFO Premises in accordance with the
     provisions of subsections (C)(ii), (iii) and (iv) above), time being of the
     essence in respect to such exercise, Landlord shall be free to lease the
     RFO Premises (or that portion of the RFO Premises not accepted by Tenant in
     Tenant's RFO Exercise Notice in accordance with the provisions of
     subsections (C)(ii), (iii) and (iv) above) for two hundred seventy (270)
     days after the date of Landlord's RFO Premises Notice for a net effective
     rental rate which is not less than 90% of Landlord's Offered Rental Terms
     contained in Landlord's RFO Premises Notice without again offering such
     space to Tenant for lease; provided, however, that (i) Landlord shall
     reoffer the applicable RFO Premises to Tenant in accordance with the terms
     and provisions of this Section 8.28 if (a) Landlord does not so lease such
     space during such two hundred seventy (270) day period, or (b) if Landlord
     proposes to lease such space in larger or smaller increments, or (c) if
     Landlord proposes to lease such space during such two hundred seventy (270)
     day period for a net effective rental rate which is less than 90% of
     Landlord's Offered Rental Terms contained in Landlord's RFO Premises
     Notice, and (ii) the terms of this Section 8.28 shall continue to apply to
     the remainder of the RFO Premises, if any, not included in Landlord's RFO
     Premises Notice and to RFO Premises included in Landlord's RFO Premises
     Notice and not leased by Tenant which is subsequently leased to another
     tenant in accordance with this Section 8.28 and thereafter becomes
     available for reletting.

     (E) If Tenant shall exercise any such Right of First Offer and if,
     thereafter, the then


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<PAGE>

     occupant of the RFO Premises with respect to which Tenant shall have so
     exercised such right wrongfully fails to deliver possession of such
     premises at the time when its tenancy is scheduled to expire, Landlord
     shall use reasonable efforts and due diligence (which shall be limited to
     the commencement and prosecution of eviction proceeding within sixty (60)
     days after the date on which the hold-over commences, but shall not require
     the taking of any appeal) to evict such occupant from such space and to
     recover from such occupant any Hold-Over Premium (as defined below) payable
     by such occupant. In such event, the commencement of the term of Tenant's
     occupancy and lease of such additional space shall, in the event of such
     holding over by such occupant, be deferred until possession of the
     additional space is delivered to Tenant. The failure of the then occupant
     of such premises to so vacate shall not constitute a default or breach by
     Landlord and shall not give Tenant any right to terminate this Lease or to
     deduct from, offset against or withhold Annual Fixed Rent or Additional
     Rent (or any portions thereof); except that if such hold over exceeds sixty
     (60) days, then Tenant may cancel the exercise of its option to lease such
     portion of the RFO Premises by giving to Landlord a written cancellation
     notice (provided, however, that if Landlord delivers such RFO Premises to
     Tenant on or before the date thirty (30) days after Landlord receives such
     cancellation notice, such cancellation notice shall be void and without
     further force or effect).

     Alternatively, in lieu of canceling the exercise of such option, Tenant
     shall have the right to require Landlord to pay to Tenant the net (i.e. net
     of the costs and expenses, including, attorneys' fees, incurred by Landlord
     in obtaining such Hold-Over Premium) amount of any Hold-Over Premium
     received by Landlord from such hold-over occupant relative to periods from
     and after the sixty-first (61st) day of any hold-over, when and if Landlord
     receives any such payment. For the purposes hereof, the term "Hold-Over
     Premium" shall be defined as the amount (if any) which a hold-over occupant
     of any portion of the RFO Premises is required to pay to Landlord in
     respect of its hold-over in the premises (whether characterized as rent,
     damages, or use and occupation) in excess of the amount of fixed rent and
     other charges which the tenant under whom such occupant claims would have
     been required to pay to Landlord had the term of such tenant's lease been
     extended throughout the period of such hold-over at the same rental rate as
     such tenant was required to pay during the last month of its tenancy.

     In the event that Tenant elects to cancel its exercise of its option
     hereunder as the result of a holding over by the existing occupant of the
     applicable portion of the RFO Premises, Landlord shall reoffer the space to
     Tenant at such time as the hold-over tenant is evicted from the space upon
     the same terms and conditions as set forth in Tenant's RFO Exercise Notice
     with respect to such space (and otherwise in accordance with the terms and
     provisions of this Section 8.28).

     (F) Landlord shall use reasonable efforts to keep Tenant informed with
     semi-annual written updates of the expected availability of the leaseable
     areas in Buildings F, G and H; provided, however, that Landlord's failure
     to provide such updates shall in no way be deemed to be a default of
     Landlord under this Lease or otherwise give rise to any liability on
     Landlord's part.


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8.29 Tenant's Expansion Rights: Buildings A and B

     (A) As long as (i) Tenant directly leases from Landlord at least 150,000
     square feet of rentable floor area, (ii) no monetary or other material
     Event of Default of Tenant exists and there have been no more than two (2)
     monetary or other material Event of Default occurrences during the Lease
     Term, (iii) this Lease is still in full force and effect, and (iv) Tenant
     has neither assigned this Lease nor sublet all or any portion of the
     Premises (except for an assignment or sublease under Section 5.6.1 above or
     any occupancy permitted pursuant to Section 5.6.6 above), Landlord agrees
     not to enter into a lease or letter of intent with a third party to lease
     all or any portion of Building B during the period commencing on the date
     of this Lease and expiring on March 31, 2008 (the "Lock-Out Period").

     (B) Landlord agrees that if at any time during the Term of this Lease from
     and after (i) the date hereof with respect to Building A and (ii) the
     expiration of the Lock-Out Period with respect to Building B, Landlord
     estimates that it will be entering into a letter of intent with a third
     party within fifteen (15) business days to lease all or any portion of
     Buildings A or B (the "First Refusal Space") then, provided that, (i)
     Tenant directly leases from Landlord at least 150,000 square feet of
     rentable floor area, (ii) there exists no monetary or other material Event
     of Default and there have been no more than two (2) monetary or other
     material Event of Default occurrences during the Term, (iii) this Lease is
     still in full force and effect and (iv) Tenant has neither assigned this
     Lease nor sublet more than twenty-five percent (25%) of the Total Rentable
     Floor Area of the Buildings of the Premises (except for an assignment or
     sublease permitted under Section 5.6.1 above or an occupancy permitted
     pursuant to Section 5.6.6 above), Landlord shall give notice of the
     availability of such space to Tenant and the business terms which Landlord
     is willing to lease such space to said third party tenant ("Landlord's
     Submitted Offer").

     (C) Tenant shall have the right to accept Landlord's Submitted Offer by
     giving Landlord notice ("Tenant's RFR Exercise Notice") of Tenant's
     acceptance within ten (10) business days after its receipt of Landlord's
     Submitted Offer and, if so accepted, Landlord and Tenant shall endeavor to
     execute, within thirty (30) days after Tenant's RFR Exercise Notice, an
     amendment to this Lease incorporating the First Refusal Space into the
     Premises upon the terms contained in Landlord's Submitted Offer and
     otherwise as substantially the same terms and conditions as contained in
     this Lease; provided, however, that the failure of the parties to so enter
     into such amendment with the aforesaid 30-day period shall not negate the
     exercise by Tenant of its rights under this Section 8.29 and Tenant shall
     be deemed to be leasing the applicable First Refusal Space on the terms and
     provisions set forth in Landlord's Submitted Offer.

     (D) If at the expiration of ten (10) business days after Tenant's receipt
     of Landlord's Submitted Offer, Tenant shall not have accepted Landlord's
     Submitted Offer by timely delivering Tenant RFR Exercise Notice, time being
     of the essence in respect to all of the same, Landlord shall be free for
     one hundred eighty (180) days after the date of Landlord's Submitted Offer
     to consummate a lease for the First Refusal Space subject to


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<PAGE>

     Landlord's Submitted Offer upon terms no less favorable to the Landlord
     than contained in Landlord's Submitted Offer without again offering such
     space to Tenant for lease, it being agreed that if Landlord does not so
     lease such First Refusal Space during such one hundred eighty (180) day
     period or if Landlord proposes to lease such First Refusal Space upon terms
     less favorable to Landlord than contained in Landlord's Submitted Offer
     during such one hundred eighty (180) day period, the terms of this Section
     shall continue to apply to such First Refusal Space subject to Landlord's
     Submitted Offer. The right under this Section 8.29 is granted to Tenant to
     become effective from time to time as and when Landlord anticipates leasing
     any First Refusal Space, and said right may become effective more than once
     during the Lease Term, as it may be extended.

     (E) If Tenant shall accept Landlord's Submitted Offer as provided above and
     if, thereafter, the then occupant of the space with respect to which Tenant
     shall have so accepted Landlord's Submitted Offer wrongfully fails to
     deliver possession of such space at the time when its tenancy is scheduled
     to expire, Landlord shall use reasonable efforts and due diligence (which
     shall be limited to the commencement and prosecution thereafter of eviction
     proceedings within sixty (60) days after the date on which the hold-over
     commences, but which shall not require the taking of any appeal) to evict
     such occupant from such additional space and to recover from such occupant
     any Hold-Over Premiums payable by such occupant. In such event,
     commencement of the term of Tenant's occupancy and lease of such additional
     space shall, in the event of such holding over by such occupant, be
     deferred until possession of such additional space is delivered to Tenant.
     The failure of the then occupant of such space to so vacate shall not give
     Tenant any right to terminate this Lease or to deduct from, offset against
     or withhold Annual Fixed Rent or Additional Rent (or any portions thereof);
     except that if such hold over exceeds sixty (60) days, then Tenant may
     cancel the exercise of its option to lease such portion of the First
     Refusal Space by giving to Landlord a written cancellation notice
     (provided, however, that if Landlord delivers such First Refusal Space to
     Tenant on or before the date thirty (30) days after Landlord receives such
     cancellation notice, such cancellation notice shall be void and without
     further force or effect).

     Alternatively, in lieu of canceling the exercise of such option, Tenant
     shall have the right to require Landlord to pay to Tenant the net (i.e. net
     of the costs and expenses, including, attorneys' fees, incurred by Landlord
     in obtaining such Hold-Over Premium) amount of any Hold-Over Premium
     received by Landlord from such hold-over occupant relative to periods from
     and after the sixty-first (61st) day of any hold-over, when and if Landlord
     receives any such payment.

     In the event that Tenant elects to cancel its exercise of its option
     hereunder as the result of a holding over by the existing occupant of the
     applicable portion of the First Refusal Space, Landlord shall reoffer the
     space to Tenant at such time as the hold-over tenant is evicted from the
     space upon the same terms and conditions as set forth in Landlord's
     Submitted Offer with respect to such space (and otherwise in accordance
     with the terms and provisions of this Section 8.29).


                                       106

<PAGE>

     (F) Landlord shall use reasonable efforts to keep Tenant informed with
     semi-annual written updates of the expected dates of availability of the
     leaseable areas in Buildings A and B; provided, however, that the failure
     of Landlord to provide such updates shall in no way be deemed to be a
     default of Landlord under this Lease or otherwise give rise to any
     liability on Landlord's part.

     (G) Notwithstanding anything contained in this Section 8.29 or in Section
     8.28 above to the contrary, in the event that Tenant directly leases from
     Landlord less than 150,000 square feet of rentable floor area but more than
     100,000 square feet of rentable floor area, Tenant shall no longer have a
     right of first refusal under this Section 8.29 with respect to Buildings A
     and B but such space shall thereafter become part of the RFO Premises under
     Section 8.28 above; provided, however, that in the event the entirety of
     Building A is offered to Tenant under Section 8.28, Tenant shall have the
     right to either accept Building A in its entirety or to accept only one
     full floor of Building A.

8.30 Waiver of Landlord's Lien

     From time to time upon Tenant's reasonable written request, Landlord agrees
     to furnish Tenant or any vendor or other supplier under any conditional
     sale, chattel mortgage or other security arrangement, any consignor, any
     holder of reserved title or any holder of a security interest, with a
     waiver of Landlord's lien upon Tenant's trade fixtures, furnishings, signs,
     equipment, machinery, inventory and personal property in or on the
     Premises, which such lien waiver shall be in the form attached hereto as
     Exhibit N.

8.31 Arbitration

     Any disputes (i) under Section 2.6.1 above as to whether Tenant has
     overpaid or underpaid Operating Expenses Allocable to the Premises and/or
     Landlord's Tax Expenses Allocable to the Premises relating to matters in
     excess of One Hundred Thousand and 00/100 Dollars ($100,000.00), (ii) under
     Section 8.17(B) above as to whether Landlord is required to reimburse
     Tenant for costs incurred by Tenant in connection with the exercise of its
     self-help rights and/or (iii) under Section 8.21(B) above as to whether or
     not the Reduction Conditions have been satisfied, shall be submitted to
     arbitration in accordance with the provisions of applicable Massachusetts
     state law, as from time to time amended. Arbitration proceedings, including
     the selection of an arbitrator, shall be conducted pursuant to the rules,
     regulations and procedures from time to time in effect as promulgated by
     the American Arbitration Association. Prior written notice of application
     by either party for arbitration shall be given to the other at least ten
     (10) days before submission of the application to the said Association's
     office in Boston, Massachusetts. Any award of an arbitrator rendered
     hereunder shall be subject to confirmation and entry of judgment thereon in
     any court of competent jurisdiction sitting in Suffolk or Middlesex
     Counties, Massachusetts, and the parties hereby consent to the jurisdiction
     of such court. The costs and administration expenses of each arbitration
     hereunder and their apportionment between the parties shall be borne
     equally by the parties, and each party shall be responsible for its own
     attorneys' fees and expert witness fees. In connection with the foregoing,
     it is expressly understood and agreed that


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<PAGE>

     the parties shall continue to perform their respective obligations under
     this Lease during the pending of any such arbitration proceeding hereunder
     (with any adjustments or reallocations to be made on account of such
     continued performance as determined by the arbitrator in his or her award).

8.32 Temporary Space

     Upon reasonable prior notice from Tenant to Landlord, Landlord agrees to
     provide Tenant with temporary space (the "Temporary Space") on either the
     second floor of Building A or the second floor of Building B of a size and
     in a location to be mutually agreed upon by Landlord and Tenant for a
     period of time commencing no earlier than sixty (60) days from the date of
     Tenant's notice requesting that the Temporary Space be made available and
     expiring on the Commencement Date of this Lease. Tenant's occupancy of the
     Temporary Space shall be subject to all of the terms and conditions of this
     Lease to the extent appropriate, except that (i) Annual Fixed Rent for the
     Temporary Space shall be payable at the annual rate equal to the product of
     (x) $4.00 and (y) the rentable floor area of the Temporary Space, (ii) for
     the purposes of determining Tenant's payments on account of Landlord's
     Operating Expenses under Section 2.6 above and Landlord's Tax Expenses
     under Section 2.7 with respect to the Temporary Space, the "Rentable Floor
     Area of the Premises" shall be deemed to be the rentable floor area of the
     Temporary Space and (iii) the Temporary Space shall be delivered to Tenant
     in its "as is" condition and no improvement allowance or brokerage
     commission shall be payable with respect thereto. In addition, it is
     acknowledged and agreed that if Tenant shall elect to lease any Temporary
     Space hereunder, Tenant shall be occupying such Temporary Space while
     Landlord is proceeding with components of the Base Building Work in
     Buildings A and B and accordingly that Tenant shall use and occupy the
     Temporary Space in such as manner as to minimize any unreasonable
     interference with Landlord's performance of the Base Building Work.

                            (signatures on next page)


                                       108

<PAGE>

EXECUTED as a sealed instrument in two or more counterparts each of which shall
be deemed to be an original.

WITNESS:                               LANDLORD:

-------------------------------------  BOSTON PROPERTIES LIMITED PARTNERSHIP

                                       By: Boston Properties, Inc., its general
                                           partner


                                       By: /s/ James Rosenfeld
                                           -------------------------------------
                                       Name: James Rosenfeld
                                             -----------------------------------
                                       Title: Senior Vice President, Development
                                              ----------------------------------


                                       TENANT:

ATTEST:                                IROBOT CORPORATION


By:                                    By: /s Colin Angle
    ---------------------------------      -------------------------------------
Name:                                  Name: Colin Angle
      -------------------------------        -----------------------------------
Title: Secretary or Assistant          Title: President or Vice President
       Secretary                              Hereto duly authorized


                                       By:
                                           -------------------------------------
                                       Name:
                                             -----------------------------------
                                       Title: Treasurer or Assistant Treasurer
                                              Hereto duly authorized


                                      109

<PAGE>

                                    EXHIBIT A

                               DESCRIPTION OF SITE

Those certain parcels of land (with the buildings thereon) situated in Bedford,
Middlesex County, Massachusetts bounded and described as follows:

PARCELS 1 and 2

Two certain parcels of land situated in Bedford, Middlesex County,
Massachusetts, shown as Lot 1 and 2 on a plan entitled "Plan of Land in Bedford,
Mass." dated March 1, 1962 by Raymond C. Pressey, Inc., recorded with Middlesex
South District Deeds as Plan No. 487 of 1962 in Book 10022, Page 278, and
together bound and described as follows:

<TABLE>
<S>             <C>
SOUTHWESTERLY   by Crosby Road by three lines measuring respectively two hundred
                eighty-three and 01/100 (283.01) feet, twenty-one and 27/100
                (21.27) feet and four hundred eighty-three and 43/100 (483.43)
                feet; thence

SOUTHERLY       by said Crosby Road by a curved line, one hundred nineteen and
                36/100 (119.36) feet; thence

SOUTHEASTERLY
SOUTHERLY and
SOUTHWESTERLY   by said Crosby Road by several lines measuring respectively two
                hundred ninety-three and 04/100 (293.04) feet, three hundred
                fifty-three and 04/100 (353.04) feet and two hundred twenty and
                97/100 (220.97) feet; thence

NORTHEASTERLY   by the parcel marked "Reserved for Town of Bedford" on said
                plan, sixteen hundred forty-six and 81/100 (1646.81) feet; and
                thence

NORTHWESTERLY   by land now or late of The Worcester Corp., by two lines
                measuring respectively 305.23 feet and 294.24 feet and by land
                now or late of Douglas by two lines measuring respectively
                170.33 feet and 64.34 feet, to the place of beginning.
</TABLE>

For Title see Deed recorded with the Middlesex South District Registry of Deeds
in Book 12926, Page 233.

PARCEL 3

A certain parcel of land situated in said Bedford, shown on a plan of land in
Bedford, Mass. Dated June 5, 1961 by Raymond C. Pressey, Inc., Registered Land
Surveyors, recorded with

                                    Exhibit A


                                   Page 1 of 2

<PAGE>

Middlesex South District Registry of Deeds at the end of Book 9844, bounded and
described as follow:

<TABLE>
<S>             <C>
SOUTHWESTERLY   by Crosby Road, two hundred ninety-eight and 63/100 (298.63)
                feet;

NORTHWESTERLY   by land now or formerly of the Worcester Corporation, two
                hundred nine and 95/100 (209.95) feet;

NORTHEASTERLY   by land now or formerly of the Worcester Corporation, two
                hundred fifty and 57/100 (250.57) feet; and

SOUTHEASTERLY   by land now or formerly of Sinbad Realty Corporation by two
                lines respectively measuring one hundred seventy and 33/100
                (170.33) feet and sixty-four and 34/100 (64.34) feet.
</TABLE>

Containing approximately 60,951 square feet of 1.4 acres according to said plan.

For Title see Deed from Cecil N. Douglas and Priscilla M. Douglas recorded with
the Middlesex South District Registry of Deeds in Book 13539, Page 732.

PARCEL 4

All right, title and interest in and to (i) that portion of Crosby Road
described in that certain Deed (a) recorded with the Middlesex South District
Registry of Deeds in Book 14013, Page 486 and (b) filed with the Middlesex South
Registry District of the Land Court as Document No. 599584 as to which
Certificate of Title No. 161163 in Registration Book 936, Page 13 was issued;
and (ii) such other applicable portions of Crosby Road abutting the westerly
boundaries of Parcels 1, 2 and 3.

Parcels 1, 2, 3 and 4 are subject to and together with the benefit of easements,
agreements restrictions, rights of way and takings of record at said Registry of
Deeds and Registry District if and to the extent in force and applicable.


                                        2

<PAGE>

                                   EXHIBIT B-1

                          LANDLORD'S BASE BUILDING WORK

A.   BUILDING EXTERIOR

     (1)  All existing bronze colored insulated glass units at Buildings A, B,
          C, D, E & G will be removed and replaced with new, Low-E, insulated
          glass units. Caulking and glazing gaskets will be replaced as
          required.

     (2)  Existing 36" high x 68" wide windows located at the first floor of
          Building C & D will be replaced with full-height, inoperable,
          aluminum-framed, insulated windows. Windows at sensitive locations
          such as restrooms or water main equipment locations will be frosted.
          The number and location of first floor windows is as follows:

<TABLE>
<CAPTION>
          LOCATION             NUMBER OF WINDOWS
          --------             -----------------
<S>                            <C>
Building C - North Elevation           13
Building C - South Elevation           22
Building D - North Elevation            1
Building D - West Elevation            21
Building D - South Elevation           12
</TABLE>

     (3)  All exterior metal elements including window frames and existing
          storefront entrances will be painted.

B.   BUILDING D ENTRANCE LOBBY

Landlord will renovate the main entrance at the southwest corner of Building D
as illustrated schematically in the attached renderings. Interior elements
included in the renovation are as follows:

     (1)  Existing stair railing to be replaced with painted metal and glass
          railing of a similar finish to that designed by ADD Inc. at 14 Crosby
          Drive and installed in 2005. The gypsum enclosure below the stair is
          to be removed and the structure revealed. The stair tread is to be
          covered with new carpet.

     (2)  The brick planter between the upper and lower lobby is to be removed
          and replaced with painted metal and glass railing of similar design to
          the stair rail.

     (3)  Floor finishes in the lower lobby are to be a ceramic tile mutually
          agreed upon by Boston Properties and iRobot (Allowance: $30psf
          Installed).

     (4)  Floor finishes in the upper lobby and on the stair are to be carpet
          mutually agreed upon by Boston Properties and iRobot (Allowance:
          $30per yard Installed).

     (5)  Remaining dry-wall elements (i.e. the lower lobby east wall) are to be
          painted a mutually agreeable color.

                                   Exhibit B-2


                                   Page 1 of 5

<PAGE>

     (6)  New recessed ceiling lighting is to be provided at the upper and lower
          level lobby. Junction boxes will be provided at the drop ceiling area
          in the center of the lower lobby and above the reception desk.

     (7)  The two-story, north wall of the upper lobby is to be drywall with
          standard latex painted finish (two-coats).

     (8)  iRobot is responsible for interior furniture, millwork, reception
          desk, etc.

C.   LANDSCAPING

The landscaping and sidewalks at the entrance to Building D (Southwest corner)
will be replaced to allow for integrated pedestrian access from the visitor
parking and employee parking areas.

D.   ELEVATORS

A new two-stop hydraulic elevator will be installed in the southern end of
Building D in a location mutually agreed upon by Boston Properties and iRobot
and located generally adjacent to the renovated entrance lobby and iRobot
reception area. The elevator will have a standard cab and be manufactured by
Otis, Thyssen Krup, or equal.

Existing freight elevator at Building E will be upgraded to include an automated
door opener.

E.   ROOFING

     (1)  A new EPDM roofing system with a 10-year warranty is to be installed
          at Building C.

     (2)  Six months after installation of the new roof top units, Boston
          Properties will conduct an infrared test on roofs at D and E to
          confirm roofing performance on these buildings and repair any
          potential defects.

F.   HEATING, VENTILATION, AND AIR CONDITIONING

     (1)  Two new rooftop units are to be provided at Building C and one new
          rooftop unit at Building D. Rooftop units to be Mammoth, AAON, or
          equal. Rooftop units will be sized to service one floor in each
          building at a ratio of 300SF/ton.

     (2)  Control units for the existing building management system will be
          expanded to incorporate the building rooftop units.

     (3)  Duct work for new units will be stubbed into the respective ceiling
          plenums of the first and second floor to allow for iRobot to connect
          their distribution ductwork. No more than 5 feet of horizontal duct
          will be provided.

G.   ELECTRICAL SYSTEMS

New electrical panel will be provided at Building D.

H.   COMMON AREA AMENITIES

                                   Exhibit B-2


                                   Page 2 of 5

<PAGE>

(1)  Boston Properties will construct a common interior corridor from Building C
     to A for access to new common area amenities in Building A.

(2)  A new fitness center will be built within Building A including restrooms,
     showers, and a locker-room area. The finishes and equipment will be of
     similar quality to other fitness centers built and managed by Boston
     Properties in our suburban assets (i.e. Prospect Place, Waltham-Weston
     Corporate Center).

(3)  The existing cafeteria facility in Building A will painted and new carpet
     will be installed in the seating area.

                                   Exhibit B-2


                                   Page 3 of 5

<PAGE>

                                    EXHIBIT C

                               LANDLORD'S SERVICES

I.   CLEANING

     Cleaning and janitorial services shall be provided as needed Monday through
     Friday (starting at or after 6pm), exclusive of holidays, Saturdays and
     Sundays.

     A.   OFFICE AREAS

          Cleaning and janitorial services to be provided in the office areas
          shall include:

          1.   Vacuuming, damp mopping of resilient floors and trash removal
               (nightly M-F).

          2.   Dusting of horizontal surfaces within normal reach (tenant
               equipment to remain in place). Hand dust all horizontal surfaces
               with treated cloths to include exposed furniture, office
               equipment, window sills, door ledges, chair rails, baseboards,
               convector tops, etc. within normal reach (minimum 1 x week).

          3.   High dusting and dusting of vertical blinds to be rendered as
               needed (minimum 1 x year).

     B.   LAVATORIES

          Cleaning and janitorial services to be provided in the common area
          lavatories of the building shall include:

          1.   Dusting, damp mopping of resilient floors, trash removal,
               sanitizing of basins, bowls and urinals as well as cleaning of
               mirrors and bright work (nightly M-F).

          2.   Refilling of soap, towel, tissue and sanitary dispensers to be
               rendered as necessary (nightly M-F).

          3.   High dusting to be rendered as needed (minimum 1 x year).

          4.   Wash down interior walls and partitions (monthly).

     C.   WINDOW CLEANING

          All exterior windows shall be washed on the inside and outside
          surfaces at a frequency necessary to maintain a first class appearance
          (minimum 1 x year).

     D.   PUBLIC AREAS

                                    Exhibit D


                                   Page 1 of 2

<PAGE>

               -    Spot clean entrance doors/all glass at interior doors
                    (nightly).

               -    Vacuum all carpets and walk-off mats (nightly).

               -    Damp mop all resilient floors (nightly).

               -    Clean & sanitize all drinking fountains (nightly).

               -    Spray Buff or high-speed burnish all resilient floors if
                    required by manufacturer specifications (weekly).

               -    Vacuum passenger elevator in Building D and wipe down all
                    surfaces (every other night).

               -    Sweep all stairways (weekly).

               -    Police Tenant designated smoking area every other day or
                    night.

     E.   GENERAL

          Landlord shall provide the following special services, for which
          Tenant shall pay all costs and a fee equal to fifteen (15%) of such
          costs:

               -    Strip and wax all resilient tile floors (one time per year).

               -    Shampoo all carpeting (one time per year).

               -    Wash down and sanitize Coffee Station(s) and Breakroom
                    counters and sinks (weekly).

II.  HVAC

     A.   Heating, ventilating and air conditioning equipment will be provided
          with sufficient capacity to accommodate a maximum population density
          of one (1) person per one hundred fifty (150) square feet of useable
          floor area served, and a combined lighting and standard electrical
          load of 3.0 watts per square foot of useable floor area. In the event
          Tenant introduces into the Premises personnel or equipment which
          overloads the system's ability to adequately perform its proper
          functions, Landlord shall so notify Tenant in writing and
          supplementary system(s) may be required and installed by Landlord at
          Tenant's expense, if within fifteen (15) days Tenant has not modified
          its use so as not to cause such overload.

          Operating criteria of the basic system shall not be less than the
          following:

               i.   Cooling season indoor temperature of not in excess of 73 -
                    79 degrees Fahrenheit when outdoor temperature is 91 degrees
                    Fahrenheit ambient.

               ii.  Heating season minimum room temperature of 68 - 75 degrees
                    Fahrenheit when outdoor temperature is 6 degrees Fahrenheit
                    ambient.

     B.   Landlord shall provide heating, ventilating and air conditioning as
          normal seasonal charges may require during the hours of 7am to 9pm
          Monday through Friday (legal holidays in all cases excepted) at
          Tenant's expense.

                                    Exhibit D


                                   Page 2 of 2

<PAGE>

          If Tenant shall require air conditioning (during the air conditioning
          season) or heating or ventilating during any other time period,
          Landlord shall use landlord's best efforts to furnish such services
          for the area or areas specified by written request of Tenant delivered
          to the Building Superintendent or the Landlord before 3:00 p.m. of the
          business day preceding the extra usage.

III. ELECTRICAL SERVICES

     A.   Landlord shall provide electrical power for a combined load of 3.0
          watts per square foot of useable area for lighting and for office
          machines through standard receptacle for the typical office space.

     B.   Landlord will furnish and install at Tenant's expense, all replacement
          lighting tubes, lamps and ballasts required by Tenant. Landlord will
          clean lighting fixtures on a regularly scheduled basis at the Tenant's
          expense.

IV.  ELEVATORS

     Landlord will provide passenger elevator service in Building D and freight
     elevator service in Building D and E.

V.   WATER

     Landlord will provide hot water for lavatory purposes and cold water for
     drinking, lavatory, and toilet purposes.

VI.  SECURITY

     Landlord will provide, through a third party security services contactor,
     random security patrols of the building perimeter and parking areas during
     non-business hours.

                                    Exhibit D


                                   Page 3 of 2

<PAGE>

                                    EXHIBIT E

                       FORM OF COMMENCEMENT DATE AGREEMENT

     DECLARATION AFFIXING THE COMMENCEMENT DATE OF LEASE

     THIS AGREEMENT made this __ day of ________ 200_, by and between __________
________________________________ (hereinafter "Landlord") and _________________
(hereinafter "Tenant").

                                 WITNESSETH THAT:

1.   This Agreement is made pursuant to Section ___ of that certain Lease dated
     _____, between the parties aforenamed as Landlord and Tenant (the "Lease").

2.   It is hereby stipulated that the Lease Term commenced on __________, (being
     the "Commencement Date" under the Lease), and shall end and expire on
     __________, unless sooner terminated or extended, as provided for in the
     Lease.

WITNESS the execution hereof under seal by persons hereunto duly authorized, the
date first above written.

                                        LANDLORD:


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        TENANT:


ATTEST:                                 ----------------------------------------


By:                                     By:
    ---------------------------------       ------------------------------------
Name:                                   Name:
      -------------------------------         ----------------------------------
Title:                                  Title:
       ------------------------------          ---------------------------------
                                               Hereunto duly authorized

                                                 (CORPORATE SEAL)

                          COMMONWEALTH OF MASSACHUSETTS

                                    Exhibit E


                                   Page 1 of 2

<PAGE>

COUNTY OF SUFFOLK

On this ___ day of __________, 200_, before me, the undersigned notary public,
personally appeared _____________________________, proved to me through
satisfactory evidence of identification, which were
_________________________________, to be the person whose name is signed on the
preceding or attached document in my presence.

-------------------------------------
NOTARY PUBLIC
My Commission Expires:

                          COMMONWEALTH OF MASSACHUSETTS

COUNTY OF ___________________________

On this ___ day of __________, 200_, before me, the undersigned notary public,
personally appeared _____________________________, proved to me through
satisfactory evidence of identification, which were
_________________________________, to be the person whose name is signed on the
preceding or attached document, and who swore or affirmed to me that the
contents of the documents are truthful and accurate to the best of [his] [her]
knowledge and belief.


-------------------------------------
NOTARY PUBLIC
My Commission Expires:

                                    Exhibit E


                                   Page 2 of 2
<PAGE>

                                   EXHIBIT F-1

                              FORMS OF LIEN WAIVERS

              CONTRACTOR'S PARTIAL WAIVER AND SUBORDINATION OF LIEN

STATE OF ____________________________   Date: __________________________________

______________________________ COUNTY   Application for Payment No.: ___________

OWNER: _________________________________________________________________________

CONTRACTOR: ____________________________________________________________________

LENDER / MORTGAGEE: None

<TABLE>
<S>                                     <C>
1.  Original Contract Amount:           $_______________________________________

2.  Approved Change Orders:             $_______________________________________

3.  Adjusted Contract Amount:           $_______________________________________
    (line 1 plus line 2)

4.  Completed to Date:                  $_______________________________________

5.  Less Retainage:                     $_______________________________________

6.  Total Payable to Date:              $_______________________________________
    (line 4 less line 5)

7.  Less Previous Payments:             $_______________________________________

8.  Current Amount Due:                 $_______________________________________
    (line 6 less line 7)

9.  Pending Change Orders:              $_______________________________________

10. Disputed Claims:                    $_______________________________________
</TABLE>

The undersigned who has a contract with _________________________ for furnishing
labor or materials or both labor and materials or rental equipment, appliances
or tools for the erection, alteration, repair or removal of a building or
structure or other improvement of real property known and identified as located
in ____________ (city or town), _________County,

                                   Exhibit F-1


                                   Page 1 of 7

<PAGE>

_________________________ and owned by _________________, upon receipt of
__________ ($__________) in payment of an invoice/requisition/application for
payment dated __________________ does hereby:

     (a)  waive any and all liens and right of lien on such real property for
          labor or materials, or both labor and materials, or rental equipment,
          appliances or tools, performed or furnished through the following date
          ________________ (payment period), except for retainage, unpaid agreed
          or pending change orders, and disputed claims as stated above;

     (b)  subordinate any and all liens and right of lien to secure payment for
          such unpaid, agreed or pending change orders and disputed claims, and
          such further labor or materials, or both labor and materials, or
          rental equipment, appliances or tools, except for retainage, performed
          or furnished at any time through the twenty-fifth day after the end of
          the above payment period, to the extent of the amount actually
          advanced by the above lender/mortgagee through such twenty-fifth day.

     Signed under the penalties of perjury this _________ day of ________, 20__.

WITNESS:                                CONTRACTOR:


-------------------------------------   ----------------------------------------
Name:                                   Name:
     --------------------------------         ----------------------------------
Title:                                  Title:
       ------------------------------          ---------------------------------

                                   Exhibit F-1


                                   Page 2 of 7

<PAGE>

                           SUBCONTRACTOR'S LIEN WAIVER

General Contractor: ____________________________________________________________

Subcontractor: _________________________________________________________________

Owner: _________________________________________________________________________

Project: _______________________________________________________________________

<TABLE>
<S>                                     <C>
Total Amount Previously Paid:           $_______________________________________

Amount Paid This Date:                  $_______________________________________

Retainage (Including This Payment)
   Held to Date:                        $_______________________________________
</TABLE>

In consideration of the receipt of the amount of payment set forth above and any
and all past payments received from the Contractor in connection with the
Project, the undersigned acknowledges and agrees that it has been paid all sums
due for all labor, materials and/or equipment furnished by the undersigned to or
in connection with the Project and the undersigned hereby releases, discharges,
relinquishes and waives any and all claims, suits, liens and rights under any
Notice of Identification, Notice of Contract or statement of account with
respect to the Owner, the Project and/or against the Contractor on account of
any labor, materials and/or equipment furnished through the date hereof.

The undersigned individual represents and warrants that he is the duly
authorized representative of the undersigned, empowered and authorized to
execute and deliver this document on behalf of the undersigned and that this
document binds the undersigned to the extent that the payment referred to herein
is received.

The undersigned represents and warrants that it has paid in full each and every
sub-subcontractor, laborer and labor and/or material supplier with whom
undersigned has dealt in connection with the Project and the undersigned agrees
at its sole cost and expense to defend, indemnify and hold harmless the
Contractor against any claims, demands, suits, disputes, damages, costs,
expenses (including attorneys' fees), liens and/or claims of lien made by such
sub-subcontractors, laborers and labor and/or material suppliers arising out of
or in any way related to the Project. This document is to take effect as a
sealed instrument.

                                   Exhibit F-1


                                   Page 3 of 7

<PAGE>

Signed under the penalties of perjury as of this ______ day of __________, 20__.

SUBCONTRACTOR:                          Signature and Printed Name of Individual
                                        Signing this Lien Waiver


-------------------------------------   ----------------------------------------

                                        ----------------------------------------

WITNESS:


-------------------------------------
Name:
      -------------------------------
Title:
       ------------------------------
Dated:
       ------------------------------

                                   Exhibit F-1


                                   Page 4 of 7

<PAGE>

         CONTRACTOR'S WAIVER OF CLAIMS AGAINST OWNER AND ACKNOWLEDGMENT
                                OF FINAL PAYMENT

Commonwealth of Massachusetts                  Date: ___________________________

COUNTY OF ___________________________   Invoice No.: ___________________________

OWNER:          ________________________________________________________________

CONTRACTOR:     ________________________________________________________________

PROJECT:        ________________________________________________________________

<TABLE>
<S>                                           <C>
1. Original Contract Amount:                  $_________________________________

2. Approved Change Orders:                    $_________________________________

3. Adjusted Contract Amount:                  $_________________________________

4. Sums Paid on Account of Contract Amount:   $_________________________________

5. Less Final Payment Due:                    $_________________________________
</TABLE>

The undersigned being duly sworn hereby attests that when the Final Payment Due
as set forth above is paid in full by Owner, such payment shall constitute
payment in full for all labor, materials, equipment and work in place furnished
by the undersigned in connection with the aforesaid contract and that no further
payment is or will be due to the undersigned.

The undersigned hereby attests that it has satisfied all claims against it for
items, including by way of illustration but not by way of limitation, items of:
labor, materials, insurance, taxes, union benefits, equipment, etc. employed in
the prosecution of the work of said contract, and acknowledges that satisfaction
of such claims serves as an inducement for the Owner to release the Final
Payment Due.

The undersigned hereby agrees to indemnify and hold harmless the Owner from and
against all claims arising in connection with its Contract with respect to
claims for the furnishing of labor, materials and equipment by others. Said
indemnification and hold harmless shall include the reimbursement of all actual
attorney's fees and all costs and expenses of every nature, and shall be to the
fullest extent permitted by law.

The undersigned hereby irrevocably waives and releases any and all liens and
right of lien on such real property and other property of the Owner for labor or
materials, or both labor and materials, or rental equipment, appliances or
tools, performed or furnished by the undersigned, and anyone claiming by,
through, or under the undersigned, in connection with the Project.

                                   Exhibit F-1


                                   Page 5 of 7

<PAGE>

The undersigned hereby releases, remises and discharges the Owner, any agent of
the Owner and their respective predecessors, successors, assigns, employees,
officers, shareholders, directors, and principals, whether disclosed or
undisclosed (collectively "Releasees") from and against any and all claims,
losses, damages, actions and causes of action (collectively "Claims") which the
undersigned and anyone claiming by, through or under the undersigned has or may
have against the Releasees, including, without limitation, any claims arising in
connection with the Contract and the work performed thereunder.

Notwithstanding anything to the contrary herein, payment to the undersigned of
the Final Payment Due sum as set forth above, shall not constitute a waiver by
the Owner of any of its rights under the contract including by way of
illustration but not by way of limitation guarantees and/or warranties. Payment
will not be made until a signed waiver is returned to Owner.

The undersigned individual represents and warrants that he/she is the duly
authorized representative of the undersigned, empowered and authorized to
execute and deliver this document on behalf of the undersigned.

                                   Exhibit F-1


                                   Page 6 of 7

<PAGE>

Signed under the penalties of perjury as a sealed instrument as of this ___ day
of ________________, _____.

                                        ____________________________ Corporation


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------
                                               Hereunto duly authorized

                          COMMONWEALTH OF MASSACHUSETTS

COUNTY OF SUFFOLK

     On this ___ day of __________, 20___, before me, the undersigned notary
public, personally appeared _____________________________, proved to me through
satisfactory evidence of identification, to be the person whose name is signed
on the preceding or attached document, and acknowledged to me that he/she signed
it as ______________ for ______________, a corporation/partnership voluntarily
for its stated purpose.


-------------------------------------
NOTARY PUBLIC
My Commission Expires:

                                   Exhibit F-1


                                   Page 7 of 7

<PAGE>

                                   EXHIBIT F-2

                       CONSTRUCTION RULES AND REGULATIONS

                                BOSTON PROPERTIES

                                    SUBURBAN

                         BUILDING RULES AND REGULATIONS
                                       FOR
                       RENOVATION / CONSTRUCTION PROJECTS

                                   Exhibit F-2


                                  Page 1 of 22

<PAGE>

                                    SUBURBAN

              Regulations for Building Improvements and Renovations

INTRODUCTION

The following regulations have been developed to ensure that modifications or
improvements to the buildings and/or building systems and equipment are
completed to Boston Properties quality standards while maintaining a level of
safety consistent with industry standards.

These regulations are not intended to be all inclusive with regard to the design
and renovation of any building, or installation of any building systems and
equipment, nor are they intended to replace and/or reduce any national, state or
local code or regulations that may be in effect at the time of design,
construction and/or installation. The purpose of this document is to provide
standard operating procedures for contractors while working in Boston Properties
Buildings, and in some cases to clarify some issues regarding optional design
methods.

In addition to the codes, standards, regulations and other design considerations
referenced in this document, the designer/engineer of record and/or the
applicable contractor is expected and responsible to ensure that all code and
regulatory requirements are met. If there is a conflict between this document
and any national, state or local code or regulatory requirements, it is the
responsibility of the applicable contractor and/or the designer/engineer of
record to bring them to the attention of Boston Properties Management.

These regulations apply to all modifications and improvements within any
building, or to building systems and equipment, at all Boston Properties
facilities and all contractors working therein.

                                   Exhibit F-2


                                  Page 2 of 22
<PAGE>

PREREQUISITES

PLAN SUBMITTAL & REVIEW

A full set of plans (wet signed/stamped) is to be submitted to Boston
Properties, Inc. for review and written approval to proceed prior to start of
work. Plan review may take approximately two to four weeks depending upon
project scope. A complete set of as-builts, and an electronic CAD Disk is to be
submitted to the management office upon projection completion.

Boston Properties specifically denies any liability in connection with the
approval of plans. The review of plans and/or specifications by Boston
Properties and/or their insurers, consultants or other representatives, does not
imply that any plans so reviewed comply with applicable laws, ordinances, codes,
standards or regulations.

CITY PERMITS/CERTIFICATES

Copies of all relevant permits (demolition, building, electrical, plumbing,
etc...) must be submitted to Boston Properties, Inc. prior to start of work.
Note that the city or town requires a separate permit for both low and high
voltage wiring. Upon completion of project, copies of all completed permits as
well as certificate of occupancy (if applicable) are to be submitted to Boston
Properties, Inc.

INSURANCE REQUIREMENTS

-    Certificates of insurance, as detailed below, must be submitted to Boston
     Properties before any work is started.

-    All policies (except for workers' compensation coverage) shall be endorsed
     to name the entities listed on Attachment A "Owner Entities", their
     subsidiaries, officers, agents and employees and any owner entity specified
     by Owner, as additional insured as respects to the work being performed at
     the property. The endorsement shall further provide that additional
     insureds shall not be affected by any breach by the Contractor of any
     provision of said policy.

-    All policies of insurance shall be with an insurance company with a current
     A.M. Best Rating of A-VIII or better; and licensed to do business in the
     Commonwealth of Massachusetts.

-    All policies shall contain a minimum of 30 days notice of cancellation.

                                   Exhibit F-2


                                  Page 3 of 22
<PAGE>

-    Contractor shall furnish certificates of insurance prior to the start of
     the work and provide renewal certificates within 60 days prior to the
     expiration of the policies.

-    All insurance policies shall include a clause stating that each underwriter
     will waive all rights of recovery, under subrogation or otherwise, against
     the Owner Entities.

-    Listed below are the required standard policy coverages and limits
     (provided, however, should these coverages differ from the coverages
     required in any contract you have with Owner, the amounts in such contract
     shall prevail).

<TABLE>
<S>                                                                  <C>
A.   Workers' Compensation........................................   Statutory limits
B.   Employers' Liability.........................................   $1,000,000
C.   Commercial General Liability including Contractual Liability:
        General Aggregate.........................................   $2,000,000
        Products/Completed Operations Aggregate...................   $2,000,000
        Each Occurrence...........................................   $1,000,000
     Personal & Advertising Injury................................   $1,000,000
     Medical Payments (per person)................................   $    5,000
     Evidence of Products/Completed Operations coverage must be
        shown for a minimum of two years following completion
        of work.
D.   Automobile Liability.........................................   $1,000,000
E.   Umbrella/Excess Liability:
        General Aggregate.........................................   $5,000,000
        Each Occurrence...........................................   $5,000,000
</TABLE>

-    Contractor shall ensure that all sub-contractors and sub-sub-contractors
     also maintain the same insurance requirements and coverage's as required in
     any contract with Owner or otherwise as referenced above, including naming
     the additional insured on their respective liability policies.

-    List of additional insureds is per specific locations and can be identified
     on Attachment "A" attached.

LICENSES

Licensed trades must provide copies of current licenses.

OWNER APPROVAL

Municipality may require written owner approval. Such applications must be
submitted to the management office before start of work. Allow five days for
processing owner approval applications.

                                   Exhibit F-2


                                  Page 4 of 22

<PAGE>

WRITTEN SCHEDULE/PROJECT COORDINATION

General contractor must submit a written schedule to the Construction Management
or Property Management office to accommodate staff/tenant notification. Any
schedule modifications must be brought to the attention of the management office
as soon as possible. Project coordination must be accomplished in conjunction
with Boston Properties' Construction Management office at 781-530-1900 or the
Property Management offices in Waltham at 781-530-1900. Emergency assistance may
be coordinated through Boston Properties' Tenant Control Center at 877-297-4411.

ON-SITE REQUIREMENTS

BUILDING ACCESS

Access to the building is gained via the main entrance twenty-four hours per day
seven days per week with prior written approval from Boston Properties, Inc.
Access information is to be provided to Boston Properties, Inc. by the tenant.
Written access approval will be posted at the security desk. Access to building
will be denied if Boston Properties' written approval is not posted. (If
applicable)

Vendor will be required to sign into the building log upon arrival. In
Cambridge, Security will issue "contractor" badge to vendor. "Contractor" badge
must be worn on the vendor's person while on site. Security will direct vendor
to appropriate floor/location and provide access as needed. Upon departure,
vendor will be required to sign out of the building log and return the
"contractor" badge to security personnel. In all other suburban facilities
contractors are required to have their own form of visible identification i.e.
card or shirt.

LOADING DOCK ACCESS

The loading dock is open weekdays between 7:00 a.m. and 5:30 p.m. Access to the
building is gained with prior written approval from Boston Properties, Inc.
Access information is to be provided to Boston Properties, Inc. by the tenant.
Written access approval will be posted at the security desk. Access to building
will be denied if Boston Properties' written approval is not posted. (If
applicable)

AFTER-HOURS LOADING DOCK ACCESS

Loading dock access outside of weekday timeframe must be scheduled twenty-four
hours in advance to coordinate security coverage. Security details are required
for access to the loading dock "after-hours". The tenant on a work order basis
schedules security details through the property management office. (If
applicable)

Written access approval will be posted at the security desk. Access to building
will be denied if Boston Properties' written approval is not posted. (If
applicable)

                                   Exhibit F-2


                                  Page 5 of 22

<PAGE>

Use of the freight elevator on weeknights after 6:00 p.m. must be coordinated to
accommodate waste removal from the building from approximately 7:00 p.m. through
8:30 p.m. Security personnel will be required after hours, and must be approved
by the Tenant via a work order.

FLOOR-TO-FLOOR ACCESS & EGRESS

Floor-to-floor access and egress via stairwells is prohibited excluding
emergency egress. Elevator access may be restricted at the discretion of the
management office.

BASE BUILDING AREA ACCESS

Boston Properties, Inc. maintenance staff or security staff, will provide access
to base building areas outside of tenant office space with prior notice by
vendor. These base building areas include, but are not limited to the mechanical
closets, electrical closets, main telephone closet and roof.

MATERIALS/EQUIPMENT DELIVERY & REMOVAL

All wheeled deliveries are prohibited through the main entry. Delivery of tools
and materials must be made through the loading dock and into the building via
the freight elevator.

Materials loading for large projects may be accomplished via crane; however,
this must be coordinated two weeks in advance with the management office.
Contractor will be responsible for all required permitting. If applicable,
copies of permits are required in advance of work being performed.

Contractor must remove all materials and/or equipment from base building areas.
Tenant will be charged on a work order basis for any materials and/or equipment
removal not accomplished by contractor.

TENANT OFFICE SPACE ACCESS

Access to tenant office space outside of work area will be provided by Boston
Properties, Inc. maintenance staff or security staff with prior notice by
vendor. A security detail may be necessary to accompany vendor while inside
tenant office space. The tenant on a work order basis schedules security details
through the property management office.

RESTROOM/SLOP SINK ACCESS

If restroom/slop sink access is required, cleaning requirements will be
applicable. Material disposal via the slop sink/restrooms is prohibited. If
necessary, any related drain cleaning/clearing costs will be billed to the
tenant on a work order basis.

                                   Exhibit F-2


                                  Page 6 of 22

<PAGE>

NO SMOKING POLICY

Per city and state ordinances, smoking is prohibited inside the office building.
In addition, Boston Properties, Inc. prohibits smoking at the main entry to the
property and within the construction work area this shall be enforced at all
times.

WASTE REMOVAL

Materials and/or equipment cannot be stored at the loading dock or in any area
outside the work area. All packing materials including pallets must be removed
from the loading dock. Any materials left at the dock will be removed at the
tenant's and/or contractor's cost on a work order basis.

Open top containers may be maintained at the property if scheduled in advance
with the property management office. It may be necessary to coordinate location,
delivery and pick-up of open top containers after hours, and on a daily basis.

PARKING

On-site parking may be available. There are no available discount rates.
Building management cannot validate parking. Parking is prohibited in the
building's loading dock and loading dock ramp areas. Any vehicles parking in
unauthorized areas will be towed from the site at the cost of the vehicle owner.
The use of on grade parking is available at some locations but contractors must
use the parking stalls that are furthest from the building.

Most cities do not allow on street parking and will tow vehicles from the site
at the cost of the vehicle owner.

BUILDING SYSTEMS

SAFETY AND LOSS CONTROL PROCEDURES

GENERAL

Contractors shall comply with all safety standards that include, but are not
limited to, federal, state, local, OSHA, NFPA regulations or codes.

-    Contractor shall take all necessary precautions to safeguard all contractor
     personnel and the public from accident and to preserve all private and
     public property.

-    Contractor will perform no overhead work where, as a result of that work,
     there is a possibility of objects falling, striking and/or causing injury
     to any person. Where necessary

                                   Exhibit F-2


                                  Page 7 of 22

<PAGE>

     or required, Contractor shall provide nets, tarpaulins, scaffolds, and
     warning signs for the protection of personnel and equipment. Contractor may
     be required to schedule such work to avoid work disruptions and minimize
     risks of injury.

-    Where tarpaulins are required for protection against hot slag, dust, paint
     drippings, or as temporary barriers, they shall be furnished by Contractor,
     be flame resistant, and in good condition. Contractor shall be responsible
     for the installation of scaffolds where necessary or required to the
     performance of the work. Contractor shall ensure compliance with all
     appropriate safety regulations.

-    Contractor shall furnish all necessary or required safety warning signs,
     barriers, or barricades.

EXITS AND EVACUATION GUIDELINES

-    Exits should be provided, as required by code, from the construction area.

-    Exits should be clearly marked and maintained unobstructed and accessible
     at all times.

-    All Contractor personnel must evacuate the work area immediately upon
     activation of the fire alarm, evacuation announcement, or instructions from
     Security. (Fire evacuation drills also apply.) Contractor personnel should
     use the most direct route to reach the designated relocation areas.
     Elevators are not to be used during emergency evacuations.

TEMPORARY LIGHTING

-    Where temporary lighting is utilized, installation should closely follow
     construction and be provided in stairwells and other exit ways, where
     necessary. Provisions for night lighting should be provided. All wiring
     should be installed in accordance with The National Fire Protection
     Association's National Electrical Code, NFPA70-1999.

-    All temporary lighting and receptacles should be removed at the end of the
     construction period.

FIRE PROTECTION SAFEGUARDS

-    A minimum of two (2) portable multi-purpose Type A-B-C dry chemical fire
     extinguishers shall be provided in all work areas. Re-deployment of any
     existing building fire extinguishers to meet this requirement is
     prohibited.

-    Ready access to all construction work areas shall be maintained for the
     Local Fire Department. Fire hose connections and extinguishers shall be
     clearly visible, never blocked and maintained accessible at all times.

-    All fire alarm communication devices shall remain visible and uncovered at
     all times.

                                   Exhibit F-2


                                  Page 8 of 22

<PAGE>

-    All penetrations through fire-rated walls and floors shall be temporarily
     packed during construction and then sealed permanently in a manner that
     will restore the fire rating. Contractor is solely responsible for
     providing approved firestopping material, as specified by Boston Properties
     Management, and having it installed by a certified installer where
     necessary, especially in any penetrations or openings that may have
     occurred, or that are discovered, during construction.

-    Hot applications of mastics or insulating materials should be avoided
     inside of the building. Where this type of application is necessary in the
     building interior, adequate ventilation should be provided to prevent the
     build-up of flammable vapor concentrations. Appropriate fire extinguishing
     equipment should be maintained in the area during the entire operation.

-    The building's fire alarm system will be left operational, wherever
     feasible, during construction to offer a maximum amount of protection. See
     "Fire Alarm System Impairments" below and Attachment B "Regulations for Hot
     Work Operations" for more information regarding all required deactivations.

-    Life Safety equipment such as emergency generators, fire pumps, fire pump
     controllers and the fire alarm system shall not be taken out of service
     during normal building hours.

LIFE SAFETY/FIRE ALARM SYSTEMS

Disconnects from the main city box must be scheduled with a minimum of 24 hours
notice by the tenant on a work order basis. Same day reconnects are required.
All related dis/reconnect charges are to be billed back to the tenant on a work
order basis.

Disconnects from the main city box and fire alarm panel operation adjustments
may be necessary to accommodate hot work (brazing, soldering, etc.)

Hot work/impairment/lock-out/tag-out procedures are to be followed. Applicable
paperwork is to be completed in conjunction with management office.

-    Contractor must adhere to the Boston Properties Hot Works Program, attached
     as Attachment C, whenever any welding, cutting, burning, spark producing
     work is being done. Hot Works permits can be obtained from on site
     engineer. Schedule work for early morning because you are required to:

     1.   Provide a fire watch one hour after the hot works has been completed
          to insure that no fire exists.

     2.   You must also monitor the area four hours beyond the fire watch.

Fire watch requirements must be met with approved personnel.

Any fire alarm system work must be reviewed and approved by Boston Properties,
Inc. A

                                   Exhibit F-2


                                  Page 9 of 22

<PAGE>

vendor authorized by Boston Properties, Inc must complete all related fire alarm
system work. It is the responsibility of the vendor to confirm that existing
fire alarm system can support any additional alarm notification/suppression
system devices.

Sprinkler system drain downs must follow Boston Properties Impairment procedures
and be coordinated with management office at least twenty-four hours in advance.
Same day refills are required. Any associated labor costs will be billed back to
tenant on a work order basis.

Any life safety/fire alarm system testing must be conducted after hours. Any
associated charges will be billed back to tenant on a work order basis.

The local Fire Department may require verification of hydraulic calculations for
the building's sprinkler system pursuant as well as a copy of the most recent
fire pump test report (performance curve and written report). Boston Properties,
Inc. will provide, if available, original hydraulic calculation information as
well as fire pump test reports upon request.

ELECTRICAL SYSTEM

Any partial or full power shutdowns must be scheduled in advance (a minimum of
two weeks). Full power shutdowns required coordination with the utility, City
and electrician approved by Boston Properties, Inc. as well as Boston
Properties, Inc. maintenance staff.

Lock-out/tag-out procedures are to be followed. Applicable paperwork is to be
completed in conjunction with management office.

MECHANICAL SYSTEM

Any work that may affect the operation of the mechanical system must be
coordinated in advance with the management office. Such work may be scheduled to
take place after hours at the discretion of the management office.

Vendor is required to balance the system and submit a written report to the
management office. Diffuser and thermostat operation is to be verified and
documented as well.

Construction filters are to be removed and replaced post-construction.

KEYING/ACCESS/HARDWARE SYSTEMS

All keying/hardware systems must match existing building standards. Keying
system must incorporate building grand master/master. Vendor must provide
management office with one copy of each changed key.

Tenant access systems must be tied into the life safety/fire alarm system of the
building. Work to be coordinated with management office. All associated expenses
will be billed back to tenant

                                   Exhibit F-2


                                  Page 10 of 22

<PAGE>

on a work order basis.

DEMOLITION/CONSTRUCTION

Controlled demolition is allowed during business hours if it does not impact
business operations outside the work area. Management office may require
suspension of demolition.

Any excessively noisy work (coring, track shooting, etc.) must be completed
before 8:00 a.m. on weekdays, after 6:00 p.m. on weeknights or weekends.
Weeknight or weekend access must be scheduled in advance.

Dust protection is required throughout the demolition/construction period and
may include, but is not limited to construction air filters at all
mechanical/air conditioning units and intakes, poly protection at all egress
points, and walk-off mats at each elevator entrance area.

Any second/third shift work will require security details and, at the discretion
of the management office, building personnel details. Associated costs will be
billed to the tenant on a work order basis.

ANY EXPOSED GLASS ENTRIES MUST BE COVERED WITH BROWN PAPER DURING CONSTRUCTION
AND MAINTAINED THROUGHOUT THE PROJECT.

Any water infiltration must be handled in a manner to prevent mold, mildew and
the like and in a manner satisfactory to Boston Properties. If there shall occur
water infiltration of any type (Including, but not limited to, water from storms
or piping or spillage) Contractor and/or Tenant shall immediately notify Boston
Properties and shall immediately rectify the problem.

                                   Exhibit F-2


                                  Page 11 of 22

<PAGE>

GENERAL

All on-site contractor/subcontractor personnel are expected to behave in a
professional manner commensurate with a business environment. Courteous and
polite interaction with building staff and occupants is required at all times.

CONSTRUCTION DOCUMENTS

At the completion of any office building construction project construction
drawings shall be provided to Boston Properties. The requirements are as
follows:

-    Drawings will be provided in electronic and paper formats.

     Note: Drawings should incorporate all sketches, revisions, addendums,
     bulletins, etc.

-    Paper copies of drawings shall be half size.

-    Electronic versions shall be provided in AutoCAD dwg (preferred) or dxf. If
     possible, do not bind x-refs.

-    Please provide all of the following that apply:

          Software & Version
          Base Drawings (specify scale if not 1:1)
          Layer Standards (Color, Linetypes, Lineweights, etc.)
          Title Sheet
          Fonts (if not standard provided by program)
          Plot configuration files (CTB or STB)

Logos or any bitmap images associated

                                   Exhibit F-2


                                  Page 12 of 22

<PAGE>

                                  ATTACHMENT A

OWNER ENTITIES

<TABLE>
<CAPTION>
LOCATION                        NAMED INSUREDS (OWNERS AND MANAGEMENT)
--------              ----------------------------------------------------------
<S>                   <C>
Bedford Office Park   Boston Properties Limited Partnership, a Delaware limited
                      partnership

                      Boston Properties, Inc., a Delaware Corporation
                      BP Management, L.P., a Delaware limited partnership
</TABLE>

                                   Exhibit F-2


                                  Page 13 of 22

<PAGE>

                                  ATTACHMENT B

                                   Exhibit F-2


                                  Page 14 of 22

<PAGE>

                       Regulation for Hot Work Operations

I. HOT WORK PROJECT PLANNING

Hot work may be conducted as a repair measure or on larger scale during
construction or tenant buildouts. Historically, hot work operations have
contributed significantly in large loss fires. In order to prevent losses, the
following guidelines are provided for your consideration in managing hot work
projects:

1.   If possible, hot work should be scheduled for periods when the building is
     unoccupied.

2.   Plan all work to minimize the exposure to fire. If possible, remove and
     relocate system/equipment component(s) to be worked on to an exterior area
     or an area designed for hot work.

3.   Hot work should not take place until all personnel, material and equipment
     are at the work location and all approvals have been provided.

4.   Do not conduct hot work in an area where the sprinkler system is impaired.
     If the hot work must be conducted in an area of sprinkler impairment or if
     sprinklers are not installed, hose lines and/or other special arrangements
     should be made in addition to these operational guidelines.

5.   Smoke detection devices should be reviewed in area of hot work. Steps to
     prevent activation of the fire alarm system due to hot work should be
     taken. Smoke detection devices sharing sprinkler waterflow alarm zones
     should not be zoned out.

6.   Special attention to the transfer of flying sparks to adjacent areas should
     be evaluated and controlled. Consideration should be given to floor and
     wall openings and air transfer systems.

7.   Building furnishings and interior finishes may have flammability
     characteristics that are unknown and should be covered with fire resistant
     materials.

8.   The products of combustion from hot work may become a problem if large
     concentrations are accumulated in an area without proper ventilation.

9.   The products of combustion from hot work may become a problem if they are
     transferred into occupied tenant areas by the air handling equipment or
     other building ventilation systems. All systems should be arranged to
     prevent transfer of products of combustion.

10.  Hot work in or near air handling units should be conducted when building is
     not occupied and the unit should be shut off.

                                   Exhibit F-2


                                  Page 15 of 22

<PAGE>

11.  Spare fire extinguishers should be used to support fire watch operations.
     Relocation of existing building fire extinguishers may cause a delay in
     others trying to retrieve extra units from known locations. The proper
     class of fire extinguisher should be selected based on combustibles in area
     and building construction.

12.  Communication systems for reporting fire emergencies should be available to
     the fire watch and tested prior to the start of the job.

<TABLE>
<CAPTION>
STEP   RESPONSIBILITY               ACTION
----   --------------               ------
<S>    <C>                          <C>
 1.    HOT WORK COORDINATOR (HWC)   manages all hot work projects as follows:

                                    -   coordinates hot work with property
                                        management.

                                    -   reviews scope of work.

                                    -   reviews hot work permit.

                                    -   reviews contractor's hot work program
                                        and monitors activities related to
                                        meeting Boston Properties' requirements.

                                    -   secures/reviews permits required by
                                        local authority having jurisdiction.

                                    directs staff in monitoring of project.

                                    completes all items on yellow Hot Work
                                    Permit tag (Part A) - [contact risk
                                    management for additional tags]

                                    inspects area where hot work will be
                                    performed prior to the start of the work.

                                    inspects condition of equipment to be used
                                    to perform hot work to determine that it is
                                    in good condition.

                                    verifies that fire watch personnel are
                                    trained in:

                                    -   preparing the area for hot work.

                                    -   following emergency guidelines for
                                        Fire/Explosion.

                                    -   operating portable fire extinguishers.

                                    -   implementing fire watch
                                        responsibilities.

                                    verifies that the sprinkler system in the
                                    area is not impaired and that additional
                                    portable fire extinguishers are brought to
                                    the area for use by the fire watch.
</TABLE>

                                   Exhibit F-2


                                  Page 16 of 22

<PAGE>

<TABLE>
<S>    <C>                          <C>
                                    posts yellow Hot Work Permit work tag(s) in
                                    area.

                                    implements Impairment Guidelines as
                                    required. (See Section 3 of this Manual.)

2.     PROPERTY MANAGER             coordinates with the HWC, engineering staff,
                                    contractors and tenants as necessary.

                                    notifies tenants of the project if it will
                                    affect their operations.

                                    terminates or suspends any operations that
                                    threatens the safety of the occupants of the
                                    building or could cause damage to the
                                    property.

3.     CHIEF BUILDING ENGINEER      reviews scope of work and supports project
                                    as required.
</TABLE>

II. FIRE WATCH

NOTE: If contractor fire watches are being provided, they must meet the minimum
standards as outlined below.

<TABLE>
<CAPTION>
STEP   RESPONSIBILITY               ACTION
----   --------------               ------
<S>    <C>                          <C>
1.     FIRE WATCH                   verifies that the HWC has inspected area and
                                    that yellow Hot Work Permit tag (Part A) has
                                    been completed and signed.

                                    maintains area free of combustible material
                                    as indicated on yellow Hot Work Permit tag
                                    (Part A)

                                    verifies that all floor openings and
                                    communicative openings to adjacent areas are
                                    covered/closed.

                                    maintains portable fire extinguisher ready
                                    for use and has, at a minimum, one back-up
                                    extinguisher.

                                    maintains a two-way radio, telephone or
                                    other means of quickly reporting a fire
                                    emergency. Emergency telephone numbers
                                    should be in possession of fire watch.

                                    conducts visual surveillance of the hot work
                                    area for possible sparks or fires during
                                    work.

                                    conducts inspections of the work area at the
                                    completion of work.

2.     HWC                          inspects work area at least once during the
                                    work day.

                                    implements corrective actions as necessary.
</TABLE>

                                   Exhibit F-2


                                  Page 17 of 22

<PAGE>

<TABLE>
<S>    <C>                          <C>
                                    suspends work if sprinkler system in area
                                    becomes impaired.
</TABLE>

III. POST-JOB INSPECTION AND REVIEW

<TABLE>
<CAPTION>
STEP   RESPONSIBILITY               ACTION
----   --------------               ------
<S>    <C>                          <C>
1.     FIRE WATCH                   verifies that all equipment used to perform
                                    hot work has been properly secured and/or
                                    removed from area.

                                    conducts inspection of work area and
                                    adjacent areas at conclusion of hot work to
                                    look for sparks or smoldering fires.

                                    restores all fire protection and building
                                    systems to normal operation and notifies
                                    Impairment Coordinator of system(s) status.

                                    conducts follow-up inspection of area for
                                    four hours after the completion of work.

                                    removes yellow Hot Work Permit tag at
                                    conclusion of final inspection (four hours).

                                    completes yellow Hot Work Permit tag (Part
                                    B).

                                    notifies the HWC.

2.     HWC                          inspects area.

                                    reviews completed yellow Hot Work Permit tag
                                    (Part B).

                                    completes Impairment Guidelines as
                                    necessary.

                                    notifies Property Manager and Chief Engineer
                                    of job completion.

                                    maintains completed yellow Hot Work Permit
                                    tag(s) in file.
</TABLE>

                                   Exhibit F-2


                                  Page 18 of 22

<PAGE>

                                  ATTACHMENT C

       CONTRACTOR'S INFORMATIONAL DATA FORM AND PRE-CONSTRUCTION CHECKLIST

THIS FORM SHALL BE COMPLETED AND RETURNED TO BOSTON PROPERTIES MANAGEMENT
OFFICE, INCLUDING ALL ATTACHMENTS AS INDICATED IN THE PRE-CONSTRUCTION
CHECKLIST, PRIOR TO THE START OF ANY WORK.

Location and Tenant Name: ______________________________________________________

Name of Contractor: ____________________________________________________________

Contractor's 24-Hour Phone Number: _____________________________________________

Name of Contractor's Foreman: __________________________________________________

Building Permit Number: ________________________________________________________

Scheduled Start Date: __________________________________________________________

Scheduled Completion Date: _____________________________________________________

PRE-CONSTRUCTION CHECKLIST

_____   Full Set of Plans.

_____   Original Building Permit.

_____   Fire Department Permit (where applicable) upon issuance.

_____   Certificate of Insurance.

_____   Schedule of Work.

_____   List of Subcontractors and Phone Numbers.

_____   Two (2) Keys for Construction Locks.

_____   MSDS log.

I CERTIFY THAT I HAVE READ AND THOROUGHLY UNDERSTAND THE ATTACHED REGULATIONS
FOR BUILDING IMPROVEMENTS AND RENOVATIONS AND AGREE TO COMPLY WITH ALL THE TERMS
AND CONDITIONS.

                                        ----------------------------------------
                                        Signature                      Date

                                        ----------------------------------------
                                        Contractor Name

                                        ----------------------------------------
                                        Local Address

                                        ----------------------------------------
                                        City/State/Zip

                                   Exhibit F-2


                                  Page 19 of 22

<PAGE>

                                  ATTACHMENT D

                           POST-CONSTRUCTION CHECKLIST

THIS FORM SHALL BE COMPLETED AND RETURNED TO BOSTON PROPERTIES MANAGEMENT
OFFICE, INCLUDING ALL ATTACHMENTS AS INDICATED IN THE POST-CONSTRUCTION
CHECKLIST, PRIOR TO THE CONTRACTOR LEAVING THE PREMISES.

Location and Tenant Name: ______________________________________________________
Name of Contractor: ____________________________________________________________
Name of Contractor's Foreman: __________________________________________________
Actual Start Date: _____________________________________________________________
Actual Completion Date: ________________________________________________________

POST-CONSTRUCTION CHECKLIST

_____   Boston Properties Management Punch List Completed.

_____   Certificate of Occupancy (Temporary approval from the City )

_____   Certified Air Balance Report.

_____   Hydrostatic Sprinkler System Test Certificate.

_____   Fire Alarm System Test.

_____   Hard Copy of As-Built Drawing as well as CAD Electronic Files of Both
        Mechanical and Architectural.

_____   Operating Manuals.

_____   Copies of Applicable Warranties.

_____   Signed affidavit for Sprinkler System from Design Engineer of record.

_____   Approved firestopping material installed for all vertical and horizontal
        penetrations.

Contractor agrees to be responsible for assuring that any and all lien claims
(filed or unfiled) pursuant to Chapter 254 of the Massachusetts General Laws as
amended arising as a result of Contractor and/or Contractor's sub-contractors
and supplier's activities are released, terminated, or otherwise disposed of
without cost or expense to the Owner (Boston Properties), and Contractor agrees
to indemnify and hold the Owner (Boston Properties) harmless from all such lien
claims except those arising from the actions or inactions of the Owner(Boston
Properties).


                                        ----------------------------------------
                                        Signature                      Date

                                        ----------------------------------------
                                        Contractor Name

                                        ----------------------------------------
                                        Local Address

                                        ----------------------------------------
                                        City/State/Zip

                                   Exhibit F-2


                                  Page 20 of 22

<PAGE>

                                  ATTACHMENT E

                                  Fee Schedule

All rates listed below are maximum numbers to be used for budgetary purposes.
Actual charges may vary based upon project size.

-    Exclusive Use of Freight Elevators:   $25.00 per hour

-    Oversized Deliveries Requiring Elevator Technicians:

               Foreman:    Regular Time $219.49   Premium Time $353.39
               Mechanic:   Regular Time $195.12   Premium Time $314.15
               Helper      Regular Time $156.04   Premium Time $251.32

One mechanic is required to run the elevator with the hatch opened. To rig items
   on top or under the car requires a minimum of one mechanic and one helper.

-    Removal, Cleaning and Storage of Blinds         $10 per blind

-    Construction Debris Clean-up                    Time and Material

-    Building Access Fee

        Vendors (ie. Telephone, Data, Furniture)     $500.00 per project

        General Contractor

           Project Cost less than $500,000           $1,000 per project

           Project Cost greater than $500,000        $2,500 per project

-    Electric Shutdown Fee (If Required)             Building Electrician Time

                                   Exhibit F-2


                                  Page 21 of 22

<PAGE>

                                    EXHIBIT G

                 BROKER DETERMINATION OF PREVAILING MARKET RENT

     Where in this Lease to which this Exhibit is attached provision is made for
a Broker Determination of Prevailing Market Rent, the following procedures and
requirements shall apply:

1.   Tenant's Request. Tenant shall send a notice to Landlord by the time set
     for such notice in the applicable section of this Lease, requesting a
     Broker Determination of the Prevailing Market Rent, which notice to be
     effective must (i) make explicit reference to this Lease and to the
     specific section of this Lease pursuant to which said request is being
     made, (ii) include the name of a broker selected by Tenant to act for
     Tenant ("Tenant's Broker"), which broker shall be affiliated with a major
     Boston commercial real estate brokerage firm selected by Tenant and which
     broker shall have at least ten (10) years experience dealing in properties
     of a nature and type generally similar to the Building located in the
     Boston Northwest Suburban Market, and (iii) explicitly state that Landlord
     is required to notify Tenant within ten (10) days of an additional broker
     selected by Landlord.

2.   Landlord's Response. Within ten (10) days after Landlord's receipt of
     Tenant's notice requesting the Broker Determination and stating the name of
     the broker selected by Tenant, Landlord shall give written notice to Tenant
     of Landlord's selection of a broker having at least the affiliation and
     experience referred to above ("Landlord's Broker").

3.   Selection of Third Broker. Within ten (10) days thereafter the two (2)
     brokers so selected shall select a third such broker also having at least
     the affiliation and experience referred to above (the "Third Broker").

4.   Rental Value Determination. Within thirty (30) days after the selection of
     the third broker, Landlord's Broker and Tenant's Broker shall each make a
     determination of the annual fair market rental value in as-is condition of
     the applicable space for the applicable period of time under this Lease.
     Such annual fair market rental value determination (i) may include
     provision for annual increases in rent during said term if so determined,
     (ii) shall take into account the as-is condition and location in the
     Building of the applicable space; (iii) shall take account of, and be
     expressed in relation to, the tax and operating cost bases and provisions
     for paying for so-called tenant electricity as contained in this Lease and
     (iv) shall take into account all other relevant factors.

     Landlord's Broker and Tenant's Broker shall each submit their individual
     determinations in writing to the Third Broker, and within thirty (30) days
     after its receipt of the two determinations, the Third Broker shall
     determine whether the proposed annual fair market rental value submitted by
     Landlord's Broker or by Tenant's Broker is closer to the actual prevailing
     market rent for the Premises (taking into account the requirements of
     Section 8.20 and this Exhibit H), and the individual determination thus
     selected by the Third

                                   Exhibit G


                                  Page 1 of 2

<PAGE>

     Broker shall thereafter be referred to as the Prevailing Market Rent.

5.   Costs. Each party shall pay the costs and expenses of the broker selected
     by it and each shall pay one half (1/2) of the costs and expenses of the
     Third Broker.

6.   Failure to Select Broker or Failure of Broker to Serve. If Tenant shall
     have requested a Broker Determination and Landlord shall not have
     designated a broker within the time period provided therefor above, then
     Tenant's Broker shall request the Greater Boston Real Estate Board to
     designate Landlord's Broker. If Tenant's and Landlord's Brokers have been
     designated but the two brokers so designated do not, within a period of
     fifteen (15) days after the appointment of the second broker, agree upon
     and designate the Third Broker willing so to act, the Tenant, the Landlord
     or either broker previously designated may request the Greater Boston Real
     Estate Board, Inc. to designate the Third Broker willing so to act. In case
     of the inability or refusal to serve of any person designated as a broker,
     or in case any broker for any reason ceases to be such, a broker to fill
     such vacancy shall be appointed by the Tenant, the Landlord, the brokers
     first appointed or the said Greater Boston Real Estate Board, Inc., as the
     case may be, whichever made the original appointment, or if the person who
     made the original appointment fails to fill such vacancy, upon application
     of any broker who continues to act or by the Landlord or Tenant, such
     vacancy may be filled by the said Greater Boston Real Estate Board, Inc.
     Any broker appointed by the Greater Boston Real Estate Board, Inc.,
     pursuant to the provisions hereof shall, for all purposes, have the same
     standing and powers as though he had been originally appointed by the party
     originally designated to make such appointment by the terms hereof.

                                   Exhibit G


                                  Page 2 of 2

<PAGE>

                                    EXHIBIT H

                            FORM OF LETTER OF CREDIT

BENEFICIARY:                            ISSUANCE DATE:

_____________________________________   ______________ 200___
_____________________________________   IRREVOCABLE STANDBY
_____________________________________   LETTER OF CREDIT NO. _______
_____________________________________

ACCOUNTEE/APPLICANT:                    MAXIMUM/AGGREGATE
                                        CREDIT AMOUNT: US$__________
____________________________            USD: _______________________

LADIES AND GENTLEMEN:

     We hereby establish our irrevocable letter of credit in your favor for
account of the applicant up to an aggregate amount not to exceed
______________________ and __/100 US Dollars (US $_______________________)
available by your draft(s) drawn on ourselves at sight accompanied by:

     Your statement, signed by a purportedly authorized officer/official
certifying that the Beneficiary is entitled to draw upon this Letter of Credit
(in the amount of the draft submitted herewith) pursuant to the Lease (the
"Lease") dated _______________ by and between ______________, as Landlord, and
____________________, as Tenant, together with the original copy of this Letter
of Credit and any amendments thereto which have been accepted by you.

     Draft(s) must indicate name and issuing bank and credit number and must be
presented at this office.

     You shall have the right to make partial draws against this Letter of
Credit, from time to time.

     This Letter of Credit is transferable at any time and from time to time
without cost to Beneficiary.

     Except as otherwise expressly stated herein, this Letter of Credit is
subject to the "Uniform Customs and practice for Documentary Credits,
International Chamber of Commerce, Publication No. 500 (1993 Revision)."

                                   Exhibit J


                                  Page 1 of 1

<PAGE>

     This Letter of Credit shall expire at our office on _______ ____, 200_ (the
"Stated Expiration Date"). It is a condition of this Letter of Credit that the
Stated Expiration Date shall be deemed automatically extended without amendment
for successive one (1) year period s from such Stated Expiration Date, unless at
least forty-five (45) days prior to such Stated Expiration Date ) (or any
anniversary thereof) we shall notify you at the address specified in this Letter
of Credit (or at such other address of which you may have notified us in
writing) and the Accountee/Applicant in writing by registered mail (return
receipt) that we elect not to consider this Letter of Credit extended for any
such additional one (1) year period.

                                   Exhibit J


                                  Page 2 of 1

<PAGE>

                                    EXHIBIT K

                      LEASE AUDIT CONFIDENTIALITY AGREEMENT

                                                      _______________ ___, 20___

     RE: LEASE DATED ______ (THE "LEASE") BETWEEN ___________ ("LANDLORD") AND
________ ("TENANT") RESPECTING CERTAIN PREMISES LOCATED AT _________ (THE
"PROPERTY") AS MORE PARTICULARLY DESCRIBED IN THE LEASE.

To whom it may concern:

     You have been engaged by Tenant to review the books and records of Landlord
respecting _________ operating expenses for the Property for calendar years
________ and/or ______ real estate taxes for fiscal years _______.

     Landlord is willing to allow you to review such books and records subject
to and in consideration of the terms and conditions set forth below:

     1.   All information made available to you pursuant to this letter, whether
          oral or written, shall be hereinafter referred to as the "Evaluation
          Material." All Evaluation Material provided to you shall remain the
          property of the Landlord. The Evaluation Material shall be handled by
          you in a confidential manner. You shall establish procedures that
          assure that such Evaluation Material shall remain confidential while
          in your possession.

     2.   The review of such books and records shall take place at Landlord's
          offices in Boston, Massachusetts during normal business hours. In no
          event shall any such audit be conducted on a contingency fee basis
          paid to you but shall be contracted and paid for on a fixed-fee basis.

     3.   The Evaluation Material shall be used only for the purpose of
          reviewing the operating expense charges and/or real estate taxes paid
          by Tenant pursuant to the Lease. To this end, you may disclose same to
          your partners, officers, directors and employees, provided, however,
          that you inform each partner, officer, director and employee who has
          access to the Evaluation Material of your obligations under this
          letter. The Evaluation Material may not be disclosed to any third
          party including, without limitation, any other tenant at the Property.

     4.   It is understood and agreed that money damages would not be sufficient
          remedy for any breach of this agreement and that Landlord shall be
          entitled to specific performance and injunctive or other equitable
          relief as a remedy for any such breach and you further agree to waive
          any requirement for the security or posting of any bond in connection
          with such remedy. Such remedy shall not be deemed

                                    Exhibit K


                                   Page 1 of 2

<PAGE>

          to be the exclusive remedy for breach of this agreement but shall be
          in addition to all other remedies available at law or equity to the
          Landlord.

     5.   In the event of litigation relating to this agreement, if a court of
          competent jurisdiction determines in a final, non-appealable order
          that a party has breached this agreement, then such party shall be
          liable and pay to the non-breaching party the reasonable legal fees
          such non-breaching party has incurred in connection with such
          litigation, including any appeal therefrom.

     6.   You agree to indemnify, defend and hold the Landlord, its affiliates
          and agents (including Boston Properties, Inc. and its principals and
          affiliates), and their respective officers, directors, employees and
          representatives harmless, from and against any and all claims, causes
          of action, expenses, fees (including attorney's fees) arising out of
          your actual breach of the provisions of this letter as determined in
          appropriate legal proceedings. The Landlord's and Boston Properties,
          Inc.'s affiliates who have not executed this letter are acknowledged
          to be third party beneficiaries of the provisions hereof.

     7.   This letter sets forth the entire agreement of the parties with
          respect to the subject matter hereof and supersedes all prior
          understandings (whether written, verbal, implied or otherwise) with
          respect thereto. No term or condition of this letter may be waived or
          otherwise modified except by a writing executed by both parties.

     8.   This letter shall be governed by, and construed in accordance with,
          the laws of the Commonwealth of Massachusetts.

                                        Very truly yours,

                                        [Landlord]


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Its:
                                             -----------------------------------

AGREED TO BY:
[Audit Company]


By:
    ---------------------------------
Name:
      -------------------------------
Its:
     --------------------------------
Date:
      -------------------------------


AGREED TO BY:
[Tenant]


By:
    ---------------------------------
Name:
      -------------------------------
Its:
     --------------------------------
Date:
      -------------------------------

                                    Exhibit K


                                   Page 2 of 2

<PAGE>

                                    EXHIBIT L

                                 NOTICE OF LEASE

     Notice is hereby given, pursuant to the provisions of Massachusetts General
Laws Chapter 183, Section 4, of the following Lease:

<TABLE>
<S>                                       <C>
LANDLORD:                                 Boston Properties Limited Partnership,
                                          a Delaware limited partnership

TENANT:                                   iRobot Corporation, a Delaware
                                          corporation

DATE OF EXECUTION:                        February __, 2007

ORIGINAL TERM COMMENCEMENT DATE:          The earlier of (a) the Substantial
                                          Completion Date (as determined in
                                          accordance with Section 3.4(D) of the
                                          Lease), and (b) that date that Tenant
                                          commences occupancy of any portion of
                                          the Premises for the Permitted Uses.

DESCRIPTION OF LEASED PREMISES:           157,776 rentable square feet in the
                                          buildings designated as Building C,
                                          Building D and Building E situated at
                                          4-18 Crosby Drive, Bedford, MA and
                                          more particularly shown on Exhibit A
                                          to the Lease. For legal description of
                                          the property, see Exhibit A attached
                                          to this Notice of Lease.

ORIGINAL TERM:                            One Hundred Forty-Four (144) calendar
                                          months plus the partial month, if any,
                                          immediately following the Commencement
                                          Date.

EXTENSION RIGHTS:                         Two (2) consecutive options to extend
                                          the Original Term for an additional
                                          five (5) years each.

EXPANSION RIGHTS: BUILDINGS F, G AND H:   Tenant has certain rights of first
                                          offer to lease any available space in
                                          Buildings F, G and H at the Property,
                                          all as more particularly described in
                                          Section 8.28 of the Lease.

EXPANSION RIGHTS: BUILDINGS A AND B:      Tenant has certain rights of first
                                          refusal to lease any available space
                                          in Buildings A and B at the Property,
                                          all as more particularly described in
                                          Section 8.29 of the Lease.

RIGHTS TO USE LAND RECREATION SPACE:      Tenant has certain rights to use
                                          certain areas of the land and a
                                          portion of land adjacent to the
                                          Property, all as more particularly
                                          described in Section 8.27 of the
                                          Lease.
</TABLE>

     The foregoing is a summary of certain terms of the Lease for purposes of
giving notice thereof,

                                    Exhibit L


                                   Page 1 of 5

<PAGE>

and shall not be deemed to modify or amend the terms of the Lease. For
Landlord's title to the Property, see deeds recorded with the Middlesex South
District Registry of Deeds in Book 12926, Page 233 and in Book 13539, Page 732.

     Executed as a sealed instrument on this ____ day of February, 2007.

                                          LANDLORD:

                                          BOSTON PROPERTIES LIMITED PARTNERSHIP


                                          By:
                                              ----------------------------------
                                          Name:
                                                --------------------------------
                                          Title:
                                                 -------------------------------


                                          TENANT:

                                          iROBOT CORPORATION


                                          By:
                                              ----------------------------------
                                          Name:
                                                --------------------------------
                                          Title:
                                                 -------------------------------

                                    Exhibit L


                                   Page 2 of 5

<PAGE>

COMMONWEALTH OF MASSACHUSETTS )
                              )
COUNTY OF ___________________ )

     On this ___ day of February, 2007, before me, the undersigned notary
public, personally appeared ________________________, proved to me through
satisfactory evidence of identification, which were
_____________________________________, to be the person whose name is signed on
the preceding or attached document and acknowledged to me that (he)(she) signed
it voluntarily for its stated purpose, as __________________________ for Boston
Properties Limited Partnership,


                                         ---------------------------------------
                                         (Official Signature and Seal of Notary)
                                         My Commission Expires:

COMMONWEALTH OF MASSACHUSETTS )
                              )
COUNTY OF ___________________ )

     On this ___ day of February, 2007, before me, the undersigned notary
public, personally appeared ________________________, proved to me through
satisfactory evidence of identification, which were
_____________________________________, to be the person whose name is signed on
the preceding or attached document and acknowledged to me that (he)(she) signed
it voluntarily for its stated purpose, as __________________________ for iRobot
Corporation,


                                         ---------------------------------------
                                         (Official Signature and Seal of Notary)
                                         My Commission Expires:

                                    Exhibit L


                                   Page 3 of 5
<PAGE>

                                    EXHIBIT A
                          LEGAL DESCRIPTION OF PROPERTY

Those certain parcels of land (with the buildings thereon) situated in Bedford,
Middlesex County, Massachusetts bounded and described as follows:

PARCELS 1 and 2

Two certain parcels of land situated in Bedford, Middlesex County,
Massachusetts, shown as Lot 1 and 2 on a plan entitled "Plan of Land in Bedford,
Mass." dated March 1, 1962 by Raymond C. Pressey, Inc., recorded with Middlesex
South District Deeds as Plan No. 487 of 1962 in Book 10022, Page 278, and
together bound and described as follows:

<TABLE>
<S>             <C>
SOUTHWESTERLY   by Crosby Road by three lines measuring respectively two hundred
                eighty-three and 01/100 (283.01) feet, twenty-one and 27/100
                (21.27) feet and four hundred eighty-three and 43/100 (483.43)
                feet; thence

SOUTHERLY       by said Crosby Road by a curved line, one hundred nineteen and
                36/100 (119.36) feet; thence

SOUTHEASTERLY
SOUTHERLY and
SOUTHWESTERLY   by said Crosby Road by several lines measuring respectively two
                hundred ninety-three and 04/100 (293.04) feet, three hundred
                fifty-three and 04/100 (353.04) feet and two hundred twenty and
                97/100 (220.97) feet; thence

NORTHEASTERLY   by the parcel marked "Reserved for Town of Bedford" on said
                plan, sixteen hundred forty-six and 81/100 (1646.81) feet; and
                thence

NORTHWESTERLY   by land now or late of The Worcester Corp., by two lines
                measuring respectively 305.23 feet and 294.24 feet and by land
                now or late of Douglas by two lines measuring respectively
                170.33 feet and 64.34 feet, to the place of beginning.
</TABLE>

For Title see Deed recorded with the Middlesex South District Registry of Deeds
in Book 12926, Page 233.

PARCEL 3

A certain parcel of land situated in said Bedford, shown on a plan of land in
Bedford, Mass. Dated June 5, 1961 by Raymond C. Pressey, Inc., Registered Land
Surveyors, recorded with Middlesex South District Registry of Deeds at the end
of Book 9844, bounded and described as follows:

                                    Exhibit L


                                   Page 4 of 5

<PAGE>

<TABLE>
<S>             <C>
SOUTHWESTERLY   by Crosby Road, two hundred ninety-eight and 63/100 (298.63)
                feet;

NORTHWESTERLY   by land now or formerly of the Worcester Corporation, two
                hundred nine and 95/100 (209.95) feet;

NORTHEASTERLY   by land now or formerly of the Worcester Corporation, two
                hundred fifty and 57/100 (250.57) feet; and

SOUTHEASTERLY   by land now or formerly of Sinbad Realty Corporation by two
                lines respectively measuring one hundred seventy and 33/100
                (170.33) feet and sixty-four and 34/100 (64.34) feet.
</TABLE>

Containing approximately 60,951 square feet of 1.4 acres according to said plan.

For Title see Deed from Cecil N. Douglas and Priscilla M. Douglas recorded with
the Middlesex South District Registry of Deeds in Book 13539, Page 732.

PARCEL 4

All right, title and interest in and to (i) that portion of Crosby Road
described in that certain Deed (a) recorded with the Middlesex South District
Registry of Deeds in Book 14013, Page 486 and (b) filed with the Middlesex South
Registry District of the Land Court as Document No. 599584 as to which
Certificate of Title No. 161163 in Registration Book 936, Page 13 was issued;
and (ii) such other applicable portions of Crosby Road abutting the westerly
boundaries of Parcels 1, 2 and 3.

Parcels 1, 2, 3 and 4 are subject to and together with the benefit of easements,
agreements restrictions, rights of way and takings of record at said Registry of
Deeds and Registry District if and to the extent in force and applicable.

                                    Exhibit L


                                   Page 5 of 5

<PAGE>

                                    EXHIBIT M

                        CURRENT MORTGAGEE'S FORM OF SNDA

             SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT

     THIS AGREEMENT is made and entered into as of the ____day of __________
2007, by and among IROBOT CORPORATION, a Delaware corporation ("Tenant"), whose
principal address is 63 South Avenue, Burlington, Massachusetts 01803, and NEW
YORK LIFE INSURANCE COMPANY, a New York mutual insurance company ("Lender"),
whose principal address is 51 Madison Avenue, New York, New York 10010, and
BOSTON PROPERTIES LIMITED PARTNERSHIP, a Delaware limited partnership
("Borrower"), whose address is 111 Huntington Avenue, Suite 300, Boston,
Massachusetts 02199.

                                    RECITALS:

     A. Lender has agreed to make a mortgage loan (the "Loan") to Borrower in
the amount of $______ to be secured by, among other things, a mortgage [or deed
of trust] (the "Mortgage") on the real property legally described in Exhibit "A"
attached hereto (the "Premises");

     B. Tenant is the present lessee under a lease dated ______, 2007 made by
Boston Properties Limited Partnership, ("Landlord"), demising a portion of the
Premises (said lease and all amendments now or hereafter executed with respect
thereto being referred to as the "Lease");

     C. The Loan terms require that Tenant subordinate the Lease and its
interest in the Premises in all respects to the lien of the Mortgage and that
Tenant attorn to Lender; and

     D. In return, Lender is agreeable to not disturbing Tenant's possession of
the portion of the Premises covered by the Lease (the "Demised Premises"), so
long as Tenant is not in default under the Lease.

     NOW, THEREFORE, in consideration of the mutual covenants contained herein
and other consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereby agree as follows:

                                   AGREEMENTS:

     1. Subordination. The Lease, and the rights of Tenant in, to and under the
Lease and the Demised Premises are hereby subjected and subordinated to the lien
of the Mortgage and to any modification, reinstatement, extension, renewal,
supplement, consolidation or replacement thereof as well as any advances or
re-advances with interest thereon and to any other mortgages or deeds of trust
on the Premises which may hereafter be held by Lender.

     2. Tenant Not to Be Disturbed. In the event it should become necessary to
foreclose the Mortgage or Lender should otherwise come into possession of title
to the Premises, Lender will not

                                    Exhibit M


                                   Page 1 of 8

<PAGE>

join Tenant in summary or foreclosure proceedings unless required by law in
order to obtain jurisdiction, but in such event no judgment foreclosing the
Lease will be sought, and Lender will not disturb the use and occupancy of
Tenant under the Lease so long as Tenant is not in default under the Lease
beyond applicable notice and cure periods provided for therein, and the sale of
the Premises in any such action or proceeding shall be made subject to all
rights of Tenant set forth in the Lease.

     3. Tenant to Attorn to Lender. Tenant agrees that in the event of a
foreclosure of the Mortgage or upon a transfer of the Premises pursuant to a
deed in lieu of foreclosure, it will attorn to the purchaser (including Lender)
as the landlord under the Lease. The purchaser by virtue of such foreclosure or
deed in lieu of foreclosure shall be deemed to have assumed and agreed to be
bound, as substitute landlord, by the terms and conditions of the Lease until
the resale or other disposition of its interest by such purchaser, except that
such assumption shall not be deemed of itself an acknowledgment by such
purchaser of the validity of any then existing claims of Tenant against any
prior landlord (including Landlord). All rights and obligations under the Lease
shall continue as though such foreclosure proceedings had not been brought,
except as aforesaid. Tenant agrees to execute and deliver to any such purchaser
such further assurance and other documents, including a new lease upon the same
terms and conditions of the Lease, confirming the foregoing as such purchaser
may reasonably request. Tenant waives the provisions (i) contained in the Lease
or any other agreement relating thereto and (ii) of any statute or rule of law
now or hereafter in effect which may give or purport to give it any right or
election to terminate or otherwise adversely affect the Lease and the
obligations of Tenant thereunder by reason of any foreclosure proceeding.

     4. Limitations. Notwithstanding the foregoing, neither Lender nor such
other purchaser shall in any event be:

     (a)  liable for any act or omission of any prior landlord (including
          Landlord), except to the extent any such act or omission of which
          Tenant has notified Lender or purchaser constitutes a continuing
          default under the Lease after Lender or purchaser has accepted title
          to the Premises;

     (b)  obligated to cure any defaults of any prior landlord (including
          Landlord) which occurred prior to the time that Lender or such other
          purchaser succeeded to the interest of such prior landlord under the
          Lease, except to the extent Tenant has notified Lender or purchaser of
          such default and the same constitutes a continuing default under the
          Lease after Lender or purchaser has accepted title to the Premises;

     (c)  subject to any offsets or defenses which Tenant may be entitled to
          assert against any prior landlord (including Landlord), except to the
          extent such offsets or defenses arise out of any breach of the Lease
          to the extent such breach continues after the date Lender or such
          purchaser has accepted title to the Premises and Lender has been
          notified of the same;

     (d)  bound by any payment of rent or additional rent by Tenant to any prior
          landlord (including Landlord) for more than one month in advance;

                                    Exhibit M


                                   Page 2 of 8

<PAGE>

     (e)  bound by any amendment or modification of the Lease made without the
          written consent of Lender or such other purchaser, provided, however,
          Lender's or purchaser's consent shall not be required for amendments
          or modifications that are made in connection with Tenant's exercise of
          its rights under Section 8.20, Section 8.28 and/or Section 8.29 of the
          Lease; or

     (f)  liable or responsible for, or with respect to, the retention,
          application and/or return to Tenant of any security deposit paid to
          any prior landlord (including Landlord), whether or not still held by
          such prior landlord, unless and until Lender or such other purchaser
          has actually received for its own account as landlord the full amount
          of such security deposit.

     5. Acknowledgment of Assignment of Lease and Rent. Tenant acknowledges that
it has notice that the Lease and the rent and all other sums due thereunder have
been assigned or are to be assigned to Lender as security for the Loan secured
by the Mortgage. In the event that Lender notifies Tenant of a default under the
Mortgage and demands that Tenant pay its rent and all other sums due under the
Lease to Lender, Tenant agrees that it will honor such demand and pay its rent
and all other sums due under the Lease directly to Lender or as otherwise
required pursuant to such notice. By its execution hereof, Borrower expressly
consents to the foregoing.

     6. Limited Liability. Tenant acknowledges that in all events, the liability
of Lender and any purchaser shall be limited and restricted to their interest in
the Premises (including the rents, proceeds and other income therefrom) and
shall in no event exceed such interest.

     7. Lender's Right to Notice of Default and Option to Cure. Tenant will give
written notice to Lender of any default by Landlord under the Lease by mailing a
copy of the same by certified mail, postage prepaid, addressed as follows (or to
such other address as may be specified from time to time by Lender to Tenant):

To Lender: NEW YORK LIFE INSURANCE COMPANY
           c/o New York Life Investment Management LLC
           51 Madison Avenue
           New York, New York 10010-1603
           Attn: Real Estate Group
           Director - Loan Administration Division
           Loan No.: 372-0055

Upon such notice, Lender shall be permitted and shall have the option, in its
sole and absolute discretion, to cure any such default during the period of time
during which the Landlord would be permitted to cure such default, but in any
event Lender shall have a period of thirty (30) days after the receipt of such
notification to cure such default; provided, however, that if such default does
not prevent the continued operation of Tenant's business at the Demised
Premises, Lender may have a period of not more than one hundred eighty (180)
days to effectuate such cure. Notices to Tenant shall be sent to Tenant pursuant
to the terms of the Lease.

     8. Successors and Assigns. The provisions of this Agreement are binding
upon and shall

                                    Exhibit M


                                   Page 3 of 8

<PAGE>

inure to the benefit of the heirs, successors and assigns of the parties hereof.

     9. Counterparts. This Agreement may be executed in any number of
counterparts, all of which taken together shall constitute one and the same
instrument and any of the parties hereto may execute this Agreement by signing
any such counterpart.

     10. Governing Law. This Agreement shall be construed and enforced according
to the law of the state in which the Premises are located, other than such law
with respect to conflicts of law.

     IN WITNESS WHEREOF, the parties hereto have executed these presents as of
the day and year first above written.

                           [SIGNATURE PAGES TO FOLLOW]

                                    Exhibit M


                                   Page 4 of 8

<PAGE>

                                        TENANT

                                        IROBOT CORPORATION
                                        (Printed Name of Tenant)
                                        a Delaware corporation


                                        By:
                                            -----------------------------------
                                        (Signature)

                                        ---------------------------------------
                                        (Printed Name of Signatory)

                                        Its:
                                        ---------------------------------------
                                        (Title)

COMMONWEALTH OF MASSACHUSETTS )
                              )
COUNTY OF ________________    )

     On this ___ day of _____________, 200__, before me, the undersigned notary
public, personally appeared ________________________, proved to me through
satisfactory evidence of identification, consisting of ________________________,
to be the person whose name is signed on the preceding or attached document and
acknowledged to me that (he)(she) signed it voluntarily for its stated purpose,
as __________________________ for _______________________________,


                                        ----------------------------------------
                                        (Official Signature and Seal of Notary)
                                        My Commission Expires:

                                    Exhibit M


                                   Page 5 of 8

<PAGE>

                                        LENDER

                                        NEW YORK LIFE INSURANCE COMPANY,  a
                                        New York mutual insurance company


                                        By:
                                            ------------------------------------
                                        (Signature)

                                        ----------------------------------------
                                        (Printed Name)

                                        Its:

                                        ----------------------------------------
                                        (Title)

STATE OF _______________ )
                         ) SS:
COUNTY OF ______________ )

                     [ADD STATE APPROPRIATE ACKNOWLEDGMENT]

                                    Exhibit M


                                   Page 6 of 8

<PAGE>

The terms of the above Agreement are hereby consented, agreed to and
acknowledged.

                                        BORROWER

                                        ----------------------------------------
                                        (Printed Name of Borrower)
                                        a
                                          --------------------------------------


                                        By:
                                            ------------------------------------
                                        (Signature)

                                        ----------------------------------------
                                        (Printed Name of Signatory)

                                        Its:
                                             -----------------------------------

                                        ----------------------------------------
                                        (Title)

COMMONWEALTH OF MASSACHUSETTS )
                              )
COUNTY OF ___________________ )

     On this ___ day of _____________, 200__, before me, the undersigned notary
public, personally appeared ________________________, proved to me through
satisfactory evidence of identification, consisting of ________________________,
to be the person whose name is signed on the preceding or attached document and
acknowledged to me that (he)(she) signed it voluntarily for its stated purpose,
as __________________________ for __________________________,


                                        ----------------------------------------
                                        (Official Signature and Seal of Notary)
                                        My Commission Expires:

                                    Exhibit M


                                   Page 7 of 8

<PAGE>

THIS INSTRUMENT WAS PREPARED BY AND
WHEN RECORDED SHOULD BE RETURNED TO:

_______________________, ESQ.
NEW YORK LIFE INSURANCE COMPANY
OFFICE OF THE GENERAL COUNSEL
51 MADISON AVENUE
NEW YORK, NEW YORK 10010

                                    Exhibit M


                                   Page 8 of 8

<PAGE>

                                    EXHIBIT N

                         FORM OF LANDLORD'S LIEN WAIVER

Re:  Lease dated _______________ __, 20__ by and between ____________________,
     as landlord ("Landlord") and _____________________________, as tenant
     ("Tenant") respecting certain premises (the "Premises") containing
     approximately ______ square feet of rentable floor area in the building
     known as and numbered ______________________ ___________________________
     (the "Lease").

     FOR VALUABLE CONSIDERATION, the Landlord hereby waives all claims against
or liens upon the personal property owned by Tenant and the proceeds therefrom
(and replacements, substitutions and additions for or to the foregoing)
installed or to be installed in the Premises in which
___________________________ (the "Bank"), its successors or assigns now or
hereafter holds a security interest other than additions, alterations or
improvements which are the property of the Landlord or shall remain in the
Premises upon the expiration or earlier termination of the Lease term pursuant
to the terms of the Lease (the "Collateral"), until such time as the earlier of
the following occurs: (i) all moneys due the Bank by the Tenant shall have been
paid in full or (ii) fourteen (14) days after Tenant is no longer in lawful
possession of the Premises. Notwithstanding the foregoing, Landlord does not
waive, relinquish or modify (i) any and all claims for rent and additional rent
under the Lease or (ii) any obligations on the part of the Tenant to be
performed under the Lease.

     Until the date which is fourteen (14) days after Tenant is no longer in
lawful possession of the Premises, Landlord agrees to interpose no objections to
the entry by the Bank, its successors and assigns, upon the Premises for the
purpose of removing and/or liquidating the Collateral in the event of default by
the Tenant in its obligations to the Bank, provided that (a) the Bank restores
any walls, windows, doors, partitions, roofs, floors or other parts of the
Premises damaged by it in the course of removal, to their condition at the time
of the Bank's entry into the Premises, (b) said entry is made during normal
business hours with prior written notice to Landlord and (c) no sale or viewing
of the Collateral shall take place on the Premises.

     SIGNED and SEALED on behalf of the successors and assigns of the
undersigned this ____ day of _________, 1997.

                                        LANDLORD:


                                        By:
                                            ------------------------------------

Tenant hereby consents to and agrees to be bound by the terms set forth herein.


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------
Date:
      -------------------------------

                                    Exhibit O


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