Document:

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                                                                    Exhibit 10.5

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                          LOAN AGREEMENT (SECOND LIEN)

                                     between

                              WATERFORD PARK, LLC,
                                        as Borrower

                                       and

                                 SEPRACOR, INC.
                                        as Lender

                             as of January 30, 2001

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Relating to a 192,600 (+/-) square foot office building at Solomon Pond
Corporate Center, Marlborough, Massachusetts, and secured by a second leasehold
mortgage lien thereon.

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                                TABLE OF CONTENTS

                                                                            Page
                                                                            ----

1.   DEFINITIONS AND RULES OF INTERPRETATION...................................1
   1.1    Definitions..........................................................1
   1.2    Rules of Interpretation..............................................8
2.   AGREEMENT TO MAKE ADVANCES; LIMITATIONS...................................9
   2.1    Agreement to Make Advances...........................................9
   2.2    Project Budget.......................................................9
   2.3    Amount of Advances...................................................9
   2.4    Limitation on Advances...............................................9
   2.5    Cost Overruns and Savings...........................................10
   2.6    Contingency Reserve.................................................10
   2.7    Stored Materials....................................................10
3.   MAKING THE ADVANCES......................................................10
   3.1    Draw Request........................................................10
   3.2    Notice and Frequency of Advance.....................................12
   3.3    Payment of Funds Advanced...........................................12
   3.4    Advances to Contractor to Others....................................12
   3.5    Advances Do Not Constitute a Waiver.................................12
   3.6    Right to Retain the Construction Inspector..........................12
4.   THE NOTE; REPAYMENT OF LOAN..............................................13
   4.1    The Note............................................................13
   4.2    The Record..........................................................13
   4.3    Interest on the Loan; Payments on the Loan..........................13
   4.4    Prepayment..........................................................15
   4.5    Maturity............................................................15
5.   LOAN MATURITY DATE; CONVERSION OF CONSTRUCTION LOAN......................15
   5.1    Loan Maturity Date..................................................15
   5.2    Extension of Maturity Date..........................................15
6.   FEES; PAYMENTS AND COMPUTATIONS..........................................15
   6.1    Commitment and Administration Fee...................................15
   6.2    Inspection Fee......................................................15
   6.3    Place of Payments...................................................15
7.   COLLATERAL SECURITY AND GUARANTY.........................................16
8.   REPRESENTATIONS, WARRANTIES AND COVENANTS................................16
   8.1    Organization; Authority, Etc........................................16
   8.2    Title to Assets.....................................................16
   8.3    Financial Statements................................................17
   8.4    No Material Changes, Etc............................................17
   8.5    Franchises, Patents, Copyrights, Etc................................17
   8.6    Litigation..........................................................17
   8.7    No Materially Adverse Contracts, Etc................................17
   8.8    Compliance With Other Instruments, Laws, Etc........................17

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   8.9    Tax Status..........................................................17
   8.10   No Event of Default.................................................18
   8.11   Setoff, Etc.........................................................18
   8.12   Certain Transactions................................................18
   8.13   Subsidiaries........................................................18
   8.14   Partners, Beneficiaries, Etc........................................18
   8.15   ERISA...............................................................18
   8.16   Availability of Utilities...........................................18
   8.17   Access..............................................................18
   8.18   Condition of Project................................................18
   8.19   Compliance with Requirements........................................19
   8.20   Project Approvals...................................................19
   8.21   Construction Contract; Architect's Contract.........................19
   8.22   Other Contracts.....................................................19
   8.23   Violations..........................................................20
   8.24   Plans and Specifications............................................20
   8.25   Project Budget......................................................20
   8.26   Effect of Draw Request..............................................20
9.   AFFIRMATIVE COVENANTS OF THE BORROWER....................................20
   9.1    Punctual Payment....................................................20
   9.2    Commencement, Pursuit and Completion of Construction................20
   9.3    Correction of Defects...............................................21
   9.4    Insurance; Bonds....................................................21
   9.5    Inspection of Project and Books.....................................21
   9.6    Compliance with Laws, Contracts, Licenses, and Permits..............22
   9.7    Use of Proceeds.....................................................22
   9.8    Project Costs.......................................................22
   9.9    Laborers, Subcontractors and Materialmen............................22
   9.10   Further Assurance of Title..........................................23
   9.11   Further Assurances Regarding Construction...........................23
10.  NEGATIVE COVENANTS OF THE BORROWER.......................................23
   10.1   Restriction on Change Orders........................................23
   10.2   No Amendments, Terminations or Waivers..............................24
11.  CONDITIONS TO CLOSING AND INITIAL ADVANCE................................24
   11.1   Loan Documents......................................................24
   11.2   Construction Documents..............................................24
   11.3   Subcontracts........................................................24
   11.4   Contracts...........................................................25
   11.5   Leases..............................................................25
   11.6   Certified Copies of Organization Documents..........................25
   11.7   Resolutions.........................................................25
   11.8   Incumbency Certificate; Authorized Signers..........................25
   11.9   Validity of Liens...................................................25
   11.10     Deliveries.......................................................25
   11.11     Construction Inspector Report....................................26

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   11.12     Legal and Other Opinions.........................................26
   11.13     Lien Search......................................................26
   11.14     Mechanic's Lien Law..............................................27
   11.15     Notices..........................................................27
   11.16     Appraisal........................................................27
   11.17     Fees.............................................................27
   11.18     Performance; No Default..........................................27
   11.19     Representations and Warranties...................................27
   11.20     Proceedings and Document.........................................27
   11.21     Waiver...........................................................27
   11.22     Incomplete Construction Documents................................27
12.  CONDITIONS OF SUBSEQUENT ADVANCES........................................28
   12.1   Prior Conditions Satisfied..........................................28
   12.2   Performance; No Default.............................................28
   12.3   Representations and Warranties......................................28
   12.4   No Damage...........................................................28
   12.5   Receipt of the Lender...............................................28
   12.6   Mechanic's Lien Law.................................................29
   12.7   Release of Retainage................................................30
   12.8   Waiver..............................................................30
13.  EVENTS OF DEFAULT AND REMEDIES...........................................30
   13.1   Events of Default...................................................30
   13.2   Termination of Advances and Acceleration............................33
   13.3   Completion of Project...............................................34
   13.4   Other Remedies......................................................35
   13.5   Distribution of Collateral Proceeds.................................35
   13.6   Power of Attorney...................................................36
   13.7   Waivers.............................................................36
14.  SETOFF...................................................................36
15.  SUBORDINATION; FORBEARANCE; OFFSET.......................................37
16.  TERMINATION; DISCHARGE; SUBSTITUTE MEMBERSHIP INTEREST...................37
17.  EXPENSES.................................................................38
18.  INDEMNIFICATION..........................................................39
19.  LIABILITY OF THE LENDER..................................................40
20.  RIGHTS OF THIRD PARTIES..................................................40
21.  SURVIVAL OF COVENANTS, ETC...............................................40
22.  ASSIGNMENT AND PARTICIPATION.............................................40
23.  RELATIONSHIP.............................................................41
24.  NOTICES..................................................................41
25.  GOVERNING LAW............................................................42
26.  CONSENT TO JURISDICTION; WAIVERS.........................................42
27.  HEADINGS.................................................................42
28.  COUNTERPARTS.............................................................43
29.  ENTIRE AGREEMENT, ETC....................................................43
30.  CONSENTS, AMENDMENTS, WAIVERS, ETC.......................................43

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31.  TIME OF THE ESSENCE......................................................43
32.  SEVERABILITY.............................................................43

EXHIBITS

            A   -    Construction Schedule
            B   -    Disbursement Schedule
            C   -    [Reserved]
            D   -    [Reserved]
            E   -    Plans and Specifications
            F   -    Project Budget
            G   -    Borrower's Requisition
            H   -    Contractor's Requisition Certificate
            I   -    [Reserved]
            J   -    Tenant Improvements Summary
            K   -    Lien Form
            L   -    [Reserved]
            M   -    [Reserved]
            N   -    [Reserved]

                                    SCHEDULES
            8.14            -  Partners, Beneficiaries, Etc.
            Schedule 8.20   -  Project Approvals

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                                 LOAN AGREEMENT

      This LOAN AGREEMENT (SECOND LIEN) is made as of the 30th day of January
2001, by and among WATERFORD PARK LLC, a Massachusetts limited liability company
(the "Borrower"), having its principal place of business c/o Waterford
Development Corp., 175 Highland Avenue, Needham, Massachusetts 02494 , and
SEPRACOR, INC. (the "Lender"), having an address at 111 Locke Drive,
Marlborough, Massachusetts 01752.

      1. DEFINITIONS AND RULES OF INTERPRETATION.

      1.1 Definitions. The following terms as used in this Agreement, any
Exhibit hereto, or in any other Loan Document (unless otherwise defined therein)
shall have the meanings set forth in this ss.1. Further, any and all terms which
are defined in the Note and not otherwise defined herein shall have the meanings
set forth therein:

      Advance. Any disbursement of the proceeds of the Loan made or to be made
by the Lender pursuant to the terms of this Agreement.

      Agreement. This Loan Agreement, including the Schedules and Exhibits
hereto.

      Architect. Clifford Hoffman Associates, a subcontractor under the
Construction Contract.

      Borrower's Requisition. See ss.3. 1.

      Business Day. A day of the year on which banks are not required or
authorized by law to close in Boston, Massachusetts or New York, New York.

      Closing Date. The first date on which the conditions set forth inss.11
have been satisfied for the initial Advance.

      Code. The Internal Revenue Code of 1986 and the regulations thereunder,
all as amended and in effect from time to time.

      Collateral. All of the property, rights and interests of the Borrower that
are or are intended to be subject to the security interests, assignments, and
mortgage liens created by the Security Documents, including, without limitation,
the Project.

      Construction Contract. Collectively, (i) the contract, to be entered into
between the Borrower and the Contractor, providing for the construction of the
Improvements, and (ii) the contract, to be entered into among the Borrower,
Contractor and Tenant, relating to change orders initiated by Tenant. The
Construction Contract must be reasonably satisfactory to Borrower, Lender and
Tenant. Tenant, not the Borrower, shall be responsible for the selection,
ordering and purchasing of all "Tenant Equipment and Fixtures" as referred to on
the Project

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Budget; and Tenant shall bear the burden of, and enjoy the benefit of, any cost
overruns or savings with respect thereto.

      Construction Inspector. A consulting architect, engineer or inspector
engaged by the Lender, subject to the approval of the Borrower, which approval
shall not be unreasonably withheld or delayed. The Construction Inspector's fees
and expenses shall be included in the Project Costs..

      Construction Period. The period of time during which the Project is being
constructed. The Construction Period ends on the "Commencement Date", as such
term is defined in the Tenant Lease.

      Construction Schedule. The schedule, broken down by trade, job and
subcontractor, of the estimated dates of commencement and completion of
construction of the Improvements, prepared by the Contractor, approved by the
Lender and attached hereto as Exhibit A.

      Contingency Reserve. The amount of $634,338 ($141,795 for Indirect Costs
and $492,543 for Direct Costs) has been allocated as contingency reserve in the
Project Budget, to be advanced only in accordance with the provisions of ss.2.6
hereof.

      Contractor. Erland Construction, Inc., a corporation having a usual place
of business at 63 Second Avenue, Burlington, Massachusetts 01803.

      Default. A condition or event which would, with either the giving of
notice or lapse of time or both, constitute an Event of Default.

      Development Company. Waterford Development Corp., or other Person
reasonably acceptable to the Lender with whom the Borrower has, or will, enter
into an agreement to develop the Improvements.

      Direct Costs. The costs of the Land, the Personal Property, and all labor,
materials, fixtures, machinery and equipment required to construct, equip and
complete the Improvements in accordance with the Plans and Specifications.

      Disbursement Schedule. The schedule of the amounts of Advances anticipated
to be requisitioned by the Borrower each month during the term of the
construction of the Improvements (including an itemization of Direct Costs and
Indirect Costs to be included in each such requisition), approved by the Lender
and attached hereto as Exhibit B.

      Drawdown Date. The date on which any Advance is made or is to be made.

      Draw Request. With respect to each Advance, the Borrower's Requisition for
such Advance and all other documents required by this Agreement to be furnished
to the Lender as a condition to such Advance.

      Environmental Laws. As specifically defined in the Mortgage.

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      ERISA Plan. Any employee benefit, employee pension, or multi-employer plan
within the meaning of the Employee Retirement Income Security Act of 1974, as
amended and in effect from time to time.

      Event of Default. See ss.13.1.

      Financing Statements. Uniform Commercial Code Form I Financing
Statement(s) from the Borrower in favor of the Lender.

      First Mortgage Loan. The $20,860,000 loan by Lender to Borrower with
respect to the Project, secured by a first lien on the Project.

      First Mortgage Loan Documents. The loan agreement, note and other
documents relating to the First Mortgage Loan, including the First Mortgage Loan
Security Documents.

      First Mortgage Loan Security Documents. The first mortgage, assignment of
leases and rents and other documents securing the First Mortgage Loan.

      Force Majeure. Any Act of God, war, civil commotion, embargo, flood,
unavoidable fire or other casualty, strikes, picketing or other labor
difficulties not within the reasonable control of the Borrower, governmental
restrictions or changes in law, unavailability or shortages of labor, materials
or equipment not reasonably anticipated by the Borrower, unusually severe
weather or any other cause or event which is beyond the reasonable control of
the Borrower.

      GAAP. Principles that are (a) consistent with the principles promulgated
or adopted by the Financial Accounting Standards Board and its predecessors, as
in effect from time to time and (b) consistently applied with past financial
statements of the Borrower adopting the same principles; provided that a
certified public accountant would, insofar as the use of such accounting
principles is pertinent, be in a position to deliver an unqualified opinion
(other than a qualification regarding changes in GAAP) as to financial
statements in which such principles have been properly applied.

      Governmental Authority. The United States of America, The Commonwealth of
Massachusetts, the Town of Marlborough, Massachusetts, and any political
subdivision, agency, authority, department, commission, board, bureau, or
instrumentality of any of them.

      Ground Lease. The Ground Lease, dated January 30, 2001, from Hillside
School Inc. as landlord, to Borrower as tenant, relating to the Land.

      Guarantors. Collectively, Richard N. Houlding, Margaret C. Houlding and
Robert E. Shapiro, including as to each of them their estates, heirs and legal
representatives.

      Guaranty. The Joint and Several Guaranty Agreement, dated or to be dated
on or prior to the Closing Date, made by the Guarantors in favor of the Lender
with respect to the Loan.

      Improvements. A 192,600 square foot four story office building with
parking for < > cars to be constructed on the Land in accordance with the Plans
and Specifications, together with

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offsite improvements as shown on "Offsite Highway Improvement Plans for Solomon
Pond Road-Goddard Road-Bearfoot Road" prepared by Anderson-Nichols & Co., dated
October 24, 2000. Some of such offsite improvements are to be made on the "Phase
II Land" and "Phase III Land" as defined in the Tenant Lease.

      Indebtedness. All obligations, contingent and otherwise, that in
accordance with GAAP should be classified upon the Obligors' balance sheets as
liabilities, or to which reference should be made by footnotes thereto,
including in any event and whether or not so classified: (a) all debt and
similar monetary obligations, whether direct or indirect; (b) all liabilities
secured by any mortgage, pledge, security interest, lien, charge, or other
encumbrance existing on property owned or acquired subject thereto, whether or
not the liability secured thereby shall have been assumed; (c) all liabilities
under capitalized leases; and (d) all guaranties, endorsements and other
contingent obligations whether direct or indirect in respect of indebtedness of
others, including the obligations to reimburse the issuer in respect of any
letters of credit.

      Indemnity Agreement. The Indemnity Agreement Regarding Hazardous
Materials, dated or to be dated on or prior to the Closing Date, made by the
Borrower and the Guarantors in favor of the Lender.

      Indirect Costs. All title insurance premiums, survey charges, engineering
fees, architectural fees, real estate taxes, appraisal costs, commitment fees,
brokers' commissions, permit fees and interest payable to the Lender under the
Loan, premiums for insurance, legal fees, accounting fees, overhead and
administrative costs, and all other expenses as shown on the Project Budget
which are expenditures relating to the Project and are not Direct Costs.

      Installments. The constant monthly payments of principal and interest to
be paid by the Borrower to the Lender under the amendment and restatement of the
Note provided for in Section 5.3(a)(iv) hereof.

      Investments. All expenditures made and all liabilities incurred
(contingently or otherwise) for the acquisition of stock or Indebtedness of, or
for loans, advances, capital contributions or transfers of property to, or in
respect to any guaranties (or other commitments as described under
Indebtedness), or obligations of, any Person.

      Land. The parcel of land located at Solomon Pond Corporate Center in
Marlborough, Massachusetts, which is described in Exhibit A to the Mortgage and
Schedule DL of the Tenant Lease.

      Leases. Any and all leases, licenses and agreements, whether written or
oral, relating to the use or occupation of space in the Improvements or on the
Land by Persons other than the Borrower, including without limitation the Tenant
Lease.

      Lender. Sepracor, Inc., a Delaware corporation, as lender under this Loan
Agreement and the other Loan Agreements.

      Lien Form. See ss.3.1.

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      Loan Amount. The loan or any portion thereof which is the subject of this
Agreement.

      Loan Amount. $6,458,597.

      Loan Documents. This Agreement, the Note, the Indemnity Agreement, the
Guaranty, and the Security Documents, and all other agreements, documents and
instruments now or hereafter evidencing, securing or otherwise relating to the
Loan.

      Maturity Date. February 1, 2016, but in no event earlier than the
expiration date of the Tenant Lease.

      Mechanic's Lien Law. See ss.3.1.

      Mortgage. The Mortgage and Security Agreement, dated or to be dated on or
prior to the Closing Date, made by the Borrower in favor of the Lender, relating
to the Loan.

      Non-Disturbance, Attornment and Subordination Agreement. [Intentionally
omitted because the Tenant Lease is superior to the lien of the Mortgage.]

      Note. The Note, dated as of the date hereof, in the original principal
amount equal to the Loan Amount, made by the Borrower to the order of the
Lender.

      Obligations. All indebtedness, obligations and liabilities of the Borrower
to the Lender, existing on the date of this Agreement or arising thereafter in
connection with the Loan, direct or indirect, joint or several, absolute or
contingent, matured or unmatured, liquidated or unliquidated, secured or
unsecured, arising by contract, operation of law or otherwise, including,
without limitation, the Project Obligations.

      Obligors. The Borrower, each Guarantor, and if the Borrower is a
partnership, each general partner of the Borrower.

      Organizational Documents. For any corporation, partnership, trust, limited
liability company, limited liability partnership, unincorporated association,
business or other legal entity, the documents pursuant to which such entity has
been established or organized, as such documents may be amended from time to
time.

      Other Mechanic's Lien. Any statutory lien or common law lien relating to
claims for labor, materials, or supplies, whether established under the
Mechanic's Lien Law or otherwise, except for a Section 1 Lien or Section 2 Lien.

      Party(ies). Each Obligor; if the Borrower is a partnership, each partner
authorized to execute documents on behalf of the Borrower; if the Borrower is a
limited liability company, each manager of the Borrower or each member
authorized to execute documents on behalf of the Borrower; and if the Borrower
is a trust, each trustee of the Borrower.

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      Payment, Performance and Lien Bond. [Intentionally Omitted.]

      Payment Period Date. See ss.3.1.

      Permitted Exceptions. See definition of Title Policy. The First Mortgage
Loan Security Documents are Permitted Exceptions.

      Person. Any individual, corporation, partnership, trust, unincorporated
association, business, or other legal entity, and any government or any
governmental agency or political subdivision thereof

      Personal Property. All materials, furnishings, fixtures, furniture,
machinery, equipment and all items of tangible or intangible personal property
now or hereafter owned or acquired by the Borrower, in which the Lender has
been, or will be granted an interest to secure the Project Obligations
specifically excluding, however, any personal property now or hereafter owned or
acquired by the Tenant.

      Plans and Specifications. The plans and specifications for the
Improvements prepared by the Borrower's Architect and more particularly
identified on Exhibit E attached hereto, as the same may be amended from time to
time as provided herein.

      Project. The Land, Improvements and Personal Property.

      Project Approvals. All approvals, consents, waivers, orders, agreements,
acknowledgments, authorizations, permits and licenses required under applicable
Requirements or under the terms of any restriction, covenant or easement
affecting the Project, or otherwise necessary or desirable, for the ownership,
acquisition, construction, equipping, use, occupancy and operation of the
Project and the Improvements, whether obtained from a Governmental Authority or
any other Person. Project Approvals do not include any specialized permits (or
the like) relating to Tenant's activity in or on, or use of, the Project.

      Project Budget. The budget for total estimated Project Costs, submitted by
the Borrower, approved by the Lender attached hereto as Exhibit F, which
includes: (a) a line item cost breakdown for Direct Costs by category; (b) a
line item cost breakdown for Indirect Costs by category; and (c) a schedule of
the sources of funds to pay Project Costs, indicating by item the portion of
Project Costs to be funded through the Loan, Required Equity Funds and amounts
to be funded by Tenant pursuant to the Tenant Lease, and as such Project Budget
may be revised from time to time as provided herein.

      Project Completion. With respect to the construction of the Improvements,
the determination by the Lender that (i) the Borrower has completed the
construction of the Improvements substantially in accordance with the Plans and
Specifications and the terms and conditions hereof, and (ii) the Borrower has
satisfied all of the conditions of ss.12.7, hereof, for the release of the
Retainage.

      Project Completion Date. The "Outside Completion Date" as defined in the
Tenant Lease.

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      Project Costs. The sum of all Direct Costs and Indirect Costs that have
been or will be incurred by the Borrower in connection with the acquisition of
the Land, the construction, equipping and completion of the Improvements, the
marketing and leasing of leasable space in the Improvements, and the operation
and carrying of the Project through the Construction Loan Maturity Date.

      Project Obligations. All indebtedness, obligations and liabilities of the
Borrower to the Lender existing on the date of this Agreement or arising
thereafter, direct or indirect, joint or several, absolute or contingent,
matured or unmatured, liquidated or unliquidated, secured or unsecured, arising
by contract, operation of law or otherwise, arising or incurred under this
Agreement or any of the other Loan Documents or in respect of any of the
Advances or the Note.

      Record. Any record, including computer records, maintained by the Lender
with respect to the balance due under the Loan.

      Registry. The Middlesex South Registry of Deeds, located in Cambridge,
Massachusetts.

      Requirements. Any law, ordinance, code, order, rule or regulation of any
Governmental Authority relating in any way to the acquisition, ownership,
construction, use, occupancy and operation of the Project and the Improvements.

      Required Equity Funds. The amount of $2,152,866.

      Requisition Amount. The total amount of the Direct Costs and/or Indirect
Costs to be paid on any given date pursuant hereto.

      Section 1 Lien. A lien under Section 1 of the Mechanic's Lien Law, other
than in connection with the construction of improvements on the Land containing
or designed to contain at least one, but no more than four, dwelling units.

      Section 2 Lien. A lien under Section 2 of the Mechanic's Lien Law, other
than in connection with the construction of improvements on the Land containing
or designed to contain at least one, but no more than four, dwelling units.

      Section 4 Lien. A lien under Section 4 of the Mechanic's Lien Law.

      Security Documents. The Mortgage, the Collateral Assignment of Contracts,
Licenses, Permits, Agreements, Warranties and Approvals, dated as of the date
hereof, the Assignment of Leases and Rents dated as of the date hereof, the
Financing Statements, the Indemnity Agreement and the Guaranty, and any other
agreement, document or instrument now or hereafter securing the Project
Obligations.

      Stored Materials. See ss.2.7.

      Subsidiary. Any corporation, partnership, association, trust, or other
business entity of which the designated parent shall at any time own directly,
or indirectly through a Subsidiary or Subsidiaries, at least a majority (by
number of votes) of the outstanding voting interests therein.

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      Survey. An instrument survey of the Land and the Improvements prepared in
accordance with the Lender's survey requirements, such survey to be reasonably
satisfactory to the Lender in form and substance.

      Surveyor Certificate. With respect to any Survey, a certificate executed
by the surveyor who prepares such Survey dated as of a recent date and
containing such information relating to the Project as the Lender or the Title
Insurance Company may require, such certificate to be satisfactory to the Lender
in form and substance.

      Taking. Any condemnation for public use of, or damage by reason of, the
action of any Governmental Authority, or any transfer by private sale in lieu
thereof, either temporarily or permanently.

      Tenant. Sepracor, Inc., a Delaware corporation, as tenant under the Tenant
Lease.

      Tenant Lease. The Lease, dated January 30, 2001, from Borrower as landlord
to Tenant as tenant, of the land and improvements.

      Title Insurance Company. Chicago Title Insurance Company, with a usual
place of business at 75 Federal Street, Suite 410, Boston, Massachusetts 02110.

      Title Policy. An ALTA standard form title insurance policy issued by the
Title Insurance Company (with such reinsurance or co-insurance as the Lender may
require, any such reinsurance to be with direct access endorsements) in an
amount not less than the Loan Amount insuring the priority of the Mortgage as a
second lien on the Project and that the Borrower holds a valid and subsisting
leasehold interest in the Project, under the Ground Lease, subject only to such
exceptions as the Lender may approve, ("Permitted Exceptions") and shall contain
such endorsements and affirmative insurance as the Lender in its discretion may
require provided that such endorsements and affirmative insurance is available
in The Commonwealth of Massachusetts at commercially reasonable rates.

      1.2 Rules of Interpretation.

            (a) A reference to any Loan Document, agreement, budget, document or
      schedule shall include such agreement, budget, document or schedule as
      revised, amended, modified or supplemented from time to time in accordance
      with its terms and the terms of this Agreement.

            (b) A reference to any Exhibit hereto shall be deemed to
      specifically incorporate the terms and provisions of such Exhibit herein.

            (c) The singular includes the plural and the plural includes the
      singular.

            (d) A reference to any law includes any amendment or modification to
      such law.

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            (e) A reference to any Person includes its permitted successors and
      permitted assigns.

            (f) Accounting terms not otherwise defined herein have the meaning
      assigned to them by GAAP applied on a consistent basis by the accounting
      entity to which they refer.

            (g) The words "approval" and "approved", as the context so
      determines, means an approval in writing given to the party seeking
      approval after full and fair disclosure to the party giving approval of
      the facts necessary in order to determine whether approval should be
      granted.

            Reference to a particular "ss." refers to that Section of this
      Agreement unless otherwise indicated.

      2. AGREEMENT TO MAKE ADVANCES; LIMITATIONS.

      2.1 Agreement to Make Advances. Subject to the terms and conditions of
this Agreement, the Lender agrees to lend to the Borrower and the Borrower may
borrow from time to time between the Closing Date and the Termination Date, such
amounts as are requested by the Borrower up to a maximum aggregate principal
amount equal to the Loan Amount to pay for Project Costs actually incurred by
the Borrower and reflected in the Project Budget as being funded by the Loan.

      2.2 Project Budget. The Project Budget reflects the purposes and the
amounts for which funds to be advanced by the Lender under this Agreement are to
be used. The Lender shall not be required to disburse for any category or line
item more than the amount specified therefor in the Project Budget, provided
that (i) such change has been made in accordance with Article IV of the Tenant
Lease, and (ii) the aggregate cost of the Project is not thereby increased,
unless the increase is to be paid by Tenant under the Tenant Lease or,
alternatively, a funding source for any such increase has been provided to
Lender's satisfaction.

      2.3 Amount of Advances. In no event shall the Lender be obligated to
advance more than the Construction Loan Amount, or, if less, total Project Costs
actually incurred by the Borrower less Required Equity Funds.

      2.4 Limitation on Advances. Lender shall not be obligated to fund any
Advance unless all of the following conditions have been satisfied:

            (a) As to any Requisition Amount, Lender shall pay 50% as an Advance
      only if concurrently therewith Borrower pays 50% thereof out of Required
      Equity Funds until Borrower's Required Equity Funds shall have been
      exhausted, and thereafter Lender's portion shall be 100%. Borrower shall
      be required to provide to Lender reasonable evidence of Borrower's having
      satisfied the foregoing conditions.

            (b) The relevant Requisition Amount shall be within the amounts
      shown on the Project Budget for the particular Project Costs in question.

Second Lien                           -9-
<PAGE>

Any waiver with regard to all or any of the foregoing requirements may be
granted or withheld by Lender in its sole discretion.

      2.5 Cost Overruns and Savings [Intentionally Omitted.]

      2.6 Contingency Reserve [Intentionally Omitted.]

      2.7 Stored Materials. The Lender shall not be required to disburse any
funds for any materials, furnishings, fixtures, machinery or equipment not yet
incorporated into the Land or Improvements ("Stored Materials"), however, if the
Lender elects to disburse any funds for Stored Materials, any such disbursement
shall be subject to retainage in an amount equal to ten percent (10%) and shall
be contingent upon the Lender receiving satisfactory evidence that:

            (a) the Stored Materials are components in a form ready for
      incorporation into the Land or the Improvements and shall be so
      incorporated within a period of thirty (30) days;

            (b) the Stored Materials are stored at the Land, or at such other
      site as the Lender shall reasonably approve, and are protected against
      theft and damage;

            (c) the Stored Materials have been paid for in full or will be paid
      for with the funds to be disbursed and all lien rights and claims of the
      supplier have been released or will be released upon payment with
      disbursed funds;

            (d) the Lender has or will have upon payment with disbursed funds a
      perfected, first priority security interest in the Stored Materials; and

            (e) the Stored Materials are insured for an amount equal to their
      replacement cost.

      3. MAKING THE ADVANCES

      3.1 Draw Request. At such time as the Borrower shall desire to obtain an
Advance, the Borrower shall complete, execute and deliver to the Lender a
Borrower's Requisition in the form of Exhibit G attached hereto. Such Borrower's
Requisition shall show the Requisition Amount for the Project Costs in question
and the portion thereof being funded from Borrower's Required Equity Funds
($2,152,886). The amount of the requested Advance shall be 50% thereof until
Borrower's Required Equity Funds shall have been exhausted, and thereafter,
100%. Each Borrower's Requisition shall be accompanied by:

            (a) If the Borrower's Requisition includes payments for Direct
      Costs, a completed and itemized Direct Cost Statement in the form of
      Schedule I of Exhibit G attached hereto, executed by the Borrower,
      together with invoices for all items of Direct Cost covered thereby;

            (b) If the Borrower's Requisition includes amounts to be paid to the
      Contractor under the Construction Contract: (i) a completed and fully
      itemized

Second Lien                           -10-
<PAGE>

      Application and Certificate for Payment (AIA Document G702 or similar form
      approved by the Lender) containing the certification of the Contractor and
      the Borrower's Architect as to the accuracy of same; (ii) a certificate of
      the Contractor in the form of Exhibit H attached hereto (with such changes
      therein as the Contractor may reasonably request, subject to the approval
      of the Lender which approval will not be unreasonably delayed or denied);
      (iii) a certificate of the Borrower's Architect in the form of Exhibit I
      attached hereto (with such changes therein as the Borrower's Architect may
      reasonably request, subject to the approval of the Lender which approval
      will not be unreasonably delayed or denied); and (iv) copies of
      requisitions and invoices from subcontractors and materialmen supporting
      all items of cost covered by such application;

            (c) If the Borrower's Requisition includes payments for Indirect
      Costs, it shall be accompanied by a completed and itemized Indirect Cost
      Statement in the form of Schedule II of Exhibit G attached hereto,
      executed by the Borrower, together with invoices for all items of Indirect
      Costs covered thereby;

            (d) If the Borrower's Requisition includes payments for tenant
      improvements, it shall be accompanied by a completed and itemized Tenant
      Improvements Summary in the form of Exhibit J attached hereto, executed by
      the Borrower;

            (e) If requested by the Lender or if a Section 2 Lien has been
      filed, an accurately completed and valid Partial Waiver and Subordination
      of Lien (hereinafter, the "Lien Form") in the form set forth in Chapter
      254 of the Massachusetts General Laws, as amended (hereinafter, the
      "Mechanic's Lien Law") and as annexed hereto as Exhibit K, executed by the
      Contractor, such Lien Form to provide that subject to the payment of the
      amount set forth in the Borrower's Requisition, the Contractor waives any
      and all lien rights for labor and materials, or rental equipment,
      appliances or tools, performed or furnished through the last day of the
      period ending on the date designated in the Lien Form (hereinafter, the
      "Payment Period Date"), except for Retainage, unpaid agreed or pending
      change orders, and disputed claims as stated in the Lien Form;

            (f) Lien waivers in form acceptable to the Lender executed by all
      contractors, subcontractors, laborers and materialmen for work done and
      materials supplied by them which were paid for pursuant to the next
      preceding Draw Request;

            (g) Copies of all change orders and construction change directives,
      accompanied by a change order summary prepared by and executed by the
      Borrower, copies of all subcontracts, and, to the extent requested by the
      Lender, of all inspection or test reports and other documents relating to
      the construction of the Improvements, not previously delivered to the
      Lender;

            (h) If the Borrower's Requisition includes payment for Stored
      Materials, it shall be accompanied by evidence as to the satisfaction of
      the requirements set forth in ss.2.7 hereof; and

Second Lien                           -11-
<PAGE>

            (i) such other information, documentation and certification as the
      Lender shall reasonably request.

Each Draw Request shall constitute a representation and warranty by the Borrower
that all of the conditions set forth in this Agreement to such Advance,
including, without limitation, ss.12, have been satisfied on the date of such
Draw Request.

      3.2 Notice and Frequency of Advance. Each Draw Request shall be submitted
to the Lender at least ten (10) days prior to the date of the requested Advance,
and no more frequently than once each month. Subject to the provisions hereof,
the Lender shall fund the requested Advance within ten (10) days after the Draw
Request for such Advance is made in accordance with the requirements of Section
3.1 hereof.

      3.3 Payment of Funds Advanced. The Lender shall pay the proceeds of each
Advance into a separate bank account of the Borrower established for the purpose
of funding Project Costs at an FDIC insured bank in Massachusetts selected by
the Borrower, subject to the reasonable approval of the Lender.

      3.4 Advances to Contractor to Others. At its option, at any time after a
Default or Event of Default shall have occurred and be continuing hereunder and
the Lender shall have given the Borrower two (2) days' notice of its intention
to do so, the Lender may make any or all Advances (a) for Direct Costs incurred
under the Construction Contract directly to Contractor, (b) through the Title
Insurance Company, or (c) to any Person to whom the Lender in good faith
determines payment is due. Any portion of the Loan so disbursed by the Lender
shall be deemed disbursed as of the date on which the Lender makes such
disbursement and all such advances shall satisfy pro tanto the obligations of
the Lender hereunder and shall be secured by the Mortgage and the other Security
Documents as fully as if made directly to the Borrower. The execution of this
Agreement by the Borrower shall, and hereby does, constitute an irrevocable
authorization so to advance the proceeds of the Loan. No further authorization
from the Borrower shall be necessary to warrant such advances.

      3.5 Advances Do Not Constitute a Waiver. No Advance made by the Lender
shall constitute a waiver of any of the conditions to the Lender's obligation to
make further Advances nor any of the terms and conditions of this Agreement,
nor, in the event the Borrower fails to satisfy any such condition, shall any
such Advance have the effect of precluding the Lender from thereafter declaring
such failure to satisfy a condition to be an Event of Default.

      3.6 Right to Retain the Construction Inspector.

            (a) The Lender shall have the right to retain, at the Borrower's
      cost and expense, the Construction Inspector to perform various services
      on behalf of the Lender, including, without limitation, to make periodic
      inspections (approximately at the date of each Draw Request) for the
      purpose of assuring that construction of the Improvements to date is in
      accordance with the Plans and Specifications, to advise the Lender of the
      anticipated cost of and time for completion of construction of the
      Improvements and the adequacy of any Contingency Reserve, and to review
      the Construction Contract and

Second Lien                           -12-
<PAGE>

      subcontracts. The Construction Inspector named herein is acceptable to
      Borrower, however, if Lender shall elect to appoint a new Construction
      Inspector, the Lender shall appoint a Construction Inspector that has an
      office located in The Commonwealth of Massachusetts.

            (b) The fees and expenses of the Construction Inspector shall be
      paid by the Borrower forthwith upon billing therefor (whether the same are
      charged directly to the Lender or the Borrower), and, if the Lender shall
      pay any such fees and expenses, the Borrower shall reimburse the Lender
      for such fees and expenses forthwith upon request therefor.

            (c) Neither the Lender nor the Construction Inspector shall have any
      liability to the Borrower on account of (i) the services performed by the
      Construction Inspector, or (ii) any approval by the Construction Inspector
      of construction of the Improvements. Neither the Lender nor the
      Construction Inspector assumes any obligation to the Borrower or any other
      Person concerning the quality of construction of the Improvements or the
      absence therefrom of defects.

      4. THE NOTE; REPAYMENT OF LOAN.

      4.1 The Note. The obligation of the Borrower to pay the Loan Amount or, if
less, the aggregate unpaid principal amount of all Advances made by the Lender
hereunder plus accrued interest thereon, shall be evidenced by the Note. In the
event the Note is lost, destroyed or mutilated at any time prior to payment in
full of the indebtedness evidenced thereby, the Borrower shall execute a new
note in the form of the Note. The Note shall not be necessary to establish the
indebtedness of the Borrower to the Lender on account of Advances made under
this Agreement.

      4.2 The Record. The Borrower irrevocably authorizes the Lender to make or
cause to be made, at or about the time of the Drawdown Date of any Advance or at
the time of receipt of any payment of the principal of the Note, an appropriate
notation on the Record reflecting the making of such Advance or (as the case may
be) the receipt of such payment. The outstanding amount of the Loan set forth on
the Record shall be prima facie evidence of the principal amount thereof owing
and unpaid to the Lender, but the failure to record, or any error in so
recording, any such amount on the Record shall not limit or otherwise affect the
obligations of the Borrower hereunder or under the Note to make payments of
principal or interest on the Note when due. Further, the outstanding amount of
the Loan as reflected on the Record from time to time shall be considered
correct and binding on the Borrower unless within ten (10) Business Days after
receipt of any notice by the Borrower of such outstanding amount, the Borrower
shall notify the Lender to the contrary.

      4.3 Interest on the Loan; Payments on the Loan. The Loan shall bear
interest, and be payable, as follows:

            (a) the "Interest Rate" referred to in the Note shall be determined
      as follows:

Second Lien                           -13-
<PAGE>

                  (i)   During the Construction period, the "Interest Rate" (as
                        referred to in the Note) on the outstanding principal
                        balance of the Note shall be that rate of interest per
                        annum equal to LIBOR plus two and one-half percent
                        (2.5%). As used herein, the term "LIBOR", with respect
                        to the relevant Interest Period (as defined below),
                        shall mean the rate per annum (rounded upward, if
                        necessary, to the nearest one-eighth (1/8) of one
                        percent (1%) published on the date one "Eurodollar
                        Business Day" (as defined below) immediately preceding
                        the date of the LIBOR contract for each new Interest
                        Period, as reported in the section entitled "Money
                        Rates" in the eastern edition of the Wall Street Journal
                        as the one-month London Interbank Offered Rate for U.S.
                        dollar deposits (or if the Wall Street Journal shall
                        cease to be publicly available or if the information
                        contained in the Wall Street Journal, in Lender's
                        reasonable judgment, shall cease to accurately reflect
                        such London Interbank Offered Rate, then LIBOR shall be
                        as reported by any publicly available source of similar
                        market data selected by Lender that, in Lender's
                        reasonable judgment, accurately reflects such London
                        Interbank Offered Rate). The term "Interest Period"
                        shall mean each calendar month during the term of the
                        Loan and shall be deemed to be the respective one-month
                        term of a particular LIBOR contract; provided, however,
                        that for the month of the initial Advance, the term
                        "Interest Period" shall mean the period commencing with
                        the date of the initial Advance and ending on the last
                        day of the calendar month in which the initial Advance
                        was drawn. The term "Eurodollar Business Day" shall mean
                        any day that is not a Saturday, a Sunday, a day on which
                        Lender is closed for business or a day on which banks in
                        the City of London or the City of New York are required
                        or permitted to be closed for interbank or foreign
                        exchange transactions.

                  (ii)  Upon the completion of the Construction Period, the
                        Interest Rate shall be fixed at a rate per annum equal
                        to the then applicable yield to maturity of 10-year U.S.
                        Treasury obligations as reported in the section entitled
                        "Money Rates" in the eastern edition of the Wall Street
                        Journal (or if the Wall Street Journal shall cease to be
                        publicly available or if the information contained in
                        the Wall Street Journal, in Lender's reasonable
                        judgment, shall cease to accurately reflect Treasury
                        yields, then such yields shall be as reported by any
                        publicly available source of similar market data
                        selected by Lender that, in Lender's reasonable
                        judgment, accurately reflects such yield), plus two and
                        one-half percent (2.5%).

            (b)   Payments on the Note shall be as follows:

Second Lien                           -14-
<PAGE>

                  (i)   During the Construction Period payments on the Note
                        shall be of interest only and shall be payable monthly
                        in arrears.

                  (ii)  After the end of the Construction Period and upon the
                        resetting of the Interest Rate as provided in Section
                        4.3(a)(ii) above, the Note shall continue to be payable
                        as to interest only, payments monthly in arrears. On the
                        first day of February, 2016, the entire unpaid balance
                        of the Note, unless sooner paid, shall immediately be
                        due and payable.

      4.4 Prepayment. The Borrower may prepay the Note from time to time, in
whole or in part, after giving 30 days prior written notice thereof, without
prepayment penalty.

      4.5 Maturity. The Borrower promises to pay on the Maturity Date, and there
shall become absolutely due and payable on the Maturity Date, all principal of
the Loan outstanding on such date, together with any and all accrued and unpaid
interest thereon.

      5. LOAN MATURITY DATE; CONVERSION OF CONSTRUCTION LOAN

      5.1 Loan Maturity Date. The Loan Maturity Date shall be February 1, 2016.

      5.2 Extension of Maturity Date. [Intentionally Omitted.]

      6. FEES; PAYMENTS AND COMPUTATIONS

      6.1 Commitment and Administration Fee. [Intentionally Omitted.]

      6.2 Inspection Fee. [Intentionally Omitted.]

      6.3 Place of Payments.

            (a) All payments of principal, interest, fees and any other amounts
      due under the Note or under any of the other Loan Documents shall be sent
      to the Lender at SEPRACOR, INC., 111 Locke Drive, Marlborough,
      Massachusetts 01752, or at such other location or bank account as the
      Lender may from time to time designate, in the billing invoice or
      otherwise in writing, in immediately available funds in lawful money of
      the United States.

            (b) All payments by the Borrower under the Note and under any of the
      other Loan Documents shall be made without setoff or counterclaim and free
      and clear of and without deduction for any taxes, levies, imposts, duties,
      charges, fees, deductions, withholdings, compulsory loans, restrictions or
      conditions of any nature now or hereafter imposed or levied by any
      jurisdiction or any political subdivision thereof or taxing or other
      authority therein unless the Borrower is compelled by law to make such
      deduction or withholding.

Second Lien                           -15-
<PAGE>

      7. COLLATERAL SECURITY AND GUARANTY. The Obligations shall be secured by a
perfected first priority mortgage lien and security in the Collateral, whether
now owned or hereafter acquired, pursuant to the terms of the Security Documents
to which the Borrower is a party. The Obligations shall also be guarantied
pursuant to the terms of the Guaranty.

      8. REPRESENTATIONS, WARRANTIES AND COVENANTS. The Borrower represents,
warrants, and covenants to the Lender as follows:

      8.1 Organization; Authority, Etc.

            (a) Organization; Good Standing. The Borrower is a limited liability
      company duly organized under the laws of The Commonwealth of Massachusetts
      pursuant to the Borrower's Organizational Documents, and is, and will at
      all times be, validly existing and in good standing under the laws of such
      State. The Borrower is, and will at all times be, duly organized and is,
      and will at all times be, validly existing, in good standing, and
      qualified to do business in each jurisdiction where required. The Borrower
      has, and will at all times have, all requisite power to own its property
      and conduct its business as now conducted and as presently contemplated.

            (b) Authorization. The execution, delivery and performance of this
      Agreement and the other Loan Documents to which any Party is or is to
      become a party and the transactions contemplated hereby and thereby (i)
      are within the authority of such Party, (ii) have been duly authorized by
      all necessary proceedings on the part of such Party, (iii) do not conflict
      with or result in any breach or contravention of any provision of law,
      statute, rule or regulation to which such Party is subject or any
      judgment, order, writ, injunction, license or permit applicable to such
      Party, (iv) do not conflict with any provision of the Organizational
      Documents of such Party, and (v) do not require the approval or consent
      of, or filing with, any governmental agency or authority other than those
      already obtained and the filing of the Security Documents and the
      Financing Statements in the appropriate public records with respect
      thereto.

            (c) Enforceability. The execution and delivery of this Agreement and
      the other Loan Documents to which each Obligor is or is to become a party
      will result in valid and legally binding obligations of such Obligor
      enforceable against it in accordance with the respective terms and
      provisions hereof and thereof, except as enforceability is limited by
      bankruptcy, insolvency, reorganization, moratorium or other laws relating
      to or affecting generally the enforcement of creditors' rights and except
      to the extent that availability of the remedy of specific performance or
      injunctive relief is subject to the discretion of the court before which
      any proceeding therefor may be brought.

            (d) Limitations. The Organizational Documents of the Borrower limit
      the business of the Borrower to activities relating to the ownership,
      construction, operation and maintenance of the Project and all matter
      incidental or accessory thereto.

      8.2 Title to Assets. [Intentionally Omitted.]

Second Lien                           -16-
<PAGE>

      8.3 Financial Statements. [Intentionally Omitted.]

      8.4 No Material Changes, Etc. [Intentionally Omitted.]

      8.5 Franchises, Patents, Copyrights, Etc. The Borrower possesses, and will
at all times possess, all franchises, patents, copyrights, trademarks, trade
names, licenses and permits, and rights in respect of the foregoing, adequate
for the conduct of its business substantially as now conducted or as it is
intended to be conducted with respect to the Project, without known conflict
with any rights of others.

      8.6 Litigation. There are no actions, suits, proceedings or investigations
of any kind pending or, to the actual knowledge of the Obligors, threatened
against any Obligor before any court, tribunal or administrative agency or board
or any mediator or arbitrator that, if adversely determined, might, either in
any case or in the aggregate, materially adversely affect the business, assets
or financial condition of such Person, or result in any liability not adequately
covered by insurance, or for which adequate reserves are not maintained on the
balance sheet of such Person, or which question the validity of this Agreement
or any of the other Loan Documents, any action taken or to be taken pursuant
hereto or thereto, or any lien or security interest created or intended to be
created pursuant hereto or thereto, or which will adversely affect the ability
of the Borrower to construct, use and occupy the Improvements or to pay and
perform the Project Obligations in the manner contemplated by this Agreement and
the other Loan Documents.

      8.7 No Materially Adverse Contracts, Etc. Each Obligor is not subject to
any charter, corporate or other legal restriction, or any judgment, decree,
order, rule or regulation that has or is expected in the future to have a
materially adverse effect on the business, assets or financial condition of such
Person. Each Obligor is not, and will not be, a party to any contract or
agreement that has or is expected, in the judgment of the Borrower's officers,
to have any materially adverse effect on the business of such Person.

      8.8 Compliance With Other Instruments, Laws, Etc. Each Party is not, and
will not at any time be, in violation of any provision of its Organizational
Documents or any agreement or instrument to which it may be subject or by which
it or any of its properties may be bound or any decree, order, judgment,
statute, license, rule or regulation, in any of the foregoing cases in a manner
that could result in the imposition of substantial penalties or materially and
adversely affect the financial condition, properties or business of such Party.

      8.9 Tax Status. Each Obligor and Subsidiary thereof (a) has made or filed,
and will make or file in a timely fashion, all federal and state income and all
other tax returns, reports and declarations required by any jurisdiction to
which it is subject, (b) has paid, and will pay when due, all taxes and other
governmental assessments and charges shown or determined to be due on such
returns, reports and declarations, except those being contested in good faith
and by appropriate proceedings, (c) if a partnership, limited partnership,
limited liability partnership, or limited liability company, has, and will
maintain, partnership tax classification under the Code, and (d) has set aside,
and will at all times set aside, on its books provisions reasonably adequate for
the payment of all taxes for periods subsequent to the period to which such
returns, reports or declarations apply. There are no unpaid taxes in any
material amount claimed to be due by the

Second Lien                           -17-
<PAGE>

taxing authority of any jurisdiction, and the officers, partners or trustees of
the Borrower know of no basis for any such claim.

      8.10 No Event of Default. No Default or Event of Default has occurred and
is continuing.

      8.11 Setoff, Etc. The Collateral and the Lender's rights with respect to
the Collateral are not subject to any setoff, claims, withholdings or other
defenses.

      8.12 Certain Transactions. [Intentionally Omitted.]

      8.13 Subsidiaries. The Borrower does not, and will not have any,
Subsidiaries.

      8.14 Partners, Beneficiaries, Etc. Except as set forth in Schedule 8.14,
the Borrower has no general partners, limited partners, partners, beneficiaries,
stockholders or members.

      8.15 ERISA. The Borrower does not, and will not maintain or contribute to
an ERISA Plan. The Borrower is not a "party in interest" as that term is defined
in Section 3(14) of the Employee Retirement Income Security Act of 1974, as
amended, with respect to the Plumbers & Pipefitters National Pension Plan.

      8.16 Availability of Utilities. All utility services necessary and
sufficient for the construction, development and operation of the Project are
presently, and will at all times be, available to the boundaries of the Land
through dedicated public rights of way or through perpetual private easements,
approved by the Lender, with respect to which the Mortgage creates a valid and
enforceable first leasehold lien. The Borrower will also promptly obtain all
utility installations and connections required for the operation and servicing
of the Project for its intended purposes, and will furnish the Lender with
evidence thereof.

      8.17 Access. The rights of way for all roads necessary for the full
utilization of the Improvements for their intended purposes have either been
acquired by the appropriate Governmental Authority or have been dedicated to
public use and accepted by such Governmental Authority or, if any such roads
have not been so acquired by the appropriate Governmental Authority or dedicated
to public use, the Borrower has been granted an easement, insured in the Title
Policy as appurtenant to the Property as may be necessary for the full
utilization of the Improvements for their intended purposes. All such roads
shall have been completed, or all necessary steps have been taken by the
Borrower and such Governmental Authority to assure the complete construction and
installation thereof prior to the date upon which access to the Project via such
roads will be necessary, and the right to use all such roads,. or suitable
substitute rights of way approved by the Lender, shall be maintained at all
times for the Project. All curb cuts, driveways and traffic signals shown on the
Plans and Specifications are existing or have been fully approved by the
appropriate Governmental Authority and after the completion thereof, shall be
maintained at all times for the Project.

      8.18 Condition of Project. Neither the Project nor any part thereof is now
damaged or injured as result of any fire, explosion, accident, flood or other
casualty or has been the subject of any Taking, and to the knowledge of the
Borrower, no Taking is pending or contemplated.

Second Lien                           -18-
<PAGE>

      8.19 Compliance with Requirements. The construction of the Improvements
and the use and occupancy of the Project contemplated thereby comply with, and
will at times comply with, all Requirements. The Borrower will give all such
notices to, and take all such other actions with respect to, such Governmental
Authority as may be required under applicable Requirements to construct the
Improvements and to use, occupy and operate the Project following Project
Completion.

      8.20 Project Approvals.

            (a) Except as set forth on Schedule 8.20A hereto, the Borrower has
      obtained all Project Approvals. All Project Approvals obtained by the
      Borrower are listed and described on Schedule 8-20B hereto, have been
      validly issued and are in full force and effect. The Borrower has no
      reason to believe that any of the Project Approvals not heretofore
      obtained by the Borrower will not be obtained by the Borrower in the
      ordinary course following Project Completion in accordance with the Plans
      and Specifications. No Project Approvals will terminate, or become void or
      voidable or terminable, upon any sale, transfer or other disposition of
      the Project, including any transfer pursuant to foreclosure sale under the
      Mortgage.

            (b) The Borrower will promptly obtain all Project Approvals not
      heretofore obtained by the Borrower (including those listed and described
      on Schedule 8.20A hereto and any other Project Approvals which may
      hereafter become required, necessary or desirable) and will furnish the
      Lender with evidence that the Borrower has obtained such Project Approvals
      promptly upon its request.

            (c) The Borrower will duly perform and comply with all of the terms
      and conditions of all Project Approvals obtained at any time, including
      all Project Approvals listed and described on Schedules 8.20A and 8.20B
      hereto.

      8.21 Construction Contract.. The Construction Contract is in full force
and effect and each of the parties thereto are in full compliance with their
respective obligations thereunder. The work to be performed by the Contractor
under the Construction Contract is the work called for by the Plans and
Specifications, and all work required to complete the Improvements in accordance
with the Plans and Specifications is provided for under the Construction
Contract. The foregoing representations, however, shall be applicable only after
the finalization of the Plans and Specifications, and the execution and delivery
of the Construction Contract. See Section 11.22.

      8.22 Other Contracts.

            (a) The Borrower has not made, and will not make any, contract or
      arrangement of any kind or type whatsoever (whether oral or written,
      formal or informal), the performance of which by the other party thereto
      could give rise to a lien or encumbrance on the Project, except as
      permitted by this Agreement.

Second Lien                           -19-
<PAGE>

            (b) The Borrower has not made, and will not make, any contract or
      arrangement of any kind or type whatsoever, with any affiliate of the
      Borrower unless such contract or arrangement is (x) approved in writing in
      advance by the Lender, (y) on the same terms as would be generally
      available to the Borrower in an arm's length contract or arrangement with
      a third party, and (z) evidenced by a written agreement.

      8.23 Violations. The Borrower has received no notices of, or has any
knowledge of any violations of any applicable Requirements or Project Approvals.

      8.24 Plans and Specifications. The Borrower has furnished the Lender with
true and complete sets of the Plans and Specifications as they exist as of the
date hereof. The Plans and Specifications so furnished to the Lender comply with
all Requirements, all Project Approvals, and all restrictions, covenants and
easements affecting the Project, and have been approved by the Contractor, the
Borrower's Architect, the Tenant (if required by the Lease), and such
Governmental Authority as is required for construction of the Improvements. If
and to the extent the Plans and Specifications are not absolutely complete and
agreed to by Borrower and Lender as of the date hereof, Borrower and Lender
agree to work together cooperatively to the end that mutually satisfactory Plans
and Specifications are finalized as soon as possible.

      8.25 Project Budget. The Project Budget accurately reflects all Project
Costs.

      8.26 Effect of Draw Request. Each Draw Request submitted to the Lender as
provided in ss.3.1 hereof shall constitute an affirmation that the
representations and warranties contained in this Agreement and in the other Loan
Documents remain true and correct as of the date thereof; and unless the Lender
is notified to the contrary, in writing, prior to the Drawdown Date of the
requested Advance or any portion thereof, shall constitute an affirmation that
the same remain true and correct on the Drawdown Date.

      9. AFFIRMATIVE COVENANTS OF THE BORROWER. The Borrower covenants and
agrees that, so long as the Loan is outstanding or the Lender has any obligation
to make any Advances:

      9.1 Punctual Payment. The Borrower will duly and punctually pay or cause
to be paid the principal and interest on the Loan and all other amounts provided
for in the Note, this Agreement and the other Loan Documents to which the
Borrower is a party, all in accordance with the terms of the Note, this
Agreement and such other Loan Documents.

      9.2 Commencement, Pursuit and Completion of Construction. The Borrower
will commence construction of the Improvements within the time period provided
therefor in the Construction Schedule delivered by the Borrower to the Lender in
connection with the closing of the Loan and will diligently pursue construction
of the Improvements in accordance with the Construction Schedule, will attain
Project Completion prior to the Project Completion Date, and will pay all sums
and perform all such acts as may be necessary or appropriate to complete such
construction, all in substantial accordance with the Plans and Specifications,
in full compliance with all restrictions, covenants and easements affecting the
Project, all Requirements, all Project Approvals, and with all terms and
conditions of the Loan Documents, and the Tenant Lease,

Second Lien                           -20-
<PAGE>

without deviation from the Plans and Specifications unless the Borrower obtains
the prior approval of the Lender, if required as provided herein, Tenant (if
required by the Tenant Lease) and if applicable, the surety company or companies
issuing any Payment and Performance Bonds. Such construction shall be completed
free from any liens, claims or assessments (actual or contingent) asserted
against the Project for any material, labor or other items furnished in
connection therewith. The Borrower will furnish reasonable evidence of
satisfactory compliance with this Section to the Lender on or before the Project
Completion Date.

      9.3 Correction of Defects. The Borrower will promptly correct or cause to
be corrected all material defects in the Improvements or any departure from the
Plans and Specifications not previously approved by the Lender.

      9.4 Insurance; Bonds.

            (a) The Borrower will obtain and maintain insurance with respect to
      the Project and the operations of the Borrower as required by the
      Mortgage.

            (b) The Borrower will require the Contractor, the Architect, and any
      other architect, contractor, engineer or design professional providing
      design, construction, or engineering services in connection with the
      construction of the Improvements to obtain and maintain at all times
      during the construction of the Improvements such insurance as may be
      reasonably required by the Lender, all such insurance to be in such
      amounts and form, to include such coverage and endorsements, and to be
      issued by such insurers as shall be approved by the Lender (which approval
      shall not be unreasonably withheld or delayed) and to contain the written
      agreement of the insurer to give the Lender thirty (30) days' prior
      written notice of cancellation, nonrenewal, modification or expiration.

            (c) The Borrower will cause any subcontractor having a contract for
      in excess of $1,000,000 designated by the Lender to obtain and provide to
      the Lender such Payment and Performance Bonds, and lien bonds, as the
      Lender may reasonably request.

            (d) The Borrower will provide or will cause any such Person to
      provide the Lender with certificates evidencing such insurance upon the
      written request of the Lender.

            (e) The Borrower shall pay, indemnify and hold Lender harmless from
      any legal fees and legal costs incurred by Lender in suing the Title
      Insurance Company in the event that suit must be brought in order to
      collect proceeds under the Title Policy should the Title Insurance Company
      not pay with reasonable promptness a claim properly made by Lender arising
      out of the Title Policy's affirmative coverage for access to the Project,
      the Lender to be represented in such suit by Nixon Peabody LLP or other
      counsel selected by Lender, any such other counsel to be subject to the
      reasonable approval of the Borrower.

      9.5 Inspection of Project and Books.

Second Lien                           -21-
<PAGE>

            (a) The Borrower shall permit the Lender and the Construction
      Inspector, at the Borrower's expense, to visit and inspect the Project and
      all materials to be used in the construction thereof and will cooperate
      with the Lender and the Construction Inspector during such inspections
      (including making available working drawings of the Plans and
      Specifications); provided that this provision shall not be deemed to
      impose on the Lender or the Construction Inspector any obligation to
      undertake such inspections.

            (b) The Lender shall have the right to obtain, at the Borrower's
      cost and expense, once upon completion of construction of the Improvements
      and at any time while a Default or Event of Default shall have occurred
      and be continuing hereunder, an appraisal of the Improvements. The Lender
      shall provide to the Borrower a copy of any such appraisal obtained upon
      completion of construction (but not of any appraisal obtained while a
      Default or Event of Default shall have occurred and be continuing
      hereunder).

            (c) The reasonable costs and expenses incurred by the Lender in
      obtaining such Appraisals or performing such inspections shall be paid by
      the Borrower forthwith upon billing or request by the Lender for
      reimbursement therefor.

      9.6 Compliance with Laws, Contracts, Licenses, and Permits. The Borrower
will, or will cause each Obligor to, comply with (a) the applicable laws and
regulations wherever its business is conducted, including all Environmental Laws
and, in the case of the Borrower, all Requirements, (b) the provisions of its
Organizational Documents, (c) all agreements and instruments by which it or any
of its properties may be bound, including, in the case of the Borrower, the
Construction Contract, the Tenant Lease, and all restrictions, covenants and
easements affecting the Project, (d) all applicable decrees, orders and
judgments, and (e) all licenses and permits required by applicable laws and
regulations for the conduct of its business or the ownership, use or operation
of its properties, including, in the case of the Borrower, all Project
Approvals.

      9.7 Use of Proceeds. The Borrower will use the proceeds of the Loan solely
for the purpose of paying for Project Costs in accordance with the Project
Budget.

      9.8 Project Costs. The Borrower will pay when due all Project Costs in
excess of the Loan Amount, regardless of the amount.

      9.9 Laborers, Subcontractors and Materialmen. The Borrower will furnish to
the Lender, upon request at any time, and from time to time, affidavits listing
all laborers, subcontractors, materialmen, and any other Persons who might or
could claim statutory or common law liens and are furnishing or have furnished
labor or material to the Project or any part thereof, together with affidavits,
or other evidence satisfactory to the Lender, showing that such parties have
been paid all amounts for labor and materials furnished to the Project which
were due as of the date of the most recent Borrower's Requisition. The Borrower
will also furnish to the Lender, at any time and from time to time upon demand
by the Lender, lien waivers bearing a then current date and prepared on a form
satisfactory to the Lender from the Contractor and such subcontractors or
materialman as the Lender may designate.

Second Lien                           -22-
<PAGE>

      9.10 Further Assurance of Title. If at any time the Lender or the Lender's
counsel has reason to believe that any Advance is not secured or will or may not
be secured by the Mortgage as a first lien or security interest on the Project,
then the Borrower shall, within ten (10) days after written notice from the
Lender, do all things and matters necessary, to assure to the reasonable
satisfaction of the Lender and the Lender's counsel that any Advance previously
made hereunder or to be made hereunder is secured or will be secured by the
Mortgage as a first leasehold lien or security interest on the Project, and the
Lender, at its option, may decline to make further Advances hereunder until the
Lender has received such assurance, but nothing in this Section shall limit the
Lender's right to require endorsements extending the effective date of the Title
Policy as herein set forth.

      9.11 Further Assurances Regarding Construction. The Borrower will furnish
or cause to be furnished to the Lender all instruments, documents, boundary
surveys, footing or foundation surveys, certificates, plans and specifications,
title and other insurance, reports and agreements and each and every other
document and instrument required to be furnished by the terms of this Agreement
or the other Loan Documents, all at the Borrower's expense.

      10. NEGATIVE COVENANTS OF THE BORROWER. The Borrower covenants and agrees
that, so long as the Loan is outstanding or the Lender has any obligation to
make any Advances:

      10.1 Restriction on Change Orders. The Borrower will not cause, permit or
suffer to exist any deviations from the Plans and Specifications and will not
approve or consent to any change orders or construction change directives,
without the prior approval of the Lender, Tenant (if required by the Tenant
Lease) and the surety company or companies issuing any Payment and Performance
Bonds, that:

            (a) result in a change in the quality or overall design of the
      Improvements; or

            (b) result in an increase of the original contract sum (prior to any
      change orders) in an amount in excess of $100,000; or

            (c) when added to all previous change orders will result in an
      increase in the original contract sum (prior to any change orders) in an
      amount in excess of $500,000; or

            (d) when added to all previous change orders decreasing the contract
      together with such additional information that the Lender may reasonably
      request with respect to such proposed deviation, change order or
      construction change directive and the sum will result in a decrease in the
      original contract sum (prior to any change orders) in an amount in excess
      of $500,000 (provided, however, that this subsection (c) shall not apply
      to change orders which do not modify the Plans and Specifications and
      which reduce the contract sum as a result of the Borrower or the
      Contractor rebidding and obtaining lower bids for work to be performed by
      subcontractors); or

            (e) which will in any way extend the contract time beyond the
      Project Completion Date.

Second Lien                           -23-
<PAGE>

The Borrower shall submit all proposed deviations, change orders and
construction change directives, together with such additional information as the
Lender may reasonably request with respect to such proposed deviation, change
order or construction change directive, to the Lender and the Construction
Inspector simultaneously, and Lender shall give its approval or disapproval to
the Borrower within five (5) Business Days after receipt thereof by both the
Lender and the Construction Inspector.

      10.2 No Amendments, Terminations or Waivers.

            (a) The Borrower will not amend, supplement or otherwise modify,
      whether by change order or otherwise, any of the terms and conditions of
      the Construction Contract, or the Tenant Lease without in each case the
      prior approval of the Lender, which consent shall not be unreasonably
      withheld or delayed, and in the case of the Construction Contract, without
      the prior approval of any surety or surety companies issuing any Payment,
      Performance or Lien Bonds.

            (b) The Borrower will not, directly or indirectly, terminate or
      cancel, or cause or permit to exist any condition which would result in
      the termination or cancellation of, or which would relieve the performance
      of any obligations of any other party under, the Architect's Contract, the
      Construction Contract, the Tenant Lease or the Ground Lease.

            (c) The Borrower will not, directly or indirectly, waive or agree or
      consent to the waiver of, the performance of any obligations or any other
      party under the Architect's Contract, the Construction Contract or the
      Tenant Lease.

            (d) The Borrower will not, directly or indirectly, amend, or allow
      the amendment of, any of the Organizational Documents of the Borrower in
      any material respect, including, without limitation, any such amendment
      which would allow or

            (e) authorize the expansion of Borrower's activities beyond the
      ownership, construction, operation and maintenance of the Project and all
      matter incidental or accessory thereto.

      11. CONDITIONS TO CLOSING AND INITIAL ADVANCE. The obligation of the
Lender to make the initial Advance shall be subject to the satisfaction of the
following conditions precedent:

      11.1 Loan Documents. Each of the Loan Documents shall have been duly
executed and delivered by the respective parties thereto, shall be in full force
and effect and shall be in form and substance satisfactory to the Lender.

      11.2 Construction Documents. [Intentionally Omitted.]

      11.3 Subcontracts. The Borrower shall have delivered to the Lender, and
the Lender shall have approved, a list of all subcontractors and materialmen who
have been or, to the extent identified by the Borrower, will be supplying labor
or materials for the Project, and a copy of the standard form of subcontract to
be used by the Contractor.

Second Lien                           -24-
<PAGE>

      11.4 Contracts. The Borrower shall have delivered to the Lender correct
and complete photocopies of all executed contracts with contractors,
subcontractors, engineers or consultants for the Project, and of all
development, management, brokerage, sales or leasing agreements for the Project,
all of which shall be reasonably satisfactory to Lender in form and substance.

      11.5 Leases. The Tenant Lease shall have been duly executed by the
Borrower and Tenant and shall be in full force and effect. The Lender shall have
received a certified or fully executed copy of the Tenant Lease. The Tenant
Lease shall be superior to the Mortgage, and a notice thereof shall be recorded
prior to the Mortgage.

      11.6 Certified Copies of Organization Documents. The Lender shall have
received from each of the Parties a certified copy of its Organization Documents
as in effect on such date of certification, such Organizational Documents to be
in form and substance satisfactory to the Lender.

      11.7 Resolutions. All action necessary for the valid execution, delivery
and performance by each Party of this Agreement and the other Loan Documents to
which it is or is to become a party shall have been duly and effectively taken,
and evidence thereof satisfactory to the Lender shall have been provided to the
Lender. The Lender shall have received from each such Person true copies of the
resolutions authorizing the transactions described herein, each certified as of
a recent date to be true and complete.

      11.8 Incumbency Certificate; Authorized Signers. The Lender shall have
received from each Party an incumbency certificate, dated as of the Closing
Date, giving the name and bearing a specimen signature of each individual who
shall be authorized: (a) to sign, in the name and on behalf of such Person each
of the Loan Documents to which such Person is or is to become a party; (b) in
the case of the Borrower, to make Draw Requests; and (c) to give notices and to
take other action on its behalf under the Loan Documents.

      11.9 Validity of Liens. The Security Documents shall be effective to
create in favor of the Lender a legal, valid and enforceable first lien and
security interest in the Collateral. All filings, recordings, deliveries of
instruments and other actions necessary or desirable in the opinion of the
Lender to protect and preserve such lien and security interest shall have been
duly effected. The Lender shall have received evidence thereof in form and
substance satisfactory to the Lender.

      11.10 Deliveries. The following items or documents shall have been
delivered to the Lender by the Borrower and shall be in form and substance
satisfactory to the Lender:

            (a) Plans and Specifications. Except as provided in Section 11.22,
      two complete sets of the Plans and Specifications and approval thereof by
      any necessary Governmental Authority, with a certification from the
      Borrower's Architect that the Improvements to be constructed comply with
      all Requirements and Project Approvals and that the Construction Contract
      satisfactorily provides for the construction of the Improvements.

Second Lien                           -25-
<PAGE>

            (b) Title Policy. The Title Policy, or a commitment therefor,
      together with proof of payment of all fees and premiums for such policy
      and true and accurate copies of all documents listed as exceptions under
      such policy.

            (c) Other Insurance. Duplicate originals or certified copies of all
      policies of insurance required by the Mortgage or hereunder to be obtained
      and maintained during the construction of the Improvements.

            (d) Evidence of Sufficiency of Funds. [Intentionally Omitted.]

            (e) Evidence of Access, Availability of Utilities, Project
      Approvals. [Intentionally Omitted.]

            (f) Environmental Report. An environmental site assessment report or
      reports of one or more qualified environmental engineering or similar
      inspection firms approved by the Lender, which report or reports shall
      indicate a condition of the Land and any existing improvements thereon in
      compliance with all Requirements and in all respects satisfactory to the
      Lender in its sole discretion and upon which report or reports the Lender
      is expressly entitled to rely.

            (g) Soils Report. [Intentionally omitted.]

            (h) Survey and Taxes. A Survey of the Land (and any existing
      improvements thereon) and Surveyor's Certificate, and evidence of payment
      of all real estate taxes and municipal charges on the Land (and any
      existing improvements thereon) which were due and payable prior to the
      Closing Date.

            (i) Required Equity Funds. [Intentionally Omitted.]

            (j) Payment, Performance and Lien Bonds. [Intentionally Omitted.]

            (k) Draw Request. A Draw Request complying with the provisions
      of ss.3.1 hereof.

      11.11 Construction Inspector Report. [Intentionally omitted.]

      11.12 Legal and Other Opinions. The Lender shall have received favorable
opinions in form and substance satisfactory to the Lender and the Lender's
counsel, addressed to the Lender and dated as of the Closing Date, from counsel
to the Borrower and each Guarantor acceptable to the Lender, as to the matters
set forth in Exhibit L attached hereto and such other matters as the Lender
shall reasonably request.

      11.13 Lien Search. The Lender shall have received a certification from
Title Insurance Company or counsel satisfactory to the Lender (which shall be
updated from time to time at the Borrower's expense upon request by the Lender)
that a search of the public records disclosed no conditional sales contracts,
security agreements, chattel mortgages, leases of personalty, financing
statements or title retention agreements which affect the Collateral.

Second Lien                           -26-
<PAGE>

      11.14 Mechanic's Lien Law.

            (a) Initial Advance. In the event that for any reason the initial
      Advance is not funded on the Closing Date, the terms and provisions
      of ss.12.6(a) and (b) shall be applicable for the initial Advance.

            (b) Lien Bond. [Intentionally Omitted.]

      11.15 Notices. All notices required by any Governmental Authority under
applicable Requirements to be filed prior to commencement of construction of the
Improvements shall have been filed.

      11.16 Appraisal. [Intentionally Omitted.]

      11.17 Fees. [Intentionally Omitted.]

      11.18 Performance; No Default. The Borrower shall have performed and
complied with all terms and conditions herein required to be performed or
complied with by it on or prior to the Drawdown Date of the initial Advance, and
on the Drawdown Date of the initial Advance, there shall exist no Default or
Event of Default.

      11.19 Representations and Warranties. The representations of warranties
made by the Obligors in the Loan Documents or otherwise made by or on behalf of
the Obligors in connection therewith or after the date thereof shall have been
true and correct in all respects when made and shall be true and correct in all
respects on the Drawdown Date of the initial Advance.

      11.20 Proceedings and Document. All proceedings in connection with the
transactions contemplated by this Agreement and the other Loan Documents shall
be satisfactory to the Lender and the Lender's counsel in form and substance,
and the Lender shall have received all information and such counterpart
originals or certified copies of such documents and such other certificates,
opinions or documents as the Lender and the Lender's counsel may reasonably
require.

      11.21 Waiver. Any waiver by the Lender of any of the conditions precedent
contained herein for the Closing and the initial Advance shall not be deemed to
be a waiver by the Lender of such conditions precedent for any subsequent
Advance or any other obligation of the Lender hereunder.

      11.22 Incomplete Construction Documents. Borrower and Lender agree that
the Closing and initial Advance hereunder may take place prior to any or all of
the following: (i) the finalization of the Plans and Specifications, (ii) the
execution and delivery of the Construction Contract (and the consent of the
Contractor to the assignment of the Construction Contract pursuant to Collateral
Assignment of Contracts, Liens, Permits, Agreements, Warranties and Approvals,
dated as of the date hereof), and (iii) the issuance of a building permit for
the construction of the Project. In such event, Advances hereunder shall be
limited to matters shown on the Project Budget which are related to the Ground
Lease and pre-construction expenses and are not covered by the Construction
Contract. Lender shall not be obligated to find any Advance

Second Lien                           -27-
<PAGE>

relating to the Construction Contract unless and until the matters referred to
above in clauses (i), (ii) and (iii) have been accomplished to Lender's
reasonable satisfaction.

      12. CONDITIONS OF SUBSEQUENT ADVANCES. The obligation of the Lender to
make any Advance after the initial Advance shall be subject to the satisfaction
of the following conditions precedent:

      12.1 Prior Conditions Satisfied. All conditions precedent to the initial
Advance and any prior Advance shall continue to be satisfied as of the Drawdown
Date of such subsequent Advance; including but not limited to Section 11.22 if
applicable.

      12.2 Performance; No Default. The Borrower shall have performed and
complied with all terms and conditions herein required to be performed or
complied with by it on or prior to the Drawdown Date of such Advance, and on the
Drawdown Date of such Advance there shall exist no Default or Event of Default.

      12.3 Representations and Warranties. Each of the representations and
warranties made by the Obligors in the Loan Documents or otherwise made by or on
behalf of the Obligors in connection therewith after the date thereof shall have
been true and correct in all respects on the date on when made and shall also be
true and correct in all material respects on the Drawdown Date of such Advance
(except to the extent of changes resulting from transactions contemplated or
permitted by the Loan Documents).

      In addition, the Borrower in connection with the first Advance made
subsequent to the initial Advance, the Borrower shall provide to the Lender its
representation and warranty that, excluding construction currently in progress
pursuant to the Plan and Specifications and Construction Contract, there have
been no changes to the Property that would be shown on an updated Survey of the
Land since the date of the Survey delivered by the Borrower to the Lender on the
Closing Date.

      12.4 No Damage. The Improvements shall not have been materially injured or
damaged by fire, explosion, accident, flood or other casualty so that the
requirements hereof cannot be complied with.

      12.5 Receipt of the Lender. The Lender shall have received:

            (a) Draw Request. A Draw Request complying with the requirements
      hereof, including those set forth in ss.3.1 hereof,

            (b) Endorsement to Title Policy. A "date down" endorsement to the
      Title Policy indicating no change in the state of title and containing no
      survey exceptions not approved by the Lender;

            (c) Current Survey. An updated Survey if required by the Title
      Insurance Company;

Second Lien                           -28-
<PAGE>

            (d) Approval by Construction Inspector. As to Advances with respect
      to the Construction Contract, approval of the Draw Request for such
      Advance by the Construction Inspector, accompanied by a certificate or
      report from the Construction Inspector to the effect that in its opinion,
      based on-site observations and submissions by the Contractor, the
      construction of the Improvements to the date thereof was performed in a
      good and workmanlike manner and in accordance with the Plans and
      Specifications, stating the estimated total cost of construction of the
      Improvements, stating the percentage of in-place construction of the
      Improvements, and stating that the remaining non-disbursed portion of the
      Loan and Required Equity Funds allocated for such purpose in the Project
      Budget is adequate to complete the construction of the Improvements;

            (e) Contracts. Evidence that one hundred percent (100%) of the cost
      of the remaining construction work is covered by firm fixed price or
      guaranteed maximum price contracts or subcontracts, or orders for the
      supplying of materials, with contractors, subcontractors, materialmen or
      suppliers reasonably satisfactory to the Lender.

      12.6 Mechanic's Lien Law.

            (a) Notice of Contract, Mechanic's Lien. Unless or until a lien bond
      is in full force and effect which prevents or eliminates the encumbrance
      of the Project by any lien under the Mechanic's Lien Law, the Lender may
      withhold or refuse to fund any advance hereunder if:

                  (i)   a Notice of Contract has been filed under Section 4 of
                        the Mechanic's Lien Law; or

                  (ii)  a Notice of Contract has been filed by the Contractor
                        under Section 2 of the Mechanic's Lien Law, unless (x)
                        the Project does not involve the construction of at
                        least one, but not more than four, dwelling unit and (y)
                        with respect to the subject Borrower's Requisition, an
                        accurately completed and valid Lien Form has been
                        provided to the Lender with a Payment Period Date no
                        more than twenty-five days before the date of the
                        funding of such advance, such Lien Form to provide that
                        subject to the payment of the amount set forth in the
                        Borrower's Requisition, the Contractor waives any and
                        all lien rights for labor and materials, or rental
                        equipment, appliances or tools, performed or furnished
                        through the applicable Payment Period Date, except for
                        Retainage, unpaid agreed or pending change orders, and
                        disputed claims as stated in the Lien Form; or

                  (iii) any Other Mechanic's Lien has been filed or established.

            (b) Payment Period Date. In the event that the Lender has not funded
      any Borrower's Requisition within twenty-five days after the applicable
      Payment Period Date as set forth in the Lien Form which was submitted with
      the subject Borrower's

Second Lien                           -29-
<PAGE>

      Requisition, the Lender may, at its option, withhold or refuse to fund the
      Borrower's Requisition and require the Borrower to resubmit an updated
      Borrower's Requisition in accordance with ss.3.1, above, with an updated
      Lien Form.

            (c) Lien Bond. If requested by the Lender, at any time, the Borrower
      shall provide evidence that the Borrower has obtained and recorded with
      the Registry a satisfactory lien bond in an amount equal to the unpaid
      construction costs, which lien bond shall be obtained by the Borrower and
      relate to, and therefore dissolve, any Section 2 Lien and Section 4 Lien.
      The lien bond shall name the Lender as dual obligee;

            (d) Notice of Substantial Completion. Upon the substantial
      completion of the work provided for in the Construction Contract, the
      Borrower has provided evidence that the Borrower has timely obtained from
      the Contractor and recorded with the Registry, a Notice of Substantial
      Completion as provided for in the Mechanic's Lien Law; and

            (e) Notice of Termination. In the event of the termination of the
      Construction Contract, the Borrower has provided evidence that the
      Borrower has timely recorded with the Registry, a Notice of Termination as
      provided for in the Mechanic's Lien Law.

      12.7 Release of Retainage. [Intentionally Omitted.]

      12.8 Waiver. Any waiver by the Lender of any of the conditions precedent
contained herein for any Advance shall not be deemed to be a waiver by the
Lender of such conditions precedent for any subsequent Advance or any other
obligation of the Lender hereunder.

      13. EVENTS OF DEFAULT AND REMEDIES.

      13.1 Events of Default. The occurrence of any one or more of the following
conditions or events shall constitute an "Event of Default":

            (a) any failure by the Borrower to pay, within five (5) days of the
      due date, any interest on or principal of or other sum payable under the
      Note (including, without limitation, any amounts required to be paid by
      the Borrower to the Lender on the Maturity Date pursuant to the provisions
      of Section 5.2 hereof; or

            (b) any default in the payment of any of the other Obligations
      (excluding installments of interest and principal), when and as the same
      shall have become due and payable as in the Note and any other Loan
      Document provided, or in the performance o any of Borrower's other
      obligations under any of the Loan Documents which performance consists
      solely of the payment of a sum of money, (i) prior to maturity (whether
      such maturity occurs by acceleration, lapse of time or otherwise), if such
      default shall have continued for a period of ten (10) Business Days after
      notice thereof to Mortgagor, and (ii) upon maturity (whether such maturity
      occurs by acceleration, lapse of time or otherwise); or

            (c) title to the Collateral is or becomes unsatisfactory to the
      Lender by reason of any lien, charge, encumbrance, title condition or
      exception (including without

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<PAGE>

      limitation, (x) any Other Mechanic's Lien or (y) any Section 1 Lien or
      Section 2 Lien in respect of obligations overdue) and such matter causing
      title to be or become unsatisfactory is not cured or removed (including by
      bonding) within thirty (30) days after notice thereof from the Lender to
      the Borrower; or

            (d) any refusal by the Title Insurance Company to insure any Advance
      as being secured by the Mortgage as a valid first lien and security
      interest on the Project and continuance of such refusal for a period of
      thirty (30) days after notice thereof by the Lender to the Borrower; or

            (e) Project Completion shall not have been attained by the Project
      Completion Date or, in the reasonable judgment of the Lender, Project
      Completion cannot be attained by the Project Completion Date; or

            (f) the Project or any material part thereof is subject to a
      material Taking; or

            (g) any cessation at any time in construction of the Improvements
      for more than ten 10 consecutive business days except for strikes, acts of
      God, fire or other casualty, or other causes entirely beyond the
      Borrower's control, or any cessation at any time in construction of the
      Improvements for more than sixty (60) consecutive days, regardless of the
      cause thereof, but subject to Force Majeure; or

            (h) in the reasonable judgment of the Lender, in its sole
      discretion, if the remaining undisbursed portion of the Loan, together
      with proceeds of the First Mortgage Loan and together with amounts payable
      from Tenant to the Borrower under the Tenant Lease to be applied against
      Project Costs, is or will be insufficient to fully complete and equip the
      Improvements in accordance with the Plans and Specifications, to operate
      and carry the Project after Project Completion until payment. in full of
      the Loan by the Borrower, to pay all other Project Costs, to pay all
      interest accrued or to accrue on the Loan during the term of the Loan from
      and after the date hereof, and to pay all other sums due or to become due
      under the Loan Documents (or as to any budget category or line item), and
      to pay any liens for labor and materials alleged to be due and payable at
      the time in connection with the Improvements, in each case regardless of
      how such condition may be caused, unless the Borrower shall within seven
      (7) days of written notice of the amount required by such determination
      from the Lender, except otherwise as provided in ss.13.1(i) below, deposit
      with the Lender such sums of money in cash as the Lender may require, or
      an unconditional irrevocable standby letter of credit in the amount
      required by the Lender and otherwise in form and substance satisfactory to
      the Lender from a commercial bank acceptable to the Lender, in an amount
      sufficient to remedy the condition described in such notice, and
      sufficient to pay any liens for labor and materials alleged to be due and
      payable at the time in connection with the Improvements; or

            (i) any Guarantor denies that such Guarantor has any liability or
      obligations under the Guaranty or the Indemnity Agreement, or shall notify
      the Lender of such Guarantor's intention to attempt to cancel or terminate
      the Guaranty or the Indemnity

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<PAGE>

      Agreement, or shall fail to observe or comply with any term, covenant,
      condition and agreement under the Guaranty or the Indemnity Agreement; or

            (j) any representation or warranty made or deemed to be made by or
      on behalf of any Obligor in this Agreement or in any of the other Loan
      Documents, or in any report, certificate, financial statement, Draw
      Request, document or other instrument delivered pursuant to or in
      connection with this Agreement, any Advance or any of the other Loan
      Documents, shall prove to have been false or incorrect in any material
      respect upon the date when made or deemed to be made or repeated; or

            (k) any suit or proceeding shall be filed against the Borrower or
      any Guarantor or the Project which, if adversely determined, would have a
      materially adverse affect on the ability of the Borrower or such Guarantor
      to perform each and every one of their respective obligations under and by
      virtue of the Loan Documents; or

            (l) any failure by the Borrower to obtain any Project Approvals, or
      the revocation or other invalidation of any Project Approvals previously
      obtained, after all appeals have been exhausted; or

            (m) any Obligor or Subsidiary thereof shall file a voluntary
      petition in bankruptcy under Title 11 of the United States Code, or an
      order for relief shall be issued against any such Person in any
      involuntary petition in bankruptcy under Title 11 of the United States
      Code, or any such Person shall file any petition or answer seeking or
      acquiescing in any reorganization, arrangement, composition, readjustment,
      liquidation, dissolution or similar relief for itself under any present or
      future federal, state or other law or regulation relating to bankruptcy,
      insolvency or other relief of debtors, or such Person shall seek or
      consent to or acquiesce in the appointment of any custodian, trustee,
      receiver, conservator or liquidator of such Person, or of all or any
      substantial part of its respective property, or such Person shall make an
      assignment for the benefit of creditors, or such Person shall give notice
      to any governmental authority or body of insolvency or pending insolvency
      or suspension of operation; or

            (n) an involuntary petition in bankruptcy under Title 11 of the
      United States Code shall be filed against any Obligor or Subsidiary
      thereof and such petition shall not be dismissed within sixty (60) days of
      the filing thereof, or

            (o) a court of competent jurisdiction shall enter any order,
      judgment or decree approving a petition filed against any Obligor or any
      Subsidiary thereof seeking any reorganization, arrangement, composition,
      readjustment, liquidation or similar relief under any present or future
      federal, state or other law or regulation relating to bankruptcy,
      insolvency or other relief for debtors, or appointing any custodian,
      trustee, receiver, conservator or liquidator of all or any substantial
      part of its property; or

            (p) if final judgment for the payment of money in the amount of
      $100,000 or more in excess of insurance proceeds shall be rendered against
      the Borrower, or final judgment for the payment of money in the amount of
      $500,000 or more in excess of

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<PAGE>

      insurance proceeds shall be rendered against any of the Guarantors, and
      the Borrower or such Guarantor shall have failed to discharge the same or
      cause it to be discharged within sixty (60) days from the entry thereof,
      or shall have failed to appeal therefrom or from the order, decree or
      process upon which or pursuant to which said judgment was granted, based
      or entered, and to have secured a stay of execution pending such appeal;
      or

            (q) any "Event of Default", as defined or otherwise set forth in any
      of the other Loan Documents, shall occur; or

            (r) if the Ground Lease or the Tenant Lease or any material
      provision thereof shall cease to be in full force and effect, for any
      reason whatsoever; or

            (s) any failure by any Obligor to duly observe or perform any term,
      covenant, condition or agreement under this Agreement or any other Loan
      Document (other than those defaults referred to or covered by paragraphs
      (a) through (r) above and continuance of such failure for a period of
      thirty (30) days after notice thereof from the Lender, or, in any case
      where such default is susceptible to cure but cannot with due diligence be
      cured within such thirty (30) day period, such longer period (not to
      exceed one hundred twenty (120) days) as is required diligently to effect
      the cure of such default, but only so long as such Obligor promptly
      notifies Lender of its intention to cure and commences cure of such
      default within such thirty (30) day period and at all times thereafter
      prosecutes such cure with all due diligence to completion; or

            (t) any "Event of Default", as defined or otherwise set forth in any
      of the First Mortgage Loan Documents, shall occur.

      Notwithstanding the foregoing, in the event that any Event of Default
shall occur pursuant to any of clauses (e), (g), (j), (k), or (l) for reasons of
Force Majeure, the time period set forth in such clause for curing such Event of
Default shall either be one hundred twenty (120) days or shall be extended for a
period of up to one hundred twenty (120) days, provided, however, that (i) the
Borrower shall have given written notice to the Lender within ten (10) days
after the occurrence of any event believed by the Borrower to constitute Force
Majeure, with any such notice to describe such event in reasonable detail, and
(ii) in no event shall any Default described in clause (h) above have occurred
and be continuing hereunder. Clauses (m), (n) and (o) above shall apply to the
Guarantors only during the Construction Period.

      Also notwithstanding the foregoing, in no event will a failure of Borrower
or any Guarantor to perform any Borrower or Guarantor obligation hereunder or
under any other Loan Document which is a result of or caused by a Lender failure
to perform a Lender obligation hereunder constitute an Event of Default.

      13.2 Termination of Advances and Acceleration. If any one or more of the
Events of Default shall occur and be continuing, the Lender may by notice to the
Borrower declare its obligations to make Advances hereunder to be terminated,
whereupon the same shall terminate and the Lender shall be relieved of all
obligations to make Advances to the Borrower, and/or declare all unpaid
principal of and accrued interest on the Note, together with all other amounts

Second Lien                           -33-
<PAGE>

owing under the Loan Documents, to be immediately due and payable, whereupon
same shall become and be immediately due and payable, anything in the Loan
Documents to the contrary notwithstanding, and without presentment, protest,
demand or other notice of any kind, all of which are hereby expressly waived by
the Borrower; provided that if any one or more of the Events of Default
specified in ss.13.1(l), ss.13.1(m), or ss.13.1(n), above, shall occur with
respect to any Obligor, the Lender's obligations to make Advances hereunder
automatically shall so terminate and all unpaid principal of and accrued
interest on the Note, together with all other amounts owing under the Loan
Documents, automatically shall become and be immediately so due and payable,
without any declaration or other act on the part of the Lender.

      13.3 Completion of Project. If any one or more of the Events of Default
shall have occurred and be continuing, and whether or not the Lender shall have
terminated its obligations to make Advances and accelerated the maturity of the
Loan pursuant to ss.13.2, the Lender, if the construction of the Improvements
has not been fully completed, may cause the Project to be completed and may
enter upon the Land upon two (2) Business Days' written notice to the Borrower,
and construct, equip and complete the Project in accordance with the Plans and
Specifications, with such changes therein as the Lender may, from time to time,
and in its sole discretion, deem appropriate. In connection with any
construction of the Project undertaken by the Lender pursuant to the provisions
of this Section, the Lender may:

            (a) use any funds of the Borrower, including any balance which may
      be held by the Lender as security or in escrow, and any funds remaining
      unadvanced under the Loan;

            (b) employ existing contractors, subcontractors, agents, architects,
      engineers, and the like, or terminate the same and employ others;

            (c) employ security watchmen to protect the Project;

            (d) make such additions, changes and corrections in the Plans and
      Specifications as shall, in the judgment of the Lender, be necessary or
      desirable;

            (e) take over and use any and all Personal Property contracted for
      or purchased by the Borrower, if appropriate, or dispose of the same as
      the Lender sees fit;

            (f) execute all applications and certificates on behalf of the
      Borrower which may be required by any Governmental Authority or
      Requirements or contract documents or agreements;

            (g) pay, settle or compromise all existing or future bills and
      claims which are or may be liens against the Project, or may be necessary
      for the completion of the Improvements or the clearance of title to the
      Project;

            (h) complete the marketing and leasing of leasable space in the
      Improvements, enter into new Leases, and modify or amend existing Leases,
      all as the Lender shall deem to be necessary or desirable;

Second Lien                           -34-
<PAGE>

            (i) prosecute and defend all actions and proceedings in connection
      with the construction of the Improvements or in any other way affecting
      the Land or the Improvements and take such action and require such
      performance as the Lender deems necessary under any Payment and
      Performance Bonds; and

            (j) take such action hereunder, or refrain from acting hereunder, as
      the Lender may, in its sole and absolute discretion, from time to time
      determine, and without any limitation whatsoever, to carry out the intent
      of this Section.

The Borrower shall be liable to the Lender for all costs paid or incurred for
the construction, equipping and completion of the Project, whether the same
shall be paid or incurred pursuant to the provisions of this Section or
otherwise, and all payments made or liabilities incurred by the Lender hereunder
of any kind whatsoever shall be deemed Advances made to the Borrower under this
Agreement and shall be secured by the Mortgage and the other Security Documents.
To the extent that any costs so paid or incurred by the Lender, together with
all other Advances made by the Lender hereunder, exceed the Loan Amount, the
amount of such excess costs shall be added to the Loan Amount, and the
Borrower's obligation to repay the same, together with interest thereon at the
Default Rate, shall be deemed to be evidenced by this Agreement and secured by
the Mortgage and the other Security Documents. In the event the Lender takes
possession of the Project and assumes control of such construction as aforesaid,
it shall not be obligated to continue such construction longer than it shall see
fit and may thereafter, at any time, change any course of action undertaken by
it or abandon such construction and decline to make further payments for the
account of the Borrower whether or not the Project shall have been completed.
For the purpose of this Section, the construction, equipping and completion of
the Project shall be deemed to include any action necessary to cure any Event of
Default by the Borrower under any of the terms and provisions of any of the Loan
Documents.

      13.4 Other Remedies. If any one or more of the Events of Default shall
have occurred and be continuing, and whether or not the Lender shall have
terminated its obligations to make Advances or accelerated the maturity of the
Loan pursuant to ss.13.2, the Lender may proceed to protect and enforce its
rights and remedies under this Agreement, the Note or any of the other Loan
Documents by suit in equity, action at law or other appropriate proceeding,
whether for the specific performance of any covenant or agreement contained in
this Agreement and the other Loan Documents or any instrument pursuant to which
the Obligations are evidenced, including as permitted by applicable law the
obtaining of the ex parte appointment of a receiver, and, if any amount owed to
the Lender shall have become due, by declaration or otherwise, proceed to
enforce the payment thereof or any other legal or equitable right of the Lender.
No remedy conferred upon the Lender or the holder of the Note in this Agreement
or in any of the other Loan Documents is intended to be exclusive of any other
remedy and each and every remedy shall be cumulative and shall be in addition to
every other remedy given hereunder or thereunder or now or hereafter existing at
law or in equity or by statute or any other provision of law.

      13.5 Distribution of Collateral Proceeds. In the event that, following the
occurrence or during the continuance of any Default or Event of Default, the
Lender receives any monies in connection with the enforcement of any the
Security Documents, or otherwise with respect to the realization upon any of the
Collateral, such monies shall be distributed for application as follows:

Second Lien                           -35-
<PAGE>

            (a) First, to the payment of, or (as the case may be) the
      reimbursement of the Lender for or in respect of all reasonable costs,
      expenses, disbursements and losses which shall have been incurred or
      sustained by the Lender in connection with the collection of such monies
      by the Lender, for the exercise, protection or enforcement by the Lender
      of all or any of the rights, remedies, powers and privileges of the Lender
      under this Agreement or any of the other Loan Documents or in respect of
      the Collateral or in support of any provision of adequate indemnity to the
      Lender against any taxes or liens which by law shall have, or may have,
      priority over the rights of the Lender to such monies;

            (b) Second, to all other Obligations in such order or preference as
      the Lender may determine; provided, however, that the Lender may in its
      discretion make proper allowance to take into account any Obligations not
      then due and payable;

            (c) Third, upon payment and satisfaction in full or other provisions
      for payment in full satisfactory to the Lender of all of the Obligations,
      to the payment of any obligations required to be paid pursuant to
      ss.9-504(1)(c) of the Uniform Commercial Code of the Commonwealth of
      Massachusetts; and

            (d) Fourth, the excess, if any, shall be returned to the Borrower or
      to such other Persons as are entitled thereto.

      13.6 Power of Attorney. For the purposes of carrying out the provisions
and exercising the rights, remedies, powers and privileges granted by or
referred to in this Article, the Borrower hereby irrevocably constitutes and
appoints the Lender its true and lawful attorney-in-fact after an Event of
Default, with full power of substitution, to execute, acknowledge and deliver
any instruments and do and perform any acts which are referred to in this
Article, in the name and on behalf of the Borrower. The power vested in such
attorney-in-fact is, and shall be deemed to be, coupled with an interest and
irrevocable.

      13.7 Waivers. The Borrower hereby waives to the extent not prohibited by
applicable law (a) all presentments, demands for performance, notices of
nonperformance (except to the extent required by the provisions hereof or of any
of the other Loan Documents), protests and notices of dishonor, (b) any
requirement of diligence or promptness on the Lender's part in the enforcement
of its rights (but not fulfillment of its obligations) under the provisions of
this Agreement or any of the other Loan Documents, and (c) any and all notices
of every kind and description which may be required to be given by any statute
or rule of law and any defense of any kind which the Borrower may now or
hereafter have with respect to its liability under this Agreement or under any
of the other Loan Documents.

      14. SETOFF. Regardless of the adequacy of any collateral, during the
continuance of any Event of Default, any deposits (general or specific, time or
demand, provisional or final, regardless of currency, maturity, or the branch of
the Lender where such deposits are held) or other sums credited by or due from
the Lender to the Borrower and any securities or other property of the Borrower
in the possession of the Lender may be applied to or set off against the payment
of the Project Obligations and any and all other Obligations.

Second Lien                           -36-
<PAGE>

      15. SUBORDINATION; FORBEARANCE; OFFSET. (a) The Security Documents,
including without limitation the Mortgage, are subject to and subordinate to the
First Mortgage Loan Security Documents. Lender shall not foreclose the Mortgage
or otherwise exercise remedies under the Mortgage or any of the other Security
Documents for so long as the First Mortgage Loan is outstanding except that
Lender may exercise cure rights and other remedies (not including the remedy of
foreclosure) for the limited purpose of protecting the collateral covered by the
Mortgage and the other Security Documents.

      (b) If an Event of Default as set forth in Section 13.1 shall have
occurred and be continuing solely by reason of such default by Tenant under the
Tenant Lease, Lender shall forbear from foreclosing on the Mortgage or
exercising other remedies under any of the Security Documents (except as may be
required to protect the collateral covered thereby) for a period of twenty-four
months provided that (i) Borrower and Guarantors are not in default under any of
the Loan Documents, and (ii) Borrower and Guarantors are using diligent efforts
to obtain a refinancing of the Loan. Such twenty-four month period shall be
extended if and to the extent that Tenant fails to vacate the Project within
ninety days after demand therefor by Borrower following the occurrence and
continuance of an Event of Default under and as defined in the Tenant Lease.
Interest on the Note shall continue to accrue during any such forbearance
period, but debt service (interest and/or principal) on the Note shall be offset
by 50% of each dollar of costs paid by Borrower (rather than Tenant) for real
estate taxes or operating expenses as a result of such Tenant Lease default, up
to a maximum of $750,000. Such offset shall be applied first against interest
otherwise due and payable on the Note, and then to the extent unpaid Tenant
Lease Obligations not been fully offset against interest, against principal.

      (c) In the event that one or more Advances under and best defined in the
Loan Agreement for the First Mortgage Loan is not made because Lender is unable
to do so by reason of not having available funds or by reason of being subject
to a legally enforceable restraint (such as an injunction) from using available
funds for such purpose, 75% of each dollar of Borrower's actual damages
resulting therefrom, up to a maximum of $2,000,000, shall be offset against
payments due on the Note. Moreover, in such event (i) Lender shall be required
to subordinate the Security Documents and the First Mortgage Loan Security
Documents to the mortgage and other security documents for an alternative
financing if such can be arranged by Borrower, so as to enable Borrower to
obtain alternative financing on a first lien basis, and (ii) as provided in the
Tenant Lease, Tenant shall have the right to exercise its purchase option
thereunder. The provisions of any such subordination shall be reasonably
satisfactory in form and substance to the lender providing such alternative
financing, and shall be such that Lender's entitlement to payment shall be
subordinate the new lender both as to current cash flow (as to payments of
interest) and in the case of a refinancing or sale (in each case as to both
principal and accrued interest), but shall not have the effect of negating
altogether Lender's entitlement to be repaid from the Project and the income
therefrom if and when possible.

      16. TERMINATION; DISCHARGE; SUBSTITUTE MEMBERSHIP INTEREST. If and when
Borrower refinances the First Mortgage Loan with a loan from a third party
institutional lender, the provisions of this Section 16 shall apply. Any such
refinancing shall be subject to the approval of the Lender pursuant to the Loan
Agreement for the First Mortgage Loan. Concurrently with the closing for such
refinancing loan, the Lender shall either (A) if the

Second Lien                           -37-
<PAGE>

lender for such refinancing loan is agreeable to permitting the Mortgage to
continue as a second lien on the Project, execute and deliver documents making
the Mortgage and the other Security Agreements subordinate to the documents for
such refinancing loan on terms mutually satisfactory to such lender and Lender,
or (B) execute and deliver a discharge of the Mortgage and the other Security
Documents subject to satisfaction of the following conditions:

      (a) The Note shall remain in full force and effect but shall no longer be
secured by the Mortgage and the other Security Agreements.

      (b) The entity documentation of Borrower, including without limitation its
operating agreement, will be amended so as to include Lender as a special member
of Waterford Park, LLC. The rights of Lender as member of Waterford Park LLC
shall only be as follows:

            (i) Interest on the Note shall be paid from the net cash flow
      payable to Borrower from the Project on a preferred basis prior to the
      payment of any cash flow to other members of Borrower. In the event that
      during any month there is not available from such cash flow an amount
      sufficient to pay interest then due on the Note, the unpaid portion shall
      accrue and be compounded monthly.

            (ii) As a member of Waterford Park LLC, the Lender shall not be
      entitled to any of the incidents of ownership of the Project except its
      entitlement to receive such preferred payments of net cash flow, nor shall
      Lender have any voting rights or say in the management of Waterford Park
      LLC.

            (iii) In the event of the occurrence and continuance of an Event of
      Default by Tenant under the Tenant Lease, such preferred payment of
      interest out of cash flow shall not be made, but rather such interest such
      accrue. In such case, Borrower may offset against payments otherwise due
      or accruing on the Note, one-half of the cost actually incurred by
      Borrower for taxes and operating expenses with respect to the Project, on
      a current basis (i.e., if for any given month the sum of taxes and
      operating expenses for the project equals $X, the amount to be offset for
      that month against payments otherwise due on the Note shall be 50% of $X).
      Moreover, such offsetting shall be subject to an aggregate maximum amount
      of $750,000.

            (iv) The Note shall be payable in full from the proceeds of any sale
      or refinancing of the Project to the extent proceeds are available
      therefor, and such proceeds shall be paid to Lender prior to any such
      proceeds being paid to other members of Borrower.

      (c) The Loan Documents and the Waterford Park LLC entity documents,
including its operating agreement, shall be amended in a manner consistent with
the foregoing provisions. Such amendments shall be in form and substance
reasonably satisfactory to Lender.

      17. EXPENSES. The Borrower agrees to pay (a) the reasonable costs of
producing and reproducing this Agreement, the other Loan Documents and the other
agreements and instruments mentioned herein, (b) any taxes (including any
interest and penalties in respect

Second Lien                           -38-
<PAGE>

thereto) payable by the Lender (other than taxes based upon the Lender's net
income), including any recording, mortgage or intangibles taxes in connection
with the Mortgage, or other taxes payable on or with respect to the transactions
contemplated by this Agreement, including any taxes payable by the Lender after
the Closing Date (the Borrower hereby agreeing to indemnify the Lender with
respect thereto), (c) all title insurance premiums, and the reasonable fees,
expenses and disbursements of the Lender's counsel or any local counsel to the
Lender incurred in connection with the preparation, administration or
interpretation of the Loan and the Loan Documents and other instruments
mentioned herein, the making of each Advance hereunder, and amendments,
modifications, approvals, consents or waivers hereto or hereunder, (d) the fees,
expenses and disbursements of the Lender incurred in connection with the
preparation, administration or interpretation of the Loan and the Loan Documents
and other instruments mentioned herein, and the making of each Advance hereunder
(including all fees paid to the Construction Inspector, Appraisal fees, and
surveyor fees) (e) all reasonable out-of-pocket expenses (including reasonable
attorneys' fees and costs, which attorneys may be employees of the Lender) and
the fees and costs of consultants, accountants, auctioneers, receivers, brokers,
property managers, appraisers, investment bankers or other experts retained by
the Lender in connection with (i) the enforcement of or preservation of rights
under any of the Loan Documents against the Borrower or any Obligor or the
administration thereof after the occurrence of a Default or Event of Default and
(ii) any litigation, proceeding or dispute whether arising hereunder or
otherwise, in any way related to the Lender's relationship with the Borrower or
any Party, and (f) all reasonable fees, expenses and disbursements of the Lender
incurred in connection with UCC searches, UCC filings, title rundowns, title
searches or mortgage recordings. The covenants of this Section shall survive
payment or satisfaction of payment of all amounts owing with respect to the
Note.

      18. INDEMNIFICATION. The Borrower agrees to indemnify and hold harmless
the Lender from and against any and all claims, actions and suits, whether
groundless or otherwise, and from and against any and all liabilities, losses,
damages and expenses of every nature and character arising out of this Agreement
or any of the other Loan Documents or the transactions contemplated hereby and
thereby including, without limitations, (a) any brokerage, leasing, finders or
similar fees, (b) any disbursement of the proceeds of any of the Advances, (c)
any condition of the Project whether related to the quality of construction or
otherwise, (d) any actual or proposed use by the Borrower of the proceeds of any
of the Advances, (e) any actual or alleged violation of any Requirements or
Project Approvals, or (f) the Borrower or any Party entering into or performing
this Agreement or any of the other Loan Documents, in each case including,
without limitation, the reasonable fees and disbursements of counsel and
allocated costs of internal counsel incurred in connection with any such
investigation, litigation or other proceeding. In litigation, or the preparation
therefor, the Lender shall be entitled to select its own counsel and, in
addition to the foregoing indemnity, the Borrower agrees to pay promptly the
reasonable fees and expenses of such counsel. The obligations of the Borrower
under this Section shall survive the repayment of the Loan and shall continue in
full force and effect so long as the possibility of such claim, action or suit
exists. If, and to the extent that the obligations of the Borrower under this
Section are unenforceable for any reason, the Borrower hereby agrees to make the
maximum contribution to the payment in satisfaction of such obligations which is
permissible under applicable law. The foregoing indemnification shall not be
applicable to any

Second Lien                           -39-
<PAGE>

matter arising out of the Tenant Lease or the relationship of Borrower and
Lender as landlord and tenant thereunder, as to which matters the terms and
provisions of the Tenant Lease shall govern.

      19. LIABILITY OF THE LENDER; SPECIFIC PERFORMANCE. The liability of the
Lender to the Borrower for any breach of the terms of this Agreement by the
Lender shall not exceed a sum equal to (i) the amount which the Lender shall be
determined to have failed to advance in consequence of a breach by the Lender of
its obligations under this Agreement, (ii) interest thereon at the default rate
payable by the Borrower under the terms of the Note for Advances which the
Borrower is to receive hereunder, computed from the date when the Advance should
have been made by the Lender to the date when the Advance is, in fact, made by
the Lender, and, upon the making of any such payment by the Lender to the
Borrower, the same shall be treated as an Advance under this Agreement, in the
same fashion as any other Advance under the terms of this Agreement, and (iii)
actual losses incurred by the Borrower as a result of Lender's breach which
reasonably could be foreseen by the Lender. The Lender acknowledges and agrees
that the Borrower shall have the remedy of specific performance by the Lender.

      20. RIGHTS OF THIRD PARTIES. All conditions to the performance of the
obligations of the Lender under this Agreement, including the obligation to make
Advances, are imposed solely and exclusively for the benefit of the Lender and
no other Person shall have standing to require satisfaction of such conditions
in accordance with their terms or be entitled to assume that the Lender will
refuse to make Advances in the absence of strict compliance with any or all
thereof and no other Person shall, under any circumstances, be deemed to be a
beneficiary of such conditions, any and all of which may be freely waived in
whole or in part by the Lender at any time if in its sole discretion it deems it
desirable to do so. In particular, the Lender makes no representations and
assumes no obligations as to third parties concerning the quality of the
construction by the Borrower of the Improvements or the absence therefrom of
defects.

      21. SURVIVAL OF COVENANTS, ETC. All covenants, agreements, representations
and warranties made herein, in the Note, in any of the other Loan Documents or
in any documents or other papers delivered by or on behalf of the Borrower or
any Party pursuant hereto and thereto shall be deemed to have been relied upon
by the Lender, notwithstanding any investigation heretofore or hereafter made by
it, and shall survive the making by the Lender of the Advances, as herein
contemplated, and shall continue in full force and effect either (i) so long as
any amount due under this Agreement or the Note or any of the other Loan
Documents remains outstanding or the Lender has any obligation to make any
Advances or (ii) for such longer period as may be provided for herein or in any
other Loan Document. All statements contained in any certificate or other paper
delivered to the Lender at any time by or on behalf of any Party or any
Subsidiary thereof pursuant hereto or in connection with the transactions
contemplated hereby shall constitute representations and warranties by such
Person.

      22. ASSIGNMENT AND PARTICIPATION. This Agreement, the Note and the other
Loan Documents may be assigned by Lender to any Tenant Affiliate after the
Commencement Date (as each such term is defined in the Lease), but not
otherwise, except with the written consent of Borrower, which consent will not
be unreasonably withheld or delayed.

Second Lien                           -40-
<PAGE>

      23. RELATIONSHIP. The relationship between the Lender and the Borrower is
solely that of a lender and borrower, and nothing contained herein or in any of
the other Loan Documents shall in any manner be construed as making the parties
hereto partners, joint venturers or any other relationship other than lender and
borrower.

      24. NOTICES. Except as otherwise provided herein or in any other Loan
Document, each notice, demand, election or request provided for or permitted to
be given pursuant to this Agreement (hereinafter in this Section referred to as
"Notice") must be in writing and shall be deemed to have been properly given or
served by personal delivery, or by sending same by nationally recognized
overnight courier or by depositing same in the United States Mail, postpaid and
registered or certified, return receipt requested, and addressed as follows:

      If to the Lender,

      SEPRACOR, INC.
      111 Locke Drive
      Marlborough, Massachusetts 01752
      Attn: Vice President for Finance and Administration

      with a copy to,

      Nixon Peabody LLP
      101 Federal Street
      Boston, Massachusetts 02110
      Attn: William C. Stone, PC

      if to Borrower,

      Waterford Park, LLC
      c/o Waterford Development Corp.
      175 Highland Avenue
      Needham, Massachusetts 02494
      Attn: Robert E. Shapiro

      with a copy to,

      Garrity Levin & Muir
      99 Summer Street
      Boston, Massachusetts 02110
      Attn: Jonathan Levin, Esq.

Each Notice shall be effective upon being personally delivered or upon being
sent by overnight courier or upon being deposited in the United States Mail as
aforesaid. The time period in which a response to such Notice must be given or
any action taken with respect thereto (if any),

Second Lien                           -41-
<PAGE>

however, shall commence to run from the date of receipt if personally delivered
or sent by overnight courier, or if so deposited in the United States Mail, the
earlier of three (3) Business Days following such deposit or the date of receipt
as disclosed on the return receipt. Rejection or other refusal to accept or the
inability to deliver because of changed address for which no Notice was given
shall be deemed to be receipt of the Notice sent. By giving at least thirty (30)
days' prior Notice thereof, the Borrower or the Lender shall have the right from
time to time and at any time during the term of this Agreement to change their
respective addresses and each shall have the right to specify as its address any
other address within the United States of America.

      25. GOVERNING LAW. This Agreement and each of the other Loan Documents,
except as otherwise specifically provided therein, are contracts under the laws
of The Commonwealth of Massachusetts and shall for all purposes be construed in
accordance with and governed by the laws of said Commonwealth (excluding the
laws applicable to conflicts or choice of law).

      26. CONSENT TO JURISDICTION; WAIVERS. THE BORROWER AND EACH PARTY HEREBY
IRREVOCABLY AND UNCONDITIONALLY (A) SUBMITS TO PERSONAL JURISDICTION IN THE
COMMONWEALTH OF MASSACHUSETTS OVER ANY SUIT, ACTION OR PROCEEDING ARISING OUT OF
OR RELATING TO THIS AGREEMENT OR ANY OF THE OTHER LOAN DOCUMENTS, AND (B) WAIVES
ANY AND ALL PERSONAL RIGHTS UNDER THE LAWS OF ANY STATE (I) TO THE RIGHT, IF
ANY, TO TRIAL BY JURY, (II) TO OBJECT TO JURISDICTION WITHIN THE COMMONWEALTH OF
MASSACHUSETTS OR VENUE IN ANY PARTICULAR FORUM WITHIN THE COMMONWEALTH OF
MASSACHUSETTS, AND (III) TO THE RIGHT, IF ANY, TO CLAIM OR RECOVER ANY SPECIAL,
EXEMPLARY, PUNITIVE OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES OTHER THAN ACTUAL
DAMAGES. THE BORROWER AND EACH PARTY AGREES THAT, IN ADDITION TO ANY METHODS OF
SERVICE OF PROCESS PROVIDED FOR UNDER APPLICABLE LAW, ALL SERVICE OF PROCESS IN
ANY SUCH SUIT, ACTION OR PROCEEDING MAY BE MADE BY CERTIFIED OR REGISTERED MAIL,
RETURN RECEIPT REQUESTED DIRECTED TO THE BORROWER AT THE ADDRESS SET FORTH IN
ss.22 ABOVE, AND SERVICE SO MADE SHALL BE COMPLETE FIVE (5) DAYS AFTER THE SAME
SHALL BE SO MAILED. NOTHING CONTAINED HEREIN, HOWEVER, SHALL PREVENT THE LENDER
FROM BRINGING ANY SUIT, ACTION OR PROCEEDING OR EXERCISING ANY RIGHTS AGAINST
ANY COLLATERAL AND AGAINST THE BORROWER, AND AGAINST ANY PROPERTY OF THE
BORROWER, IN ANY OTHER STATE. INITIATING SUCH SUIT, ACTION OR PROCEEDING OR
TAKING SUCH ACTION IN ANY STATE SHALL IN NO EVENT CONSTITUTE A WAIVER OF THE
AGREEMENT CONTAINED HEREIN THAT THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS
SHALL GOVERN THE RIGHTS AND OBLIGATIONS OF THE BORROWER, EACH PARTY, AND THE
LENDER HEREUNDER OR THE SUBMISSION HEREIN BY THE BORROWER AND EACH PARTY TO
PERSONAL JURISDICTION WITHIN THE COMMONWEALTH OF MASSACHUSETTS.

      27. HEADINGS. The captions in this Agreement are for convenience of
reference only and shall not define or limit the provisions hereof.

Second Lien                           -42-
<PAGE>

      28. COUNTERPARTS. This Agreement and any amendment hereof may be executed
in several counterparts and by each party on a separate counterpart, each of
which when so executed and delivered shall be an original, and all of which
together shall constitute one instrument. In proving this Agreement it shall not
be necessary to produce or account for more than one such counterpart signed by
the party against whom enforcement is sought.

      29. ENTIRE AGREEMENT, ETC. The Loan Documents and any other documents
executed in connection herewith or therewith express the entire understanding of
the parties with respect to the transactions contemplated hereby. Neither this
Agreement nor any term hereof may be changed, waived, discharged or terminated,
except as provided in ss.29.

      30. CONSENTS, AMENDMENTS, WAIVERS, ETC. Except as otherwise expressly set
forth in any particular provision of this Agreement, any consent or approval
required or permitted by this Agreement to be given by the Lender may be given,
and any term of this Agreement or of any other instrument related hereto or
mentioned herein may be amended, and the performance or observance by the
Borrower of any terms of this Agreement or such other instrument or the
continuance of any Default or Event of Default may be waived (either generally
or in a particular instance and either retroactively or prospectively) with, but
only with, the written consent of the Lender. No waiver shall extend to or
affect any obligation not expressly waived or impair any right consequent
thereon. No course of dealing or delay or omission on the part of the Lender in
exercising any right shall operate as a waiver thereof or otherwise be
prejudicial thereto. No Advance made by the lender hereunder during the
continuance of any Default or Event of Default shall constitute a waiver
thereof. No notice to or demand upon the Borrower shall entitle the Borrower to
other or further notice or demand in similar or other circumstances.

      31. TIME OF THE ESSENCE. Time is of the essence with respect to each and
every covenant, agreement and obligation of the Borrower under this Agreement
and the other Loan Documents.

      32. SEVERABILITY. The provisions of this Agreement are severable, and if
any one clause or provision hereof shall be held invalid or unenforceable in
whole or in part in any jurisdiction, then such invalidity or unenforceability
shall affect only such clause or provision, or part thereof, in such
jurisdiction, and shall not in any manner affect such clause or provision in any
other jurisdiction, or any other clause or provision of this Agreement in any
jurisdiction.

         [The remainder of this page has been left intentionally blank]

Second Lien                           -43-
<PAGE>

      IN WITNESS WHEREOF, the undersigned have duly executed this Agreement as a
sealed instrument as of the date first set forth above.

                                        WATERFORD PARK, LLC

                                        By: /s/ Richard N. Houlding
                                           -------------------------------
                                            Richard N. Houlding, its Manager

                                        SEPRACOR, INC.

                                        By: /s/ Robert F. Scumaci
                                           -----------------------------------
                                            Robert F. Scumaci, Vice President of
                                            Finance and Administration

Second Lien                           -44-
<PAGE>

                                    Exhibit A

                              Construction Schedule

                                    Exhibit B

                              Disbursement Schedule

                                    Exhibit C

                                   [Reserved]

                                    Exhibit D

                                   [Reserved]

                                    Exhibit E

                            Plans and Specifications

                                    Exhibit F

                                 Project Budget

                                    Exhibit G

                             Borrower's Requisition

                                    Exhibit H

                      Contractor's Requisition Certificate

                                    Exhibit I

                                   [Reserved]

                                    Exhibit J

                           Tenant Improvements Summary

                                    Exhibit K

                                    Lien Form

                                    Exhibit L

                                   [Reserved]

                                    Exhibit M

Second Lien                           -45-
<PAGE>

                                   [Reserved]

                                    Exhibit N

                                   [Reserved]

Second Lien                           -46-
<PAGE>

                                  Schedule 8.14

                          Partners, Beneficiaries, Etc.

                            Schedules 8.20S and 8.20B

                                Project Approvals

Second Lien                           -47-<PAGE>

                                                                    Exhibit 10.6

                             Location of Property:

                              Town of Marlborough

                              County of Middlesex

                         Commonwealth of Massachusetts

                          Dated as of January 30, 2001

                   LEASEHOLD MORTGAGE AND SECURITY AGREEMENT

                              ("Second Mortgage")

                                      From

                       WATERFORD PARK, LLC, as Mortgagor

                                       to

                          SEPRACOR, INC., as Mortgagee

                   This instrument was prepared by and, after
                          recording, please return to:

                           Thomas Howard Brown, P.C.
                               Nixon Peabody LLP
                               101 Federal Street
                                Boston, MA 02110

<PAGE>

                               TABLE OF CONTENTS
                                                                            Page
                                                                            ----

ARTICLE I SECURED OBLIGATIONS..................................................2

   1.1  Security...............................................................2

   1.2  Secured Obligations....................................................2

ARTICLE II GRANT OF MORTGAGED PROPERTIES.......................................2

   2.1  Mortgaged Property.....................................................2

   2.2  Release of Mortgage....................................................5

ARTICLE III SECURITY AGREEMENT.................................................6

   3.1  Grant of Security Interest.............................................6

   3.2  Covenants of Debtor....................................................6

ARTICLE IV CERTAIN REPRESENTATIONS, WARRANTIES AND COVENANTS OF MORTGAGOR .....7

   4.1  Payment of Indebtedness................................................8

   4.2  Title..................................................................8

   4.3  Maintenance of Existence; Due Authorization; Compliance with Laws;
         Etc...................................................................8

   4.4  Compliance With Law and Insurance Requirements; Maintaining Permits;
         Etc...................................................................9

   4.5  Taxes and other Charges; Deposits with Mortgagee......................10

   4.6  Discharge of Liens....................................................11

   4.7  Contest of Impositions................................................12

   4.8  Mortgagee's Taxes.....................................................12

   4.9  Use of Mortgaged Property.............................................12

   4.10    Maintenance of Mortgaged Property..................................13

   4.11    Maintenance of Personal Property...................................13

   4.12    Alterations........................................................13

   4.13    Waste..............................................................14

   4.14    Insurance..........................................................14

   4.15    Damage or Destruction..............................................18

   4.16    Condemnation; Knowledge of Proceedings.............................19

   4.17    General Right of Entry.............................................21

   4.18    Separate Tax Lots..................................................22

   4.19    Books of Account; Financial Statements.............................22

   4.20    Limitations on Transfer............................................24

   4.21    Recording, Filing and Perfection of Security Interests; Fees.......24

<PAGE>

   4.22    Further Acts and Assurances........................................24

ARTICLE V EVENTS OF DEFAULT...................................................25

   5.1  Events of Default.....................................................25

ARTICLE VI REMEDIES AND RELATED MATTERS.......................................25

   6.1  Remedies..............................................................25

   6.2  Foreclosure and Sale; Application of Proceeds; Waiver of Right of
         Redemption; Etc......................................................26

   6.3  No Conditions Precedent to Exercise of Remedies.......................31

   6.4  No Merger.............................................................31

   6.5  Remedies Cumulative...................................................31

   6.6  Mortgagee's Performance of Mortgagor's Obligations....................32

ARTICLE VII MISCELLANEOUS.....................................................32

   7.1  Enforceability........................................................32

   7.2  Maximum Rate of Interest..............................................32

   7.3  Notices...............................................................34

   7.4  No Release............................................................35

   7.5  Attorneys' Fees and Costs of Mortgagee................................35

   7.6  Brokerage.............................................................35

   7.7  Indemnification.......................................................35

   7.8  Environmental Matters.................................................37

   7.9  Limitations on Recourse...............................................37

   7.10    Estoppel Certificates..............................................37

   7.11    Effect of Extensions and Amendments................................38

   7.12    No Joint Venture...................................................38

   7.13    Funds Held in Accounts.............................................38

   7.14    Expenses of Mortgagee..............................................38

   7.15    Governing Law......................................................38

   7.16    Captions and Pronouns..............................................38

   7.17    Amendments, Waivers, Etc...........................................39

   7.18    Entire Agreement; Controlling Provisions...........................39

   7.19    Covenants Running With the Land; Successors and Assigns............39

   7.20    Statutory Condition................................................39

   7.21    Forbearance; Subordination.........................................39

   EXHIBIT A: LAND DESCRIPTION.................................................1

                                       ii
<PAGE>

      This LEASEHOLD MORTGAGE AND SECURITY AGREEMENT (hereinafter called the
"Second Mortgage") is made as of the 30th day of January, 2001, by WATERFORD
PARK, LLC, a Massachusetts limited liability company ("Mortgagor"), having a
principal place of business c/o Waterford Development Corp., 175 Highland
Avenue, Needham, Massachusetts 02494, as Mortgagor, to SEPRACOR, INC., a
Delaware corporation having an address at 111 Locke Drive, Marlborough,
Massachusetts 01752, and any subsequent holder of the Secured Obligations
hereinafter set forth (all of whom shall be included within the term "Mortgagee"
as used herein), as Mortgagee, Assignee, and Secured Party, as more fully
hereinafter set forth.

                              W I T N E S S E T H:

      WHEREAS, Mortgagee has loaned (the "Loan") to Mortgagor the aggregate
principal amount of SIX MILLION FOUR HUNDRED FIFTY-EIGHT THOUSAND FIVE HUNDRED
NINETY-SEVEN and 00/100 Dollars ($6,458,597.00), evidenced by a note, dated
January 30, 2001, in such amount (the "Note"); and

      WHEREAS, Mortgagor alone, or Mortgagor and/or certain other parties, as
the case may be, have executed and delivered to Mortgagee simultaneously with
the execution and delivery of the Note, a Loan Agreement (Second Lien) dated as
of January 30, 2001 (the "Second Loan Agreement"), an Environmental Indemnity
Agreement dated as of January 30, 2001 (the "Indemnity Agreement"), a Joint and
Several Limited Guaranty Agreement dated as of January 30, 2001 (the
"Guaranty"), an Assignment of Leases and Rents dated as of January 30, 2001 (the
"Assignment of Leases") and Collateral Assignment of Contracts, Licenses,
Permits, Agreements, Warranties and Approvals dated as of January 30, 2001 (the
"Assignment of Contracts");

      WHEREAS, simultaneously with the execution and delivery of the Note, the
Second Loan Agreement, the Indemnity Agreement, the Guaranty, the Assignment of
Leases and the Assignment of Contracts, Mortgagor has entered into this Second
Mortgage with Mortgagee to secure, among other things, the payment of the Note,
the obligations and payments of Mortgagor under the Second Loan Agreement, the
Indemnity Agreement, the Guaranty, the Assignment of Leases and the Assignment
of Contracts, and all of the advances made and which may be made under the
Second Mortgage covering all of the interests of Mortgagor in and to the
Mortgaged Property (as hereinafter defined);

      WHEREAS, Mortgagor and/or certain other parties, as the case may be, have
executed and delivered to Mortgagee simultaneously with the execution of the
Note and Second Loan Agreement, a Note, First Loan Agreement (First Lien) and
Leasehold Mortgage and Security Agreement (the "Mortgage") for the principal
amount of $20,860,000.

      NOW, THEREFORE, the parties hereto agree as follows:

<PAGE>

                                   ARTICLE I

                              SECURED OBLIGATIONS

      1.1 Security. This Second Mortgage is executed and delivered by Mortgagor
to secure the payment and performance of certain indebtedness, liabilities and
obligations owing and to become owing to or in favor of Mortgagee, as follows:

            1.1.1 The outstanding principal balance of the Note, payable to the
order of Mortgagee in the aggregate original principal amount of SIX MILLION and
00/100 Dollars ($6,000,000.00), together with all interest accruing thereon,
being payable in the amounts, at the interest rates and on the dates stipulated
therein and in the Second Loan Agreement, said Note being dated January 30,
2001;

            1.1.2 Any and all other amounts, liabilities, and obligations for
which or for the performance of which Mortgagor may become indebted or obligated
under the terms of this Second Mortgage, the Note, the Second Loan Agreement,
the Indemnity Agreement, the Assignment of Leases and the Assignment of
Contracts and any other documents, instruments, recordings or filings that may
hereafter be entered into by and between Mortgagor and Mortgagee or may be
executed and delivered by Mortgagor on behalf of Mortgagee in connection with
the Loan (this Second Mortgage, the Note, the Second Loan Agreement, the
Indemnity Agreement, the Assignment of Leases and the Assignment of Contracts
and all such documents, instruments, recordings and filings are herein
collectively referred to as the "Loan Documents", but the First Mortgage Loan
Documents (as defined in the Loan Agreement) shall not be included in the Loan
Documents);

            1.1.3 Any and all renewals, increases, rearrangements,
modifications, supplements, restatements and extensions of the foregoing items
of indebtedness and obligations.

      1.2 Secured Obligations. Each and every item of indebtedness described and
included in this Second Mortgage is intended to be fully secured by the liens,
assignments, and security interests created under and by virtue of this Second
Mortgage; and all such items so secured (now or hereafter existing) are
hereinafter collectively called the "Secured Obligations." Secured Obligations
do not, however, include any obligation of Borrower to Lender set forth in the
First Mortgage Loan Documents or the Tenant Lease (hereinafter defined).

                                   ARTICLE II

                         GRANT OF MORTGAGED PROPERTIES

      2.1 Mortgaged Property. For the purposes and trusts hereinafter set forth,
and for TEN AND 0O/000 DOLLARS ($10.00) and other good and valuable
consideration paid to Mortgagor, the receipt and sufficiency of which are hereby
acknowledged, Mortgagor has GRANTED and by these presents does GRANT unto
Mortgagee, WITH MORTGAGE

                                       2
<PAGE>

COVENANTS, all the following described property (collectively, the "Mortgaged
Property"), to wit:

            2.1.1 All of Mortgagor's right, title and interest in and to those
certain tracts, pieces and parcels of land described in Exhibit A attached
hereto and hereby made a part hereof (the "Land") (the State in which the Land
is located is sometimes hereinafter referred to as the "Jurisdiction"), as
lessee under the Ground Lease dated as of January 30, 2001, from HILLSIDE
SCHOOL, INC., a Massachusetts non-profit corporation ("Fee Owner"), as landlord,
and Mortgagor as tenant (the "Ground Lease"), a notice of the Ground Lease being
recorded with the Middlesex South District Registry of Deeds herewith;

            2.1.2 All of Mortgagor's right, title and interest in and to all
structures, improvements, buildings and any additions and alterations thereto or
replacements thereof, now or hereafter erected upon the Land (all of the
foregoing being collectively referred to as the "Improvements"), and in
addition, all of Mortgagor's right, title and interest in and to all equipment,
apparatus, furnishings, furniture, machinery, fixtures of every kind and nature
whatsoever (the "Personal Property") now or hereafter located in and about said
Improvements, including without limitation all fixtures, fittings, appliances,
apparatus, equipment, machinery, furnishings and articles of personal property
now or hereafter attached or affixed to, placed upon or used in any way in
connection with the use, enjoyment, operation or occupancy of the Improvements,
including without limitation all landscaping and gardening equipment, all
heating and incinerating apparatus and equipment whatsoever, all boilers,
engines, motors, dynamos, generating equipment, piping and plumbing fixtures,
ranges, cooking utensils and apparatus and mechanical kitchen equipment,
refrigerators, cooling, ventilating, sprinkling and vacuum cleaning systems,
fire extinguishing and prevention apparatus, gas and electrical fixtures,
elevators, escalators, partitions, lockers, cabinets, window covering and all
hardware therefor, carpeting and other floor coverings, lighting fixtures, lamps
and office furniture, window shades, blinds, screens, storm sashes, awnings,
furnishings of public spaces, halls and lobbies and shrubbery and plants, all of
which property mentioned in this paragraph shall be deemed part of the realty
mortgaged hereby (the Land, the Improvements and the Personal Property being
collectively referred to herein as the "Premises"). Notwithstanding the
agreement hereinabove expressed that certain articles of property form a part of
the realty covered by this Second Mortgage and be appropriated to its use and
deemed to be realty, to the extent that such agreement and declaration may not
be effective and that any of said articles may constitute goods (as said term is
used in the Uniform Commercial Code as enacted in the Jurisdiction), this
instrument shall constitute a security agreement, creating a security interest
in such goods, as collateral, in Mortgagee as a secured party and Mortgagor as
debtor, all in accordance with said Uniform Commercial Code, as more
particularly set forth in Article III hereof;

            2.1.3 All of Mortgagor's estate, of whatever nature, in and to all
of the easements, rights, privileges, appurtenances, air rights and development
rights now or hereafter belonging or in any wise appertaining to the Premises
(the "Appurtenant Rights"), and all of the estate, right, title, interest, claim
or demand whatsoever, either in law or in equity, in possession or expectancy of
Mortgagor therein and in the streets and

                                       3
<PAGE>

ways, open or proposed, adjacent thereto, and in and to all strips and gores,
vaults, alleyways, sidewalks and passages used in connection with the Land;

            2.1.4 All of Mortgagor's right, title and interest in all reserves
and/or escrow accounts or the like maintained with respect to the Mortgaged
Property and whether held by or in the name of either Mortgagor or Mortgagee,
all inventory accounts, accounts receivable, contract rights, general
intangibles, chattel paper, instruments, documents, Note, drafts, letters of
credit and insurance policies (including without limitation environmental and/or
flood insurance policies) arising from or related to the Premises (collectively,
the "Accounts") and including all replacements and substitutions for, or
additions to, all products and proceeds of any of the foregoing;

            2.1.5 All of Mortgagor's interest in all agreements, contracts,
certificates, instruments and other documents, now or hereafter entered into,
pertaining to the construction, operation or management of the Premises and all
right, title and interest of Mortgagor, therein;

            2.1.6 All unearned premiums accrued or to accrue under all insurance
policies for the Premises obtained by Mortgagor, all proceeds of the conversion,
voluntary or involuntary, of any of the foregoing into cash or liquidated
claims, proceeds of insurance and condemnation awards, and all rights of
Mortgagor to refunds of real estate taxes and assessments with respect to the
Premises (the "Proceeds");

            2.1.7 A non-exclusive right to Mortgagor's right, title and interest
in and to all trade names, trademarks and service marks now or hereafter used in
connection with the Premises or any part thereof or any other part of the
Premises, together with good will appurtenant thereto;

            2.1.8 All of Mortgagor's right, title and interest in and to all
leases, subleases, lettings, licenses and other occupancy agreements, and
guarantees thereof, for the Premises or any part thereof including without
limitation the Lease dated as of January 30, 2001 between Mortgagor, as landlord
and Sepracor, Inc., as tenant (the "Tenant Lease") (collectively, "Leases" and,
individually, a "Lease"), including any cash or other security deposited
thereunder, and the rents, issues, profits, revenue, royalties (collectively the
"Rents") payable under the Leases; the Tenant Lease being a Permitted Exception
(as hereinafter defined);

            2.1.9 All of Mortgagor's right, title and interest in and to all of
the books, computer software, records and files of or relating to the Premises
now or hereafter maintained by Mortgagor or for its account;

            2.1.10 All of Mortgagor's right, title and interest in and to all
awards and claims for damages made and to be made for the taking by eminent
domain of the whole or any part of the Premises, including without limitation
any awards for change of grade of streets, all of which awards Mortgagor hereby
assigns to Mortgagee;

            2.1.11 All of Mortgagor's right, title and interest in and to all
licenses, permits, and warranties attributable, allocable or relating to all or
any portion of the

                                       4
<PAGE>

Premises, both real and personal, but only to the extent such licenses, permits
and warranties may be assigned, transferred or pledged without violation of the
terms thereof; and

            2.1.12 All of Mortgagor's right, title and interest in and to all
mineral, water, oil and gas rights and privileges and royalties pertaining to
the Premises;

            2.1.13 This Mortgage and the lien hereof (i) is subject and
subordinate to all rights of Sepracor, Inc. in and to the "Specialized Leasehold
Improvements", and (ii) do not encumber or create any security interest in any
personal property owned by Sepracor, Inc. and located in the Improvements.

      TO HAVE AND TO HOLD the Mortgaged Property unto Mortgagee and its
substitutes or successors forever, and Mortgagor does hereby bind itself, its
successors, assigns, executors and administrators to warrant and forever defend
all and singular the Mortgaged Property unto Mortgagee, its successors and
assigns, against every person whomsoever lawfully claiming or to claim an
interest in the same, or any part thereof. Subject only to the specific matters
set forth in Schedule B, Section 2 of the Commitment for Title Insurance issued
by Chicago Title Insurance Company, No. 2051-25071, as approved by Mortgagee,
and any future matters expressly permitted by this Second Mortgage, the Second
Loan Agreement or the Assignment of Leases or approved in writing by Mortgagee
as permitted exceptions (collectively, "Permitted Exceptions"). Permitted
Exceptions include taxes which are a lien on the Premises but are not delinquent
and any Leases permitted under the Assignment of Leases.

      2.2 Release of Mortgage. This conveyance, however, is intended as a
mortgage and security agreement and is made upon the following trust, terms, and
conditions, to wit: In the event Mortgagor shall perform and pay the Secured
Obligations (including payment of all principal and interest, and all charges,
disbursements and fees of Mortgagee's attorneys, if any, owing or to become
owing thereon) to Mortgagee in accordance with the applicable Loan Documents,
then this Second Mortgage shall be null and void and shall be released at
Mortgagor's sole cost and expense; otherwise this Second Mortgage shall continue
in full force and effect.

      2.3 Prior Mortgages. Mortgagor shall perform all of Mortgagor's
obligations under any mortgage or other security agreement with a lien that has
priority over this Second Mortgage, including Mortgagor's covenants to make
payments when due. Mortgagor shall pay or cause to be paid all taxes,
assessments, and other charges, fines and impositions attributable to the
Premises which may attain priority over this Second Mortgage, and leasehold
payments or ground rents, if any. This Second Mortgage, and the lien hereof, is
subordinate to the First Mortgage, and the lien thereof.

                                       5
<PAGE>

                                  ARTICLE III

                               SECURITY AGREEMENT

      3.1 Grant of Security Interest. Without limiting any of the other
provisions of this Second Mortgage, Mortgagor, as Debtor (referred to in this
Article III as "Debtor," whether one or more), expressly GRANTS unto Mortgagee,
as Secured Party (referred to in this Article III as "Secured Party," whether
one or more), a security interest in all the Mortgaged Property (including both
those now and those hereafter existing) to the full extent that any portion of
the Mortgaged Property may be subject to the Uniform Commercial Code as enacted
in the Jurisdiction (hereinafter referred to as the "Uniform Commercial Code").

      3.2 Covenants of Debtor. Debtor covenants and agrees with Secured Party
that:

            3.2.1 In addition to any other remedies granted in this Second
Mortgage to Secured Party (including specifically, but not limited to, the right
to proceed against the Mortgaged Property in accordance with the rights and
remedies in respect of the Mortgaged Property which are real property pursuant
to the Uniform Commercial Code), Secured Party may, should an Event of Default
(as defined in Article V hereof) occur and be continuing, proceed under the
Uniform Commercial Code as to all or any part of the personal property (tangible
or intangible) and fixtures included in the Mortgaged Property (such portion of
the Mortgaged Property being referred to in this Article III as the
"Collateral"), and shall have and may exercise with respect to the Collateral
all the rights, remedies, and powers of a secured party under the Uniform
Commercial Code, including without limitation the right and power to sell, at
one or more public or private sales, or otherwise dispose of, lease, or utilize
the Collateral and any part or parts thereof in any manner authorized or
permitted under the Uniform Commercial Code after default by a debtor. Without
limiting the foregoing, Secured Party shall have the right upon any such public
sale or sales, and, to the extent permitted by law, upon any such private sale
and sales, to purchase the whole or any part of the Collateral so sold, free of
any right or equity of redemption in Debtor, whether on Land or elsewhere.
Debtor further agrees to allow Secured Party to use or occupy the Mortgaged
Property, without charge, for the purpose of perfecting any of Secured Party's
remedies in respect of the Collateral. The net proceeds of any such collection,
recovery, receipt, appropriation, realization or sale, after deducting all
actual expenses of every kind incurred therein or incidental to the care,
safekeeping or otherwise of any or all of the Collateral or in any way relating
to the rights of Secured Party hereunder, including all attorneys' charges,
disbursements and reasonable fees, shall be received by Secured Party and
credited against the payment in whole or in part of the indebtedness secured
hereby. To the extent permitted by applicable law, Debtor waives all claims,
damages, and demands against Secured Party arising out of the repossession,
retention or sale of the Collateral, except for claims, damages and demands due
to the gross negligence or willful misconduct of Secured Party (including its
agents, employees and contractors) in dealing with such Collateral. Mortgagor
agrees that Secured Party need not give more than ten (10) days' notice of the
time and place or any public sale or of the time at which a private sale will
take place and that such notice is reasonable notification of such matters.

                                       6
<PAGE>

            3.2.2 Debtor hereby authorizes Secured Party to file financing and
continuation statements with respect to the Collateral without the signature of
Debtor whenever lawful, and Debtor irrevocably constitutes and appoints each of
Secured Party, and each of the officers of Secured Party, as Debtor's
attorney-in-fact coupled with an interest for such purpose; and Debtor agrees to
execute such financing and continuation statements as Secured Party may
reasonably request.

            3.2.3 Debtor hereby represents and warrants that no financing
statement (other than financing statements which will be terminated promptly
following the date hereof and financing statements showing Secured Party as the
sole secured party, or with respect to liens or encumbrances, if any, expressly
permitted by this Second Mortgage covering any of the Collateral or any proceeds
thereof) is on file in any public office except pursuant hereto; and Debtor will
at its own cost and expense, upon demand, furnish to Secured Party such further
information and will execute and deliver to Secured Party such financing
statements and other documents in form reasonably satisfactory to Secured Party
and will do all such acts as Secured Party may at any time or from time to time
reasonably request or as may be necessary or reasonably appropriate to establish
and maintain a perfected security interest in the Collateral as security for the
Secured Obligations, subject to no other liens or encumbrances, other than liens
or encumbrances benefiting Secured Party and no other party and to liens and
encumbrances (if any) expressly permitted by this Second Mortgage or the Second
Loan Agreement; and Debtor will pay the actual expense of filing or recording
such financing statements or other documents, and this instrument, in all public
offices wherever filing or recording is reasonably deemed by Secured Party to be
desirable.

            3.2.4 To the extent permitted by applicable law, the security
interest created hereby is specifically intended to cover all rents, royalties,
issues and profits, and all inventory accounts, accounts receivable and other
revenues of the Mortgaged Property.

            3.2.5 Certain of the Collateral is or will become "fixtures" (as
that term is defined in the Uniform Commercial Code) on the Land and
Improvements, and this Mortgage upon being filed for record in the Middlesex
South District Registry of Deeds shall operate also as a financing statement and
fixture filing upon such of the Collateral which is or may become fixtures.

            3.2.6 Any copy of this Second Mortgage which is signed by Debtor or
any carbon, photographic or other reproduction of this Second Mortgage may also
serve as a financing statement under the Uniform Commercial Code by Debtor,
whose address is set forth hereinabove, in favor of Secured Party, whose address
is set out hereinabove.

                                   ARTICLE IV

                      CERTAIN REPRESENTATIONS, WARRANTIES
                           AND COVENANTS OF MORTGAGOR

      Mortgagor hereby represents and warrants to and covenants with Mortgagee
as follows:

                                       7
<PAGE>

      4.1 Payment of Indebtedness. Mortgagor shall (a) punctually pay the
Secured Obligations at the time and place and in the manner specified in the
Loan Documents, according to the true intent and meaning thereof, all in such
coin or currency of the United States of America which at the time of such
payment shall be legal tender for the payment of public and private debts, and
(b) timely, fully and faithfully perform, discharge, observe and comply with
each and all of Mortgagor's obligations to be performed under the Loan
Documents. Mortgagor hereby represents and warrants that, as of the date hereof,
there exist no offsets, counterclaims or defenses against the Secured
Obligations.

      4.2 Title. Mortgagor has and will at all times have (subject to the
further provisions of this Second Mortgage) a valid and subsisting leasehold
estate in and to the Mortgaged Property as lessee under the Ground Lease,
subject to no lien, pledge, mortgage, mechanic's or materialman's lien, deed of
trust, security interest, claim, lease, charge, option, right of first refusal,
easement, restrictive covenant, encumbrance or other restriction, limitation,
charge or right of others of any kind whatsoever (collectively, "Liens"), other
than the Permitted Exceptions. Mortgagor will pay and perform, in timely manner,
all obligations of the tenant under the Ground Lease. This Second Mortgage is
and will at all times remain a valid and enforceable first lien on such
leasehold estate in the Mortgaged Property, subject only to the Permitted
Exceptions. Subject to the Permitted Exceptions, Mortgagor hereby covenants and
agrees that it will preserve such title, and will forever warrant and defend the
same to Mortgagee, its successors and assigns, and will forever warrant and
defend the validity and priority of the lien of this Second Mortgage against the
claims of all persons and parties whomsoever.

      4.3 Maintenance of Existence; Due Authorization; Compliance with Laws;
Etc.

            4.3.1 Mortgagor is and shall remain a limited liability company
validly organized and existing under the laws of The Commonwealth of
Massachusetts, and Mortgagor covenants that it will do or cause to be done all
things necessary to preserve and keep in full force and effect the existence,
rights and privileges of Mortgagor as a limited liability company under the laws
of such commonwealth. Mortgagor now has and shall continue to have the full
right, power and authority to operate and lease the Premises, to encumber the
Mortgaged Property as provided herein and to perform all of the other
obligations to be performed by Mortgagor under the Loan Documents. Mortgagor is
solvent, and no bankruptcy, reorganization, insolvency or similar proceeding
under any state or federal law with respect to Mortgagor has been initiated.

            4.3.2 The execution and delivery of the Loan Documents by the
Mortgagor, and performance by Mortgagor of its obligations thereunder have been
duly authorized by all necessary action on the part of Mortgagor and its
constituent entities, and do not and will not violate any law or any regulation,
order, writ, injunction or decree of any court or governmental or
quasi-governmental body, agency or other instrumentality (collectively,
"Governmental Authorities") applicable to Mortgagor or the Mortgaged Property
(collectively, "Laws"), or result in a breach of any of the terms, conditions or
provisions of, or constitute a default under, or (except as created by this
Second Mortgage and/or the other Loan Documents) result in the creation or
imposition of any lien of any nature whatsoever upon any of the assets of
Mortgagor pursuant to the terms of, any mortgage,

                                       8
<PAGE>

deed of trust, indenture, agreement or instrument to which Mortgagor is a party
or by which it or any of its properties is bound.

            4.3.3 All authorizations, consents and approvals of, notices to,
registrations or filings with, or other actions in respect of or by any
Governmental Authority, required in connection with (i) the execution and
delivery of the Loan Documents by the Mortgagor have been, or concurrently
herewith will be, duly obtained, given or taken and are in full force and
effect, and (ii) the performance by Mortgagor of its obligations thereunder have
been, or will be in timely manner, duly obtained, given or taken and are, or
will be in timely manner, in full force and effect.

            4.3.4 No material default has occurred and is continuing under any
indenture or other material agreement or instrument to which Mortgagor is a
party or by which its property is bound, including without limitation the Ground
Lease.

            4.3.5 Mortgagor is and shall remain a single asset entity and agrees
that it will not engage in any activities or acquire any interest in any
property other than the Mortgaged Property (including future Improvements and
Fixtures thereto, if any) without the prior written consent of Mortgagee which
consent may be withheld in Mortgagee's sole discretion.

      4.4 Compliance With Law and Insurance Requirements; Maintaining Permits;
Etc.

            4.4.1 Mortgagor, at no cost or expense to Mortgagee and subject to
the tenant's rights under the Tenant Lease, shall promptly comply with (or cause
to be complied with) in all material regards all Laws, and all orders, rules and
regulations (collectively, "Orders") of the National and Local Boards of Fire
Underwriters or any other body or bodies exercising similar functions, foreseen
or unforeseen, ordinary as well as extraordinary, applicable to the Mortgaged
Property or any part thereof, or to the use or manner of use of the Mortgaged
Property or the owners, tenants or occupants thereof, whether or not any such
Laws or Orders shall necessitate structural changes or improvements or interfere
with the use or enjoyment of the Mortgaged Property. Mortgagor shall also
procure, pay for and maintain (or cause to be procured, paid for and maintained)
all permits, licenses, approvals and other authorizations, necessary for the
operation of its business at the Premises and the lawful use and occupancy of
the Premises, or any part thereof, in connection therewith.

            4.4.2 Mortgagor shall, at no cost or expense to Mortgagee, observe
and comply (or cause to be observed and complied with) in all material respects
with the requirements of the policies of public liability, fire and all other
insurance at any time in force with respect to the Mortgaged Property, and
Mortgagor shall, in the event of any violation or attempted violation of the
provisions of this subsection or subsection 4.4.1 by any occupant of any portion
of the Premises, take steps, immediately upon actual knowledge of such violation
or attempted violation, to remedy or prevent the same, as the case may be.

                                       9
<PAGE>

            4.4.3 Mortgagor shall have the right, with Notice to Mortgagee, to
contest by appropriate legal proceedings, diligently conducted in good faith, in
the name of Mortgagor, the validity or application of any Laws, Orders or other
matters of the nature referred to in subsection 4.4.1, subject to the following:

                  (i) If by the terms of any such Law, Order or other matter,
compliance therewith pending the prosecution of any such proceeding may legally
be delayed without subjecting Mortgagor or Mortgagee to any liability (other
than for the payment or accrual of interest and civil penalties), civil or
criminal, for failure so to comply therewith, or if any lien, charge or civil
liability would be incurred by reason of any such delay, the same would not
subject the Mortgaged Property or any part thereof to forfeiture, loss or
suspension of operations, and Mortgagor (a) furnishes Mortgagee security
reasonably satisfactory to Mortgagee against any loss or injury by reason of
such contest or delay, and (b) prosecutes the contest with due diligence, then
Mortgagor may delay compliance therewith until the final determination of any
such proceeding.

      Mortgagor covenants that Mortgagee shall not suffer or sustain any
liabilities or expenses by reason of any act or thing done or omitted to be done
by Mortgagor pursuant to this subsection and that Mortgagor shall indemnify and
hold harmless Mortgagee from any such liability or expense.

      4.5 Taxes and other Charges; Deposits with Mortgagee.

            4.5.1 Subject to the provisions of Section 4.7 hereof, and subject
to the tenant's rights under the Tenant Lease, Mortgagor, from time to time when
the same shall become due and payable and before any fine, penalty or additional
interest may be added or imposed for late payments, will pay and discharge, or
cause to be paid and discharged, all of the following to the extent that they
are or may become a lien on the Mortgaged Property: taxes of every kind and
nature (including real and personal property taxes and income, franchise,
withholding, profits and gross receipts taxes), all general and special
assessments, levies, permits, inspection and license fees, all water and sewer
rents and charges, and all other public charges, whether of a like or different
nature, and any easement fees or charges, imposed upon or assessed against the
Mortgaged Property or any part thereof or upon the revenues, rents, issues,
income and profits of the Mortgaged Property or arising in respect of the
occupancy, use, possession or sale thereof (collectively, "Impositions"). If any
special assessment is payable in installments without payment of any penalty or
premium, other than interest at a non-default rate prior to the due date of such
installment, then Mortgagor may pay the same in installments. Mortgagor will
deliver to Mortgagee receipts or other evidence reasonably satisfactory to
Mortgagee of the payment of all Impositions promptly after receipt of a specific
request from Mortgagee. Mortgagor shall not claim or demand or be entitled to
any credit or credits on account of the Secured Obligations for any part of the
Impositions, and no deduction shall otherwise be made or claimed from the
taxable value of this Second Mortgage or the Secured Obligations.

            4.5.2 Except to the extent such matters are obligations of tenant
under the Tenant Lease and the Tenant Lease is not in default, Mortgagee may, at
its option to be exercised at any time, require the monthly deposit by Mortgagor
of an additional amount

                                       10
<PAGE>

sufficient to discharge the obligations of Mortgagor under subsection 4.5.1
above with respect to real and personal property taxes and assessments when they
become due and to pay all of the premiums on any insurance policies required by
this Second Mortgage. The determination of the amount so payable and of the
fractional part thereof to be deposited with Mortgagee, so that the aggregate of
such deposits shall be sufficient for this purpose, shall be made by Mortgagee
in its reasonable discretion. Such amounts shall be held by Mortgagee in an
interest bearing account and applied to the payment of the obligations in
respect of which such amounts were deposited on or before the respective dates
on which the same or any of them would become delinquent or, at Mortgagee's
option, after an Event of Default, to the payment of any Secured Obligation in
such order and priority as Mortgagee shall determine. Subject to the tenant's
rights under the Tenant Lease, if Mortgagee shall reasonably determine that the
amounts then on deposit therefor shall be insufficient for the payment of such
obligations in full, Mortgagor shall, within ten business days after demand,
deposit the amount of the deficiency with Mortgagee. Nothing herein contained
shall be deemed to affect any right or remedy of Mortgagee under any provisions
of this Mortgage or of any Law to pay any such amount and to add the amount so
paid, together with interest at the Default Rate (as defined in the Note), to
the Secured Obligations.

      4.6 Discharge of Liens. Subject to the tenant's rights under the Tenant
Lease, Mortgagor shall pay, from time to time when the same shall become due,
all claims and demands of mechanics, materialmen, laborers and others which, if
unpaid, would result in or permit the creation of a lien on the Mortgaged
Property or any part thereof, or on the revenues, rents, royalties, issues,
income and profits arising therefrom, and in general will do or cause to be done
everything necessary so that the first lien of the Second Mortgage shall be
fully preserved at the sole cost and expense of Mortgagor and without expense to
Mortgagee. Subject to the tenant's rights under the Tenant Lease, if any such
liens are filed, Mortgagor will cause the same to be permanently discharged of
record by payment or otherwise, unless Mortgagor shall in good faith and at its
own expense, be contesting such lien or liens or the validity thereof by
appropriate legal proceedings which shall operate to prevent the collection
thereof or other realization thereon or the sale or forfeiture of the Mortgaged
Property or any part thereof to satisfy the same; provided that during such
contest Mortgagor shall provide either (a) an indemnity bond, title insurance or
other security reasonably satisfactory to Mortgagee to cover the amount of the
contested item or items and the amount of the interest and penalties covering
the period through which such proceedings may be expected to last, and in any
event assuring the discharge of Mortgagor's obligation under this Section 4.6
and of any additional charge, penalty or expense arising from or incurred as a
result of such contest; and if Mortgagor shall have posted a bond as security
against payment of any such lien, interest, penalties and other charges related
thereto, Mortgagee shall be named as an additional obligee under the bond; or
(b) title insurance specifically insuring the priority of the lien of this
Second Mortgage over such lien (but such title insurance shall be sufficient
only during the period of such contest). Except as provided above, Mortgagor
will not directly or indirectly create, incur or suffer to exist any lien on the
Mortgaged Property or any part thereof (including without limitation any lien
securing the repayment of a loan made to Mortgagor by any partner(s),
shareholder(s), officer(s), director(s) or trustee(s) of Mortgagor), whether or
not junior to the lien of this Second Mortgage, other than the Permitted
Exceptions, such other documents as may be executed as further security for the
Note or in favor of Mortgagee,

                                       11
<PAGE>

and such other matters (if any) as may be expressly permitted by the provisions
of any Loan Document or as may be approved by Mortgagee.

      4.7 Contest of Impositions. Nothing in Section 4.5 shall require the
payment or discharge of any Imposition so long as Mortgagor or the tenant under
the Tenant Lease shall in good faith and at its own expense, contest the same or
the validity thereof by appropriate legal proceedings which shall operate to
prevent the collection thereof or other realization thereon or the sale or
forfeiture of the Mortgaged Property or any part thereof to satisfy the same;
provided that during such contest Mortgagor shall provide security reasonably
satisfactory to Mortgagee to cover the amount of the contested item or items and
the amount of the interest and penalties covering the period through which such
proceedings may be expected to last, and in any event assuring the discharge of
Mortgagor's obligation under this Section 4.7 and of any additional charge,
penalty or expense arising from or incurred as a result of such contest. If
Mortgagor shall have posted a bond as security against payment of any
Imposition, interest, penalties and other charges related thereto, Mortgagee
shall be named as an additional obligee under the bond.

      4.8 Mortgagee's Taxes. Mortgagor will pay all Massachusetts taxes incurred
by Mortgagee by reason of Mortgagee's ownership of the Note, this Second
Mortgage or any other Loan Document, including without limitation all real
estate transfer and like taxes imposed in connection with a transfer of
ownership of all or a portion of the Mortgaged Property pursuant to a
foreclosure, a deed in lieu of foreclosure or otherwise. Notwithstanding the
foregoing, Mortgagor shall not be required to pay any net income or franchise
taxes imposed on Mortgagee or any taxes incurred due to an assignment of the
Loan Documents or any interest therein by Mortgagee or its successors and/or
assigns.

      4.9 Use of Mortgaged Property. Mortgagor will maintain, preserve and renew
from time to time such rights of way, easements, grants, privileges, licenses
and franchises as are necessary for the use and operation of the Mortgaged
Property for Permitted Purposes (as hereafter defined), and will not use or
operate, or permit the use or operation of, the Mortgaged Property for any other
purpose without the consent of the Mortgagee, subject to the provisions of
Section 7.18, or initiate, join in or consent to any new private restrictive
covenant (apart from any Permitted Exception) easement or other public or
private restrictions to the use of the Mortgaged Property, without the consent
in each instance of Mortgagee, subject to the provisions of Section 7.18, and
except for the contemplated development activities as set forth in the Second
Loan Agreement. Mortgagor shall, moreover, comply in all material respects with
all lawful and restrictive covenants which may at any time affect the Mortgaged
Property and with zoning ordinances and other private or public restrictions as
to the use thereof. Mortgagor will not cause or maintain any nuisance in, at or
on the Mortgaged Property. Mortgagor will pay or cause to be paid all charges
for all public and private utility services, all public or private rail and
highway services (if any), all public or private communications services and all
sprinkler systems and protective services at any time rendered to or in
connection with the Mortgaged Property or any part thereof, will comply in all
material respects or use reasonable efforts to cause compliance with all
contracts relating to any such services, and will do all other things required
for the maintenance and continuance of all such services. However, Mortgagor
will not be required to pay or cause to be paid such charges if incurred by
third parties (such as tenants) unless the failure to pay such charges would

                                       12
<PAGE>

result in a lien on the Mortgaged Property. "Permitted Purposes" means general
office use, research and development and laboratory use, uses permitted by the
Tenant Lease and any other Lease specifically approved by Lender, parking and
storage relating to the foregoing, and other incidental uses related to the
foregoing uses; provided, however, that the foregoing shall be limited to uses
which are in compliance with all applicable laws, regulations, governmental
permits and/or approvals and the provisions of any insurance policies maintained
with respect to the Mortgaged Property; and provided further that "Permitted
Purposes" shall mean any lawful use subsequent to a termination of the Tenant
Lease.

      4.10 Maintenance of Mortgaged Property. Except as provided in or permitted
by the Second Loan Agreement, Mortgagor shall maintain or cause to be maintained
the Mortgaged Property, including all streets, sidewalks and curbs comprising
same, in good repair and condition, and will continuously (other than during
periods of repair after casualty or condemnation, with respect to the portions
of the Mortgaged Property damaged or condemned) operate the Mortgaged Property
only for Permitted Purposes, and, at no cost or expense to Mortgagee, will make
or cause to be made, as and when the same shall become necessary, all structural
and non-structural, exterior and interior, ordinary or extraordinary, foreseen
and unforeseen repairs, renewals and replacements necessary to that end, and
upon being apprised of any material defect in the repair or condition of the
Mortgaged Property, will repair or cure, or cause to be repaired or cured, such
defect, in each case with due diligence and no cost or expense to Mortgagee. All
such repairs, renewals and replacements shall be at least substantially equal in
quality to the original Improvements. To the extent that the Tenant Lease
requires that all or any of the foregoing obligations be performed by the tenant
thereunder, Mortgagor shall be relieved of such obligations hereunder for so
long as the Tenant Lease shall be in effect.

      4.11 Maintenance of Personal Property. Mortgagor shall cause the
Improvements to be equipped with the Personal Property as, to the extent and in
the manner, as shall be necessary, appropriate or required for the operation of
the Premises. Except where appropriate replacements, free of superior liens, are
promptly made of a value at least equal to the value of the Personal Property
being removed, no Personal Property covered hereunder with a value of more than
$10,000 shall be permanently removed from the Premises without the consent of
Mortgagee, subject to the provisions of Section 7.18. The Personal Property so
disposed of shall be promptly replaced by Personal Property of the same
character and of at least equal usefulness and quality. Mortgagor shall not be
required to replace any item of Personal Property which has become unnecessary
or inappropriate for the operation or maintenance of the Premises. To the extent
that the Tenant Lease requires that all or any of the foregoing obligations be
performed by the tenant thereunder, Mortgagor shall be relieved of such
obligations hereunder for so long as the Tenant Lease shall be in effect.

      4.12 Alterations. Except as provided in or permitted by the Second Loan
Agreement, or the Tenant Lease, Mortgagor shall not, without the consent of
Mortgagee, construct any new Improvements on the Premises other than those which
are permitted by the following provisions of this Section 4.12. Mortgagor shall
give Mortgagee Notice of, and a copy of any plans prepared for any alteration
(excluding, however, tenant improvements unless they involve structural work)
which is reasonably estimated to cost $1,000,000 (the

                                       13
<PAGE>

"Alteration Threshold") (inclusive of architectural and engineering fees) or is
structural. So long as no Event of Default shall have occurred and be continuing
hereunder, Mortgagor shall have the right at any time and from time to time to
make or cause to be made reasonable alterations of and additions to the
Mortgaged Property or any part thereof, provided that any alteration or addition
(i) shall not change the general character of the Mortgaged Property, or reduce
the fair market value thereof below its fair market value immediately before
such alteration or addition, or otherwise materially and adversely alter the
overall quality of the Mortgaged Property, (ii) shall be effected with due
diligence, in a good and workmanlike manner and with first-class materials and
in compliance in all material respects with all requirements of applicable Laws,
(iii) shall (subject to Mortgagor's right to contest the same in accordance with
the provisions of Section 4.6 hereof) be promptly and fully paid for, or caused
to be paid for, by Mortgagor at no cost or expense to Mortgagee, if failure to
make such payment would result in a lien on the Mortgaged Property, and (iv)
shall be made, in case the estimated cost of such alteration or addition
(excluding, however, tenant improvements unless they involve structural work)
exceeds the Alteration Threshold, (1) only after Mortgagee shall have consented
thereto prior to the commencement of such work and in all material respects in
accordance with plans and specifications reasonably satisfactory to Mortgagee,
(2) only after Mortgagor shall have furnished to Mortgagee a completion or
performance bond, a letter of credit or cash deposit or other security
reasonably satisfactory to Mortgagee as security for the completion of such
work, and (3) if structural, only after submission of appropriate plans to
Mortgagee and approval thereof by Mortgagee (such approval not to be
unreasonably withheld or delayed). For purposes of clause (iv) of this
subsection, the Alteration Threshold limitation shall apply to any alteration or
addition taken separately or, if such alteration or addition is made together
with other alterations or additions that constitute a single construction plan
or project (whether accomplished in successive stages or procedures), then taken
in the aggregate as well. The cost of all such alterations and additions to the
Mortgaged Property shall be paid in cash or its equivalent, so that the
Mortgaged Property shall at all times be free of liens for labor and materials
supplied or claimed to have been supplied to the Mortgaged Property (subject to
Mortgagor's rights of contest provided for in Section 4.6 hereof). All
alterations of and additions to the Mortgaged Property shall immediately become
and shall remain a part of the Mortgaged Property, and shall be subject to the
lien of this Second Mortgage; but tenant improvements shall also be subject to
the rights therein of the relevant tenants. To the extent that the Tenant Lease
requires that all or any of the foregoing obligations be performed by the tenant
thereunder, Mortgagor shall be relieved of such obligations hereunder for so
long as the Tenant Lease shall be in effect.

      4.13 Waste; No Impairment. Mortgagor shall not commit or suffer any waste
of the Mortgaged Property, or do or permit to be done thereon anything that may
in any way materially impair the security of this Second Mortgage.

      4.14 Insurance.

            4.14.1 Mortgagor shall effect and maintain, or cause to be
maintained, insurance for Mortgagor and the Mortgaged Property providing at
least the following coverages:

                                       14
<PAGE>

            (i) comprehensive all risk insurance on the Improvements and the
Personal Property, including coverage against loss or damage by fire, collapse,
lightning, windstorm, tornado, hail, vandalism and malicious mischief,
electrical short circuit, sprinkler leakage, water damage, back-up of sewers and
drains, bursting water mains, debris removal, and against loss or damage by such
other, further and additional risks as now are or hereafter may be embraced by
the standard extended coverage forms of endorsements, in each case (A) in an
amount equal to 100% of their "Full Replacement Cost," which for purposes of
this Second Mortgage shall mean actual replacement value (exclusive of costs of
excavations, foundations, underground utilities and footings); (B) containing an
agreed amount endorsement with respect to the Improvements and Personal Property
waiving all co-insurance provisions; (C) containing an endorsement that all
covered losses will be paid on a replacement cost basis, which shall mean the
actual cost to repair or without deduction for depreciation; and (D) providing
for no deductible in excess of $25,000.

            (ii) Commercial General Liability insurance against claims for
personal injury or bodily injury including death or property damage occurring
upon, in or about the Premises, occurring as a result of construction and use
and occupancy of facilities located in or on the Premises or as a result of the
construction thereof, such insurance to (A) be on the so-called "occurrence"
form with a combined single limit and appropriate annual aggregate limitations;
(B) afford immediate protection at the date hereof to the limit of not less than
$2,000,000 in respect of each personal injury, bodily injury or death to any
person, to the limit of not less than $5,000,000 in respect of any one
occurrence, and to the limit of not less than $1,000,000 in respect of any one
occurrence for property damage (the foregoing limits may be achieved through
so-called "umbrella" coverage); and (C) continue at not less than the said
limits until required to be changed by Mortgagee, by Notice to Mortgagor, by
reason of changed economic conditions making such protection inadequate;

            (iii) as and if available at commercially reasonable rates, business
interruption insurance or, as the case may be, rental loss insurance, (A) with
loss payable to Mortgagee; (B) covering all risks required to be covered by the
insurance provided for in subdivision (i) above; (C) containing an agreed amount
endorsement waiving all co-insurance provisions; (D) agreeing to pay for losses
whether the Premises are open to the public or not; and (E) in an amount equal
to 100% of the projected gross income from the Premises for a period of twelve
(12) months. The amount of such business interruption insurance shall be
determined prior to the date hereof and at least once each year thereafter based
on Mortgagor's reasonable estimate of the gross income from the Premises for the
succeeding twelve-month period. In the event that all or any portion of the
Premises shall be damaged or destroyed, Mortgagor shall and hereby does assign
to Mortgagee all claims under the policies of such insurance, and all amounts
payable thereunder, and all net amounts, when collected by Mortgagee under such
policies, shall be held in trust by Mortgagee and shall be applied to taxes,
insurance premiums, other operating expenses of the Premises which are
obligations of Mortgagor and to any other Secured Obligations from time to time
due and payable hereunder and under the Note; provided, however, that nothing
herein contained shall be deemed to relieve Mortgagor of its obligations to pay
the Secured Obligations on the respective dates of payment provided for in the
Note except to the extent such amounts are actually paid out of the proceeds of
such business interruption insurance;

                                       15
<PAGE>

            (iv) at all times when required due to construction, structural
repairs or alterations with respect to the Improvements (A) owner's contingent
or protective liability insurance covering claims not covered by or under the
terms or provisions of the above mentioned Commercial General Public Liability
insurance policy; and (B) the insurance provided for in subdivision (i) of this
subsection written in a so-called builder's risk completed value form (1) on a
non-reporting basis, (2) against all risks insured against pursuant to
subdivision (i) of this subsection, and (3)including permission to occupy the
Premises and with an agreed amount endorsement waiving co-insurance;

            (v) workers' compensation, subject to the statutory limits of the
Jurisdiction, and employer's liability insurance with a limit of at least
$1,000,000.00 per accident, disease per employee, and disease aggregate, in
respect of any work or operations on, about, or in connection with, the
Mortgaged Property (if applicable);

            (vi) comprehensive boiler and machinery insurance, in such amounts
as shall be reasonably required by Mortgagee; and

            (vii) such other insurance and in such amounts as Mortgagee from
time to time may reasonably request against such other insurable hazards which
at the time are commonly insured against in respect of property similar to the
Premises located in or around the greater Boston area.

            4.14.2 All insurance provided for in subsection 4.14.1 hereof shall
be effected under valid and enforceable policies, in such forms and, from time
to time after the date hereof, in such amounts as may from time to time be
reasonably satisfactory to Mortgagee, issued by financially sound and
responsible insurance companies authorized to do business in the Jurisdiction as
approved admitted or unadmitted carriers which have been approved by Mortgagee
said carriers to be rated A- or better for claims paying ability by A. M. Best &
Co. unless Mortgagee has consented to a different rating, subject to the
provisions of Sections 7.18 hereof. Prior to the date hereof, and thereafter not
less than thirty (30) days prior to the expiration dates of the policies
theretofore furnished to Mortgagee pursuant to subsection 4.14.1, certified
copies of the policies accompanied by evidence satisfactory to Mortgagee of
payment of the first installment of the premiums, shall be delivered by
Mortgagor to Mortgagee; provided, however, that in the case of renewal policies,
Mortgagor may furnish Mortgagee with binders therefor to be followed by
certified copies of the policies when issued. Mortgagee shall have the right to
hold the policies and renewals thereof, subject to terms of any other mortgage
or other security agreement with a lien that has priority over this Second
Mortgage.

            4.14.3 Mortgagor shall not take out (1) separate insurance
concurrent in form or contributing in the event of loss with that required in
subsection 4.14.1 to be furnished by, or which may be reasonably required to be
furnished by, Mortgagor, or (2) any casualty policy intended to provide any
coverage from time to time required hereunder with respect to the Mortgaged
Property unless, in each case, Mortgagee is included therein as an insured, with
loss payable as in this Second Mortgage provided. Mortgagor shall immediately
notify Mortgagee of the taking out of any such separate insurance or umbrella or
blanket policy by it and shall cause certified copies of the policies therefor
to be delivered

                                       16
<PAGE>

as required in subsection 4.14.1. Any blanket insurance policy shall
specifically allocate to the Mortgaged Property the amount of coverage from time
to time required hereunder and shall otherwise provide the same protection as
would a separate policy insuring only the Mortgaged Property in compliance with
the provisions of subsection 4.14.1.

            4.14.4 All policies of insurance provided for or contemplated by
subsection 4.14.1 shall name Mortgagee and Mortgagor, as the insured or
additional insured, as their respective interests may appear, and in the case of
property damage insurance, shall contain a so-called New York standard mortgagee
clause in favor of Mortgagee providing that the loss thereunder shall be payable
to Mortgagee.

            4.14.5 All policies of insurance provided for in subsection 4.14.1
hereof shall contain clauses or endorsements to the effect that:

            (i) no act or negligence of Mortgagor, or anyone acting for
Mortgagor, or of any tenant under any Lease or other occupant or failure to
comply with the provisions of any policy which might otherwise result in a
forfeiture of such insurance or any part thereof shall in any way affect the
validity or enforceability of such insurance insofar as Mortgagee is concerned;

            (ii) such policies shall not be materially changed (other than to
increase the coverage provided thereby) canceled or non-renewed without at least
30 days' written notice to Mortgagee; and

            (iii) Mortgagee shall not be liable for any premiums thereon or
subject to any assessments thereunder.

            4.14.6 Claims under each policy of insurance provided for or
contemplated by subsection 4.14.1 (excluding third party liability, Workers
Compensation and Employers liability insurance) in excess of $500,000 shall be
adjusted with the insurers and/or underwriters by Mortgagee and Mortgagor,
respectively (provided that, so long as no Event of Default shall then have
occurred and be continuing, Mortgagee agrees that it shall not settle any such
claims without Mortgagor's consent (not to be unreasonably withheld, conditioned
or delayed), and Mortgagor shall (subject to Mortgagee's reasonable discretion)
be entitled to lead all negotiations with insurers and underwriters in
connection with such claims). Any such claims which do not exceed $500,000
shall, so long as no Event of Default exists hereunder, be adjusted by
Mortgagor. All costs and expenses of collecting or recovering any insurance
proceeds under such policies (including without limitation the actual and
reasonable out-of-pocket expenses incurred by Mortgagee, if any), including
without limitation any and all reasonable fees of attorneys, appraisers and
adjusters, shall be paid by Mortgagor.

            4.14.7 To the extent that the Tenant Lease requires that all or any
of the foregoing obligations be performed by the tenant thereunder, Mortgagor
shall be relieved of such obligations hereunder for so long as the Tenant Lease
shall be in effect.

                                       17
<PAGE>

      4.15 Damage or Destruction.

            4.15.1 In the event of any damage to or destruction of the Premises
for which the cost of repair might reasonably be expected to exceed $500,000,
Mortgagor shall, promptly after obtaining knowledge of the occurrence thereof,
give notice thereof to Mortgagee and shall, regardless of the dollar amount of
such damage, proceed with reasonable diligence, at Mortgagor's sole cost and
expense, to repair and restore or cause to be repaired or restored the Premises
or the portion thereof so damaged as nearly as practically possible to the
condition the same were in immediately prior to such damage. If any Personal
Property is damaged or lost as a result of such fire or other casualty,
Mortgagor shall likewise, at its sole cost and expense, whether or not any
insurance proceeds are available or adequate for such purpose, replace or cause
to be replaced the Personal Property so damaged or lost. In the event that
Mortgagor fails to advance any funds required for the completion of any such
repairs or restoration, Mortgagee may, but shall not be obligated to, advance
the required funds or any portion thereof, and Mortgagor shall, on demand,
reimburse Mortgagee for all sums advanced and actual expenses incurred by
Mortgagee in connection therewith, together with interest thereon at the Default
Rate (as defined in the Note) from the date each such advance is made to the
date of receipt by Mortgagee of reimbursement from Mortgagor, which amounts and
interest shall become part of the Secured Obligations and be secured hereby. All
repairs and restoration required to be made by Mortgagor hereunder shall be
performed in material compliance with all Laws and Orders and shall be without
any liability or actual expense of any kind to Mortgagee. Notwithstanding the
foregoing, Mortgagor should not be obligated to repair, restore or replace the
Premises and/or Personal Property in the event that (i) Mortgagee requires
(pursuant to clause (A) of Section 4.15.2(ii)) the application of insurance
proceeds to the payment of Secured Obligations at a time when no Event of
Default has occurred and is continuing or (ii) Mortgagor elects not to restore
pursuant to Section 4.15.2(iii).

            4.15.2 If by reason of any damage or destruction, any insurance
proceeds are paid under any insurance policy maintained pursuant to subsection
4.14.1 hereof or otherwise (other than business interruption insurance proceeds
or, as the case may be, rental loss insurance proceeds, which shall be paid as
provided in clause (iii) of subsection 4.14.1), such proceeds shall be paid as
follows:

            (i) If the aggregate insurance proceeds received by reason of any
single instance of damage or destruction shall not exceed $500,000, such
insurance proceeds shall be paid over to Mortgagor, and Mortgagor shall hold the
same as a trust fund, to be used first for the payment of the entire cost of
repairing and restoring the Premises and/or Personal Property and the balance
thereof shall be paid to the Mortgagor; provided, however, that, if any Event of
Default shall exist hereunder at the time all such insurance proceeds are so to
be paid over to Mortgagor, or if Mortgagee shall have accelerated the Secured
Obligations, all such insurance proceeds (in whatever amount) shall be paid over
to Mortgagee and not to Mortgagor for application pursuant to clause (B) below.

            (ii) If the aggregate insurance proceeds received by reason of any
single instance of damage or destruction shall exceed $500,000, such insurance
proceeds shall be paid over to Mortgagee and held in an interest-bearing
account. The Mortgagee shall apply

                                       18
<PAGE>

such insurance proceeds to the repair and restoration of the Mortgaged Property
by disbursing the same to Mortgagor on a periodic basis and with such retainage
(not to exceed 10%) as Mortgagee reasonably shall deem appropriate, but no more
frequently than monthly, as the repair and restoration work progresses, upon
receipt by Mortgagee of such guaranties of completion (from Mortgagor and/or
other third parties acceptable to Mortgagee), surety bonds, requisitions,
architect's certificates and title updates as Mortgagee shall in its good faith
discretion require (including without limitation requiring Mortgagor, inter
alia, to provide to Mortgagee for its approval appropriate plans and
specifications and budgets, and to show that there are at all times sufficient
funds (in addition to the available insurance proceeds, as the case may be)
available for the completion of the repair and restoration in question and to
pay all amounts due under this Second Mortgage and the Note during such repair
and restoration). All amounts held by Mortgagee as retainage shall be paid to
Mortgagor upon substantial completion of the repair and restoration work. If any
excess proceeds shall remain after the repair and restoration work has been
completed and paid for in full out of such insurance proceeds, such excess
proceeds shall be paid to Mortgagor if the Premises have been restored to their
condition prior to such change or destruction, but otherwise such excess
proceeds shall be retained by Mortgagee and applied to the partial prepayment of
the Note, at par. Interest earned on insurance proceeds while held by Mortgagee
shall be added to the amount of such insurance proceeds. If while any such
insurance proceeds are held by Mortgagee an Event of Default shall have occurred
and be continuing or Mortgagee shall have accelerated the Secured Obligations,
Mortgagee shall have no duty to make advances to Mortgagor as provided for in
this clause (ii).

            4.15.3 No destruction of or damage to the Mortgaged Property, or any
part thereof, by fire or other casualty whatsoever, whether such damage or
destruction be partial or total or otherwise, shall relieve Mortgagor from its
liability to pay in full as and when due the Secured Obligations, or from
timely, fully and faithfully performing all its other obligations hereunder and
under the Loan Documents. No application of insurance proceeds to the reduction
of the Secured Obligations shall have the effect of releasing the lien of this
Second Mortgage from all or any portion of the Mortgaged Property until and
unless all of the Secured Obligations have been paid in full.

            4.15.4 For so long as the Tenant Lease shall be in effect and not in
default, if and to the extent that the provisions of the Tenant Lease are
inconsistent with the provisions of this Section 4.15, such provisions of the
Tenant Lease shall govern, including without limitation, that if the tenant
under the Tenant Lease is required to restore the Premises under the Tenant
Lease, the Mortgagee shall make insurance proceeds available for such purpose.

      4.16 Condemnation; Knowledge of Proceedings.

            4.16.1 Mortgagor, promptly upon obtaining knowledge of the
institution or pending institution of any proceedings for the condemnation of
the Mortgaged Property or any material portion thereof, shall notify Mortgagee
thereof, and Mortgagee may participate in any such proceedings and be
represented by counsel of its selection. Mortgagor shall not make any agreement
in lieu of condemnation of the Mortgaged Property or any portion thereof without
the prior written consent of Mortgagee in each

                                       19
<PAGE>

instance, which consent shall not be (i) unreasonably withheld or delayed in the
case of the taking of any insubstantial portion of the Mortgaged Property or
(ii) withheld or delayed if the Secured Obligations will be paid in full from
the net condemnation proceeds. In the event of the condemnation of the Mortgaged
Property, or any portion thereof, any awards for condemnation or payments in
lieu thereof are hereby assigned and shall be paid to Mortgagee, subject to the
terms of any mortgage or other security agreement with a lien that has priority
over this Second Mortgage.

            4.16.2 In the event that Mortgagee shall determine in its good faith
judgment after an event of condemnation that the taking of the Mortgaged
Property was so extensive as to make continued operation thereof after
restoration not commercially viable, all of the Secured Obligations shall become
immediately due and payable, and any awards for condemnation or payments in lieu
thereof shall be paid over to Mortgagee and applied in reduction of the Secured
Obligations in such order as Mortgagee may determine in its discretion, but
without any prepayment premium, and any excess shall be paid to Mortgagor. Any
remaining Secured Obligations shall be prepaid by Mortgagor without any
prepayment premium. Otherwise, whether or not any condemnation proceeds are
available therefor, Mortgagor shall proceed with reasonable diligence, at
Mortgagor's sole cost and expense, to repair and restore or cause to be repaired
or restored the Mortgaged Property into an architectural and commercially viable
premises comparable to or better than (to the greatest extent possible) the
previously existing structure, with such additional improvements as Mortgagor
may elect to add. In the case of a condemnation which is not so extensive as to
make continued operation of the Mortgaged Property after restoration not
commercially viable, the Mortgagee shall hold the condemnation proceeds in an
interest bearing account and apply such proceeds to the repair and restoration
of the Mortgaged Property by disbursing the same to Mortgagor on a periodic
basis and with such retainage (not to exceed 10%) as Mortgagee reasonably shall
deem appropriate, but no more frequently than monthly, as the repair and
restoration work progresses, and upon receipt by Mortgagee of such guaranties of
completion, surety bonds, requisitions, architect's certificates and title
updates as Mortgagee shall in its good faith discretion require (including
without limitation requiring Mortgagor to show that there are at all times
sufficient funds (in addition to the available condemnation proceeds, as the
case may be) available for the repair and restoration in question). Provided
that Mortgagee shall not have elected to cause the acceleration of the Secured
Obligations pursuant to the first sentence of this subsection, in the event that
Mortgagor fails to make any payment in respect of any such repairs and
restorations, Mortgagee may, but shall not be obligated to, advance funds
required for the completion of such repairs or restoration, and Mortgagor shall,
on demand, reimburse Mortgagee for all sums advanced and expenses actually
incurred by Mortgagee in connection therewith (including without limitation the
charges, disbursements and reasonable fees of Mortgagee's counsel), together
with interest thereon at the Default Rate (as defined in the Note) from the date
each such advance is made or expense paid by Mortgagee until the date on which
repayment thereof is received by Mortgagee, which amounts and the interest
thereon shall become part of the Secured Obligations and be secured hereby. All
amounts held by Mortgagee as retainage shall be paid to Mortgagor upon
substantial completion of the repair and restoration work. In the event that
there are surplus proceeds of any award for condemnation or payments in lieu
thereof, all such surplus proceeds shall be paid over to and/or retained by
Mortgagee and shall be applied in accordance with the Second Loan Agreement.

                                       20
<PAGE>

            4.16.3 Notwithstanding any taking by public or quasi-public
authority through eminent domain or otherwise, Mortgagor agrees to continue to
pay all amounts due in respect of the Secured Obligations, which shall not be
reduced until any award or payment therefor shall have been actually received by
Mortgagee for application to the discharge of the Secured Obligations in
accordance with the Second Loan Agreement. No application of the proceeds of any
award for condemnation or payments in lieu thereof to the reduction of the
Secured Obligations shall have the effect of releasing the lien of this Second
Mortgage from the portion, if any, of the Mortgaged Property not taken until and
unless the principal sum secured hereby, the interest thereon and the remainder
of the Secured Obligations have been paid in full.

            4.16.4 In the event of any temporary taking of the Mortgaged
Property or any portion thereof in condemnation or by eminent domain, Mortgagor
shall continue to pay all principal, interest and other sums and charges secured
hereby when due and payable under the Note and the other Loan Documents and, so
long as there has occurred no Event of Default, receive the proceeds of any
award for a temporary taking; provided, however, that if any award payable to
Mortgagor on account of such taking is made in a lump sum or is payable other
than in equal monthly installments, then the award shall be paid over to
Mortgagee (who shall hold the same in an interest bearing account) and applied
by Mortgagee to the payment of each monthly installment of interest and
principal due under the Note and all of the other Secured Obligations as and
when the same become due and payable; and provided, further, that the excess (if
any) of such award received by Mortgagee over such monthly installment of
interest and other Secured Obligations falling due for the entire period with
respect to which such award was paid shall, monthly, be paid to or on behalf of
Mortgagor for use solely in paying, with respect to the Premises, real estate
and personal property taxes, insurance premiums, labor charges, repairs,
utilities, accounting and legal expenses and other operating expenses; and
provided further, that any unapplied portion of such award held by Mortgagee
when such taking ceases or expires, or after all of the Secured Obligations
shall have been paid in full (whichever first occurs), plus any interest accrued
thereon, shall be repaid to Mortgagor. If while the proceeds of any such award
are held by Mortgagee an Event of Default shall have occurred and be continuing,
or Mortgagee shall have accelerated the Secured Obligations, Mortgagee may apply
such proceeds in reduction of the Secured Obligations in such order and priority
as Mortgagee shall in its discretion determine.

            4.16.5 For so long as the Tenant Lease shall be in effect, if and to
the extent that the provisions of the Tenant Lease are inconsistent with the
provisions of this Section 4.16, such provisions of the Tenant Lease shall
govern.

      4.17 General Right of Entry. Mortgagor agrees that it will permit
Mortgagee from time to time upon reasonable advance notice (not exceeding one
business day) and during regular business hours (or upon occurrence of any
emergency situation, without advance notice and at any time), but subject to the
rights of tenants under their leases, to enter upon and inspect the Mortgaged
Property to determine its compliance with the requirements of this Second
Mortgage and the other Loan Documents and to ascertain its condition.

                                       21
<PAGE>

      4.18 Separate Tax Lots. Mortgagor agrees that if and to the extent the
Mortgaged Property is not assessed for real estate tax purposes as a wholly
independent tax lot (or lots), separate from any adjoining land or improvements
not constituting a part of such lot or lots, it will enter into, or cause to be
entered into, a tax sharing agreement (or agreements), reasonably satisfactory
in form and substance to Mortgagee, with the respect to the party or parties
responsible for paying real estate taxes as to any such adjacent land or
improvements.

      4.19 Books of Account; Financial Statements.

            4.19.1 Mortgagor will keep adequate records and books of account of
Mortgagor and the Premises at the principal office of Mortgagor or the
management agent for the Premises in accordance with generally accepted
accounting principles, tax accounting principles or other sound accounting
principles consistently applied reflecting all financial transactions of the
Mortgagor in respect of the Mortgaged Property and will permit Mortgagee (at the
cost and expense of Mortgagee unless an error in excess of 5% of net operating
income is discovered in which event the cost of such examination shall be borne
by Mortgagor), by its agents, accountants and attorneys, to visit the Mortgaged
Property and the office of Mortgagor and examine and make copies and extracts of
Mortgagor's records and books of account and to discuss Mortgagor's affairs,
finances and accounts with the officers of Mortgagor and its accountants, at
such reasonable times during business hours with reasonable advance notice
(which may be by telephone) of not less than one business day. Promptly upon
demand by Mortgagee, but not more than once in any twelve (12) month period, the
Mortgagor, shall use reasonable efforts to cause to be delivered to Mortgagee
reports established and/or maintained by any rating agency and/or credit
verification organization designated by Mortgagee (collectively, the "Credit
Agencies") with respect to the credit status and/or financial condition of,
and/or history of default with respect to credit transactions by, Mortgagor
and/or the Guarantors (as defined in Section 7.9) (collectively the "Credit
Reports") and Mortgagor hereby expressly grants to Mortgagee the right, license
and privilege to obtain the Credit Reports directly from the Credit Agencies at
Mortgagee's cost.

            4.19.2 Mortgagor covenants that it will, at its own expense, deliver
to the Mortgagee, within (10) ten days after any request by Mortgagee (which
request shall reference this subsection and such ten (10) day requirement) a
written certificate, in recordable form, setting forth to its knowledge the
amount then due under this Second Mortgage and whether to its knowledge any
offsets or defenses exist against the indebtedness secured hereby; and, if any
such offsets or defenses are alleged to exist, then the nature of such offsets
or defenses. Such certificate shall also contain a statement that the Mortgagor
has no knowledge of the occurrence of any Event of Default nor of any other
event, which, with the giving of notice or passage of time, or both, would
constitute an Event of Default which has occurred and remains uncured as of the
date of such certificate; or, if any such Event of Default or other default has
occurred and remains uncured as of the date of such certificate, then such
certificate shall contain a statement specifying the nature thereof, the time
for which the same has continued and the action which the Mortgagor has taken or
proposes to take with respect thereto and setting forth or describing such
additional matters with respect to the Mortgagor, Loan or the Mortgaged Property
as the Mortgagee shall reasonably request and such additional information as the

                                       22
<PAGE>

Mortgagee may reasonably request. Such certificate shall be certified to, and
may be relied upon by, such parties as the Mortgagee shall direct.

            4.19.3 Mortgagor will deliver to Mortgagee within ninety (90) days
after the close of its respective fiscal year its balance sheets and statements
of profit and loss setting forth in comparative form, figures for the preceding
year reviewed or audited by a reputable certified public accounting firm.
Mortgagor shall also deliver within ninety (90) days after the close of the
calendar year an annual operating statement for Mortgaged Property setting
forth, in comparative form, figures for the preceding year, and a schedule
showing all Leases (excluding subleases) and basic information with respect
thereto in form approved by Mortgagor and Mortgagee as part of the application
by Mortgagor for the loan secured hereby, in each case certified by a principal
financial or accounting officer of Mortgagor. Throughout the term of this Second
Mortgage, Mortgagor, with reasonable promptness, will deliver to Mortgagee such
other information with respect to Mortgagor as Mortgagee may reasonably request
from time to time. All financial statements of Mortgagor shall be prepared in a
manner reasonably satisfactory to Mortgagee shall be delivered in duplicate, and
in the case of Mortgagor, shall be accompanied by the certificate of a principal
financial or accounting officer of Mortgagor, dated within five (5) days of the
delivery of such statements to Mortgagee, stating that such financial statements
are, to the best of such officer's knowledge after diligent inquiry, true and
correct and that he/she knows of no Event of Default, nor of any default which
after notice or lapse of time or both would constitute an Event of Default,
which has occurred and is continuing, or, if any such default or Event of
Default has occurred and is continuing, specifying the nature and period of
existence thereof and what action Mortgagor has taken or proposes to take with
respect thereto, and, except as otherwise specified, stating that, to the best
of such officer's knowledge after diligent inquiry, Mortgagor has fulfilled all
its obligations under this Second Mortgage which are required to be fulfilled on
or prior to the date of such certificate.

                                       23
<PAGE>

      4.20 Limitations on Transfer. Mortgagor hereby covenants and agrees that
neither Mortgagor will, without the prior written consent in each instance of
Mortgagee, which may be withheld in Mortgagee's sole discretion, (i) convey,
sell, assign, lease or otherwise transfer any interest of Mortgagor in the
Mortgaged Property or any portion thereof, (ii) pledge, mortgage, hypothecate,
place a deed of trust or other lien on or otherwise encumber Mortgagor's
interest in the Mortgaged Property or any portion thereof, (iii) permit the
conveyance, sale, assignment, pledge, mortgage, hypothecation or other transfer
or disposition, either directly or indirectly or through one or more step
transactions or tiered transactions, of interests in Mortgagor or in the
partners, shareholders, principals, trustee or beneficiary of Mortgagor or in
the partners, shareholders, principals, trustees or beneficiaries of such
partners, shareholders, principals, trustee or beneficiary, or any portion
thereof, or (iv) enter into or permit to be entered into any agreement or
arrangement to do any of the foregoing unless such agreement or arrangement is
expressly made subject to Mortgagee's approval (each of the aforesaid acts
referred to in clauses (i) through (iv) above being referred to herein as a
"Transfer"). Any conveyance, sale, assignment, lease, pledge, mortgage,
hypothecation, encumbrance or transfer deemed to be such by operation of Law
shall also be deemed to be a Transfer. Any attempted Transfer in violation of
this Section shall be void and of no force or effect. Transfers of membership
interests in the Borrower shall not be permitted without the prior written
consent of Mortgagee, which consent will not be unreasonably withheld or
delayed. Notwithstanding the same, transfers which (i) do not result in more
than a majority of the membership interests of Class B Members of spouse, child
or entity for which the member, a spouse and/or child are the sole
beneficiary(ies), shall be permitted without consent of Mortgagee.

      4.21 Recording, Filing and Perfection of Security Interests; Fees.

            4.21.1 Mortgagor, promptly upon the execution and delivery of the
Note, this Second Mortgage, the Assignment of Leases and the Indemnity Agreement
and thereafter from time to time, will cause this Second Mortgage, the
Assignment of Leases and any other Loan Document creating a lien or evidencing
the lien of this Second Mortgage upon the Mortgaged Property and each instrument
of further assurance to be filed, registered or recorded in such manner and in
such places as may be required by any present or future law in order to publish
notice of and to protect the lien hereof upon, and the interest of Mortgagee in,
the Mortgaged Property.

            4.21.2 Mortgagor will pay all filing, registration and recording
fees, and all expenses incident to the execution and acknowledgment of the
Second Mortgage and any other Loan Document (including any security instrument
with respect to the Personal Property and Proceeds) and any instrument of
further assurance, and all federal, state, county and municipal mortgage
recording taxes, stamp taxes and other taxes, duties, imports, assessments and
charges arising out of or in connection with the execution and delivery of the
Loan Documents, any deed of trust supplemental hereto, any supplemental security
instrument with respect to the Personal Property and Proceeds or any instrument
of further assurance.

      4.22 Further Acts and Assurances. Mortgagor will, at its sole cost and
expense, and without actual expense to Mortgagee, do, execute, acknowledge and
deliver all and

                                       24
<PAGE>

every such further acts, deeds, conveyances, deeds of trust, mortgages,
assignments, notices of assignment, transfers and assurances as Mortgagee shall
from time to time reasonably require for the better assuring, conveying,
assigning, transferring and confirming unto Mortgagee the property and rights
hereby conveyed or assigned or intended now or hereafter so to be, or which
Mortgagor may be or may hereafter become bound to convey or assign to Mortgagee,
or for carrying out the intention or facilitating the performance of the terms
of this Second Mortgage, or filing, registering or recording this Second
Mortgage, and, on demand, will execute and deliver, and hereby authorizes
Mortgagee to execute and file in Mortgagor's name, to the extent it may lawfully
do so, one or more financing statements, chattel mortgages or comparable
security instruments, to evidence more effectively the lien of this Second
Mortgage or the lien intended hereby upon the Mortgaged Property.

                                   ARTICLE V

                               EVENTS OF DEFAULT

      5.1 Events of Default. It shall be an event of default ("Event of
Default") hereunder if any one or more Event of Default as defined in the Second
Loan Agreement shall occur.

                                   ARTICLE VI

                          REMEDIES AND RELATED MATTERS

      6.1 Remedies. Upon the occurrence and continuance of any Event of Default,
the Mortgagee, at the option of the Mortgagee, may:

            6.1.1 by Notice to the Mortgagor, declare the entire principal
amount under the Note then outstanding, and all accrued and unpaid interest
thereon, to be immediately due and payable, and upon such declaration such
principal amount and said accrued and unpaid interest and all other Secured
Obligations shall become and be immediately due and payable, anything in either
Note or in this Second Mortgage to the contrary notwithstanding;

            6.1.2 by itself, its agents or attorneys, or by a court-appointed
receiver, enter into and upon all or any part of the Mortgaged Property and each
and every part thereof and exclude the Mortgagor, its agents and servants wholly
therefrom; and having and holding the same, use, operate, manage and control the
Mortgaged Property and conduct the business thereof, either personally or by its
superintendents, managers, agents, servants, attorneys or receivers; and upon
every such entry, at the expense of the Mortgaged Property, from time to time,
either by purchase, repairs or construction, maintain and restore the Mortgaged
Property and, likewise make all necessary or proper repairs, renewals and
replacements and such alterations, betterments, additions and improvements
thereto and thereon as it may deem advisable and insure the same; and in every
such case the Mortgagee shall have the right to manage and operate the Mortgaged

                                       25
<PAGE>

Property and to carry on the business thereof and exercise all rights and powers
of the Mortgagor, as its attorney-in-fact, coupled with an interest, or
otherwise, as it shall deem best; and the Mortgagee shall be entitled to collect
and receive all Rents and other earnings, revenues, issues, profits and income
of the Mortgaged Property and after deducting the expenses of conducting the
business thereof and all maintenance, repairs, renewals, replacements,
alterations, additions, betterments and improvements and amounts necessary to
pay for taxes, assessments, insurance and prior or other proper charges upon the
Mortgaged Property or any part thereof, as well as just and reasonable
compensation for the services of all attorneys, counsel, agents, clerks,
servants and other employees engaged or employed by it, the Mortgagee may apply
the remainder of the monies so received by it, first to the payment of any other
sums required to be paid by the Mortgagor under this Second Mortgage; then to
the payment of all other Secured Obligations in such order as Mortgagee shall
elect; and the balance, if any, shall be turned over to the Mortgagor or such
other person as may be lawfully entitled thereto;

            6.1.3 with or without entry, personally or by its agents or
attorneys insofar as applicable:

                  (a) foreclose the lien and security interest of this Second
Mortgage against the Mortgaged Property, or any portion thereof, in accordance
with the laws of The Commonwealth of Massachusetts and the provisions hereof for
all Secured Obligations secured hereby or for any portion of such Secured
Obligations or any other sums secured hereby which are then due and payable,
subject to the continuing lien of this Second Mortgage for the balance of the
Secured Obligations not then due; it being agreed that several sales may be made
hereunder without exhausting the rights of sale for any other breach by the
Mortgagor of any of the Secured Obligations secured hereby, it being the purpose
to provide for foreclosure and sale of the Mortgaged Property, or any portion
thereof, for any matured portion of any of the Secured Obligations secured
hereby or otherwise provided for herein without exhausting the power to
foreclose and sell the Mortgaged Property, or any portion thereof, for any other
part of the Secured Obligations secured hereby, whether matured at the time or
subsequently maturing; or

                  (b) take such other steps to protect and enforce their
respective rights, whether by action, suit or proceeding in equity or at law for
the specific performance of any covenant, condition or agreement in the Note,
this Second Mortgage, the Second Loan Agreement or any other Loan Document, or
in aid of the execution of any power granted herein or in the Note, this Second
Mortgage, the Second Loan Agreement or any other Loan Document, or for any
foreclosure hereunder, or for the enforcement of any other appropriate legal or
equitable remedy or otherwise as the Mortgagee may elect.

      6.2 Foreclosure and Sale; Application of Proceeds; Waiver of Right of
Redemption; Etc.

            6.2.1 Foreclosure and Sale. During the continuance of any Event of
Default, the Mortgagee, personally or by its agents or attorneys, may sell the
Mortgaged Property, or any part or parts thereof, and all estate, right, title,
interest, claim and demand therein, at public auction at such time and place and
upon such terms and conditions as the Mortgagee may deem appropriate or as may
be required or permitted by applicable law or

                                       26
<PAGE>

rule of court, having first given notice prior to the sale of such time, place
and terms by advertisement in at least one newspaper published or having a
general circulation in the county or counties in which the Mortgaged Property is
located or at such time or times as may be required by applicable law or rule of
court, and at such other times and by such other methods, if any, as the
Mortgagee may deem appropriate.

            6.2.2 Adjournment of Sale. The Mortgagee may adjourn from time to
time any sale to be made by it under or by virtue of this Second Mortgage by
announcement at the time and place appointed for such sale or for such adjourned
sale or sales; and, except as otherwise provided by an applicable provision of
law or rule of court, the Mortgagee, without further notice or publication, may
make such sale at the time and place to which the same shall be so adjourned.

            6.2.3 Effect of Sale Upon Mortgagor. Any sale or sales made under or
by virtue of this Article, whether made under the power of sale herein granted
or under or by virtue of judicial proceedings or of a judgment or decree of
foreclosure and sale, shall operate to divest all the estate, right, title,
interest, claim and demand whatsoever, whether at law or in equity, of the
Mortgagor in and to the properties and rights so sold, and shall be a perpetual
bar both at law and in equity against the Mortgagor and against any and all
persons claiming or who may claim the same, or any part thereof from, through or
under the Mortgagor.

            6.2.4 Acceleration Upon Sale. In the event of any sale or sales made
under or by virtue of this Subsection, whether made under the power of sale
herein granted or under or by virtue of judicial proceedings or of a judgment or
decree of foreclosure and sale, all Secured Obligations, if not previously due
and payable, and all other sums required to be paid by the Mortgagor pursuant to
the Note, this Second Mortgage and the other Loan Documents, shall, at the
option of the Mortgagee, immediately become due and payable, in full, anything
in the Note, this Second Mortgage, the Second Loan Agreement or the other Loan
Documents to the contrary notwithstanding. If an Event of Default should occur,
and following the acceleration of maturity as herein provided, a tender of
payment by the Mortgagor of the amount then necessary to satisfy all Secured
Obligations made at any time prior to any sale made under or by virtue of this
Subsection, whether made under the power of sale herein granted or under or by
virtue of judicial proceedings or of a judgment or decree of foreclosure and
sale, shall constitute an evasion of the provisions of the Note prohibiting
prepayment, and, to the extent permitted by applicable law, such payment shall
include the Prepayment Premiums (as defined in the Note), and other payments
required by the Note.

            6.2.5 Appointment of Receiver. During the continuance of an Event of
Default, the Mortgagee shall be entitled (and, to the extent permitted under the
laws of The Commonwealth of Massachusetts, with five (5) days' notice, without
regard to the adequacy of any security for the Secured Obligations and without
regard to the solvency of any person, partnership or entity liable for the
payment thereof) to the appointment of a receiver or receivers of the Mortgaged
Property and of all of the earnings, revenues, rents, issues, profits and income
there from, and the Mortgagor hereby consents to the appointment of such
receiver and agrees that it will not oppose any such appointment; provided,
however, that notwithstanding the appointment of any receiver as aforesaid, the

                                       27
<PAGE>

Mortgagee shall be entitled to retain possession and control of the Mortgaged
Property. Such receiver shall have all of the powers and authority permitted by
applicable law.

            6.2.6 Application of Proceeds. The proceeds of any sale made under
or by virtue of this Article, whether made under the power of sale herein
granted or under or by virtue of judicial proceedings or of a judgment or decree
of foreclosure and sale, together with any other sums which may then be held by
the Mortgagee pursuant to this Second Mortgage, whether under the provisions of
this Subsection or otherwise, shall be applied as follows:

                  First: To the payment of the actual costs and expenses of such
sale or sales, including compensation to Mortgagee and the fees, charges and
disbursements of its agents, and the charges, disbursements and reasonable fees
of its counsel, and of any judicial or other proceedings wherein the same may be
made, and of all expenses, liabilities and advances made or incurred by
Mortgagee under this Second Mortgage, together with interest at the Default Rate
(as defined in the Note) on all advances made by Mortgagee, and of taxes,
assessments or other charges, except any taxes, assessments or other charges
subject to which the Mortgaged Property shall have been sold.

                  Second: To the payment of any actual expenses, charges,
losses, indemnities, penalties, premiums (including, without limitation,
Prepayment Premiums (as defined in the Note) and late payment premiums) and all
other amounts due under the Loan Documents, excluding interest and principal.

                  Third: To the payment of interest on the unpaid principal due
under the Note including Additional Interest.

                  Fourth: To the payment of principal due under the Note.

                  Fifth: To the payment of all other Secured Obligations.

                  Sixth: To the payment of the surplus, if any, to whomsoever
may be lawfully entitled to receive the same (including, if applicable,
Mortgagor, or the beneficiary of Mortgagor).

            6.2.7 Application of Purchase Money. In the event of any sale made
under or by virtue of this Section 6.2, whether made under the power of sale
herein granted or under or by virtue of judicial proceedings or of a judgment or
decree of foreclosure and sale, the receipt of the officer making the sale under
judicial proceedings or of the Mortgagee for the payment of the purchase money
shall be full and sufficient discharge of the purchaser of the Mortgaged
Property for the purchase money and no such purchaser, after paying such
purchase money and receiving such a receipt, shall be bound or liable to see to
the application of such purchase money.

            6.2.8 Conveyance of the Mortgaged Property. Upon the completion of
any sale or sales made under or by virtue of this Section, whether made under
the power of sale herein granted or under or by virtue of judicial proceedings
or of a judgment or decree of foreclosure and sale, the Mortgagee or an officer
of the court empowered so to do, shall

                                       28
<PAGE>

execute and deliver to the purchaser or purchasers a good and sufficient
instrument or instruments, conveying, assigning and transferring all estate,
right, title and interest of the Mortgagor in and to the Mortgaged Property and
rights sold, including the estate of the Mortgagor as lessor under the Leases
(excluding subleases), but without any covenant or warranty, express or implied.
The recitals in such instrument(s) of any matters of fact shall be conclusive
proof of the truthfulness thereof. The Mortgagee is hereby appointed, which
appointment is coupled with an interest and is irrevocable, and which
appointment shall become effective upon the occurrence of an Event of Default,
the true and lawful attorney of the Mortgagor, in its name and stead, to make
all necessary conveyances, assignments, transfers and deliveries of the
Mortgaged Property and rights so sold and for that purpose the Mortgagee may
execute all necessary instruments of conveyance, assignment and transfer, and
may substitute one or more persons with like power, the Mortgagor hereby
ratifying and confirming all that its said attorney or such substitute or
substitutes shall lawfully do by virtue hereof. Nevertheless, the Mortgagor, if
so requested by the Mortgagee, shall ratify and confirm any such sale or sales
by executing and delivering to the Mortgagee or to such purchaser or purchasers,
all such instruments as may be advisable, in the judgment of the Mortgagee, for
that purpose, and as may be designated in any such request.

            6.2.9 Purchase of Mortgaged Property. The Mortgagee shall have the
right to be a purchaser at any sale made under or by virtue of this Second
Mortgage, whether made under the power of sale herein granted or under or by
virtue of judicial proceedings or of a judgment or decree of foreclosure and
sale, and on so purchasing shall have the right to be credited upon the amount
of the bid made therefor with the amount payable to the Mortgagee out of the net
proceeds of such sale. In the event of any such sale, the Secured Obligations,
if not previously due, shall be and become immediately due and payable without
demand or notice of any kind.

            6.2.10 Waiver of Right of Redemption - Exemptions Waived. The
Mortgagor will not at any time insist upon, or plead, or in any manner whatever
claim or take any benefit or advantage of a stay or extension or moratorium law,
any exemption from attachment, execution or sale of the Mortgaged Property, or
any part thereof, whether enacted now or at any time hereafter in force, which
may affect the covenants and terms of performance of this Second Mortgage, nor
claim, take or insist upon any benefit or advantage of any law now or hereafter
in force providing for the valuation or appraisal of the Mortgaged Property, or
any part thereof, prior to any sale or sales thereof which may be made pursuant
to any provision herein, or pursuant to the decree, judgment or order of any
court of competent jurisdiction; nor after any such sale or sales, claim or
exercise any right under any statute heretofore or hereafter enacted to redeem
the Mortgaged Property so sold, or any part thereof, and the Mortgagor hereby
expressly waives all benefit and advantage of any such law or laws, and
covenants not to hinder, delay or impede the execution of any right, power or
remedy herein granted or delegated to the Mortgagee, but to suffer and permit
the execution of every right, power or remedy as though no such law or laws had
been made or enacted. The Mortgagor, for itself and all who claim under it,
waives, to the extent that it lawfully may, the benefit of any homestead
exemption and any and all right to have the Mortgaged Property marshaled upon
any sale or foreclosure hereunder.

                                       29
<PAGE>

            6.2.11 Recovery of Judgment. A. During the continuation of any Event
of Default, the Mortgagee shall be entitled and empowered to institute such
actions or proceedings at law or in equity as it may consider advisable for the
collection of the Secured Obligations, and may prosecute any such action or
proceeding to judgment or final decree, and may enforce any such judgment or
final decree against the Mortgagor in any manner provided by law. The Mortgagee
shall be entitled to recover judgment as aforesaid either before, after or
during the pendency of any proceeding for the enforcement of any remedies
provided for in the Note, this Second Mortgage, the Second Loan Agreement or the
other Loan Documents and the right of the Mortgagee to recover judgment as
aforesaid shall not be affected by any sale hereunder, or by the passage or
entry of a decree for the sale of the Mortgaged Property, or any part thereof,
or by the enforcement of the provisions of the Note, this Second Mortgage, the
Second Loan Agreement and the other Loan Documents or the foreclosure of the
lien hereof. In the event of a sale of the Mortgaged Property, and of the
application of the proceeds of sale, as in this Second Mortgage provided, to the
payment of the Secured Obligations, the Mortgagee, except as otherwise provided
in the Note, shall be entitled to enforce payment of, and to receive all amounts
then remaining due and unpaid with respect to the Secured Obligations, and shall
be entitled to recover judgment for any portion of the Secured Obligations
remaining unpaid, together with interest as provided in the Note. In case of
proceedings against the Mortgagor in insolvency or bankruptcy or any proceedings
for its reorganization or involving the liquidation of its assets, then the
Mortgagee shall be entitled to prove the whole amount due on account of the
Secured Obligations, without deducting therefrom any proceeds obtained from the
sale of the whole or any part of the Mortgaged Property; provided, however, that
in no case shall the Mortgagee receive a greater amount than the total amount
due on account of the Secured Obligations from the aggregate amount of the
proceeds of the sale of the Mortgaged Property and the distribution from the
estate of the Mortgagor.

                  B. No recovery of any judgment upon the Mortgaged Property or
upon any other property of the Mortgagor shall affect, in any manner or to any
extent, the lien of this Second Mortgage upon the Mortgaged Property, or any
part thereof, or any liens, rights, powers or remedies of the Mortgagee
hereunder, but such liens, rights, powers and remedies of the Mortgagee shall
continue unimpaired as before.

            6.2.12 Discontinuance of Proceedings. If the Mortgagee shall
commence any proceeding to enforce any right, power or remedy hereunder or under
the Note or the other Loan Documents and such proceeding shall be discontinued
or abandoned for any reason, then in every such case the parties shall be
restored to their former positions and the rights, powers and remedies of the
Mortgagee shall continue as if no such proceeding had been commenced.

            6.2.13 Judicial Foreclosure. The provisions hereinabove set forth
relating to the remedy of foreclosure of the lien of this Second Mortgage by
public sale to be conducted by the Mortgagee, are not intended as an exclusive
method of foreclosure hereunder or to deprive the Mortgagee of any other legal
or equitable remedies available to it. Accordingly, it is specifically agreed
that such remedy shall be cumulative and shall not in any way be construed as an
exclusive remedy, and Mortgagee shall be fully entitled to a court

                                       30
<PAGE>

foreclosure and to avail itself of any and all other legal or equitable remedies
at any time available under the laws of The Commonwealth of Massachusetts.

            6.2.14 Request for Notice of Default. Mortgagor and Mortgagee hereby
request the holder of any mortgage with a lien which has priority over this
Second Mortgage to give Notice to Mortgagee, at Mortgagee's address set froth on
page one of this Second Mortgage, of any default under the superior encumbrance
and of any sale or other foreclosure action thereunder.

      6.3 No Conditions Precedent to Exercise of Remedies. The Mortgagor shall
not be relieved of any obligation by reason of the failure of the Mortgagee to
comply with any request of the Mortgagor or of any other person to take action
to foreclose on this Mortgage or otherwise to enforce any provisions of the
Note, this Second Mortgage, the Second Loan Agreement or the other Loan
Documents, or by reason of the release, regardless of consideration, of all or
any part of the Mortgaged Property, or by reason of any agreement or stipulation
between any subsequent owner of the Mortgaged Property and the Mortgagee
extending the time of payment or modifying the terms of the Note, this Second
Mortgage or the other Loan Documents without first having obtained the consent
of the Mortgagor, and, in the latter event, the Mortgagor shall continue to be
liable to make payment according to the terms of any such extension or
modification agreement, unless expressly released and discharged in writing by
the Mortgagee. The Mortgagee shall not be required to proceed hereunder before
proceeding against any other security held by the Mortgagee for the payment of
the Secured Obligations or for the performance by the Mortgagor of all of its
obligations under the Note, this Second Mortgage or any of the Loan Documents,
nor shall the Mortgagee be required to proceed against such other security
before proceeding hereunder. The Mortgagee shall be entitled to proceed
hereunder and against such other security in such order and manner as it may
elect and no such action by the Mortgagee shall operate to preclude it from
proceeding against any or all of any security at the same time or in any order.

      6.4 No Merger. It is the intention of the parties hereto that if the
Mortgagee shall at any time hereafter acquire title to all or any portion of the
Mortgaged Property, then, and until the Secured Obligations have been satisfied
in full, the interest of the Mortgagee hereunder and the lien of this Second
Mortgage shall not merge or become merged in or with the estate and interest of
the Mortgagee as the holder and owner of title to all or any portion of the
Mortgaged Property and that, until such payment, the estate of the Mortgagee in
the Mortgaged Property and the lien of this Second Mortgage and the interest of
the Mortgagee hereunder shall continue in full force and effect to the same
extent as if the Mortgagee had not acquired title to all or any portion of the
Mortgaged Property.

      6.5 Remedies Cumulative. The remedies specified in this Section shall be
in addition to all other rights and remedies provided herein or in any other
Loan Document and which the Mortgagee may have at law or in equity and no single
or partial exercise by the Mortgagee of any right or remedy hereunder or under
any other Loan Document or which the Mortgagee may have at law or in equity
shall exhaust the same or shall preclude any other or further exercise thereof
or of any other right or remedy hereunder or under any other Loan Document or
which the Mortgagee may have at law or in equity, and every

                                       31
<PAGE>

such right or remedy hereunder or under any other Loan Document or which the
Mortgagee may have at law or in equity may be exercised at any time and from
time to time after the occurrence of an Event of Default.

      6.6 Mortgagee's Performance of Mortgagor's Obligations. If, after the
giving of any applicable notice and expiration of any applicable grace and/or
cure period, Mortgagor shall fail timely to perform any of the covenants
contained in this Second Mortgage, the Note, the Second Loan Agreement or any
other Loan Document, Mortgagee may make advances to perform the same on
Mortgagor's behalf (except that Mortgagee agrees that it shall not make advances
under this Section to pay any amount(s) secured by a Lien, or any Imposition,
which Mortgagor is then contesting fully in accordance with the provisions of
Section 4.6 or Section 4.7, as applicable). Inaction of Mortgagee shall never be
considered as a waiver of any right accruing to it on account of any Event of
Default nor shall the provisions of this Section 6.6 or any exercise by
Mortgagee of its rights hereunder prevent any default from constituting an Event
of Default. Mortgagee, in making any payment hereby authorized (a) relating to
Impositions, may do so according to any bill, statement or estimate, without
inquiry into the validity of any such Imposition; (b) for the purchase,
discharge, compromise or settlement of any lien, may do so without inquiry as to
the validity or amount of any claim for lien which may be asserted; or (c) in
connection with the completion of construction or alterations, furnishing or
equipping of the Improvements or the rental, operation or management of the
Mortgaged Property or the payment of operating costs thereof, may do so in such
amounts and to such persons as Mortgagee may deem appropriate. Nothing contained
herein shall be construed to require Mortgagee to advance monies for any
purpose.

                                  ARTICLE VII

                                 MISCELLANEOUS

      7.1 Enforceability. In the event that any provision of this Second
Mortgage, the Note, the Second Loan Agreement or any other Loan Document or the
application thereof to Mortgagor or any circumstance in any jurisdiction
governing this Second Mortgage, the Note, the Second Loan Agreement or such Loan
Document shall, to any extent, be invalid or unenforceable under any Law, such
provision shall be deemed inoperative only to the extent that it may conflict
therewith and shall be deemed modified to conform to such Law, and the remainder
of this Second Mortgage, the Note, the Second Loan Agreement or such Loan
Document and the application of such invalid or unenforceable provision to
parties, jurisdictions or circumstances other than to whom or to which it is
held invalid or unenforceable shall not be affected thereby nor shall the same
affect the validity or enforceability of any other provision of this Second
Mortgage, the Note, the Second Loan Agreement or such Loan Document.

      7.2 Maximum Rate of Interest. Notwithstanding any contrary provision of
this Second Mortgage, in no event shall the aggregate of the interest payable
hereunder or under the Note, the Second Loan Agreement or any other Loan
Document, or penalties or premiums for late payments, Prepayment Premiums (as
defined in the Note) loan servicing fees, application fees, commitment fees,
"points" or any other amounts, fees or charges

                                       32
<PAGE>

which would under any applicable Law be deemed "interest" ever exceed the
maximum amount of interest which under any applicable Law could be lawfully
charged on the principal balance of the Note from time to time outstanding. In
this connection, it is expressly stipulated and agreed that it is the intention
of Mortgagee and Mortgagor in the execution and delivery of the Note, this
Second Mortgage, the Second Loan Agreement, the Assignment of Leases, the
Indemnity Agreement and any other Loan Document contractually to limit the
maximum amounts charged to, contracted for with, or received from Mortgagor in
connection with the Secured Obligations which would be deemed "interest" under
any applicable Law to the maximum non-usurious amount of interest which would be
permitted under such Law. In furtherance thereof, it is stipulated and agreed
that none of the terms of this Second Mortgage, the Note, the Second Loan
Agreement, the Assignment of Leases, the Indemnity Agreement or any other Loan
Document shall ever be construed to create a contract to pay for the use,
forbearance or detention of money interest at a rate in excess of the maximum
non-usurious interest rate permitted to be charged to, contracted for with, or
received from Mortgagor by Mortgagee under any applicable Law; neither Mortgagor
nor any Guarantor (as defined in Section 7.9) under the Guaranty (as defined in
Section 7.9), endorser or other parties now or hereafter becoming liable for the
payment of the Secured Obligations shall ever be liable for interest in excess
of the maximum non-usurious interest that under any applicable Law could be
charged, contracted for or received from Mortgagor by Mortgagee; and the
provisions of this Section shall be deemed to govern the maximum rate and amount
of interest which may be paid under the Note, the Second Loan Agreement, the
Indemnity Agreement, the Assignment of Leases and any other Loan Document, and
shall control over all other provisions of this Second Mortgage, the Note, the
Second Loan Agreement, the Assignment of Leases or any other Loan Document which
might be in apparent conflict herewith. Specifically and without limiting the
generality of the foregoing, it is expressly provided:

            7.2.1 If and when any installment of the interest calculated under
the Note becomes due and the aggregate amount thereof, when added to the
aggregate amount of any other amounts which constitute interest on the
indebtedness evidenced thereby and which have been heretofore paid on said
indebtedness, would be in excess of the maximum non-usurious amount of interest
permitted by any applicable Law, in light of all discounts, payments or
prepayments theretofore made on said indebtedness and presuming the Secured
Obligations will be paid at their stated maturity date, then the aggregate
amount of such interest installment shall be automatically reduced to the
maximum sum, if any, which could lawfully be paid as interest on the principal
balance of the Note on such date under such circumstances.

            7.2.2 If under any circumstances the aggregate amounts paid on the
Note, this Second Mortgage, the Second Loan Agreement, the Indemnity Agreement,
the Assignment of Leases and any other Loan Document prior to and incident to
final payment thereof include any amounts which under any applicable Law would
be deemed interest and which would exceed the maximum non-usurious amount of
interest which, under any applicable Law, could lawfully have been collected on
such indebtedness, Mortgagor and Mortgagee stipulate that such payment and
collection will have been and will be deemed to have been the result of
mathematical error on the part of both Mortgagor and Mortgagee, and the person
or entity receiving such excess payment shall promptly refund the amount of such
excess (to the extent only of the excess of such interest payments above the

                                       33
<PAGE>

maximum non-usurious amount which could lawfully have been collected and
retained under any applicable Law) upon discovery of such error by the person or
entity receiving such payment or Notice thereof from the person or entity making
such payment; and

      7.2.3 All amounts paid or agreed to be paid in connection with the Secured
Obligations which would under any applicable Law be deemed "interest" shall, to
the extent permitted by such Law, be amortized, prorated, allocated and spread
throughout the full term of the Note.

      7.3 Notices. All notices, requests for approval or consent, demands,
consents, approvals and other communications (collectively, "Notices") hereunder
shall be in writing and shall be sent by hand, or by telecopy (with a duplicate
copy sent the same day by reputable overnight courier service, postage prepaid),
or by postage prepaid, certified or registered mail, return receipt requested,
or by reputable overnight courier service, postage prepaid, addressed to the
party to be notified as set forth below:

                  (a)      if to Mortgagee,

                           SEPRACOR, INC.
                           111 Locke Drive
                           Marlborough, Massachusetts  01752
                           Attn: Vice President for Finance and Administration

                           with a copy to:

                           Nixon Peabody LLP
                           101 Federal Street
                           Boston, MA 02110
                           Attn: William C. Stone, PC
                           Telecopy No.: 617-345-1300

                  (b)      if to Mortgagor,

                           WATERFORD PARK, LLC
                           c/o Waterford Development Corp.
                           175 Highland Avenue
                           Needham, MA 02494
                           Attn: Robert E. Shapiro

                           with a copy to:

                           Garrity Levin & Muir
                           99 Summer Street
                           Boston, Massachusetts  02110
                           Attn: Jonathan Levin, Esq.

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<PAGE>

      Notices shall be deemed given when so delivered by hand or when a legible
copy is received by telecopier (with receipt being verified by telephone
confirmation and provided that a copy is sent on the same day by reputable
overnight courier service), or if mailed, five (5) business days after mailing
(or one (1) business day for reputable overnight courier service), with failure
to accept delivery constituting delivery for this purpose. Any party hereto may
change the addresses for Notices set forth above by giving at least ten (10)
days' prior Notice of such change in writing to the other party as aforesaid and
otherwise in accordance with these provisions.

      7.4 No Release. Mortgagor agrees that no other security, now existing or
hereafter taken, for the Secured Obligations shall be impaired or affected in
any manner by the execution hereof; no security subsequently taken by any holder
of the Secured Obligations shall impair or affect in any manner the security
given by this Second Mortgage; all security for the payment of the Secured
Obligations shall be taken, considered, and held as cumulative; and the taking
of additional security shall at no time release or impair any security by
endorsement or otherwise previously given. Mortgagor further agrees that any
part of the security herein described may be released without in any way
altering, varying, or diminishing the force, effect, or lien of this Second
Mortgage, or of any renewal or extension of said lien, and that this Second
Mortgage shall continue as a first lien, assignment, and security interest on
all the Mortgaged Property not expressly released until all Secured Obligations
are fully discharged and paid.

      7.5 Attorneys' Fees and Costs of Mortgagee. Mortgagor agrees to pay,
within ten (10) business days of demand of Mortgagee, all actual reasonable
out-of-pocket expenses incurred by Mortgagee, including without limitation
attorneys' charges, disbursements and reasonable fees, in connection with the
enforcement by Mortgagee of any of the Note, this Second Mortgage, the Second
Loan Agreement, the Guaranty, the Indemnity Agreement, the Assignment of Leases
or any of the other Loan Documents.

      7.6 Brokerage. Mortgagor hereby indemnifies and holds harmless Mortgagee
against all liability, cost and expense, including without limitation attorneys'
charges, disbursements and reasonable fees, incurred in connection with any
claims which may be asserted by any broker or finder or similar agent alleging
to have dealt with Mortgagor in any of the transactions contemplated hereby;
excluding however such amounts, if any, which Mortgagee has agreed in writing to
pay.

      7.7 Indemnification. Mortgagor will protect, indemnify and save harmless
Mortgagee from and against any and all liabilities, obligations, claims,
damages, penalties, assessments, fines, causes of action and actual reasonable
out-of-pocket expenses (including without limitation attorneys' disbursements,
charges and reasonable fees) imposed upon or incurred by or asserted against
Mortgagee or the Mortgaged Property or any of Mortgagee's interest therein, by
reason of the execution of this Second Mortgage, the Note, the Second Loan
Agreement or any other Loan Document or the Guaranty, or the consummation of the
transactions contemplated hereby or thereby, or the occurrence or existence
during or prior to the term of this Second Mortgage of any of the following: (i)
ownership by Mortgagor of any interest in the Mortgaged Property or receipt of
any rent or other sum therefrom during any period when Mortgagor has not been
excluded from possession; (ii) any accident, injury to or death of persons or
loss of or damage to property

                                       35
<PAGE>

occurring on or about the Mortgaged Property or any part thereof or the
adjoining sidewalks, curbs, vaults and vault space, if any, and streets and ways
during any period when Mortgagor has not been excluded from possession; (iii)
any design, construction, operation, use, nonuse or condition of the Mortgaged
Property or any part thereof or the adjoining sidewalks, curbs, vaults and vault
space, if any, and streets and ways, including, without limitation, claims or
penalties arising from violation of any requirement of law or insurance
requirements as well as any claim based on any patent or latent defect, whether
or not discoverable by Mortgagor, any claim as to which the insurance is
inadequate, and any claim in respect of any adverse environmental impact or
effect; (iv) any negligence or tortious act or omission on the part of Mortgagor
or any of its agents, contractors, servants, employees, sublessees, licensees,
guests or invitees; (v) any failure by Mortgagor to perform its obligations
under this Second Mortgage, the Note, the Second Loan Agreement, the Indemnity
Agreement, the Assignment of Leases, the Assignment of Contracts or any other
Loan Document; or (vi) any claims arising from the alleged or actual breach of
Mortgagor's obligations under Section 7.6 hereof, whether such claim proves true
or false. Mortgagor further agrees that its obligations under this Section 7.7
shall include, but are not limited to, liability for damages resulting from the
personal injury or death of an employee of Mortgagor, regardless of whether
Mortgagor has paid the employee under the worker's compensation laws of the
Jurisdiction, or other similar federal or state legislation for the protection
of employees. Mortgagor agrees that its obligations under this Section 7.7 shall
include indemnifying Mortgagee for all reasonable attorney's charges,
disbursements and fees, and all other actual and reasonable out-of-pocket
expenses incurred by Mortgagee to enforce the terms of this Section. Mortgagor's
obligations under this Section are exclusive of, and in addition to, any and all
insurance obligations which Mortgagor has under this Second Mortgage and any of
its obligations under the Indemnity Agreement. If any action or proceeding shall
be commenced (including without limitation an action to foreclose this Second
Mortgage or to collect the indebtedness secured hereby or to enforce Mortgagee's
rights under the Note, the Second Loan Agreement, the Indemnity Agreement, the
Assignment of Leases and the Assignment of Contracts or any other Loan Document)
by Mortgagee or Mortgagor or any third party, to which action or proceeding
Mortgagee is made a party by reason of the execution of this Second Mortgage,
the Note, the Second Loan Agreement, the Indemnity Agreement, the Assignment of
Leases and the Assignment of Contracts or any other Loan Document in which it
becomes necessary to enforce, defend or uphold the lien of this Second Mortgage
or Mortgagee's rights under the Note, all actual and reasonable out-of-pocket
expenses incurred by Mortgagee in connection with any litigation to enforce,
prosecute or defend the rights and lien created hereby or otherwise incurred in
connection with any action or proceeding referred to in this Section (including
without limitation attorneys' charges, disbursements and reasonable fees) shall
be paid by Mortgagor to Mortgagee within ten (10) days after demand. In case any
action, suit or proceeding is brought against Mortgagee by reason of any such
occurrence, Mortgagor, upon request of Mortgagee, will, at Mortgagor's sole cost
and expense, resist and defend such action, suit or proceeding or cause the same
to be resisted or defended by counsel designated by Mortgagor and approved by
Mortgagee, which approval shall not be unreasonably withheld or delayed.
Notwithstanding the foregoing, Mortgagor shall have no obligations under this
Section 7.7 with respect to any claims arising solely out of the grossly
negligent or intentional acts of Mortgagee or its employees, agents or other
persons acting on its behalf.

                                       36
<PAGE>

      7.8 Environmental Matters. Without limiting the foregoing obligations and
indemnities of Mortgagor, Mortgagor hereby represents and warrants that, to the
best of its knowledge and belief after reasonable investigation, it is currently
in compliance in all material regards with, and covenants and agrees (subject to
the rights of the tenant under the Tenant Lease) that it will manage and operate
the Mortgaged Property and will, in accordance with prudent commercial business
practices, cause each tenant under any Lease to occupy its demised portion of
the Mortgaged Property in compliance in all material regards with, Environmental
Laws (as that term is defined in the Indemnity Agreement). Subject to the rights
of the tenant under the Tenant Lease, Mortgagor further covenants and agrees
that, in accordance with prudent commercial business practices, it shall not
install or permit to be installed in the Mortgaged Property any Hazardous
Materials (as that term is defined in the Indemnity Agreement) (other than those
lawful amounts of cleaning supplies and other materials incidental to the
Permitted Uses of the Mortgaged Property, and except as disclosed in the
Existing Reports, as that term is defined in the Indemnity Agreement). Mortgagor
hereby represents and warrants that, to the best of its knowledge after
reasonable investigation, it has heretofore delivered to Mortgagee true, correct
and complete copies of all reports, citations, notices and other writings,
including without limitation hazardous waste disposal manifests, which Mortgagor
has received from or delivered to any governmental authority empowered to
regulate or oversee any of the foregoing activities; and Mortgagor covenants and
agrees that it shall from and after the date hereof deliver to Mortgagee within
ten (10) days of receipt thereof, true, correct and complete copies of all such
writings prepared or received by Mortgagor. Mortgagor shall use reasonable
efforts to cause the tenant under the Tenant Lease to remove from the Mortgaged
Property and dispose of any Hazardous Materials in violation of Environmental
Laws in a manner consistent with and in compliance with applicable Environmental
Laws and shall take any and all other action to remedy, rectify, rehabilitate
and correct any violation of any applicable Environmental Law or any violation
of any agreement entered into between Mortgagor and Mortgagee and/or any third
party with respect to Hazardous Materials. Mortgagor agrees to indemnify, defend
with counsel reasonably acceptable to Mortgagee (at Mortgagor's sole cost and
expense), and hold Mortgagee harmless against any claim, response or other
actual expenses, damages, liability or demand (including without limitation all
reasonable attorneys' charges, disbursements and reasonable fees incurred by
Mortgagee) arising out of any claimed violation by Mortgagor of any
Environmental Laws or breach of any of the foregoing covenants or agreements
except to the extent caused solely by the actions of Mortgagee or its employees,
agents or other persons acting on its behalf. The foregoing provision shall not
be construed as imposing on Borrower any obligation or liability for any act or
omission of tenant under the Tenant Lease.

      7.9 Limitations on Recourse. The provisions of Section 10 of the Note,
Limitations on Recourse, are applicable to this Second Mortgage.

      7.10 Estoppel Certificates. Mortgagor and Mortgagee agree at any time and
from time to time, upon ten (10) business days prior written notice from either
party, to execute and deliver to such party, or to any person or entity
designated by such party, a statement in writing certifying (i) the outstanding
principal balance of the Secured Obligations, (ii) the last date to which
interest has been paid by Mortgagor, (iii) that the Loan is in full force and
effect, (iv) to the knowledge of Mortgagor, whether Mortgagor has any defenses

                                       37
<PAGE>

or offsets thereto, and (v) whether any default on the part of Mortgagor has
occurred (if made by Mortgagee, subject to its knowledge).

      7.11 Effect of Extensions and Amendments. If the payment of the Secured
Obligations, or any part thereof, shall be extended or varied, or if any part of
the security or guaranties therefor be released, all persons (including, without
limitation the Guarantors under the Guaranty now or at any time hereafter liable
therefor, or interested in the Mortgaged Property, shall be held to assent to
such extension, variation or release, and their liability, and the lien, and all
provisions hereof, shall continue in full force and effect; the right of
recourse against all such persons being expressly reserved by Mortgagee,
notwithstanding any such extension, variation or release (subject to the express
limitations set forth in Section 7.9). Any person, firm or corporation taking a
junior deed of trust or other Lien upon the Mortgaged Property or any part
thereof or any interest therein, shall, without waiving any other limitations in
this Second Mortgage on such Liens, take the said Lien subject to the rights of
Mortgagee to amend, modify, extend or release the Note, this Second Mortgage or
any other document or instrument evidencing, securing or guarantying the
indebtedness secured hereby, in each case without obtaining the consent of the
holder of such junior Lien and without the lien of this Second Mortgage losing
its priority over the rights of any such junior Lien.

      7.12 No Joint Venture. Mortgagor acknowledges that the relationship
between the parties is that of mortgagor and mortgagee and that in no event
shall Mortgagee be deemed to be a partner or joint venturer with Mortgagor.
Mortgagee shall not be deemed to be such a partner or joint venturer by reason
of its becoming a mortgagee in possession or exercising any rights pursuant to
this Second Mortgage or any other of the Loan Documents.

      7.13 Funds Held in Accounts. Mortgagor hereby agrees that Mortgagee shall
have no liability for any investment losses or reduction in value which accrue
or occur with respect to any amounts held by Mortgagee in any accounts hereunder
for the benefit or account of Mortgagor or the Premises (such as insurance
proceeds or partial condemnation awards) and any such losses shall be borne
solely by Mortgagor except where such losses are caused by Mortgagee's gross
negligence or willful misconduct. In addition, Mortgagor agrees that all
interest and/or other income on such funds shall for income tax purposes be
deemed to belong to Mortgagor.

      7.14 Expenses of Mortgagee. Any reference herein to "actual expenses
incurred by Mortgagee" shall be deemed to refer to actual costs and expenses
incurred by Mortgagee paid or payable to third parties (as opposed to
Mortgagee's general overhead expenses).

      7.15 Governing Law. This Second Mortgage shall be governed by and
construed in accordance with the laws of The Commonwealth of Massachusetts and
any applicable laws of the United States of America.

      7.16 Captions and Pronouns. The captions and headings of the various
sections of this Second Mortgage are for convenience only, and are not to be
construed as confining or limiting in any way the scope or intent of the
provisions hereof. Whenever the context

                                       38
<PAGE>

requires or permits, the singular shall include the plural, the plural shall
include the singular, and the masculine, feminine and neuter shall be freely
interchangeable.

      7.17 Amendments, Waivers, Etc. No amendment, modification, termination, or
waiver of any provision of this Second Mortgage nor consent to any departure
therefrom shall in any event be effective unless the same shall be in writing
and signed by the party against which such action or waiver is sought to be
charged, and then such action or waiver shall be effective only in the specific
instance and for the specific purpose for which given or omitted. No notice to
or demand on Mortgagor in any case shall entitle Mortgagor to any other or
further notice or demand in similar or other circumstances except as provided in
this Second Mortgage.

      7.18 Entire Agreement; Controlling Provisions. This Second Mortgage, the
Note, the Second Loan Agreement, the Indemnity Agreement, the Assignment of
Leases and the other Loan Documents embody the entire agreement between the
parties hereto and supersede all prior agreements and understandings between
them relating to the same subject matter. If and to the extent the provisions of
this Second Mortgage conflict with the provisions of the Second Loan Agreement,
the provisions of the Second Loan Agreement shall govern.

      7.19 Covenants Running With the Land; Successors and Assigns. All of the
grants, covenants, terms, provisions and conditions of this Second Mortgage
shall run with the land and shall apply to and bind the successors and assigns
of Mortgagor, and apply to and inure to the benefit of the successors and
assigns of Mortgagee.

      7.20 Statutory Condition. This Second Mortgage is upon the STATUTORY
CONDITION, subject to the applicable notice, grace and cure provisions provided
herein, and upon the further condition that all covenants and agreements of
Mortgagor contained herein shall be kept and performed and for any breach of
which Mortgagee shall have the STATUTORY POWER OF SALE.

      7.21 Forbearance; Subordination. Under the circumstances described in, and
subject to the terms and conditions of, Section 15 of the Loan Agreement,
Mortgagee is obligated to forebear from exercising remedies hereunder and to
subordinate the lien hereof to an alternative financing by Borrower.

              [The remainder of this page is intentionally blank.]

                                       39
<PAGE>

      IN WITNESS WHEREOF, Mortgagor has executed this Second Mortgage under seal
as of date first set forth above.

                                   WATERFORD PARK, LLC,

                                   By: /s/ Richard N. Houlding
                                       ---------------------------------
                                        Richard N. Houlding

                          COMMONWEALTH OF MASSACHUSETTS

SUFFOLK, ss.                                                  January ____, 2001

         Then appeared the above-named Richard N. Houlding, Manager of WATERFORD
PARK, LLC, and acknowledged the foregoing to be his free act and deed as Manager
of WATERFORD PARK, LLC, before me

                                     ------------------------------------
                                     Notary Public
                                     My Commission Expires:_____________

                                                                          (Seal)

                                       40
<PAGE>

                                   EXHIBIT A

                                LAND DESCRIPTION

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

                                       1

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