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                                                                   EXHIBIT 10.10



                               MOUNT VERNON PLACE

                                LEASE AGREEMENT

         THIS LEASE, made and entered into as of this ________ day of November,
1999, by and between MOUNT VERNON PLACE PARTNERS, L.L.C., a Georgia limited
liability company (hereinafter referred to as the "Landlord") and INTERNET
SECURITY SYSTEMS, INC., a Georgia corporation (hereinafter referred to as the
"Tenant");

                             W I T N E S S E T H :

         1.       PREMISES. The Landlord, for and in consideration of the
rents, covenants, agreements, and stipulations hereinafter mentioned, reserved,
and contained, to be paid, kept and performed by the Tenant, has leased and
rented, and by these presents does lease and rent, unto the said Tenant, and
said Tenant hereby agrees to lease and take upon the terms and conditions which
hereinafter appear, the following described property (hereinafter referred to
as the "Premises") two buildings known as Mount Vernon Place (hereinafter
collectively referred to in the singular as the "Building" and respectively as
the "Phase I Building" and the "Phase II Building") to be situated in Land Lot
35 of the 17th District, Fulton County, Georgia. A legal description of the
land on which the Building is to be situated is attached hereto as Exhibit "B"
(hereinafter referred to as the "Land").

                  (a)      Exhibit "A" attached hereto represents a description
         and approximation of the Premises to be leased pursuant to this Lease,
         such Premises to comprise approximately 238,600 rentable square feet
         within the Building (inclusive of the bridges to be constructed by
         Landlord pursuant to Special Stipulation 2 attached to this Lease).
         For purposes of this Lease, the parties agree that the rentable square
         feet of the Premises shall be measured and determined in accordance
         with the Building Owners and Managers Association International
         standard of measurement ANSI/BOMA Z65.1 1996. Upon the final Drawings
         and Specifications, as this term is defined in the Work Letter, being
         ascertained, Landlord and Tenant's architect, Warner, Summers, Ditzel,
         Benefield, Ward & Associates, Inc. shall measure the rentable square
         footage of the Premises in accordance with such standard, which
         measure by Landlord and Tenant's architect shall be controlling, and
         the 238,600 rentable square foot figure set forth above shall be
         adjusted accordingly. The standard of measurement ANSI/BOMA Z65.1 1996
         shall be used as the same is in effect as of the date of this Lease
         even if such standard shall change hereafter.

                  (b)      Within five (5) days after the Commencement Date (as
         defined below), Landlord shall deliver to Tenant a completed Tenant
         Acceptance Agreement (the "Tenant Acceptance Agreement") attached
         hereto as Exhibit "C" and incorporated herein, which shall contain an
         acknowledgment of the date upon which the Commencement Date (as
         defined below) of this Lease occurred, and Landlord's calculation of
         the exact number of rentable square feet within the Premises. Tenant
         shall have the right to object to the
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         Tenant Acceptance Agreement by delivering written notice to Landlord
         within five (5) days after Landlord delivers the Tenant Acceptance
         Agreement to Tenant, failing which Tenant shall be deemed to have
         agreed that all information contained in the Tenant Acceptance
         Agreement is correct. If Tenant objects to the Tenant Acceptance
         Agreement within said five (5) day period, Landlord and Tenant shall
         work together to resolve their differences and, after such differences
         have been resolved, Landlord shall execute the Tenant Acceptance
         Agreement and deliver same to Tenant and Tenant shall have a period of
         five (5) days to give written notice to Landlord objecting to the
         Tenant Acceptance Agreement, failing which Tenant shall be deemed to
         have agreed that the Tenant Acceptance Agreement is correct. Upon
         Tenant agreeing or being deemed to have agreed that all information
         contained in the Tenant Acceptance Agreement is correct, the
         Commencement Date as shown on the Tenant Acceptance Agreement shall be
         the Commencement Date for purposes of Section 2 of this lease and for
         all other purposes under this Lease and the rentable square feet of
         the Premises as shown on the Tenant Acceptance Agreement shall replace
         the rentable square feet of the leased premises referenced and defined
         in Section 1 above, and shall be deemed to be the rentable square feet
         of the Premises for all purposes under this lease. All payments of
         Base Monthly Rental (as defined below), and all other payments of rent
         and other sums of money required of Tenant herein shall be made as and
         when required herein, notwithstanding any unresolved objections to the
         Tenant Acceptance Agreement. All such payments shall be based upon the
         Tenant Acceptance Agreement prepared by Landlord until such objections
         have been finally resolved, whereupon any overpayment or any
         underpayment theretofore made shall be adjusted by increasing or
         reducing, as the case may be, the next installment of Base Monthly
         Rental coming due.

         2.       TERM. The term of this Lease shall be for a period of eleven
(11) years and six (6) months commencing on the Commencement Date (as defined
below) (such term being hereinafter referred to as the "Term"), unless sooner
terminated as may be hereinafter provided.

         3.       COMPLETION OF IMPROVEMENTS. (a) Landlord agrees to proceed
with due diligence to prepare the Premises in accordance with the Work Letter
attached hereto as Exhibit "D" (hereinafter referred to as the "Work Letter")
and in accordance with the terms of this Lease. Subject to Force Majeure (as
defined in Section 45) and subject to Tenant Delay, as defined in Section
2.01(b) of the Work Letter, Landlord shall deliver the Premises to Tenant on or
before November 1, 2000. At the time of delivery of the leased premises to
Tenant, the "Base Building Condition" as described in Section 1.02 of the Work
Letter (the "Base Building Condition") shall be constructed and installed by
Landlord and Tenant's leasehold improvements shall be constructed and installed
by Landlord pursuant to the terms, conditions and provisions of the Work
Letter. SEE SPECIAL STIPULATION 25. SEE SPECIAL STIPULATION 28.

         As used herein, "Commencement Date" means the earlier of (i) the
Commencement Date as calculated pursuant to Special Stipulation 4 or (ii) the
date upon which Tenant commences conducting its business from all or any
portion of the Premises; provided, however, in no event shall the Commencement
Date be earlier than November 1, 2000.



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         4.       QUIET ENJOYMENT. Landlord hereby represents and warrants
that, on the Commencement Date, Landlord will own indefeasible fee simple title
in and to the Land and Building. So long as Tenant shall observe and perform
the covenants and agreements binding on it hereunder and subject to the terms
and provisions hereof, Tenant shall at all times during the Term peacefully and
quietly have and enjoy possession of the Premises.

         5.       BASE MONTHLY RENTAL. Tenant agrees to pay Landlord, by
payments to Mount Vernon Place Partners, L.L.C., and delivered to Landlord c/o
Griffin Management Services, Inc., 800 Mt. Vernon Highway, Suite 300, Atlanta,
Georgia 30328, promptly on the first day of each month in advance, during the
Term of this Lease, without deduction or set off, in legal tender, a monthly
rental as determined under Special Stipulation 16 (hereinafter referred to as
"Base Monthly Rental"). If the Term commences on a day other than the first day
of a month, or terminates on a day other than the last day of a month, the Base
Monthly Rental for the first or last partial month shall be prorated based upon
the actual number of days in such a month.

         Tenant hereby acknowledges that if any monthly payment of rent or any
monies due hereunder from Tenant shall not be received by Landlord within five
(5) business days after written notice from Landlord to Tenant that such
payment is due, then Tenant shall pay the Landlord a late charge equal to
2 1/2% of such delinquent amount. Any amounts payable hereunder by Tenant to
Landlord which are not paid within five (5) business days after written notice
from Landlord to Tenant that such payment is due shall bear interest at the
rate of one percent (1%) per month until paid.

          6.      BASE MONTHLY RENTAL ADJUSTMENT. For purposes of this Section
6 and all other provisions of this Lease, Base Monthly Rental shall be composed
of two (2) components: (i) Net Rental which is defined as the total Base
Monthly Rental less operating expenses per square foot of the Premises for the
first twelve (12) months of the term of this Lease, and (ii) Remaining Rental
which is defined as the remainder of Base Monthly Rental other than Net Rental,
such that Net Rental and Remaining Rental when combined shall equal the total
Base Monthly Rental. Commencing one year from the date of the initial Lease
term hereof and continuing on the same day of each year during the initial and
any renewal term hereof, the Net Rental component of Base Monthly Rental, as
increased by previous rental adjustments hereunder, shall be increased by the
lesser of the following: (i) the amount of the CPI Increase, as this term is
defined below; or (ii) two and one-half percent (2 1/2%).

         As used in this Section 6, the term "Lease Year" shall mean the twelve
(12) month period commencing on the Commencement Date, or, if the Commencement
Date is not on the first day of the calendar month, commencing on the first day
of the first calendar month following the Commencement Date, and each
successive twelve (12) month period thereafter during the Term. The term
"Subsequent Year" shall mean each Lease Year of the Term following the first
year. The term "Prior Year" shall mean the Lease Year prior to the subsequent
year. The term "Index" shall mean the Consumer Price Index-Seasonally Adjusted
U.S. City Average for All Urban Consumers (Base Year 1982-1984 = 100) published
by the Bureau of Labor Statistics of the United States Department of Labor. The
term "Base Month" shall mean the calendar month which is two (2) months prior
to the month during which the Lease is fully executed by Landlord and Tenant.
The



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term "Comparison Month" shall mean the calendar month which is two (2) months
prior to the first full month of each Subsequent Year in question. On the first
day of each Subsequent Year, the CPI Increase shall be calculated as follows:
the Net Rental component of Base Monthly Rental shall be increased to an amount
equal to Net Rental for the first Lease Year plus an amount equal to the
product of ten (10) times the percentage increase in the Index for the
Comparison Month as compared to the Index for the Base Month multiplied by Net
Rental for the first Lease Year; provided, however, in no event shall Net
Rental for a Subsequent Year be less than Net Rental applicable to the Prior
Year. In the event the Base Year (1982-1984 = 100) used in computing the Index
is changed, the figures used in making the adjustment above shall accordingly
be changed. Likewise, if the Index is discontinued, the index increase shall be
in accordance with an industry wide standard for measuring the cost of living
increase and used at the time of such discontinuation acceptable to Landlord.

         An estimated annual rent schedule of the Net Rental annual rate,
assuming an annual escalation of two and one-half percent (2 1/2%) per year in
Net Rental occurs pursuant to this Section 6 and assuming operating expenses
for the first year of the Term of this Lease are $4.87 per square foot of the
Premises, is set forth in the illustrative chart below:

<TABLE>
<CAPTION>
         LEASE YEAR                 NET RENTAL ANNUAL RATE
         ----------                 ----------------------

         <S>                        <C>
         First Year                 $16.18
         Second Year                $16.58
         Third Year                 $17.00
         Fourth Year                $17.42
         Fifth Year                 $17.86
         Sixth Year                 $18.31
         Seventh Year               $18.76
         Eighth Year                $19.23
         Ninth Year                 $19.71
         Tenth Year                 $20.21
         Eleventh Year              $20.71
         Last Six Months            $21.23
</TABLE>

         In the event actual Operating Expenses for the first year of the Term
are greater than $4.87 per square foot of the Premises, then the above Net
Rental annual rates shall be adjusted downward accordingly.

         7.       [RESERVED]

         8.       ADDITIONAL RENT, OPERATING EXPENSE ADJUSTMENT. The Operating
Expense Base Year of the rentable area of the Building shall be the calendar
year of January 1, 2001 through December 31, 2001. Subject to Section 1(a)
above, the total rentable area of the Building is anticipated to be 238,600
rentable square feet. SEE SPECIAL STIPULATION 2. If in any calendar year after
the Operating Expense Base Year during the term hereof, the Operating



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Expenses of the rentable area of the Building should exceed the Operating
Expenses of the Base Year (such excess being hereinafter referred to as the
"Operating Expense Differential"), then as additional rent for the calendar
year, Tenant shall pay within thirty (30) days after written notice by Landlord
of said amount being due for each rentable square foot of floor space leased
hereunder, and in any expansion or extensions hereof. For the purpose of this
Paragraph 8, Operating Expenses are defined in Exhibit "E" of this Lease. In
addition Operating Expenses shall be adjusted and grossed up so as to show
actual Operating Expenses without computing or taking into account reduced
costs because of first year warranties on materials and equipment.

              If during any calendar year of the Lease, the occupancy of the
rentable area of the Building averages less than one hundred percent (100%),
then it is agreed that the Operating Expense will be adjusted for such year so
that all such Operating Expenses shall be computed as though the rentable area
of the Building has been one hundred percent (100%) occupied for such calendar
year. All such expense categories will be accounted for and reported in
accordance with generally accepted accounting principles.

              At any time during the term of this Lease but not later than
fifteen (15) days prior to the date an additional rental payment is due
pursuant to this Section 8, Landlord may deliver to Tenant a written estimate
of any additional rents which may be reasonably anticipated hereunder,
estimated divided by the number of months remaining in the calendar year, and
Tenant shall pay as additional rental to Landlord promptly on the first day of
each month in advance without deduction or set off in legal tender the monthly
amount called for under such estimate from Landlord to Tenant for those months
for which such additional rental is due pursuant to this Section 8. Any such
written estimate from Landlord to Tenant, as contemplated in this paragraph,
may also include amounts reasonably estimated by Landlord to be due as a result
of Landlord's replacing light bulbs and fixtures in the Premises, as
contemplated in Section 14 of this Lease, or as a result of Landlord's paying
utility bills on behalf of Tenant and thereafter receiving reimbursement from
Tenant for such payments by Landlord on Tenant's behalf, as contemplated under
Section 17 of this Lease. SEE SPECIAL STIPULATION 31.

              Statements showing the actual Operating Expenses of the Building
and Tenant's proportionate share thereof (hereinafter referred to as "Statement
of Actual Adjustment") shall be delivered by Landlord to Tenant within one
hundred twenty (120) days after the end of any calendar year in which
additional rental was paid or due by Tenant under provisions hereof. Within
thirty (30) days after written notice by Landlord to Tenant of such Statement
of Actual Adjustment, Tenant shall pay to Landlord the amount of any rentals
shown as being due and unpaid thereon. Should such Statement of Actual
Adjustment show the Tenant had paid to Landlord an aggregate amount in excess
of the additional rental due for the preceding calendar year and Tenant is not
then in default hereunder, Landlord shall refund the amount of overpayment.

         If the Term of this Lease begins on a day other than the first day of
the calendar year, or should this Lease terminate on a day other than the last
day of the calendar year, the amount shown as due by Tenant on the Statement of
Actual Adjustment shall reflect a proration based on the proportion that the
number of days this Lease was in effect during such calendar year bears to



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360. The Landlord's right to recover Operating Expenses Adjustment shall
survive the termination of this Lease.

         Provided Tenant is not in default under the terms of this Lease Tenant
shall have the right to inspect Landlord's books and records with respect to
Operating Expenses and its proportionate share thereof for any preceding
calendar year. This inspection shall be completed at the Tenant's sole cost and
expense by independent, certified public accountants practicing for an
accounting firm of national prominence and for the exclusive purpose of
determining whether Landlord has complied with the terms of this Lease relating
to Operating Expenses. Should Tenant's inspection reveal that Landlord has
overstated or understated Operating Expenses an appropriate adjustment will be
made. If Tenant owes any amount to Landlord based on such adjustment, it shall
be paid to Landlord within thirty (30) days after the request thereof; if
Landlord owes any amount to Tenant based on such adjustment, such amount shall
be credited against the rent next coming due under this Lease.

         9.       USE OF PREMISES. The Premises shall be used for general
office purposes, and purposes related thereto (which may include a cafeteria or
food service facility for use by Tenant's employees if permitted by applicable
laws, ordinances and regulations), and no other purposes, all in accordance
with the Rules and Regulations attached hereto and incorporated herein by this
reference. The Tenant shall not use, permit or allow the Premises to be used
other than as strictly provided in this Lease and shall not use, permit or
allow the Premises or any part thereof to be used for any unlawful purpose or
otherwise in violation of any federal, state or local statute, law, ordinance,
rule or regulation, including, without limitation, in violation of any zoning
ordinances; nor shall the Tenant knowingly permit any nuisance within the
Premises or permit the Premises to be used in any manner which will be a source
of material annoyance or in any way knowingly interfere with the peaceful
possession, enjoyment and proper use of other areas of the Building, nor shall
the Premises be knowingly used in any manner so as to vitiate the insurance or
increase the rate of insurance on the Premises or the Building, nor shall the
Premises be used for any unlawful purpose which would tend to lower the quality
or character of the Building, create unreasonable elevator loads or otherwise
materially interfere with Building operations. Not by way of limitation of the
foregoing but in addition thereto, neither the Premises nor any portion thereof
shall be used or occupied for any or all of the following: governmental or
quasi-governmental offices, spas (other than a health club or exercise facility
for employees of Tenant), massage parlors, escort services offices, retail
sales purposes, classroom facility purposes (other than in connection with
Tenant's employee and client training), schools, auto leasing or auto sales
offices, equipment or appliance repair shops, day care centers (other than for
Tenant's employees' children), nurseries, churches, or places of religious or
quasi-religious worship, religious facilities or offices of religious
organizations, or retail or wholesale sale purposes, medical research
laboratories or offices for medical or quasi-medical professionals providing
medical treatments.

         10.      NO NUISANCE. Tenant shall conduct its business in such a
manner so as not to knowingly create any nuisance or interference with Landlord
in its operation of the Building.

         11.      ASSIGNMENT AND SUBLETTING. Tenant may sublease or assign any
or all of the Premises without Landlord's prior written consent; provided,
however, any assignee or



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subtenant of Tenant shall be bound by all of the terms, conditions and
provisions of this Lease, including, without limitation, the provisions of
Section 9 concerning use of the Premises, and Tenant shall remain primarily
liable on this Lease for the entire Term hereof and shall in no way be released
from the full and complete performance of all of the terms, obligations
(including, without limitation, those under Special Stipulation 10), covenants
and agreements contained herein. Prior to the time of any such assignment or
sublease by Tenant, Tenant shall first provide Landlord with written
notification of Tenant's intent to so assign or sublease and such written
notification from Tenant to Landlord shall include, at a minimum, the following
information regarding any applicable proposed assignee or sublessee: (i)
financial statements and other relevant financial information regarding any
proposed assignee or sublessee; (ii) the identity and type of business of such
proposed assignee or sublessee; and (iii) such proposed assignee or sublessee's
proposed use of the Premises which shall in all events be consistent and in
compliance with the permitted use provisions set forth under Section 9 above.
Landlord's consent shall not be required with respect to any such proposed
assignee or sublessee; rather, the purpose of the preceding provisions
regarding such notification and information from Tenant to Landlord shall be
that of notifying Landlord with respect to any proposed assignee or sublessee.
Further, in the event Tenant fails to comply with its obligations set forth
under this Section 11 with respect to providing such information to Landlord
and otherwise notifying Landlord as called for above under this Section 11,
then any such breach by Tenant shall be considered a nonmonetary breach
pursuant to nonmonetary event of default 16(ii) in Section 16 of this Lease
which follows, as opposed to a monetary event of default pursuant to 16(i) in
Section 16 of this Lease which follows, and accordingly, shall be subject to
the notice and cure provisions set forth in said 16(ii).

         12.      HOLDING OVER. Should Tenant or any of its successors in
interest continue to hold the Premises after termination of this Lease, whether
such termination occurs by lapse of time or otherwise, with Landlord's
acquiescence, and without any distinct agreement between the parties, then for
the first six (6) month period of such holding over by Tenant, such holding
over shall constitute and be construed as a tenancy at will at a monthly rental
equal to 125% of the monthly rental (including Base Monthly Rental and any
adjusted and additional rent) provided herein at the time of such termination.
At all times following the first six (6) month period of such holding over by
Tenant, such holding over shall then constitute and be construed as a month to
month tenancy at will at a monthly rental equal to one hundred fifty percent
(150%) of the monthly rental (including Base Monthly Rental and any adjusted
and additional rent). At all times during the period of such holding over by
Tenant (but only during such period of such holding over by Tenant and not
prior to the expiration of the normal term of this Lease), Tenant shall be
entitled to terminate this Lease upon thirty (30) days prior written notice to
Landlord. Similarly, at all times following the first six (6) month period of
such holding over by Tenant, Landlord shall be entitled to terminate this Lease
upon sixty (60) days prior written notice to Tenant and at all times following
the expiration of such sixty (60) day notice period from Landlord to Tenant,
Tenant shall be regarded as a tenant at sufferance and not as a tenant at will;
subject, however, to all the terms, provisions, covenants and agreements on the
part of Tenant hereunder. At all times during the period of such tenancy at
sufferance, no payments of money by Tenant to Landlord after the termination of
this Lease shall reinstate, continue, renew or extend the Term and no extension
of this Lease after the termination hereof shall be valid unless and until the
same shall be reduced to writing and signed by both Landlord and Tenant. With
respect to such tenancy at sufferance, Tenant shall be liable to



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Landlord for all damage which Landlord shall suffer by reason of Tenant's
holding over and Tenant shall indemnify, defend and hold Landlord harmless
against all claims made by any other tenant or prospective tenant against
Landlord resulting from delay by Landlord in delivering possession of the
Premises to such other tenant or prospective tenant.

         13.      ALTERATIONS AND IMPROVEMENTS. (a) No structural alteration
in, or structural addition to, the Premises or the mechanical, electrical, or
any other systems (other than security) of the Premises will be made without
first obtaining Landlord's prior written consent, which shall not be
unreasonably withheld, conditioned, or delayed, and any such work consented to,
although paid for by Tenant, may be done by Landlord's contractor. However, in
the event the same is performed by Tenant then all such work performed by
Tenant shall meet any and all applicable building codes, and shall otherwise be
performed in full compliance with any and all applicable laws, ordinances,
codes and regulations, and further, Tenant shall (i) perform all such work in a
reasonable manner; (ii) utilize only contractors or other vendors with a first
class reputation; (iii) cause such work to be completed promptly on a lien free
basis; (iv) cause such work to be completed in compliance with all applicable
laws, ordinances, regulations and rules; (v) utilize the same or similar
materials as any materials which may be replaced; (vi) obtain Landlord's prior
written approval of all contractors, subcontractors and other vendors to be
utilized by Tenant in performing any such work; and (vii) obtain any and all
required building permits and other required approvals prior to performing any
such work. Tenant shall, however, be entitled to perform nonstructural
alterations or nonstructural additions to the Premises and shall be entitled to
work on the security system (but not any other Building system) without
Landlord's prior written consent but subject to and in compliance with the
terms and conditions set forth in this Section 13 regarding any work performed
by Tenant.

                  (b)      If Tenant's actions, omissions or occupancy of the
Premises shall knowingly cause the rate of fire or other insurance either on
the Building or the Premises to be increased, Tenant shall pay, as additional
rent, the amount of any such increase promptly upon demand by Landlord; and

                  (c)      All erections, additions, fixtures and improvements,
whether temporary or permanent in character (except only the movable office
furniture of Tenant) made in or upon the Premises shall be and remain
Landlord's property and shall remain upon the Premises at the termination of
this Lease by lapse of time or otherwise, with no compensation to Tenant. At
the expiration of the Term of this Lease, Tenant shall leave the Premises broom
clean and in good condition, normal wear and tear accepted.

         14.      REPAIRS TO THE PREMISES. Landlord shall not be required to
make any repairs or improvements to the Premises, except roof and structural
repairs and repairs of latent defects necessary for safety and, tenantability,
together with repairs to the mechanical, electrical and power, plumbing
(including hot and cold water), HVAC, elevators and restrooms as may be
required. Tenant shall, at its own cost and expense, keep in good repair all
portions of the Premises, including but not limited to windows, interior glass,
doors, interior walls and finish work, floors and floor coverings, and
supplemental or special heating and air conditioning systems, and shall take
good care of the Premises and its fixtures and permit no waste, except normal
wear and tear with due consideration for the purpose for which the Premises are
leased. Landlord shall maintain and



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replace, at its cost and expense, all light bulbs and fixtures in the Premises.
To the extent Landlord incurs costs pursuant to the preceding sentence in
excess of Landlord's costs associated with the Building's standard two foot by
four foot fluorescent light fixtures and bulbs and any other Building standard
lighting, Landlord shall invoice Tenant for such excess costs incurred by
Landlord, and Tenant shall pay any and all such invoices as additional rental
in accordance with the provisions of Section 8 and Special Stipulation 31 of
this Lease. Tenant shall indemnify Landlord against any loss, damage, or
expense arising by reason of any failure of Tenant to keep the Premises in good
repair and tenantable condition as expressly required herein or due to any act
or neglect of Tenant, its agents, employees, contractors, invitees, licensees,
tenants, or assignees. If Tenant fails to perform after five (5) days prior
written notice from Landlord to Tenant that any such maintenance or repair is
required (except in the event of emergency in which event no such prior written
notice shall be required), or cause to be performed, such maintenance and
repairs, then at the option of Landlord, in its sole discretion, any such
maintenance or repair may be performed or caused to be performed by Landlord
and the cost and expense thereof charged to Tenant, and Tenant shall pay the
amount thereof to Landlord on demand as additional rental. Tenant shall
promptly report to Landlord in writing any damage to, or defective condition in
or about the Building or Premises known to Tenant.

                  15.      LANDLORD'S RIGHT TO ENTER PREMISES. Tenant shall not
change the locks on any entrance to the Premises without prior written notice
to Landlord, and in this event, Tenant shall provide copy keys to Landlord to
the Premises; provided, however, Tenant shall have the right to utilize a card
access system for entry to the Premises to which Landlord shall be subject but
Landlord shall at all times have full access to the Premises and Building.
However, notwithstanding the foregoing, Landlord and Tenant will agree upon
certain limited specific areas of the Premises which will be off limits to
Landlord at all times with such agreement by Landlord and Tenant to be
reflected in an amendment to this Lease. Designated agents, employees, and
contractors of Landlord shall have the right to enter the Premises upon one (1)
business day prior written notice from Landlord to Tenant (except in the event
of emergency in which event no such notice shall be required), at such times as
Landlord deems reasonably necessary, to make necessary repairs, additions,
alterations, and improvements to the Premises or the Building, including,
without limitation, the erection, use, and maintenance of pipes and conduits.
Landlord shall also be allowed to take into and through the Premises any and
all needed materials that may be required to make such repairs, additions,
alterations, and improvements, all without being liable to Tenant in any manner
whatsoever. During such time as work is being carried on in or about the
Premises, provided such work is carried out in a manner so as not to interfere
unreasonably with the conduct of Tenant's business therein, the rent provided
herein shall in no way abate, and Tenant waives any claim and cause of action
against Landlord for damages by reason of loss or interruption to Tenant's
business and profits therefrom because of the prosecution of any such work or
any part thereof. In the event of emergency, or if otherwise necessary to
prevent injury to persons or damage to property, such entry to the Premises may
be made by force without any liability whatsoever on the part of Landlord for
damage resulting from such forcible entry.

                  16.      DEFAULT AND REMEDIES. The following events shall be
deemed to be events of default by Tenant under this Lease: (i) Tenant shall
fail to pay any installment of Base Monthly Rental, Additional Rent or any
other charge or assessment against Tenant pursuant to the terms



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hereof within ten (10) days after notice thereof to Tenant; (ii) Tenant shall
fail to comply with any term, provision, covenant or warranty made under this
Lease by Tenant, other than the payment of the Base Monthly Rental or
additional rent or any other charge or assessment payable by Tenant, and shall
not cure such failure within thirty (30) days after notice thereof to Tenant
except that if such matter, by its nature, requires more than thirty (30)
business days to cure, then Tenant shall be entitled to additional time (but
not to exceed an additional forty-five (45) business days) provided Tenant
commences such cure promptly and diligently pursues such cure to completion in
all events within such additional forty-five (45) business day period; (iii)
Tenant or any guarantor of this Lease shall make a general assignment for the
benefit of creditors, or shall admit in writing its inability to pay its debts
as they become due, or shall file a petition in bankruptcy, or shall be
adjudicated as bankrupt or insolvent, or shall file a petition in any
proceeding seeking any reorganization, arrangement, composition, readjustment,
liquidation, dissolution or similar relief under any present or future statute,
law or regulation, or shall file an answer admitting or fail timely to contest
the material allegations of a petition filed against it in any such proceeding;
(iv) a proceeding is commenced against Tenant or any guarantor of this Lease
seeking any reorganization, arrangement, composition, readjustment,
liquidation, dissolution or similar relief under any present or future statute,
law or regulation, and such proceeding shall not have been dismissed within
sixty (60) business days after the commencement thereof; (v) a receiver or
trustee shall be appointed for the Premises or for all or substantially all of
the assets of Tenant or of any guarantor of this Lease; or (vi) Tenant shall
fail to take possession of the Premises as provided in this Lease; (vii) Tenant
shall knowingly do or permit to be done anything which creates a lien upon the
Premises or the Building and such lien is not removed or discharged within
thirty (30) business days after the filing thereof.

         Upon the occurrence of any of the aforesaid events of default, without
notice or demand of Tenant in any instance, Landlord shall have the option to
pursue any one or more of the following remedies:

                  (a)      Terminate this Lease by giving Tenant notice of
termination, in which event this Lease shall expire and terminate on the date
specified in such notice of termination, with the same force and effect as
though the date so specified were the date herein originally fixed as the
termination date of the Term of this Lease, and all rights of Tenant under this
Lease and in and to the Premises shall expire and terminate, and Tenant shall
remain liable for all obligations under this Lease arising up to the date of
such termination, and Tenant shall surrender the Premises to Landlord on the
date specified in such notice and if Tenant fails to do so, Landlord may
without prejudice to any other remedy which it may have for possession or
arrearage in rent, enter upon and take possession of the Premises and expel or
remove Tenant and any other person who may be occupying the Premises or any
portion thereof.

                  (b)      Landlord may immediately, or at any time thereafter
so long as such event of default remains uncured, terminate this Lease, and in
the event this Lease is so terminated, Landlord shall be entitled to recover
forthwith against Tenant, as liquidated damages and not as a penalty, the
present value determined by application of a reasonable discount rate selected
by Landlord of the Aggregate Gross Rent (defined below) and the actual or
estimated (as reasonably determined by Landlord) Reletting Costs (defined
below) less the aggregate fair market rental



                                    - 10 -
<PAGE>   11

value of the Premises for what otherwise would have been the unexpired balance
of the Lease Term (Landlord and Tenant hereby agreeing that Landlord's actual
damages in such event are impossible to ascertain and the amount set forth
hereinabove as Landlord's liquidated damages is a reasonable estimate of the
amount of actual damages which Landlord probably would suffer). In determining
the aggregate fair market rental value pursuant to the preceding sentence, the
parties hereby agree that all relevant factors shall be considered as of the
time Landlord seeks to enforce such remedy, including, but not limited to, (i)
the length of time remaining in what otherwise would have been the unexpired
balance of the Lease Term (exclusive of renewals and extensions), (ii) the then
current market conditions in the metropolitan Atlanta, Georgia area, (iii) the
likelihood of reletting the Premises for a period of time equal to what
otherwise would have been the unexpired balance of the Lease Term, (iv) the net
effective rental rates (taking into account all concessions) then being
obtained for space of similar type and size in similar type buildings in the
metropolitan Atlanta, Georgia area, (v) the vacancy levels in comparable
quality multi-tenant office buildings in the metropolitan Atlanta, Georgia
area, (vi) the anticipated duration of the period the Premises will be
unoccupied prior to the reletting, (vii) the anticipated cost of reletting, and
(viii) the current levels of new construction of multi-tenant office buildings
in the metropolitan Atlanta, Georgia area that will be completed during the
period in what otherwise would have been the unexpired balance of the Lease
Term and the degree to which such new construction will likely affect vacancy
rates and rental rates in comparable quality multi-tenant office buildings in
the metropolitan Atlanta, Georgia area. In the event Landlord shall relet the
Premises for the period which otherwise would have constituted the unexpired
portion of the Term (or any part thereof), the amount of rent and other sums
payable by the tenant thereunder shall be deemed prima facie to be the rental
value for the Premises (or the portion thereof so relet) for the Lease Term of
such reletting. Tenant shall in no event be entitled to any rents collected or
payable in respect of any reletting, whether or not such rents shall exceed the
Base Monthly Rental and any additional rent reserved in this Lease. As used
herein, the term "Aggregate Gross Rent" shall mean the Base Monthly Rental and
any additional rent and any other sums due hereunder as of the date of
termination of this Lease plus the Base Monthly Rental and any additional rent
which would have been owing by Tenant hereunder for the balance of the Lease
Term had this Lease not been terminated, less the net proceeds, if any,
received as a result of any reletting of the Premises by Landlord subsequent to
such termination, after deducting all of Landlord's expenses including, without
limitation, all repossession costs, brokerage commissions, legal expenses,
attorneys' fees, expenses of employees, alteration and repair costs and
expenses of preparation for such reletting (collectively, the "Reletting
Costs").

                  (c)      Without terminating this Lease, terminate Tenant's
right of possession and enter into and upon and take possession of the Premises
or any part thereof, and at Landlord's option, expel and remove persons and
property therefrom by entry (including the use of force if necessary),
dispossessing suit or otherwise, without thereby releasing Tenant from any
liability hereunder, without terminating this Lease, and without being liable
to prosecution or any claim for damages therefor. Such property, if any, may be
removed and stored in a warehouse or elsewhere at the cost of, and for the
account of Tenant, all without being deemed guilty of trespass or becoming
liable for any loss or damage which may be occasioned thereby, and Landlord
may, but shall be under no obligation to do so relet the Premises or any
portion thereof in Landlord's or Tenant's name, but for the account of Tenant,
with or without advertisement, and by private negotiations, and receive the



                                    - 11 -
<PAGE>   12

rent therefore, and for any term and upon such terms and conditions as Landlord
may deem necessary or desirable. Landlord shall in no way be responsible or
liable for any rental concessions or any failure to lease the Premises or any
part thereof, or for any failure to collect any rent due upon such reletting.
Upon each such reletting, all rentals received by Landlord from such reletting
shall be applied as follows: first, to the payment of any indebtedness (other
than any amounts due hereunder) from Tenant to Landlord; second, to the payment
of any costs and expenses of such reletting, including, without limitation,
brokerage fees and attorneys' fees and costs of alterations and repairs (Tenant
agreeing that Landlord shall have the right to make such alterations and
repairs as, in Landlord's judgement, may be necessary to relet the Premises);
third, to the payment of rental and other charges then due and unpaid
hereunder; and the residue, if any, shall be held by Landlord to the extent of
and for application in payment of future amounts due hereunder as the same may
become due and payable hereunder. In reletting the Premises as aforesaid,
Landlord may grant rent concessions and Tenant shall not be credited therefor.
If such rentals received from such reletting shall at any time or from time to
time be less than sufficient to pay to Landlord the entire sums then due from
Tenant hereunder, Tenant shall pay any such deficiency to Landlord. Such
deficiency shall, at Landlord's option, be calculated and paid monthly. No such
reletting shall be construed as an election by Landlord to terminate this Lease
unless a written notice of such election has been given to Tenant by Landlord.
Notwithstanding any such reletting without termination, Landlord may at any
time thereafter elect to terminate this Lease for any such previous event of
default provided same has not been cured. Notwithstanding anything contained
herein to the contrary, no termination of Tenant's right of possession of the
Premises by dispossessory action or otherwise shall release Tenant from the
performance of Tenant's obligations under this Lease, including, without
limitation, the timely payment of all rent reserved hereunder for the balance
of the Term of this Lease following such termination of Tenant's right of
possession, and Tenant agrees to so perform said obligations.

                  (d)      Without liability to Tenant or any other party and
without constituting a constructive or actual eviction, suspend, or discontinue
furnishing or rendering to Tenant any property, material, labor, utilities or
other service, wherever Landlord is obligated to furnish or render the same, so
long as Tenant is in default under this Lease.

                  (e)      Allow the Premises to remain unoccupied and collect
Base Monthly Rental and other charges due hereunder from Tenant as they come
due.

                  (f)      Landlord may perform, as agent for and at the
expense of Tenant, any obligation of Tenant under this Lease which Tenant has
failed to perform and of which Landlord shall have given Tenant notice and
opportunity to cure as provided herein, the cost of which performance by
Landlord together with interest thereon at the default rate from the date of
such expenditure, shall be deemed additional rental and shall be payable by
Tenant to Landlord upon demand, and Tenant agrees that Landlord shall not be
liable for any damages resulting to Tenant from such action, whether caused by
negligence of Landlord or otherwise.

                  (g)      Landlord may exercise any other legal or equitable
right or remedy which it may have, including, but not limited to Landlord's
right judicially to obtain possession pursuant to Georgia statutory law.



                                    - 12 -
<PAGE>   13

         Any costs and expenses incurred by Landlord (including, without
limitation, reasonable (non-statutory) attorneys' fees actually incurred) in
successfully enforcing any of its rights or remedies under this Lease shall be
deemed additional rent and shall be repaid to Landlord by Tenant demand.

         Pursuit of any of the foregoing remedies shall not preclude pursuit of
any other remedy herein provided or any other remedy provided by law or at
equity, nor shall pursuit of any remedy herein provided constitute an election
of remedies thereby excluding the later election of an alternate remedy, or a
forfeiture or waiver of any Base Monthly Rental, additional rent or other
charges and assessments payable by Tenant and due to Landlord hereunder or of
any damage accruing to Landlord by reason or violation of any of the terms,
covenants, warranties and provisions herein contained. No course of dealing
between Landlord and Tenant or any failure or delay on the part of Landlord in
exercising any rights of Landlord under this paragraph, or under any other
provisions of this Lease, shall operate as a waiver of any rights of Landlord
hereunder or under any other provisions of this Lease, nor shall any waiver of
an event of default on one occasion operate as a waiver of any subsequent event
of default or of any other event of default. No express waiver shall affect any
condition, covenant, rule, or regulation other than the one specified in such
waiver and that one only for the time and in the manner specifically stated.

         If this Lease is terminated by Landlord pursuant to clause (b) above,
"present value" may be computed by discounting the amount of such excess to
present worth at a discount rate equal to one percent (1%) above the discount
rate then in effect at the Federal Reserve Bank of Atlanta, Georgia. Neither
the commencement of any action or proceeding, nor the settlement thereof, nor
entry of judgment thereon shall bar Landlord from bringing subsequent actions
or proceedings from time to time, nor shall the failure to include in any
action or proceeding any sum or sums then due be a bar to the maintenance of
any subsequent actions or proceedings for the recovery of such sum or sums so
omitted. Landlord's pursuit of any remedy or remedies, including, without
limitation, any one or more of the remedies stated above, shall not (i)
constitute an election of remedies or preclude pursuit of any other remedy or
remedies provided in this Lease or separately or concurrently or in any
combination, or (ii) serve as the basis for any claim of constructive eviction,
or allow Tenant to withhold any payments under this Lease.

         The failure of Landlord to insist upon strict performance of any of
the terms, conditions and covenants herein shall not be deemed to be a waiver
of any subsequent breach or default in the terms, conditions, and covenants
herein contained except as may be expressly waived in writing.

         Landlord shall in no event be in default in the performance of any of
its obligations in this Lease unless and until Landlord shall have failed to
perform such obligation within thirty (30) days or such additional time as is
reasonably required to correct any such default, after notice by Tenant to
Landlord properly specifying wherein Landlord has failed to perform any such
obligation.

         If Tenant shall at any time be in default hereunder, and if Landlord
shall deem it necessary to engage attorneys to enforce Landlord's rights
hereunder, the determination of such necessity to be in the reasonable
discretion of Landlord or if Landlord is made a party to litigation involving
or



                                    - 13 -
<PAGE>   14

pertaining to Tenant due to no fault of Landlord, then Tenant will reimburse
Landlord for the reasonable expenses incurred thereby, including but not
limited to court costs and reasonable attorneys' fees and other legal expenses.

         Tenant hereby covenants that, prior to the exercise of remedies, it
will give the holder of any Mortgage (as defined below) notice and thirty (30)
days to cure said default unless said default cannot be cured within thirty
(30) days, in which case such holder shall have the right, but not the
obligation, to commence and to diligently prosecute the cure of Landlord's
default.

         17.      LANDLORD'S SERVICES. Landlord shall furnish the following
services to Tenant during the Term of this Lease:

         (a)      Janitor service shall be provided Monday through Friday of
each week, exclusive of New Years Day, Memorial Day, Independence Day, Labor
Day, Thanksgiving Day and Christmas Day, pursuant to specifications therefor
described on Exhibit "G" attached hereto and incorporated herein by reference.
The janitorial staff shall be subject to Tenant's security clearance procedures
for the Premises. Additionally, Tenant shall have the right to replace the
janitorial services provided by Landlord, and if Tenant so elects, then the
rental under this Lease shall be reduced by Landlord's previous cost in
providing such janitorial services as documented by an amendment to this Lease
to be executed by Landlord and Tenant.

         Tenant will design Tenant's electrical system serving any equipment
producing non-linear electrical loads to accommodate such non-linear electrical
loads, including, but not limited to, over-sizing neutral conductors, de-rating
transformers and/or providing power line filters. Tenant's final contract
documents for the Tenant Improvements (as defined in the Work Letter) shall
include a calculation of Tenant's fully connected design load with and without
demand factors and shall indicate the number of watts of un-metered and
sub-metered loads.

         The design and installation of any additional electrical equipment (or
any related meter) required by Tenant shall be subject to the prior approval of
Landlord (which approval shall not be unreasonably withheld). All expenses
incurred by Landlord in connection with the review and approval of any
additional electrical equipment shall also be reimbursed to Landlord by Tenant.

         If any of Tenant's electrical equipment requires conditioned air in
excess of Building Standard air conditioning, the same shall be installed by
Tenant at Tenant's sole cost in a manner previously approved by Landlord in
writing, and Tenant shall pay all design, installation, metering and operating
costs relating thereto.

         To the extent the services described hereinabove require electricity
and water supplied by public utilities, Landlord's covenants thereunder shall
only impose on Landlord the obligation to use its good faith, reasonable
efforts to cause the applicable public utilities to furnish the same. All of
the services (other than janitorial) contemplated under this Section 17 as well
as any other applicable utility services shall be provided by Landlord to
Tenant solely at Tenant's cost, and in no event, notwithstanding any other
provision of this Lease to the contrary, shall Landlord incur



                                    - 14 -
<PAGE>   15

any costs whatsoever associated with utility invoices from the applicable
utilities. Rather, Landlord's only responsibility shall be to receive and remit
payment for such invoices on Tenant's behalf to be reimbursed by Tenant in
accordance with the following: In the course of Landlord's management of the
Building, Landlord shall receive and remit payment for the utility invoices
associated with the services set forth under this Section 17, and Tenant shall
reimburse Landlord for such payments made by Landlord on Tenant's behalf within
fifteen (15) days of Landlord's presentation of Landlord's invoice to Tenant
associated with Landlord's payment on Tenant's behalf of any such utility
payments. SEE SECTION 8 AND SPECIAL STIPULATION 31. Landlord's management of
the Building shall include landscaping and other services commensurate with the
following standard: such management shall be in a first class manner comparable
to other office properties in the Central Perimeter Office Market of Atlanta,
Georgia. SEE SPECIAL STIPULATION 19.

         18.      WINDOW DRESSINGS. All exterior windows of the Premises shall
be equipped only with Building-standard blinds provided by the Landlord. Tenant
may install other window treatments so long as same have solid white linings
and so long as the Building-standard blinds remain affixed between the window
glass and the other window treatments.

         19.      TELEPHONE SERVICE. Tenant acknowledges and agrees that
securing and arranging for telephone service to the Premises is the sole
responsibility of Tenant and that Landlord has no responsibility or obligation
to provide or arrange such telephone service.

         20.      DESTRUCTION OF PREMISES. Should the Premises be so damaged by
fire or other cause that rebuilding or repairs cannot, in the estimation of
Landlord, be completed within one hundred twenty (120) days from the date of
the fire, or other cause of damage, then either Landlord or Tenant may
terminate this Lease by written notice to the other given within thirty (30)
days of the date of such damage or destruction, in which event rent shall be
abated from the date of such damage or destruction. However, if the damage or
destruction is such that rebuilding or repairs can be completed within one
hundred twenty (120) days, Landlord covenants and agrees, subject to the
provisions of this paragraph, to make such repairs with reasonable promptness
and dispatch within such one hundred twenty (120) day period, and to allow
Tenant an abatement in the Base Monthly Rental for such time as the Premises
are untenantable or proportionately for such portion of the Premises as shall
be untenantable, and Tenant covenants and agrees that the terms of this Lease
shall not be otherwise affected. In no event shall Landlord be required to
repair or replace any trade fixtures, furniture, equipment or other property
belonging to Tenant nor shall Landlord be required to rebuild, repair or
replace any part of the partitions, fixtures, additions, or other improvements
which may have been placed in or about the Premises by Tenant. Notwithstanding
anything to the contrary contained in this paragraph, Landlord shall not have
any obligation whatsoever to repair, reconstruct or restore the Premises when
the damage resulting from any casualty contained under this paragraph occurs
during the last six (6) months of the Term of this Lease, but rent shall abate
to the extent set forth above in this Section 20 until such repairs are
completed.

         21.      CONDEMNATION. If the whole of the Premises or access to the
Premises, or such portion thereof, as will make Premises unusable for the
purposes herein leased, be condemned by



                                    - 15 -
<PAGE>   16

any legally constituted authority for any public use or purpose, then, in
either of said events, the Term hereby granted shall cease from the date when
possession thereof is taken by public authorities, and rental shall be
accounted for as between Landlord and Tenant as of said date. Such termination,
however, shall be without prejudice to the rights of either Landlord or Tenant
to recover compensation and damage caused by condemnation from the condemnor;
provided, however, Tenant shall not be entitled to claim compensation for items
which would reduce Landlord's award.

         22.      INSURANCE. Landlord shall insure the initial Tenant
Improvements to the Premises. Subject to the foregoing, Tenant shall insure
subsequent alterations, additions, and improvements to the Premises and shall
otherwise carry the required insurance under this Lease as follows: Tenant
shall carry fire and extended coverage insurance insuring Tenant's interest in
its improvements and betterment to the Premises and any and all furniture,
equipment, supplies, and other property owned, leased, held, or possessed by it
and contained therein, against loss or damage by fire, flood, windstorms, hail,
earthquakes, explosion, riot, damage from aircraft and vehicles, smoke damage,
vandalism and malicious mischief and such other risks as are from time to time
covered under "extended coverage" endorsements and special extended coverage
endorsements commonly known as "all risks" endorsements, such insurance
coverage to be in an amount equal to the full replacement value of such
improvements and property.

         Tenant also agrees to carry a policy or policies of workers'
compensation and commercial general liability insurance, including personal
injury and property damage in an amount of not less than Two Million and No/100
Dollars ($2,000,000.00) for the property damage and Five Million and No/100
Dollars ($5,000,000.00) per occurrence for personal injuries or deaths of
persons occurring in or about the Premises. Said policies shall: (i) name
Landlord, its agents and mortgagees as additional insureds and insure
Landlord's contingent liability under this Lease (except for the workers'
compensation policy, which shall instead include waiver of subrogation
endorsement in favor of Landlord); (ii) be issued by an insurance company which
is acceptable to Landlord and licensed to do business in the State of Georgia
and maintains an A.M. Best credit rating of "B+" or better; and (iii) provide
that said insurance shall not be cancelled unless thirty (30) days' prior
written notice shall have been given to Landlord. Said policy or policies, or
certificate thereof, shall be delivered to Landlord by Tenant upon commencement
of the Term of the Lease and upon each renewal and/or modification of said
insurance. If during the Term or any extension thereof additional coverage
and/or higher limits of insurance than those mentioned above shall be deemed
necessary by Landlord, Tenant shall procure such additional coverage provided
such additional coverage is appropriate, customary and generally required for
like premises utilized for similar purpose. If Tenant shall fail at any time to
procure and/or maintain the insurance required herein, Landlord may, at its
option, procure such insurance on Tenant's behalf and the cost thereof shall be
payable upon demand, as additional rent. Payment by Landlord of any insurance
premium or the carrying by Landlord of any such insurance policy shall not be
deemed to waive or release the default of Tenant with respect thereto.

         Landlord shall procure and maintain at its expense (but with the
expense to be included in Operating Expenses) throughout the Term a policy or
policies of special form/all risk insurance covering the Building including the
initial Tenant Improvements in the Premises up to the amount



                                    - 16 -
<PAGE>   17

of the Tenant Improvement Allowance, but excluding Tenant's personal property
and equipment, in an amount equal to the full insurable replacement costs
thereof as such may increase from time to time (but such insurance may provide
for a commercially reasonable deductible), and in an amount sufficient to
comply with any coinsurance requirements in such policy, and a policy of
worker's compensation insurance, if any, as required by applicable law. In
addition, Landlord shall procure and maintain at its expense (but with the
expense to be included in Operating Expenses) and shall thereafter maintain
throughout the Term, a commercial general liability insurance policy covering
the Building with combined single limits for damage to property and personal
injury of not less than One Million Dollars ($1,000,000.00) per occurrence,
subject to annual aggregate limits of not less than Two Million Dollars
($2,000,000.00). Landlord may also carry such other types of insurance in form
and amounts which Landlord shall determine to be appropriate from time to time,
and the costs thereof shall be included in Operating Expenses. All such
policies procured and maintained by Landlord pursuant to this Section 22 shall
be carried with companies licensed to do business in the State of Georgia. Any
insurance required to be carried by Landlord hereunder may be carried under
blanket policies covering other properties of Landlord and/or its members
and/or their respective related or affiliated corporations and entities as long
as such blanket policies provide insurance at all times for the Building as
required by this Lease. Tenant shall be named as an additional insured on all
such insurance carried by Landlord with respect to the Building.

         23.      WAIVER OF SUBROGATION. Landlord and Tenant each hereby
releases the other from any and all liability or responsibility to the other or
anyone claiming through or under them by way of subrogation or otherwise for
any loss or damage to property caused by fire or any other perils that is
insured against or that are required to be insured against under the terms of
the Lease, even if such loss or damage shall have been caused by the fault or
negligence of the other party, or anyone for whom such party may be
responsible, including, without limitation, any other tenants or occupants of
the remainder of the Building in which the Premises are located; provided,
however, that this release shall be applicable and in force and effect only to
the extent that such release shall be lawful at that time and in any event only
with respect to loss or damage occurring during such time as the releaser's
policies shall contain a clause or endorsement to the effect that any such
release shall not adversely affect or impair said policies or prejudice the
right of the releaser to recover thereunder and then only to the extent of the
insurance proceeds payable under such policies. Landlord and Tenant each agrees
that it will request its insurance carriers to include in its policies such a
clause of endorsement. If extra cost shall be charged therefor, each party
shall advise the other thereof and of the amount of the extra cost, and the
other party, at its election, may pay the same, but shall not be obligated to
do so. If such other party fails to pay such extra costs, the release
provisions of this paragraph shall be inoperative against such other party to
the extent necessary to avoid invalidation of such releaser's insurance.

         24.      NO ESTATE IN LAND. This contract shall create the
relationship of Landlord and Tenant between the parties hereto; no estate shall
pass out of Landlord. Tenant has only a usufruct, not subject to levy and sale,
and not assignable by Tenant except by Landlord's consent.

         25.      INDEMNITY. Excepting for the willful acts or negligence of
Landlord, its agents and employees, Tenant indemnifies and shall hold Landlord,
its agents and employees, harmless from



                                    - 17 -
<PAGE>   18

and defend Landlord, its agents, officers, directors, partners, attorneys and
employees, against any and all claims or liability for injury or death to any
person or damage to any property whatsoever:

                  (a)      either (i) occurring in, on, or about the Premises;
or (ii) occurring in, on, or about any facilities (including, without
limitation, elevators, stairways, passageways or hallways) the use of which
Tenant may have in conjunction with other occupants of the Building, when such
injury, death or damage shall be caused in part or in whole by the act, neglect
or fault of, or omission of any duty with respect to the same by Tenant, its
agents, employees, contractors, invitees, licensees, tenants, or assignees; or

                  (b)      arising from any work or thing whatsoever done by or
benefiting the Tenant in or about the Premises or from transactions of the
Tenant concerning the Premises; or

                  (c)      arising from any breach or default on the part of
the Tenant in the performance of any covenant or agreement on the part of the
Tenant to be performed pursuant to the terms of this Lease; or

                  (d)      otherwise arising from any act or neglect of the
Tenant, or any of its agents, employees, contractors, invitees, licensees,
tenants or assignees; and from and against all costs, expenses, counsel fees,
and court costs incurred or assessed in connection with any or all of the
foregoing. Furthermore, in case any action or proceeding be brought against
Landlord by reason of any claims or liability, Tenant agrees to cause such
action or proceeding to be defended at Tenant's sole expense by counsel
reasonably satisfactory to Landlord. The provisions of this Lease with respect
to any claims or liability occurring or caused prior to any expiration or
termination of this Lease shall survive such expiration or termination.

         Tenant shall give immediate notice to Landlord in case of casualty or
accidents in the Premises. The provisions of this paragraph shall survive the
expiration or sooner termination of this Lease.

         Except for the willful acts or negligence of Tenant, its agents,
contractors, employees, invitees, licensees, visitors, and customers, Landlord
hereby indemnifies and shall hold Tenant harmless from and defend Tenant
against any and all claims or liability for injury or death to any person or
damage to any property whatsoever arising from any breach or default on the
part of Landlord in the performance of any covenant or agreement on the part of
Landlord to be performed pursuant to the terms of this Lease.

         26.      LIABILITY OF LANDLORD. Subject to the provisions of Special
Stipulations 18 and 19, Landlord shall not be liable to Tenant or to any
persons, firm, corporation, or other business association claiming by, through,
or under Tenant for failure to furnish or for delay in furnishing any service
provided for in this Lease, and no such failure or delay by Landlord shall be
an actual or constructive eviction of Tenant nor shall any such failure or
delay operate to relieve Tenant from the prompt and punctual performance of
each and all the covenants to be performed herein by Tenant; nor for water
discharged from sprinkler systems, if any, or from water pipes and plumbing
facilities in the Building; nor for the theft, mysterious disappearance, or
loss of any property of



                                    - 18 -
<PAGE>   19

Tenant whether from the Premises or any part of the Building; and nor from
interference, disturbance, or acts to or omitted against Tenant by third
parties, including, without limitation other occupants of the Building and any
such occurrences shall not constitute an actual or constructive eviction of
Tenant.

         27.      LIMITATION OF LIABILITY. Landlord's obligations and liability
with respect to this Lease shall be limited solely to Landlord's interest in
the Building any insurance proceeds received by Landlord in connection
therewith to the extent not yet applied by Landlord, as such interest is
constituted from time to time, and neither Landlord nor any officer, director,
shareholder, or partner of Landlord, or of any partner of Landlord, shall have
any personal liability whatsoever with respect to this Lease. In no event shall
Landlord be liable to Tenant nor shall any interest of Landlord in the Building
be subject to execution by Tenant, for any indirect, special or consequential
damages.

         28.      NO WAIVER OF RIGHTS. No failure or delay of Landlord to
exercise any right or power given it herein or to insist upon strict compliance
by Tenant of any obligation imposed on it herein and no custom or practice of
either party hereto at variance with any term hereof shall constitute a waiver
or a modification of the terms hereof by Landlord or any right it has herein to
demand strict compliance with the terms hereof by Tenant. No person has or
shall have any authority to waive any provision of this Lease unless such
waiver is expressly made in writing and signed by Landlord.

         29.      ENTIRE AGREEMENT AND EXHIBITS. This Lease constitutes and
contains the sole and entire agreement of Landlord and Tenant and no prior or
contemporaneous oral or written representation or agreement between the parties
and affecting the Premises shall have legal effect. The content of each and
every exhibit which is referenced in this Lease as being attached hereto is
incorporated into this Lease as fully as if set forth in the body of this
Lease.

         30.      NOTICES. All notices required or desired to be given with
respect to this Lease shall, in order to be effective, be in writing and shall
be effectively given or delivered if hand delivered to the addresses for
Landlord and Tenant specified hereinbelow, or if deposited, postage prepaid, to
the United States mail, certified, return receipt requested, properly addressed
to the addresses specified hereinbelow, or if delivered by Federal Express or
other overnight commercial courier to the addresses for Landlord and Tenant
hereinbelow. Any notice mailed or sent by overnight commercial courier shall be
deemed to have been given upon receipt or refusal thereof. Notice effected by
hand delivery shall be deemed to have been given at the time of actual
delivery. In the event of a change of address by either party, such party shall
give written notice thereof to the other party in accordance with the
foregoing. Additionally, Tenant agrees to send copies of all notices required
or permitted to be given to Landlord to each lessor under any ground or land
lease covering all or any part of the Land and each holder of a mortgage or
deed to secure debt encumbering the Building and/or the Land that notifies
Tenant in writing of its interest in the address to which notices are to be
sent.



                                    - 19 -
<PAGE>   20
         If to Tenant                    INTERNET SECURITY SYSTEMS, INC.
         (prior to Commencement Date):   6600 Peachtree-Dunwoody Road, N.E.
                                         300 Embassy Row, Fifth Floor
                                         Atlanta, Georgia 30328
                                         Attention: Mr. Richard Macchia

         If to Tenant
         (after Commencement Date):      INTERNET SECURITY SYSTEMS, INC.
                                         6303 Barfield Road
                                         Suite 100
                                         Atlanta, Georgia 30328
                                         Attn: Mr. Richard Macchia

         If to Landlord:                 MOUNT VERNON PLACE PARTNERS, L.L.C.
                                         c/o Griffin Management Services, Inc.
                                         800 Mount Vernon Highway, Suite 300
                                         Atlanta, Georgia 30328
                                         Attn: Mr. Joel J. Griffin

         The foregoing addresses may be changed by thirty (30) days written
notice from time to time.

         Tenant hereby appoints as his agent to receive the service of all
dispossessory or distraint proceedings and notices thereunder, and all notices
required under this Lease, the person in charge of or occupying the Premises at
the time; and if no person is in charge of or occupying same, then such service
or notice may be made by attaching the same on the main entrance to the
Premises. To the extent permitted by law, Tenant hereby submits to the
jurisdiction of any state or federal court located in Fulton County, Georgia,
as well as to the jurisdiction of all courts from which an appeal may be taken
from the aforesaid courts for the purpose of any suit, action or other
proceeding arising out of Tenant's obligations under or with respect to this
Lease and Tenant hereby expressly waives any and all objections that Tenant may
have as to jurisdiction and/or venue in any of such courts.

         31.      SUCCESSORS AND ASSIGNS. The covenants, conditions and
agreements herein contained shall inure to the benefit of and be binding upon
Landlord, its successors and assigns, and shall be binding upon Tenant, its
heirs, executors, administrators, successors and assigns, and shall inure to
the benefit of Tenant. Nothing contained in this Lease shall in any manner
restrict Landlord's right to assign or encumber this Lease in its sole
discretion. Should Landlord assign this Lease as provided for above, Tenant
shall be bound to said conditions of this Lease for the balance of the Term
hereof remaining after such succession, and Tenant shall attorn to such
succeeding party as its landlord under this Lease promptly under any such
successions. Tenant agrees that should any party so succeeding to the interest
of Landlord require a separate agreement of attornment regarding the matters
covered by this Lease, then Tenant shall enter into any such "attornment
agreement," provided the same does not modify any of the provisions of this
Lease and has no adverse effect upon Tenant's continued occupancy of the
Premises.



                                    - 20 -
<PAGE>   21

         32.      SUBORDINATION. Landlord will obtain within thirty (30) days
from the date of this Lease from its lender financing the acquisition of the
Land, as this term is defined in Special Stipulation 1, and the construction of
the Building in connection therewith, a subordination, non-disturbance and
attornment agreement between Landlord, such lender, and Tenant. Tenant agrees
that this Lease shall, subject to obtaining the aforesaid subordination,
non-disturbance attornment agreement be and remain subject and subordinate to
all present and future mortgages, deeds to secure debt or other security
instruments (the "Security Deeds") affecting the Premises provided that such
future lenders will not disturb Tenant as long as Tenant remains in full
compliance with all terms and conditions of this Lease. Tenant shall promptly
execute and deliver to Landlord such certificate or certificates in writing as
Landlord may request, confirming the subordinate nature of the Lease to such
Security Deeds.

         33.      ESTOPPEL CERTIFICATE. Tenant shall, within ten (10) days
after request from Landlord, at any time and from time to time execute,
acknowledge and deliver to Landlord a written statement certifying as follows:
(a) that this Lease is unmodified and in full force and effect (or if there has
been modification thereof, that the same is in full force and effect as
modified and stating the nature thereof); (b) that to the best of its knowledge
there are no uncured defaults on the part of Landlord (or if any such default
exists, the specific nature and extent thereof); and (c) the date to which any
rents and other charges have been paid in advance, if any; and (d) such other
matters as Landlord may reasonably request.

         34.      TIME IS OF THE ESSENCE. Time is of the essence with the
respect to the performance of each of the covenants and agreements of this
Lease; provided, however, that failure of Landlord to provide Tenant with any
notification regarding adjustments in Base Monthly Rental, or any other charges
provided for hereunder, within the time periods prescribed in this Lease shall
not relieve Tenant of its obligation to make such payments, which payments
shall be made by Tenant at such time as notice is subsequently given. Unless
specifically provided otherwise, all references to terms of days or months
shall be construed as references to calendar days or calendar months,
respectively.

         35.      CAPTIONS; GOVERNING LAW. The captions of this Lease are for
convenience of reference only and in no way define, limit or describe the scope
or intent of this Lease. The laws of the State of Georgia shall govern the
validity, performance and enforcement of this Lease.

         36.      DEFINITIONS. "Landlord" as used in this Lease shall include
his heirs, representatives, assigns and successors in title to Premises.
"Tenant" shall include its heirs and representatives, and if this Lease shall
be validly assigned or sublet, shall include also Tenant's assignees or
sublessees, as to premises covered by such assignment or sublease. "Broker" and
"Co-Broker" shall include its successors, assigns, heirs, and representatives.
"Landlord," "Tenant," "Broker" and "Co-Broker," shall include male and female,
singular and plural, corporation, partnership or individual, as may fit the
particular parties.

         37.      SEVERABILITY. If any clause or provision of this Lease is or
becomes illegal, invalid, or unenforceable because of present or future laws or
any rule or regulation of any



                                    - 21 -
<PAGE>   22

governmental body or entity, effective during its term, the intention of the
parties hereto is that the remaining parts of this Lease shall not be affected
thereby, unless such invalidity is, in the sole determination of Landlord,
essential to the rights of both parties in which event Landlord has the right
to terminate this Lease on written notice to Tenant.

         38.      LAWS AND REGULATIONS; BUILDING RULES AND REGULATIONS. Subject
to the provisions of Special Stipulation 11, Tenant shall comply with, and
Tenant shall cause its agents, contractors, customers, employees, invitees,
licensees, servants and visitors to comply with (i) all applicable laws,
ordinances, orders, directions, requirements, rules and regulations (state,
federal, municipal and other agencies or bodies having any jurisdiction
thereof) now in force or which may hereafter be in force, which shall impose
any duty upon Landlord or Tenant relating to the use, condition or occupancy of
the Premises or the conduct of Tenant's business therein, including, without
limitation, the Americans With Disabilities Act of 1990 (as now or hereafter
amended); and (ii) the Building Rules and Regulations set forth in Exhibit "F,"
as such Rules and Regulations are modified and supplemented by Landlord from
time to time, and such other rules and regulations as are reasonably adopted by
Landlord from time to time, for the safety, care or cleanliness of the Premises
and the Building, or for preservation of good order therein, all of which will
be sent by Landlord to Tenant in writing and shall be thereafter carried out
and observed by Tenant, its agents, contractors, customers, employees,
invitees, licensees, servants and visitors. Tenant hereby expressly waives the
benefit of all existing and future rent control laws and similar governmental
rules and regulations, whether in time of war or not, to the full extent
permitted by law.

         39.      SPECIAL STIPULATIONS. The Special Stipulations attached
hereto are hereby incorporated herein and made a part hereof. In the event the
Special Stipulations conflict with any of the foregoing provisions of this
Lease, the Special Stipulations shall control.

         40.      BROKER COMMISSION. Tenant represents and warrants to Landlord
that, other than Insignia/ESG, Inc. ("Broker"), no broker, agent, commissioned
salesperson or other person has represented Tenant in the negotiations for and
procurement of this Lease, and that no commissions, fees or compensation of any
kind are due in connection herewith to any broker, agent, commissioned
salesperson or other person, other than Broker, which has acted as broker for
Tenant in this transaction. Landlord shall pay Broker a real estate commission
in connection with this transaction pursuant to the terms of a separate written
Commission Agreement between Landlord and Broker. Landlord has disclosed that
The Griffin Company ("Co-Broker") is acting on behalf of Landlord in this
transaction and is receiving a commission pursuant to the terms of a separate
written Commission Agreement.

         41.      REMOVAL OF PERSONAL PROPERTY. Tenant may (if not in default
hereunder) prior to the expiration of this Lease, or any extension thereof,
remove all unattached and movable personal property and equipment which Tenant
has placed in the Premises, provided Tenant repairs all damages to Premises
caused by such removal. All personal property of Tenant remaining on the
Premises after the end of the Term shall be deemed conclusively abandoned,
notwithstanding that title to or a security interest in such personal property
may be held by an individual or entity other than Tenant, and Landlord may
dispose of such personal property in any manner it deems proper, in



                                    - 22 -
<PAGE>   23

its sole discretion. Tenant hereby waives and releases any claim against
Landlord arising out of the removal or disposition of such personal property.
Tenant shall reimburse Landlord for the cost of removing such personal
property.

         42.      SIGNAGE. Subject to applicable laws, regulations, and
ordinances, Tenant, at Tenant's sole cost and expense (but with Tenant allowed
to use a portion of the Tenant Improvement Allowance as set forth in the Work
Letter attached as Exhibit "D") and subject to Landlord's prior written
approval as to the exact location and as to the plans and specifications for
such signage, shall be entitled to install signage including Tenant's corporate
name and logo on each Building and the parking deck together with a monument
sign adjacent to each Building and the walls of elevator lobbies of the
Building and on entrance doors to the Building on any full floors of the
Building leased by Tenant. The location of such signage together with all plans
and specifications for such signage shall be provided by Tenant to Landlord
subject to Landlord's prior written approval not to be unreasonably withheld by
Landlord. Subject to the foregoing, Tenant shall not place any other signs,
decals, or other materials upon the windows or suite doors of the Premises nor
on the exterior walls of Premises. Any additional signage other than as
provided for under this Section 42 desired by Tenant shall be approved, in
writing, by Landlord and the management company of the Building, which shall be
granted in their sole discretion.

         43.      EFFECT OF TERMINATION OF LEASE. No termination of this Lease
prior to the normal ending thereof, by lapse of time or otherwise, shall affect
Landlord's right to collect rent for the period prior to termination thereof.

         44.      RIGHTS CUMULATIVE. All rights, powers and privileges
conferred hereunder upon parties hereto shall be cumulative but not restrictive
to those given by law.

         45.      FORCE MAJEURE. In the event of strike, lockout, labor
trouble, civil commotion, act of God, or any other cause (hereinafter
collectively referred to as "Force Majeure") outside and beyond Landlord's
control, resulting in the impairment of Landlord's ability to perform any
obligation or provide any service hereunder, this Lease shall not terminate,
and Tenant's obligation to pay Base Monthly Rental, additional rental and all
other charges and sums due payable by Tenant shall not be altered or excused
and Landlord shall not be considered to be in default under this Lease or
liable in damages to Tenant in any manner.

         46.      TENANT CORPORATION, PARTNERSHIP OR INDIVIDUAL. If Tenant
executes this Lease as a corporation, each of the persons executing this Lease
on behalf of Tenant does hereby covenant, warrant and represent that Tenant is
a duly organized and validly existing corporation, that Tenant has and is
qualified to do business in Georgia, that the corporation has full right and
authority to enter into this Lease, and that each and all persons signing on
behalf of the corporation were authorized to so do. Upon Landlord's request,
Tenant shall provide Landlord with evidence reasonably satisfactory to Landlord
confirming the foregoing covenants and warranties. If Tenant executes this
Lease as a partnership, Tenant does hereby covenant, warrant and represent that
all the persons who are general or managing



                                    - 23 -
<PAGE>   24

partners in said partnership have executed this Lease on behalf of Tenant, or
that this Lease has been executed and delivered pursuant to and in conformity
with a valid and effective authorization therefor, by all of the general or
managing partners of such partnership, and is and constitutes the valid and
binding agreement of the partnership and each and every partner therein in
accordance with its terms. Also, it is agreed that each and every present and
future partner of Tenant shall be and shall remain at all times jointly and
severally liable hereunder, and that the death, resignation, or withdrawal of
any partner shall not release the liability of such partner under the terms of
this Lease unless and until Landlord consents in writing to such release. If
Tenant executes this Lease as an individual, Tenant does hereby covenant,
warrant and represent that his legal residence address is that set forth below
his signature on this Lease. If more than one individual or entity comprises
and constitutes Tenant, then all individuals and entities comprising Tenant are
and shall each be jointly and severally liable for the due and proper
performance of Tenant's covenants, duties and obligations arising under or in
connection with this Lease.

         47.      SUBMISSION OF LEASE. The submission of this Lease for
examination does not constitute an offer to lease nor a reservation of space
even if said lease is executed by Landlord, and this Lease shall be effective
only upon execution hereof by Landlord and Tenant.

         48.      NO RECORDATION OF LEASE. This Lease is not in recordable
form, and Tenant agrees not to record or permit the recording of this Lease or
other evidence thereof except that Tenant shall be entitled to record a
memorandum of this Lease, previously approved in writing by Landlord, which
memorandum shall provide that this Lease is subject to present and future
lenders as set forth in Section 32 of this Lease and subject to the terms and
conditions of Section 32 of this Lease.

         49.      HAZARDOUS SUBSTANCES. Tenant hereby covenants and agrees that
Tenant shall not cause or knowingly permit any "Hazardous Substances" (as
hereinafter defined) to be generated, placed, held, stored, used, located or
disposed of at the Building or any part thereof, except for Hazardous
Substances as are commonly and legally used or stored as a consequence of using
the Demised Premises for general office and administrative purposes, but only
so long as the quantities thereof do not pose a threat to public health or to
the environment or would necessitate a "response action", as that term is
defined in CERCLA (as hereinafter defined), and so long as Tenant strictly
complies or causes compliance with all applicable governmental rules and
regulations concerning the use or production of such Hazardous Substances. For
purposes of this paragraph, "Hazardous Substances" shall mean and include those
elements or compounds which are contained in the list of Hazardous Substances
adopted by the United States Environmental Protection Agency (EPA) or the list
of toxic pollutants designated by Congress or the EPA which are defined as
hazardous, toxic, pollutant, infectious or radioactive by any other federal,
state or local statute, law, ordinance, code, rule, regulation, order or decree
regulating, relating to or imposing liability (including, without limitation,
strict liability) or standards of conduct concerning, any hazardous, toxic or
dangerous waste, substance or material, as now or at any time hereinafter in
effect (collectively "Environmental Laws"). Tenant hereby agrees to indemnify
Landlord and hold Landlord harmless from and against any and all losses,
liabilities, including strict liability, damages, injuries, expenses, including
reasonable attorneys' fees, costs of settlement or judgment and claims of any
and every kind whatsoever paid, incurred or suffered by, or asserted against,
Landlord by any person, entity or governmental agency for, with respect to, or
as a direct or indirect result of, the presence in, or the escape, leakage,
spillage, discharge,



                                    - 24 -
<PAGE>   25

emission or release from, the Demised Premises of any Hazardous Substances
(including, without limitation, any losses, liabilities, including strict
liability, damages, injuries, expenses, including reasonable attorneys' fees,
costs of any settlement or judgment or claims asserted or arising under the
Comprehensive Environmental Response, Compensation and Liability Act
["CERCLA"], any so-called federal, state or local "Superfund" or "Superlien"
laws or any other Environmental Law); provided, however, that the foregoing
indemnity is limited to matters arising solely from Tenant's violation of the
covenant contained in this Article. The obligations of Tenant under this
Article shall survive any expiration or termination of this Lease. SEE SPECIAL
STIPULATION 12.

         50.      EXECUTION. This Lease may be executed in any number of
counterparts, each of which shall be deemed an original and any of which shall
be deemed to be complete in itself and may be introduced into evidence or used
for any purpose without the production of the other counterparts. No
modification or amendment of this Lease shall be binding upon the parties
hereto unless such modification or amendment is in writing and signed by
Landlord and Tenant.

         51.      LANDLORD AND TENANT RELATIONSHIP. The relationship between
Landlord and Tenant shall be solely that of landlord and tenant only, and no
provision of this Lease including, without limitation, the provisions of
Special Stipulation 8 of this Lease, shall be deemed or construed by the
parties hereto, or by any third party, as creating the relationship of
principal and agent, or of partnership, or of joint venture, between the
parties hereto, and accordingly, without limiting the generality of the
foregoing provisions, Tenant shall have no authority to bind or enter into any
agreements on behalf of Landlord whatsoever.

         52.      AUTHORITY. As a material inducement to Landlord to enter into
this Lease, Tenant, acknowledging that Landlord may rely on each such
representation and warranty, represent and warrant to Landlord that:

         (a)      the execution, delivery and full performance of this Lease by
                  Tenant do not and shall not constitute a violation of any
                  contract, agreement, undertaking, judgment, statute,
                  regulation, governmental or court order or other restriction
                  of any kind to which Tenant is or may be bound;

         (b)      Tenant has executed and entered into this Lease free from
                  fraud, undue influence, duress, coercion or other defenses to
                  the execution of this Lease;

         (c)      Tenant is duly organized, validly existing and in good
                  standing under the laws of the state of Georgia and has full
                  power and authority to enter into this Lease, to perform
                  Tenant's obligations under this Lease in accordance with the
                  terms hereof, and to transact business in the State of
                  Georgia; and

         (d)      the execution and delivery of this Lease by the individual or
                  individuals executing this Lease on behalf of Tenant, and
                  Tenant's performance of its obligations under this Lease,
                  have been duly authorized and approved by all necessary
                  corporate or partnership action, as the case may be, and
                  Tenant's execution, delivery and



                                    - 25 -
<PAGE>   26

                  performance of this Lease are not in conflict with Tenant's
                  bylaws or articles of incorporation, or other charters,
                  agreements, rules or regulations governing Tenant's business,
                  as any of the foregoing may have been supplemented, modified,
                  amended, or altered in any manner.

         IN WITNESS WHEREOF, the parties hereto have set their hands and seals
hereunder and have caused this Lease to be executed in their names and their
corporate seals to be affixed by their officers duly authorized thereunto, upon
the day and year set forth above.


                                          TENANT:


Signed, sealed and delivered              INTERNET SECURITY SYSTEMS, INC.,
in the presence of:                       a Georgia corporation



                                          By:
-------------------------------------        ----------------------------------
Notary Public or Witness



                                          Name:
-------------------------------------          --------------------------------
Name (Please Print)                                   (Please Print)

                                          Title:
                                                -------------------------------


                                          Attest:
                                                -------------------------------

                                          Name:
                                               --------------------------------
                                                      (Please Print)

                                          Title:
                                                -------------------------------
                                                      [CORPORATE SEAL]


                                          LANDLORD:

Signed, sealed and delivered              MOUNT VERNON PLACE PARTNERS,
in the presence of:                       L.L.C., A GEORGIA LIMITED LIABILITY
                                          COMPANY



                                          By
-------------------------------------        ----------------------------------
Notary Public or Witness                     JOEL J. GRIFFIN
                                             MANAGING MEMBER


-------------------------------------
Name        (Please Print)



                                    - 26 -
<PAGE>   27
                               MOUNT VERNON PLACE

                              SPECIAL STIPULATIONS


1.       Notwithstanding any provision of this Lease to the contrary,
         Landlord's obligations under this Lease are contingent upon Landlord's
         acquisition of the Land by December 31, 1999 and in the event Landlord
         has not acquired the Land by December 31, 1999, then Landlord shall be
         entitled to terminate this Lease by written notice to Tenant in which
         event neither party shall have any further liability or obligation
         hereunder to the other. Alternatively, Landlord may extend the
         contingency date for Landlord's acquisition of the Land from December
         31, 1999, as described above, to January 31, 2000, and if Landlord
         elects to extend such date, then in the event Landlord has not then
         acquired the Land by January 31, 2000, then Landlord or Tenant shall
         then be entitled to terminate this Lease by written notice to the
         other in which event neither party shall have any further liability or
         obligation hereunder to the other. Upon the execution of this Lease,
         Landlord has paid to Tenant a payment of $25.00 as an option payment
         from Landlord to Tenant thereby making this Lease a mutually binding
         option agreement notwithstanding that this Lease is not binding upon
         Landlord unless and until the contingency set forth above in this
         Special Stipulation 1 with regarding Landlord's acquisition of the
         Land is removed. Tenant hereby acknowledges the receipt and
         sufficiency of such $25.00 option payment from Landlord to Tenant.

2.       Within the thirty (30) days of the date of this Lease, Landlord shall
         apply for any and all necessary permits and approvals so as to allow
         for Landlord's construction of two (2) bridges connecting the Phase I
         Building and the Phase II Building, and Landlord shall diligently
         pursue any and all such required permits and approvals (collectively
         "Approvals"). In the event the Approvals are obtained, then Landlord
         shall construct such bridges connecting the Phase I and Phase II
         Buildings, but in the event Landlord is unable to obtain such
         Approvals, then Landlord shall not be obligated to construct such
         bridges nor shall Landlord be deemed to be in breach or default under
         this Lease; provided, however, Landlord shall construct a covered walk
         way between the Phase I building and the Phase II building pursuant to
         plans and specifications mutually acceptable to Landlord and Tenant.
         In the event such bridges are not constructed, then the rentable
         square feet of the Building shall be adjusted accordingly.

3.       Landlord shall construct the Building substantially in accordance with
         the following plans and specifications: those certain project manuals
         and drawings styled "Mount Vernon Place Office Building, Atlanta,
         Georgia, November 4, 1999, Project Manuals & Drawings" as further
         enumerated in Exhibit "A-1" attached hereto and made a part hereof by
         reference. Any modifications by Landlord to the construction of the
         Building as determined by Landlord shall remain substantially in
         accordance with such plans and specifications provided that Landlord
         shall notify Tenant when any such modifications are made by Landlord
         to such plans and specifications. Landlord's general construction of
         the Building shall be comparable in quality to the following facility:
         Perimeter Place Office Building located at 800 Mount Vernon Highway.
<PAGE>   28

4.       Notwithstanding any provision of this Lease to the contrary, the Term
         of this Lease shall be for eleven (11) years and six (6) months
         commencing on the Commencement Date which shall be the date the
         construction of the Tenant Improvements is completed pursuant to the
         Work Letter (the "Work Letter") attached hereto as Exhibit "D" and
         made a part hereof by reference and a certificate of occupancy is
         issued by Fulton County. The target Commencement Date of November 1,
         2000 would result in an expiration date of the Term on April 31, 2012.
         However, in the event of Tenant Delay, as this term is defined under
         Section 6 of the Work Letter, the Commencement Date shall be the date
         construction of the Tenant Improvements would have been completed
         pursuant to the Work Letter and a certificate of occupancy would have
         been issued by Fulton County had not such Tenant Delay occurred. The
         method for determining the rental Commencement Date set forth in this
         Special Stipulation 4 shall apply to each and every respective phase
         of the staged occupancy of the Premises described below in Special
         Stipulation 5.

5.       The following represents the parties' agreement regarding staged
         occupancy of the Premises and the payment of rental in connection
         therewith: On the first initial Commencement Date (with an initial
         target Commencement Date of November 1, 2000), as determined pursuant
         to Special Stipulation 4 above, Tenant shall occupy and begin paying
         rental for all five (5) floors of the Phase I Building (consisting of
         115,500 rentable square feet). Similarly, on the second target
         Commencement Date of February 1, 2001, with the actual second
         Commencement Date being determined as set forth above in Special
         Stipulation 4, Tenant shall begin paying rental for two (2) floors of
         the Phase II Building together with the two (2) bridges constructed by
         Landlord pursuant to Special Stipulation 2 above consisting of a total
         of 53,800 rentable square fee (46,200 square feet for such two (2)
         floors of the Phase II Building and 7,600 rentable square feet for
         such two (2) bridges). Similarly, on the third target Commencement
         Date of August 1, 2001, with the actual third Commencement Date being
         determined pursuant to Special Stipulation 4 above, Tenant shall begin
         paying rental for an additional floor of the Phase II Building
         consisting of 23,100 rentable square feet. Similarly, on the fourth
         target Commencement Date of February 1, 2002, with the actual fourth
         Commencement Date being determined pursuant to Special Stipulation 4
         above, Tenant shall begin paying rental for an additional floor of the
         Phase II Building consisting of 23,100 rentable square feet. Finally,
         upon the fifth target Commencement Date of August 1, 2002, with the
         actual fifth Commencement Date being determined pursuant to Special
         Stipulation 4 above, Tenant shall begin paying rental for the last
         floor of the Phase II Building consisting of 23,100 rental square
         feet. Landlord and Tenant shall agree within sixty (60) days of the
         date of this Lease as to the exact sequences of floors in the Phase II
         Building to be occupied by Tenant on the respective second through
         fifth target Commencement Dates of February 1, 2001, August 1, 2001,
         February 1, 2002, and August 1, 2002 as set forth above in this
         Special Stipulation 5, and when Landlord and Tenant reach such
         agreement within such sixty (60) day period, an amendment to this
         Lease shall be executed reflecting such agreement by the parties. The
         schedule of Tenant's rental obligations for the staged occupancy of
         the Premises as set forth in this Special Stipulation 5 is set forth
         in Special Stipulation 17 below subject to the assumptions and terms
         and conditions set forth in Special Stipulation 17 below. Tenant shall
         occupy the respective
<PAGE>   29

         portions of the Premises at the respective Commencement Dates as
         determined pursuant to Special Stipulation 4 and Special Stipulation 5
         of this Lease.

6.       Tenant shall not be liable for any increase of, or reassessment in,
         real property taxes and assessments resulting from a sale, transfer,
         reapportionment of proprietary interest, or any other change in
         ownership of the Building or site during the Term or from major
         alterations, improvements, modifications, or renovations to the
         Building or site. However, subject only to the restrictions set forth
         in the preceding sentence, Tenant shall remain fully liable for real
         property taxes and assessments to the extent set forth in Section 8
         and Exhibit "E" of the Lease and otherwise.

7.       If used by Tenant to pay for the Tenant Costs, as such term is defined
         under Section 3.02 of the Work Letter attached hereto as Exhibit "D",
         up to $2.50 per rentable square foot of the Premises over and above
         the total $24.00 per rentable square foot Tenant Improvement
         Allowance, as this term is defined in Section 3.01 of the Work Letter,
         may be amortized as set forth herein and added as additional rental
         (over and above the amounts of the first sixty (60) monthly
         installments of Base Monthly Rental) with such amortization to be at
         an interest rate of ten percent (10%) per annum over the first five
         (5) years of the Term of this Lease, to the extent such extra amounts
         are used by Tenant to pay for the Tenant Costs. To the extent the
         total $24.00 per rentable square foot Tenant Improvement Allowance is
         not used in full ("Savings"), then Tenant may use such Savings for
         relocation expenses, wiring expenses, telecommunication expenses and
         for similar items and/or for moving expenses and/or for the permitted
         purposes set forth in Section 3.01 of the Work Letter and/or Tenant
         may elect to have Landlord apply up to $2.50 per rentable square foot
         of the Premises of such Savings (but not in excess of up to $2.50 per
         rentable square foot of the Premises of such Savings) as a credit
         toward Tenant's initial rental obligations under this Lease.

8.       Subject to the terms, conditions and agreements set forth in this
         Special Stipulation 8, Landlord shall pay to Tenant a portion of the
         net cash flow (for purposes of this Special Stipulation 8, the term
         "net cash flow" shall be defined as Landlord's actual cash flow from
         Landlord's operation of the Building (after the Preferred Return, as
         this term is defined below, has been paid in full to each of
         Landlord's members) less Landlord's payment of expenses in connection
         with Landlord's operation of the Building and less Landlord's
         maintenance of reserves in connection with Landlord's operation of the
         Building subject to the limitation that any loans from Landlord's
         members to Landlord shall not bear interest at a rate in excess of the
         Preferred Return) otherwise payable to Landlord's members from the
         operation of the Building, which payments by Landlord to Tenant, the
         parties agree, shall constitute an expense of Landlord in the
         operation of the Building (but which shall not constitute an Operating
         Expense as set forth in Exhibit "E" and other applicable provisions of
         this Lease) upon the following terms and conditions: Unless otherwise
         approved by Tenant, Landlord's permanent financing for the Building
         shall contain an amortization based upon a period of not less than
         twenty-five (25) years. Landlord shall be entitled to determine the
         payment of all operating expenses and the maintenance of all reserves
         in connection with Landlord's operation of the Building. Each of
         Landlord's members has contributed and/or will from time to time
         contribute cash and/or other equivalent value
<PAGE>   30

         associated with each such member's investment in its membership
         interests in Landlord and otherwise as set forth in the operating
         agreement of Landlord and the books and records of Landlord maintained
         in connection therewith (hereinafter the respective contributions by
         each of Landlord's members are referred to respectively as "Cash
         Invested"). For purposes of this Special Stipulation 8, the respective
         amounts of the Cash Invested for each such member of Landlord shall
         not be decreased in any respect whatsoever and shall be deemed to be
         entitled to a twelve percent (12%) per annum preferred interest return
         ("Preferred Return") as further set forth in this Special Stipulation
         8 and shall not be diminished by depreciation, return of capital, or
         any other accounting event which might otherwise be deemed to decrease
         the amount of Cash Invested or the capital account of any such member;
         rather, the aggregate Cash Invested, as the same may be increased from
         time to time, shall in no event ever be diminished for purposes of
         this Special Stipulation 8. Each member of Landlord shall be entitled
         to the Preferred Return on each such member's Cash Invested from and
         after the respective times of each increment of such Cash Invested by
         such member, and after each such member has received such member's
         total current Preferred Return on any and all Cash Invested, then
         subject to Landlord's payment of expenses in connection with the
         Building and the maintenance of normal reserves, as determined by
         Landlord, the remaining net cash flow shall on an annual basis within
         sixty (60) days from the expiration of each calendar year, or more
         frequently if net cash flow is distributed to the members of Landlord
         more frequently, be divided as follows: Landlord shall pay as an
         expense of Landlord in its operation of the Building to Tenant thirty
         percent (30%) of such net cash flow with the remaining seventy percent
         (70%) of such net cash flow to be distributed to Landlord's members
         contemporaneous with the payment of such thirty percent (30%) of net
         cash flow to Tenant. Such payment of thirty percent (30%) of net cash
         flow from Landlord to Tenant shall continue only for the first eight
         and one-half (8 1/2) years of the term of this Lease and shall not
         continue thereafter. In the event the Building is sold or refinanced
         during such eight and one-half (8 1/2) years initial term of this
         Lease, but not thereafter, then after the Preferred Return is paid to
         Landlord's members, Tenant shall be entitled to receive as an expense
         payment from Landlord to Tenant thirty percent (30%) of the remaining
         net proceeds from any such sale or refinancing with the remaining 70%
         to be distributed to Landlord's members. At any and all times during
         all terms of this Lease, Landlord shall be entitled to determine the
         financing of Landlord (both temporary and permanent) in connection
         with its acquisition, construction, and operation of the Building
         subject only to the restriction that permanent financing shall be
         based on an amortization period of not less than twenty-five (25)
         years as set forth above in this Special Stipulation 8, and further,
         Landlord shall determine expenses to be paid in connection with the
         operation of the Building, reserves to be maintained in connection
         therewith, and the terms of any such sale or refinancing. In no event
         shall Tenant be entitled to any payment of net cash flow or net
         proceeds from any sale or refinancing or any other payment under this
         Special Stipulation 8 after the first eight and one-half (8 1/2) years
         of the initial term of this Lease (the "Tenant Participation Period").
         Further, following any sale of the Building from the initial landlord,
         Mount Vernon Place Partners, L.L.C. to a successor during the Tenant
         Participation Period, provided that Tenant is paid thirty percent
         (30%) of the remaining net proceeds from such sale as described above
         in this Special Stipulation 8, then Tenant shall not be entitled to
         receive any further payments from any successor landlord,
<PAGE>   31

         and the provisions of this Special Stipulation 8 shall accordingly,
         only be binding upon the initial landlord Mount Vernon Place Partners,
         L.L.C. during the Tenant Participation Period. Notwithstanding the
         preceding sentence, in the event the term of this Lease is extended
         past eleven and one-half (11 1/2) years by a mutually acceptable
         written extension agreement between Landlord and Tenant which is
         executed and entered into during such Tenant Participation Period,
         then the Tenant Participation Period shall also be extended by the
         same period as the extension term set forth in any such written
         extension agreement; provided, however, that in all events, Tenant's
         rights to receive the portion of net cash flow from operations and net
         proceeds from any sale or refinancing, as set forth above in this
         Special Stipulation 8, shall cease upon the date when three (3) years
         are left on the term of this Lease. Accordingly, in no event shall
         Tenant be entitled to any portion of net cash flow or net proceeds
         from any sale or refinancing during the last three (3) years of the
         Term of this Lease, and accordingly, the Tenant Participation Period
         shall not be extended by any holdover by Tenant either pursuant to
         Section 12 of this Lease or otherwise. However, in the event Tenant
         extends the Term of this Lease pursuant to Special Stipulation 13
         below regarding Tenant's renewal of the Term of this Lease, then the
         Tenant Participation Period shall be extended in the manner set forth
         above, and if Tenant's rights to receive thirty percent (30%) of net
         cash flow as set forth above have lapsed, then such rights shall be
         revived by such extension of the Tenant Participation Period except
         that all lapsed payments due from Landlord to Tenant associated with
         such extension shall be paid by Landlord to Tenant as an expense in
         Landlord's operation of the Building (but which shall not constitute
         an Operating Expense as set forth in Exhibit "E" and other applicable
         provisions of this Lease) in the current year when such lapsed rights
         to receive payments are revived by such extension. Except as set forth
         in the preceding sentence, the Tenant Participation Period shall not
         be extended for any other reason except only as set forth above in
         this Special Stipulation 8.

9.       Landlord agrees to provide Tenant in increments up to the aggregate
         amount of $700,000.00 to be utilized by Tenant to offset or buyout of
         Tenant's existing rental obligation for approximately 90,000 square
         feet at Embassy Row. Such amounts shall be payable by Landlord to
         Tenant to the extent of and at the respective times Tenant incurs
         offset or buyout obligations with respect to Tenant's office space at
         Embassy Row as indicated by the following illustrative examples: In
         the event Tenant buys out of its existing rental obligation at Embassy
         Row, then the payments from Landlord to Tenant pursuant to this
         Special Stipulation 9 shall be on or about the same time or times as
         Tenant's respective payments obligations under such buyout and
         similarly, in the event Tenant sublets its office space at Embassy
         Row, then for the incremental difference between the amount received
         by Tenant pursuant to such sublease and the amount due from Tenant to
         the landlord at Embassy Row, then Landlord shall pay the amounts of
         such incremental differences to Tenant pursuant to this Special
         Stipulation 9 on or about the respective times of Tenant's obligations
         for such incremental difference to its landlord at Embassy Row. To the
         extent such $700,000.00 amount set forth above in this Special
         Stipulation 9 is not utilized in full by Tenant pursuant to this
         Special Stipulation 9, then up to, but not in excess of, $350,000.00
         of such unutilized amount will be applied by Landlord as a credit
         against Tenant's rental obligations under this Lease.
<PAGE>   32

10.      On or before November 19, 1999 (with the form of the letter of credit
         to be provided for Landlord's review and approval by November 10,
         1999), Tenant shall deliver to Landlord an irrevocable standby letter
         of credit as security for Tenant's performance under this Lease and to
         compensate Landlord for Landlord's expenses incurred (said letter of
         credit and each letter of credit substituted therefor as hereinafter
         provided, being hereinafter referred to as the "Letter of Credit")
         issued in form and substance and by an issuing banking institution
         acceptable to Landlord containing the following terms and conditions:

         (i)      the Letter of Credit shall provide for multiple draws;

         (ii)     Landlord or Landlord's successor-in-title to the Premises
                  shall be the beneficiary under the Letter of Credit;

         (iii)    draws under the Letter of Credit shall be honored by the
                  issuing lending institution upon presentation by an
                  authorized representative of Landlord accompanied by (a)
                  Landlord's sight draft, (b) a certification by Landlord that
                  Tenant has defaulted under this Lease and, as a result of
                  such default, Landlord is entitled to present the Letter of
                  Credit for payment, and (c) a certification by Landlord that
                  Landlord is entitled to payment of the sums set forth as
                  rental due under this Lease, together with a certificate as
                  to additional sums representing itemized costs and expenses
                  incurred by Landlord as a result of the default by Tenant
                  under this Lease and otherwise;

         (iv)     the term of the Letter of Credit shall be one (1) year from
                  the date of issuance thereof; and

         (v)      in the event the Letter of Credit has not been replaced by
                  Tenant with a substitute Letter of Credit in the amount set
                  forth below by five (5) business days prior to the expiring
                  date thereof, Landlord shall be entitled to present the
                  Letter of Credit for payment of the entire remaining
                  undisbursed balance thereof, accompanied solely by Landlord's
                  sight draft.

         The first Letter of Credit shall be in the face amount of Ten Million
         and No/100 Dollars ($10,000,000.00); each successive Letter of Credit
         shall be in the face amount of One Million and No/100 Dollars
         ($1,000,000.00) less than the Letter of Credit replaced by such
         successive Letter of Credit, until the amount of the next successive
         Letter of Credit is $0.00 at which time Landlord shall return the
         issued and outstanding Letter of Credit and Tenant shall have no
         further obligation to cause the issuance of additional Letters of
         Credit.
<PAGE>   33

11.      Landlord warrants that the Building, Premises and all common areas
         will meet building codes in Fulton County at the Commencement Date and
         that the Premises will be in compliance with the Americans With
         Disabilities Act (42 U.S.C.ss. 12101 et. seq.). Landlord warrants that
         the offices, rooms, buildings, structures, and adjacently owned
         property, including all parking lots, walkways, entrances, hallways
         and other public spaces, elevators, and other devices or pathways for
         ingress and egress to the leased property that might be used by
         customers, clients, invitees of Tenant and the general public, conform
         to the requirements of the Americans with Disabilities Act and all
         regulations issued by the U.S. Attorney General or other authorized
         agencies under the authorization of the American with Disabilities
         Act. The Landlord promises to reimburse and indemnify and defend the
         Tenant for any expenses incurred because of the failure of the leased
         Premises and adjacently owned property to conform with the above cited
         law and regulations, including the costs of making any alterations,
         renovations, or accommodations required by the Americans with
         Disabilities Act, or any governmental enforcement agency, or any
         court, any and all fines, civil penalties, and damages awarded against
         the Tenant resulting from a violation or violations of the above-cited
         law and regulations, and all reasonable legal expenses incurred in
         defending claims made under the above-cited law and regulations,
         including reasonable attorneys' fees.

         Consistent with the foregoing, in addition, Tenant shall, at Tenant's
         sole expense but subject to Landlord's prior written approval, make
         each and every alteration or addition to the interior, non-structural
         portion of the Leased Premises required to bring the interior,
         non-structural portion of the Leased Premises into compliance with the
         requirements imposed by the Americans With Disabilities Act, (42
         U.S.C. ss. 12101 et. seq.) and any regulations promulgated pursuant
         thereto (collectively such Act and regulations are referred to as "ADA
         Requirements") effective from time to time during the Term if (a) the
         requirement for such alteration or addition arises as a result of (i)
         any alteration or addition by Tenant; or (ii) any violation by Tenant
         of any ADA Requirements; or (iii) a special use of the Leased Premises
         or any part thereof by Tenant or any assignee or subtenant of Tenant
         (including, but not limited to, use for a facility which constitutes,
         or, if open to the public generally, would constitute, a "place of
         public accommodation" under the ADA Requirements); or (iv) the special
         needs of the employee(s) of Tenant or any assignee or subtenant of
         Tenant; or (b) the ADA Requirements would otherwise make Tenant,
         rather than Landlord, primarily responsible for making such alteration
         or addition.

12.      Landlord represents that there is no asbestos or Hazardous Substances
         in, on or about the Building, including the Premises and the Land.
         Excepting for the willful act or negligence or violations of
         Environmental Laws by Tenant, or its agents, employees, contractors,
         customers, invitees, licensees, or visitors, Landlord indemnifies and
         shall hold Tenant harmless from and defend Tenant against any and all
         claims or liability solely resulting from a breach of the foregoing
         representation in the preceding sentence.
<PAGE>   34

13.      Landlord agrees to grant to Tenant, but not any sublessee, the right
         to renew this Lease on the same conditions and terms contained herein,
         except as hereafter provided, for three 5-year renewal terms, provided
         Tenant is not in default under this Lease at the time of Tenant's
         exercise of said right or at the commencement of each renewal term.
         Tenant shall give written notice to Landlord of Tenant's intent to
         negotiate of said right twelve (12) months prior to the Lease
         expiration or said right to renew shall expire.

         If Tenant exercises the right to renew, the annual base rent for each
         renewal term shall be equal to 95% of the then "current effective
         market rate" for comparable space in low rise Class "A" office
         buildings in the North Central/I 285 and North Fulton/Georgia 400
         office submarkets of metropolitan Atlanta, Georgia, taking into
         account "free rent," tenant finish allowances, types and amount of
         parking, and other financial concessions as are typically given to
         tenants for such comparable space at the time of renewal.

         Within thirty (30) days of receipt of notice of Tenant's exercise of
         the right to renew, Landlord shall provide Tenant written notice of
         Landlord's proposal of the "current effective market rate." Should
         Tenant agree with Landlord's proposal, then Tenant shall within thirty
         (30) days execute an amendment renewing this Lease. In the event
         Tenant finds such proposal to be unsatisfactory, Tenant shall notify
         Landlord, in writing, within fifteen (15) days of receipt of
         Landlord's proposal and such notice shall contain Tenant's proposal
         for the "current effective market rate". Should Landlord agree with
         Tenant's proposal, then Tenant shall within thirty (30) days execute
         an amendment renewing this Lease. In the event Landlord finds Tenant's
         proposal unsatisfactory, Landlord shall so notify Tenant, in writing,
         within five (5) business days of the receipt of Tenant's proposal and
         in such event, Landlord and Tenant agree to negotiate in good faith in
         an attempt to agree upon the "current effective market rate."

         If Tenant and Landlord are unable to agree on the amount of the
         "current effective market rate" within an additional thirty (30) days
         after notification by Landlord that Tenant's proposal is
         unsatisfactory then at Tenant's option, such amount shall be
         determined by arbitration as described below, or the option to renew
         will expire.

         Landlord and Tenant shall agree to each choose an arbitrator to choose
         a third party arbitrator to determine the "current effective market
         rate". Upon such third party arbitrator determining the "current
         effective market rate", Landlord and Tenant shall renew the Lease by
         immediately executing an amendment renewing this Lease at such rate
         determined by the third party arbitrator. Such third party arbitrator
         shall determine the "current effective market rate" within thirty (30)
         days of being chosen. The third party arbitrator shall have at least
         ten (10) years' business experience in independent appraisal in
         commercial real estate transactions in the metropolitan Atlanta,
         Georgia area. Landlord and Tenant agree that each party shall pay for
         the costs incurred by the arbitrator it selects, and that the costs of
         the third party arbitrator will be divided equally between Landlord
         and Tenant.
<PAGE>   35

14.      During the Term and any renewals of this Lease, Landlord shall provide
         Tenant exclusive use a total of 785 parking spaces in the parking deck
         adjacent to the Building, at no charge for such primary term and any
         renewals. All such spaces, subject to the remaining terms and
         conditions of this Lease, will be available twenty-four (24) hours per
         day, seven (7) days per week, every day of the year. Additionally, by
         the Commencement Date, Landlord agrees to restripe and refurbish that
         certain additional parking lot (the "Additional Lot") consisting of
         surface parking available at the Sanbury Building located at 6405
         Barfield Road, Fulton County, Georgia, and as of the Commencement
         Date, Tenant shall have the nonexclusive use of the parking from and
         out of such Additional Lot. It is also possible that Landlord may
         construct a third building upon the Land. Tenant acknowledges and
         agrees that in all events Landlord shall be fully entitled to
         construct such third building, and that if Landlord so elects to
         construct such third building, then any such construction by Landlord
         may be upon the Additional Lot, and accordingly, during the time of
         such construction and at all times thereafter, Tenant shall lose its
         right of parking use of the Additional Lot set forth in this Special
         Stipulation 14. Tenant agrees that Landlord shall not be deemed to be
         in breach or default of any provision of this Lease whatsoever if
         Landlord elects to construct the third building and Tenant accordingly
         loses its right to use such Additional Lot. Additionally, at any time
         during the first five (5) years of the Term of this Lease, Tenant
         shall have the right to notify Landlord in writing that Tenant
         requests forty-seven (47) additional parking spaces in addition to the
         seven hundred eighty-five (785) parking spaces described above, and if
         Tenant so notifies Landlord, Landlord shall provide such forty-seven
         (47) additional parking spaces to Tenant from and out of newly
         constructed parking by Landlord, which construction shall be at
         Landlord's cost but which construction shall not constitute an
         Operating Expense under Exhibit "E" and other applicable provisions of
         this Lease.

15.      Landlord hereby acknowledges and agrees that Tenant shall have the
         right to install and operate satellite dishes (not to exceed one meter
         in diameter) for service to the Premises at a location on the roof and
         in a first-class manner acceptable to Landlord (hereinafter referred
         to as the "dish space") during the term of this Lease and any
         extension thereof.

         Tenant hereby agrees to install any such satellite dish on the dish
         space in a good and workmanlike manner, maintain and repair such
         satellite dish and dish space in proper condition and to secure all
         permits required for the installation and operation thereof, at no
         cost to Landlord, and hereby indemnifies Landlord from and against any
         claims against Landlord for personal injury, property damage or other
         damage, including reasonable attorney's fees, arising from the
         installation, use, operation, maintenance, repair and removal of the
         dish space, the satellite dish, or any cables or related equipment
         thereof. The provisions of this paragraph shall survive the expiration
         date or sooner termination of this Lease. The insurance required to be
         carried by Tenant under the Lease shall also apply to the satellite
         dish and dish space.

         Landlord understands and agrees that the satellite dish and related
         equipment is considered the personal property of Tenant, and that
         Tenant has the right to remove the same at any time during the Term,
         or during any renewals or extensions thereafter.
<PAGE>   36

         Accordingly, Tenant shall remove the satellite dish and restore the
         dish space to substantially the same condition as existed prior to the
         installation of the satellite dish, reasonable wear and tear excepted.

         All direct expenses incurred by Tenant in connection with the
         installation, operation or removal of the satellite dish shall be paid
         promptly by Tenant, and Tenant shall not permit any mechanic's or
         other lien to be filed against Landlord in connection with the
         installation, operation or removal of the satellite dish. Tenant shall
         provide Landlord with an executed contractor's lien waiver within
         thirty (30) days of completion of the work. Tenant shall be
         responsible for any and all utilities to be used in connection with
         the operation of the satellite dish should Landlord determine an
         additional charge is necessary for its operation.

         Tenant shall properly and promptly repair any damage or potentially
         damaging condition existing or caused by the existence or operation
         and use of the satellite dish or connecting cables or any part thereof
         within ten (10) days after receipt of Landlord's written notice;
         provided, however, if such repair cannot reasonably be cured within
         the said ten-day period, and Tenant shall, in good faith, commence to
         repair and diligently proceed to effect such repair, then the ten-day
         period shall be extended for such reasonable period as Tenant shall
         require to effect such repair. Should Tenant fail to satisfy the terms
         of this provision within said ten-day period, Landlord may repair the
         damaged condition at Tenant's cost.

         Tenant represents and warrants to Landlord that the specifications,
         location and contemplated use of the satellite dish comply with all
         laws, ordinances, codes and regulations promulgated by any
         governmental authority having jurisdiction over the Premises or the
         installation and operation of the satellite dish. The construction and
         installation shall be accomplished in a good and workmanlike manner
         and with no disruption to the other occupants of the Building. Tenant
         shall provide Landlord, prior to installation of the satellite dish,
         detailed drawings and specifications on the mounting method to be used
         in affixing the proposed dish to the roof. Tenant shall require all
         contractors and subcontractors to provide Landlord with certificates
         of insurance with Landlord being named as Additional Loss Payee prior
         to installation.

16.      The scheduled rental payments from Tenant to Landlord with respect to
         the Base Monthly Rental due under Section 5 of the Lease taking into
         account the staged occupancy of the Premises as described in Special
         Stipulation 5 above are as set forth in the illustrative chart below:

         For purposes of calculating the Base Monthly Rental under Section 5 of
         the Lease, the monthly rental shall be calculated based upon an annual
         rental rate (the "Base Rental Rate") of $21.05 per rentable square
         foot of the Premises, as the rentable square footage of the Premises
         shall increase pursuant to Special Stipulation 5 above. Base Monthly
         Rental shall also increase as a result of increases in Net Rental as
         described under Section 6 of the Lease. Accordingly, the parties'
         agreement with respect to Tenant's rental
<PAGE>   37

         obligations to Landlord are set forth in Sections 5, 6 and 8 of the
         Lease and as set forth in Special Stipulations 4 and 5 above with
         respect to the staged occupancy of the Premises. The following
         illustrative chart of Tenant's rental obligations to Landlord for the
         first three (3) years of the Term of this Lease assumes that (i)
         Tenant's initial occupancy and staged occupancy of the respective
         portions of the Premises occurs on all of the target Commencement
         Dates of November 1, 2000, February 1, 2001, August 1, 2001, February
         1, 2002, and August 1, 2002 as set forth in Special Stipulation 4,
         Special Stipulation 5 and other applicable provisions of this Lease
         and that (ii) the bridges are constructed by Landlord pursuant to
         Special Stipulation 2 and that (iii) Operating Expenses for the first
         twelve (12) months of the term of the Lease are $4.87 per square foot
         of the Premises and that the annual increase in Net Rental which
         results under Section 6 of this Lease is two and one-half percent (2
         1/2%) per year for each and every year and that (iv) any payment
         obligations from Tenant to Landlord pursuant to Section 8 of the Lease
         and other applicable provisions resulting from increased Operating
         Expenses above those of the Operating Expense Base Year of calendar
         year 2001 are invoiced by Landlord to Tenant separately from and over
         and above the rental expenses set forth in the illustrative chart
         below and are therefore due in addition to those rental expenses set
         forth in the chart below, and accordingly, assuming that all of the
         foregoing assumptions in (i) through (iv) inclusive above apply,
         Tenant's Base Monthly Rental obligations for the period from November
         1, 2000 through October 31, 2003 would be as follows:

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------
MONTH                RENTABLE SQUARE    BASE RENTAL            AMOUNT OF BASE
                     FOOTAGE OF         RATE                   MONTHLY RENTAL
                     PREMISES                                  SUBJECT TO
                                                               ASSUMPTIONS SET
                                                               FORTH ABOVE
-------------------------------------------------------------------------------
<S>                  <C>                <C>                    <C>
November, 2000       115,500            $  21.05               $202,606.25
-------------------------------------------------------------------------------
December, 2000       115,500            $  21.05               $202,606.25
-------------------------------------------------------------------------------
January, 2001        115,500            $  21.05               $202,606.25
-------------------------------------------------------------------------------
February, 2001 *     169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
March, 2001          169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
April, 2001          169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
May, 2001            169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
June, 2001           169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
July, 2001           169,300            $  21.05               $296,980.42
-------------------------------------------------------------------------------
August, 2001*        192,400            $  21.05               $337,501.67
-------------------------------------------------------------------------------
September, 2001      192,400            $  21.05               $337,501.67
-------------------------------------------------------------------------------
October, 2001        192,400            $  21.05               $337,501.67
-------------------------------------------------------------------------------
November, 2001       192,400            $21.4545**             $343,987.15
-------------------------------------------------------------------------------
December, 2001       192,400            $21.4545               $343,987.15
-------------------------------------------------------------------------------
January, 2002        192,400            $21.4545               $343,987.15
-------------------------------------------------------------------------------
February, 2002*      215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
March, 2002          215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
April, 2002          215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
May, 2002            215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
June, 2002           215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
</TABLE>

<PAGE>   38

<TABLE>
<S>                  <C>                <C>                    <C>
July, 2002           215,500            $21.4545               $385,287.06
-------------------------------------------------------------------------------
August, 2002*        238,600            $21.4545               $426,586.98
-------------------------------------------------------------------------------
September, 2002      238,600            $21.4545               $426,586.98
-------------------------------------------------------------------------------
October, 2002        238,600            $21.4545               $426,586.98
-------------------------------------------------------------------------------
November, 2002       238,600            $21.8691**             $434,830.85
-------------------------------------------------------------------------------
December, 2002       238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
January, 2003        238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
February, 2003       238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
March, 2003          238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
April, 2003          238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
May, 2003            238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
June, 2003           238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
July, 2003           238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
August, 2003         238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
September, 2003      238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
October, 2003        238,600            $21.8691               $434,830.85
-------------------------------------------------------------------------------
</TABLE>

         *  Rentable square footage of Premises increases as per target
Commencement Dates of staged occupancy

         ** Base Rental Rate increases as a result of annual 2 1/2% assumed
increase in Net Rental

         For the remaining months of the Term of this Lease from November, 2003
         through April, 2012, subject to the above assumptions, Net Rental
         shall continue to increase as set forth in Section 6 of this Lease (as
         of November of each applicable year if the initial target date of
         November 1, 2000 is met) resulting in increases in the Base Rental
         Rate and the Base Monthly Rental in connection therewith calculated in
         the manner set forth under Section 6 of the Lease.

         Additionally, at any time any rental rate changes as a result of any
         provision of this Lease, then Tenant agrees to execute an amendment to
         this Lease setting forth the revised rental rates as a result of such
         changes if requested to do so by Landlord provided, however, that any
         such amendment shall not change any other substantive provision of
         this Lease.

17.      Notwithstanding the provisions of Special Stipulation 8, Special
         Stipulation 9, or any other provisions of this Lease, Tenant shall not
         be entitled to receive any payments from Landlord during any period
         that Tenant is in default under this Lease, and accordingly, any such
         payment due from Landlord to Tenant pursuant to Special Stipulation 8,
         Special Stipulation 9, or any other provisions of this Lease may be
         held by Landlord and at Landlord's election applied so as to cure any
         such default by Tenant.

18.      Landlord shall not be relieved of liability pursuant to Section 26 of
         the Lease to the extent such liability results from Landlord's
         negligence or willful act.
<PAGE>   39

19.      If Landlord fails to maintain any portion of the Building which
         Landlord is expressly required to maintain in accordance with the
         terms of this Lease or if Landlord fails to provide any services to
         the Premises which Landlord is expressly required to provide in
         accordance with the terms of this Lease, and (i) as a result of such
         failure, Tenant's use and enjoyment of the Premises is interfered with
         in a material manner, and (ii) Landlord fails to commence to cure such
         failure within three (3) days after written notice from Tenant of such
         failure (specifying in such notice the nature of the failure), and
         thereafter fails to proceed with due diligence to cure such failure
         until completion, then Tenant shall have the right to perform such
         maintenance work on the Premises subject to the terms and limitations
         of this Special Stipulation 19. If Tenant is entitled and elects to
         perform any maintenance as aforesaid, Tenant shall (i) perform such
         maintenance work in a reasonable manner; (ii) utilize only contractors
         or other such vendors with a first class reputation; (iii) cause such
         work to be completed promptly and on a lien free basis; (iv) cause
         such work to be completed in compliance with all applicable laws,
         ordinances, regulations and rules; and (v) utilize the same or similar
         materials as replaced. Tenant shall not be entitled to alter the
         Building structure under any circumstance. Landlord shall reimburse
         Tenant, within thirty (30) days after receipt of copies of the
         invoices or other written evidence, reasonably satisfactory to
         Landlord in Landlord's reasonable judgment, of the costs incurred by
         Tenant for which Tenant claims reimbursement for the reasonable costs
         and expenses incurred by Tenant in curing Landlord's breach as
         aforesaid. In addition, in the event Landlord fails to commence to
         cure such failure within the three (3) day written notice period
         provided for above, then Landlord shall pay to Tenant $5,000.00 per
         day for each of the first five (5) days and $13,000.00 per day
         thereafter until Landlord commences to cure such failure (or if Tenant
         validly elects to cure such failure itself subject to the terms and
         conditions set forth above in this Special Stipulation 19, then the
         $5,000.00 per day payment for each of the first five (5) days and
         $13,000.00 per day thereafter shall continue until Tenant commences to
         effect such cure). Tenant agrees that the remedies in favor of Tenant
         under this Special Stipulation 19 and the payments from Landlord to
         Tenant as set forth in this Special Stipulation 19 shall constitute
         Tenant's sole remedies for any breach of the Lease by Landlord
         described or contemplated under this Special Stipulation 19. Landlord
         shall pay to Tenant the payments called for by Landlord under this
         Special Stipulation 19 within thirty (30) days from the time Landlord
         is obligated to pay such payments to Tenant.

20.      As a part of the construction of the initial Tenant Improvements
         pursuant to the Work Letter, Tenant shall present a proposal to
         Landlord within thirty (30) days from the date of this Lease as to the
         location, size, specifications and other pertinent information
         regarding emergency generators that Tenant desires Landlord to install
         as a part of the initial Tenant Improvements and, subject to
         Landlord's written approval (not to be unreasonably withheld by
         Landlord) of the location, size, specifications and other pertinent
         information regarding such emergency generators, such emergency
         generators shall be installed by Landlord at Tenant's cost as a part
         of the initial Tenant Improvements to the Premises.

21.      Notwithstanding the provisions of Rule and Regulation No. 1, Rule and
         Regulation No. 18, or any other provision of this Lease to the
         contrary, Tenant shall be responsible for all
<PAGE>   40

         security for the Premises and Building, and Landlord shall not be
         responsible for providing any such security services.

22.      Landlord shall construct the Building such that seven and one-half
         (7 1/2) watts live load of power per square foot of Tenant office space
         will be available at the buss duct on each floor of the Building.

23.      At all times during the Term of this Lease, Tenant shall be entitled
         to use any and all common areas of the Building for Tenant's purposes
         consistent with the requirements of this Lease. In addition, Tenant
         shall have exclusive use of the Building and those areas of the Land
         which are crosshatched on Exhibit "H" attached hereto and made a part
         hereof by reference.

24.      Subject to the approval of applicable utilities providers, Landlord
         shall construct the Phase I Building and the Phase II Building such
         that power and fiber optic feeds are available at the north and south
         corners of the Phase I Building and the Phase II Building.

25.      In the event any of the following occur: (i) Landlord has not begun
         construction of the footings for the Phase I Building by June 5, 2000;
         (ii) Landlord has not begun construction of the structure of the Phase
         I Building by July 17, 2000; (iii) Landlord has not begun construction
         of the precast for the Phase I Building by October 2, 2000; (iv)
         Landlord has not begun construction of the tenant finish for the Phase
         I Building by December 4, 2000; or (v) the initial Commencement Date
         for the Phase I Building has not occurred by March 1, 2001
         (hereinafter any of such events are referred to as a "Material Delay")
         then as a result of such Material Delay, Tenant shall have a
         termination right subject to the terms and conditions of this Special
         Stipulation 26 provided, however, that Tenant shall have no such
         termination right if Material Delay has occurred if any of the
         following have caused such Material Delay: (i) Force Majuere, as this
         term is defined in Section 45 of this Lease; or (ii) Tenant Delay, as
         this term is defined in Section 2.01(b) of the Work Letter; or (iii)
         if Material Delay has occurred solely because Fulton County or any
         other applicable municipality, agency or jurisdiction has delayed in
         its issuance of the certificate of occupancy or any other required
         approvals for the Premises, and in the event Material Delay has
         occurred and such Material Delay is not due to either (i), (ii), or
         (iii) above, and Tenant desires to exercise such termination right,
         then prior to the exercise of such termination right, Tenant shall
         first provide Landlord thirty (30) days prior written notice and right
         to cure such breach by Landlord, and Landlord shall cure such breach
         within such thirty (30) day period, or longer if such breach by its
         nature requires longer to cure provided that Landlord promptly
         commences such cure within such thirty (30) day period and thereafter
         diligently pursues cure until completion, and in the event Landlord
         continues to breach and cause Material Delay beyond the applicable
         notice and cure period set forth in this Special Stipulation 25, then
         Tenant shall be entitled to terminate this Lease by written notice to
         Landlord in which event neither party shall have any further rights or
         obligations under this Lease, but Tenant shall have no claim for
         damages whatsoever against Landlord and Landlord shall not be liable
         to Tenant for any such damages in connection with such termination by
         Tenant.
<PAGE>   41

         Notwithstanding the preceding paragraph, in the event the initial
         Commencement Date for the Phase I Building has not occurred by July 1,
         2001, then unless such initial Commencement Date has not occurred due
         to Tenant Delay, Tenant shall have the termination right set forth in
         this Special Stipulation 25 subject to the notice and cure provisions
         and the remaining provisions set forth in this Special Stipulation 25
         (except that the termination right described in this second paragraph
         of this Special Stipulation 25 shall accrue in favor of Tenant even if
         the delay described in this second paragraph of this Special
         Stipulation 25 is attributable either to Force Majuere or to the
         failure of any governmental entity to issue any certificate of
         occupancy or other required approval).

26.      [Reserved.]

27.      Within thirty (30) days from the expiration of each calendar year
         during the term of this Lease, Tenant shall provide to Landlord
         audited annual financial statements of ISS Group, Inc., a Delaware
         corporation, prepared in accordance with generally accepted accounting
         principles and certified in writing to Landlord by the chief financial
         officer of Tenant.

28.      In the event Landlord fails to deliver the Phase I Building on or
         before December 1, 2001, and such failure is not attributable to Force
         Majuere or Tenant Delay, then (i) notwithstanding the provisions of
         Section 3 of this Lease, the Commencement Date shall become the
         earlier of the following: (a) the date upon which Tenant commences
         conducting its business from all or any portion of the Premises; or
         (b) February 1, 2001. (Tenant shall not be obligated to occupy the
         Phase I Building prior to February 1, 2001 in the event Landlord fails
         to deliver the Phase I Building to Tenant on or before December 1,
         2000 and such failure is not attributable to Force Majuere or Tenant
         Delay), and in the event this Special Stipulation 28 is invoked such
         that this (i) is applicable, then (a) the Term of the Lease shall
         remain eleven and one-half (11 1/2) years following the newly adjusted
         Commencement Date and (b) the respective terms of the required letter
         of credit and replacement letters of credit under Special Stipulation
         10 above shall be in accordance with such newly adjusted Term and (c)
         the increases in Net Rental pursuant to Section 6 of this Lease shall
         also be in accordance with such newly adjusted Term, but (d) the
         staged occupancy schedule for the Premises set forth in Special
         Stipulation 5 shall remain as set forth in Special Stipulation 5
         without change or adjustment; and (ii) again, in the event Landlord
         fails to deliver the Phase I Building to Tenant on or before December
         1, 2000 and such failure is not attributable to Force Majuere or
         Tenant Delay, then additionally Tenant shall receive a two (2) month
         abatement in Base Monthly Rental for the months of February and March,
         2001.

29.      If Tenant occupies any other portion of the Premises other than the
         Phase I Building earlier than any of the subsequent target
         Commencement Dates set forth in Special Stipulation 5, then Tenant
         during the period of such early occupancy prior to any such subsequent
         target Commencement Date shall pay only one-half (1/2) of the rental
         with respect to the applicable portion of the Premises which Tenant
         occupies early and during the period of
<PAGE>   42

         such early occupancy only, and not thereafter, and only with respect
         to the applicable portion of such Premises which Tenant has occupied
         early.

30.      The parties acknowledge that Tenant is applying for a property tax
         abatement with respect to the Premises. Any such savings which result
         from Tenant's successfully obtaining such property tax abatement shall
         inure to Tenant's benefit thereby resulting in a reduction of the
         additional rental otherwise due under Section 8 of this Lease with
         respect to ad valorem tax increases. For purposes of calculating
         Operating Expenses for either the first year of the Term or the base
         year of 2001, Operating Expenses shall be calculated based upon a
         fully assessed and occupied Building.

31.      Notwithstanding the provisions of Section 8, Section 14, Section 17,
         or any other provision of this Lease to the contrary, the parties
         agree that Landlord may render to Tenant written estimates of amounts
         reasonably anticipated to be due from Tenant to Landlord as a result
         of Landlord's maintaining and replacing light bulbs and fixtures in
         the Premises as contemplated under Section 14 of the Lease or as a
         result of Landlord's paying utility bills on Tenant's behalf to be
         reimbursed by Tenant as contemplated under Section 17 of this Lease
         with respect to any and all months during the Term of this Lease
         (notwithstanding that Landlord shall not be entitled to render
         estimates to Tenant of additional Operating Expenses to be paid by
         Tenant until after the base year of 2001). It is acknowledged and
         agreed that such estimates may be rendered at all times from and after
         the Commencement Date, with fifteen (15) days prior notice, during the
         years 2000 and 2001 as well as the remainder of the Term of this Lease
         and any renewals thereof. To the extent as a result of such estimates
         rendered from Landlord to Tenant with respect to the applicable
         expenses under either Section 14 or Section 17 of this Lease, Tenant
         either overpays or underpays such expenses, then any such overpayment
         or underpayment shall be reconciled within one hundred twenty (120)
         days after the end of any calendar year and as otherwise provided in
         the manner set forth in the fourth (4th) paragraph of Section 8 of
         this Lease. As with all other written estimates from Landlord to
         Tenant described in either the third paragraph of Section 8 of this
         Lease or in this Special Stipulation 31, Tenant shall pay as
         additional rental to Landlord promptly on the first day of each month
         in advance without deduction or set off in legal tender the monthly
         amount called for under such estimate from Landlord to Tenant for
         those months for which additional rental is due pursuant to such
         estimates and as otherwise contemplated under this Lease.

         With respect to amounts due from Tenant to Landlord as a result of
         Landlord's maintaining and replacing light bulb and fixtures in the
         Premises as contemplated under Section 14 of the Lease, Landlord shall
         render such estimates to Tenant and Tenant shall pay such amounts in
         accordance with the terms and conditions of Section 8 and this Special
         Stipulation 31. With respect to amounts due from Tenant to Landlord as
         a result of Landlord's paying utility bills on Tenant's behalf to be
         reimbursed by Tenant as contemplated under Section 17 of this Lease,
         Landlord shall be entitled to either (i) render invoices to Tenant
         which shall be paid by Tenant within fifteen (15) days of Tenant's
         receipt of such invoice, as provided in Section 17 of this Lease; or
         (ii) render estimates and annual reconciliations to Tenant as provided
         in Section 8 and this Special Stipulation 31 of this
<PAGE>   43

         Lease. With respect to any particular utility bill due to be
         reimbursed by Tenant to Landlord, Landlord shall be entitled to chose
         from the foregoing (i) or (ii) as applicable.

32.      The parties shall negotiate in good faith in an attempt to reach
         within ninety (90) days from the date of this Lease a conceptual plan
         for Landlord's development of and Tenant's leasing from Landlord of a
         Phase III building to be located upon the Land. Neither party shall be
         obligated to enter into any such lease. Rather, the parties' only
         obligations shall be to negotiate in good faith, and in no event shall
         this Lease be deemed dependant upon the parties' entering into any
         such subsequent lease. Further, in no event shall Tenant be required
         to occupy such Phase III building sooner than twelve (12) months
         following the last actual Commencement Date with respect to Tenant's
         staged occupancy of the Premises as described under Special
         Stipulation 5.

<PAGE>   44
                               MOUNT VERNON PLACE

                       INTERNET SECURITY SYSTEMS , INC.,
                             A GEORGIA CORPORATION

                                  EXHIBIT "A"


         The Premises shall consist of the entirety of the Phase I Building and
the Phase II Building as these terms are defined in this Lease to be
constructed pursuant to the project manuals and drawings more particularly
described and enumerated in Exhibit "A-1" attached hereto and made a part
hereof by reference. It is acknowledged that no floor plan of the Premises is
attached to this Lease because Tenant is instead leasing the entirety of such
Phase I and Phase II Building according to the terms and conditions of this
Lease.


                                  EXHIBIT "A"
<PAGE>   45

                               MOUNT VERNON PLACE

                        INTERNET SECURITY SYSTEMS, INC.,
                             A GEORGIA CORPORATION

                        EXHIBIT "B" - LEGAL DESCRIPTION









                                [TO BE ATTACHED]


                                  EXHIBIT "B"
<PAGE>   46

                               MOUNT VERNON PLACE

                       INTERNET SECURITY SYSTEMS, INC.,
                             A GEORGIA CORPORATION

                   EXHIBIT "C" - TENANT ACCEPTANCE AGREEMENT

         THIS AGREEMENT is an amendment to the Lease Agreement (the "Lease")
for space in the office buildings known as MOUNT VERNON PLACE, located at 6303
Barfield Road, Atlanta, Fulton County, Georgia 30328, dated as of the ______
day of ____________, 1999, by and between MOUNT VERNON PLACE PARTNERS, LLC, as
Landlord, and Internet Security Systems _____, a _____________________________,
as Tenant.

         Pursuant to the provisions of Paragraph 3 of the Lease, Landlord and
Tenant hereby mutually agree that:

         1.       Except for those items shown on the attached "Punch List,"
which Landlord will remedy within ____________ days hereof, Landlord has fully
completed the construction work required under the terms of the Lease.

         2.       Tenant is in possession of, and has accepted the Premises.
The Premises are tenantable, the Landlord has no further obligation for
construction (except as specified above), and Tenant acknowledges that both the
Building and the Premises are satisfactory in all respects except for any
latent defects for which Landlord shall be and remain responsible. All
conditions of the Lease required of Landlord as of this date have been
fulfilled (except as specified above), and there are no defenses or setoffs
against the enforcement of the Lease by Landlord.

         3.       The Commencement Date of the Lease is hereby agreed to be the
______ day of ___________________, 2000.

         4.       The Expiration Date of the Lease is hereby agreed to be
the ______ day of ____________________, 2012.

         5.       The Premises are hereby agreed to contain _________________
rentable square feet.

         6.       The Building is hereby agreed to contain __________________
rentable square feet.

         7.       Tenant's Percentage Share is hereby agreed to be ____________
percent.

         All other terms and conditions of the Lease are hereby ratified and
acknowledged to be unchanged.


                                  EXHIBIT "C"
<PAGE>   47

         Agreed and Executed this ___________ day of __________________, 1999.


                              TENANT:

Signed, sealed and delivered  INTERNET SECURITY SYSTEMS, INC.,
this ________ day of          a Georgia corporation
____________________, 1999
in the presence of:


                              By:  (Exhibit Purposes Only - Not for Signature)
----------------------------     ----------------------------------------------
Notary Public/Witness


                              Name:
----------------------------       --------------------------------------------
Name (Please Print)                               (Please Print)
                              Title:
                                    -------------------------------------------

                              Attest:
                                     ------------------------------------------

                              Name:
                                   --------------------------------------------

                              Title:
                                    -------------------------------------------

                              LANDLORD:
                                       ----------------------------------------


Signed, sealed and delivered  MOUNT VERNON PLACE PARTNERS, LLC
this ________ day of          A GEORGIA LIMITED LIABILITY COMPANY
____________________, 1999
in the presence of:



                              By: (Exhibit Purposes Only - Not for Signature)
----------------------------     ----------------------------------------------
Witness                           Joel J. Griffin, Managing Member



----------------------------
Name (Please Print)
<PAGE>   48

                               MOUNT VERNON PLACE

                                  WORK LETTER

         WHEREAS, the undersigned Landlord and Tenant have executed, sealed and
delivered the Lease, to which this Agreement is attached, and into which this
Agreement is fully incorporated by this reference, as Exhibit "D";

         WHEREAS, said Lease provides for the leasing of office space (the
"Premises") within MOUNT VERNON PLACE located at 6303 Barfield Road, Atlanta,
Fulton County, Georgia 30328 (the "Building");

         WHEREAS, the terms "Landlord" and "Tenant," "Premises" and "Building,"
as used herein, shall have the same meanings ascribed thereto as set forth in
the Lease; and

         WHEREAS, Landlord and Tenant desire to set forth herein their
respective agreements regarding design and construction of the improvements to
the Premises.

         NOW THEREFORE, in consideration of the Premises, the execution and
delivery of the Lease by the parties hereto, the mutual covenants contained
herein, and other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, Landlord and Tenant, intending to be legally
bound, hereby agree as follows:

SECTION 1. TENANT IMPROVEMENTS.

Section 1.01.   Definition.

                The term "Tenant Improvements" shall mean all improvements
constructed or installed in or on the Premises in accordance with the Drawings
and Specifications, as hereinafter defined.

Section 1.02.   Base Building Condition.

                Landlord agrees that the following shall be furnished,
installed and, if appropriate, made operational as part of the Base Building at
Landlord's sole expense:

                a)  Finish interior of exterior walls, with drywall portions of
                    such interior walls taped and floated and ready for surface
                    treatment. All window glass and frames installed and ready
                    for final finishing. All exterior windows equipped with
                    Building-standard blinds;

                b)  Building standard ceiling system and tile throughout
                    elevator lobbies and other appropriate common Building
                    facilities as shown on the Base Building plans;

                c)  Broom-clean unfinished concrete floors;


                                  EXHIBIT "D"
<PAGE>   49

                d)  Building standard light fixtures throughout elevator
                    lobbies and other appropriate common Building facilities as
                    shown on the Base Building plan;

                e)  Landlord and Tenant agree that Base Building shall include
                    the men's and women's restrooms on the Premises, as shown
                    in Exhibit "A," including all bathroom and light fixtures,
                    mirrors, doors, and partitions constructed to Building
                    standard in compliance with applicable codes;

                f)  Building standard drinking fountains;

                g)  Main heating, ventilating and air conditioning (HVAC) plant
                    and equipment as shown on the Base Building plans;

                h)  Concrete columns unfinished;

                i)  Building standard ceiling grid installed in the Premises;

                j)  Sprinkler risers, main loop and sprinkler heads on the
                    floor with capacity and number of heads as required by
                    applicable laws, based on an open floor plan. Sprinkler
                    heads in areas with unfinished ceilings will be turned up
                    toward the structure;

                k)  Building stairways and exits with surrounding walls taped,
                    floated and finished and painted;

                l)  Building core with surrounding walls taped, floated and
                    ready for final finishing;

                m)  Life safety systems as required by all applicable laws as
                    shown on the Base Building Plans;

                n)  Elevator, elevator shaft doors, frames and door facings
                    prime painted and ready for final finishing;

                o)  Building standard 2 x 4 parabolic light fixtures will be
                    provided for installation by Landlord's Contractor at a
                    ratio of one (1) fixture per eighty (80) square feet; and

                p)  HVAC will be provided in all restrooms and elevator
                    lobbies. Perimeter slot diffusers and P.I.U.'s will be
                    installed on all tenant floors.

Section 1.03. Architect.

         The term "Architect" herein referred to shall be Warner, Summers,
Ditzel, Benefield, Ward & Associates, Inc., the architect for the Base Building
and the architect selected by Tenant for the design, drawings, specifications
and finish schedule for the Premises.
<PAGE>   50

SECTION 2. DRAWINGS AND SPECIFICATIONS.

Section 2.01.   Definition.

                The term "Drawings and Specifications" shall mean the final
drawings, specifications, and finish schedules for the Tenant Improvements
which shall be prepared by Tenant and approved by Landlord in accordance with
the following procedure:

                a)  As provided in Section 3.02 (b) hereof, the cost of
                    preparing the drawings, specifications, finish schedules
                    and the like shall be paid by Tenant and be a part of
                    Tenant Costs.

                b)  As soon as reasonably possible but in all events not later
                    than December 1, 1999, Tenant shall submit to Landlord for
                    Landlord's review and comments Tenant's preliminary space
                    plan for the Premises. Within thirty (30) days of
                    Landlord's receipt of Tenant's preliminary space plan for
                    the Premises, Landlord shall provide comments regarding
                    such preliminary space plan, and promptly following
                    Tenant's receipt of Landlord's comments, Tenant shall cause
                    such preliminary space plan to be revised in accordance
                    with Landlord's comments so as to cause such preliminary
                    space plan to be acceptable to Landlord. In all events,
                    Tenant shall provide a final space plan for the Premises
                    acceptable to Landlord (which shall then become the
                    "Drawings and Specifications" as defined above) not later
                    than February 1, 2000. Landlord shall within one (1) month
                    of Landlord's receipt of Tenant's final space plan for the
                    Premises acceptable to Landlord, provide an initial
                    construction estimate to Tenant. At its option, Tenant may
                    review the initial construction estimate (which shall
                    include a breakdown of the bids of the trades together with
                    all other costs to be included within Tenant's Construction
                    Costs with each such bid and cost to be set forth on a
                    "line item basis") for all or any part of the work and if
                    dissatisfied with the costs of all or any trade portion(s)
                    or other cost items of such proposal, Tenant may require
                    Landlord to solicit bids or obtain proposals from others or
                    otherwise object to such costs items as hereinafter
                    provided. If Tenant disapproves any portion of Landlord's
                    initial construction estimate, Tenant may with regard to
                    any trade bid (a) require Landlord to obtain no less than
                    three (3) subcontractor bids and Tenant shall then have the
                    right to select the chosen bid; (b) require the work to be
                    performed on a time and materials basis by such trades.
                    Tenant shall promptly provide any comments regarding
                    Landlord's initial construction estimate. Further, Tenant
                    shall promptly exercise all of its rights regarding
                    Tenant's review and approval of Landlord's construction
                    estimate, and Tenant shall in all events be responsible for
                    causing such initial construction estimate to be finally
                    approved by Tenant not later than May 1, 2000 ("Final Price
                    Approval"). Within one (1) month of Landlord's receipt of
                    Final Price Approval from Tenant, Landlord will apply for a
                    building permit for construction for the Tenant
                    Improvements for the Premises and Landlord will begin
                    construction of
<PAGE>   51

                    such Tenant Improvements no later than August 1, 2000. (THE
                    PRECEDING SCHEDULE SET FORTH IN THIS SECTION 2.01(B) IS
                    ONLY APPLICABLE TO THE PHASE I BUILDING AND LANDLORD'S
                    CONSTRUCTION OF THE TENANT IMPROVEMENTS FOR THE PHASE I
                    BUILDING. WITH RESPECT TO TENANT'S SUBSEQUENT STAGED
                    OCCUPANCY OF THE PREMISES AS SET FORTH IN SPECIAL
                    STIPULATION 5, THE PARTIES SHALL, BY A SERIES OF AMENDMENTS
                    TO THIS LEASE, AGREE UPON AND EXECUTE SUBSEQUENT
                    CONSTRUCTION SCHEDULES COMPARABLE IN FORMAT AND TIMING IN
                    RELATION TO SUCH SUBSEQUENT STAGES OF OCCUPANCY AS SET
                    FORTH ABOVE IN THIS SECTION 2.01(B). THE REMAINING
                    PROVISIONS OF THIS WORK LETTER SHALL ALSO APPLY TO EACH OF
                    SUCH OTHER CONSTRUCTION SCHEDULES ASSOCIATED WITH EACH
                    SUBSEQUENT STAGED OCCUPANCY OF THE PREMISES.)

                    As used herein throughout this Work Letter and throughout
                    the body of the Lease, the term "Tenant Delay" shall mean
                    any actual delay in causing the Premises to be ready for
                    occupancy which is due to any act or omission of Tenant,
                    its agents, contractors, or employees including, without
                    limitation, Tenant's failure to adhere to the schedule and
                    time frames and deadlines set forth above in this
                    subparagraph (b). Tenant Delay shall include, without
                    limitation: (i) delays due to changes by Tenant in or
                    additions to the Drawings and Specifications or to the work
                    and/or other plans and specifications in connection
                    therewith, (ii) delays resulting from Tenant's failure to
                    timely perform its obligations under the approved schedule
                    set forth above, including any failure to submit or
                    finalize any drawings, plans or specifications by the
                    applicable dates and/or within the applicable time periods
                    indicated in such approved schedule and including any
                    failure to timely perform any of Tenant's work required in
                    order for Landlord to obtain a certificate of occupancy for
                    the Premises, and (iii) delays because of Tenant's
                    specifications for materials or equipment (including,
                    without limitation, computer room materials) not permitting
                    timely completion under normal circumstances. For items
                    identified by Landlord to cause a delay in construction,
                    Tenant shall have the right to either (i) accept such items
                    as Tenant Delay items or (ii) substitute materials that
                    would eliminate such delay. Notwithstanding the foregoing,
                    if any materials which Landlord did not designate as Tenant
                    Delay items, because of Landlord's reasonable reliance on
                    third party representations that such materials were
                    available, should become unavailable during the course of
                    construction for reasons beyond Landlord's reasonable
                    control, such that completion of the Tenant Improvements
                    for the Premises would be delayed, then Tenant shall
                    cooperate in good faith with Landlord to use substitute
                    materials which would avoid any such delay.

                c)  Landlord shall be responsible for causing the Architect to
                    certify to Landlord and Tenant that the proposed final
                    working drawings, specifications and the like will comply
                    with all state and local zoning laws, building laws, public
                    safety, or any other ordinances applicable hereunder.
                    Landlord's approval of the Drawings and Specifications
                    shall not relieve Tenant from its obligation hereunder.

                d)  For the purpose of this Agreement, Landlord shall retain
                    and supervise, as its agent, the general contractor.
                    Landlord agrees that the general contractor retained by
<PAGE>   52

                    Landlord as Landlord's Contractor shall perform the Tenant
                    Improvements. The aggregate cost for the Tenant
                    Improvements, shall hereinafter be referred to as "Tenant
                    Improvement Costs". Upon determination of the Tenant
                    Improvement Costs, Tenant shall be deemed to have given
                    final approval to the Drawings and Specifications and
                    Landlord shall be deemed to have been authorized to
                    proceed, through Landlord's Contractor, with the work of
                    constructing and installing the Tenant Improvements in
                    accordance with the Drawings and Specifications.

SECTION 3. PAYMENT OF COSTS.

Section 3.01.   Landlord's Allowance for Tenant Costs.

                Landlord shall pay the Tenant Costs up to, but not in excess
of, an amount equal to $24.00 per rentable square foot of the Premises (the
"Landlord's Allowance for Tenant Costs" and also sometimes referred to as the
"Tenant Improvement Allowance") as and when same are due. The Landlord's
Allowance for Tenant Costs" may be used by Tenant to cover the costs of (i) its
space planning, architectural and engineering firms, together with (ii)
Tenant's signage costs, and together with (iii) the acquisition and
installation of Tenant's furniture, fixtures and equipment, but not to exceed
$2.50 per rentable square foot of the Premises for such acquisition and
installation of Tenant's furniture, fixtures and equipment.

Section 3.02.   Tenant Costs.

                The aggregate of all costs described in the following
subparagraphs (a) through (d) of this Section 3.02 are hereinafter referred to
collectively as "Tenant Costs."

                a)  The Tenant Improvement Costs;

                b)  The cost of preparing and finalizing all drawings,
                    specifications, finish schedules and the like as set forth
                    in Sections 2.01(a) through (d) above;

                c)  Fees for architects, engineers required for Tenant's space,
                    interior designers, and other professionals and design
                    specialists reasonably incurred by Landlord or Tenant in
                    connection with the Tenant Improvements; and

                d)  The cost of making any and all changes in and to the
                    Drawings and Specifications and any increased or decreased
                    costs in the Tenant Improvement Costs resulting therefrom;

                In the event the aggregate of Tenant Costs, as defined above,
exceeds Landlord's Allowance for Tenant Costs, as specified in Section 3.01
above, then Tenant shall promptly pay the excess to Landlord upon demand;
provided, however, that Tenant may amortize up to $2.50 per rentable square
foot of the Premises of such excess amount as outlined in Special Stipulation 7
of this Lease.
<PAGE>   53

Section 3.03.   Changes in Drawings and Specifications.

                Landlord, at its option, may require Tenant to pay in lump sum
to Landlord any and all increases in the Tenant Improvement Costs which result
from approved changes to the Drawings and Specifications. Any delays in
completing the Tenant Improvements which result from either changes in the
Drawings and Specifications made by Tenant or from the unavailability of
materials specified by Tenant, shall not operate to delay or extend the
Commencement Date under the Lease nor the payment of the Base Monthly Rental or
other charges due under this Lease.

Section 3.04.   Failure to Pay Tenant Costs.

                Failure by Tenant to pay Tenant Costs, in accordance with this
Section 3, will constitute a failure by Tenant to pay rent when due under the
Lease and for such failure to pay Tenant Costs, Landlord shall have all of the
remedies available to it under this Lease and at law or in equity for
nonpayment of rent.

SECTION 4. INSPECTION.

         Landlord and Tenant each reserve the right to perform periodic
inspections prior to the Commencement Date of the Tenant Improvements and
Tenant shall notify Landlord at least twenty-four (24) hours in advance of such
inspection procedures by Tenant. Tenant and the Architect shall be permitted to
visit and walk through the Premises at any time during normal business hours.

         Any defective Tenant Improvement work discovered during either
Landlord's or Tenant's inspection or work failing to conform to the Drawings
and Specifications, together with any latent defects in the initial
improvements shall be promptly corrected by Landlord's Contractor at Landlord's
sole cost.


SECTION 5. FINISH WORK IN ADDITION TO TENANT IMPROVEMENTS.

         All work in or about the Premises which is not within the scope of the
work necessary to construct and install the Tenant Improvements, such as
delivering and installing furniture, telephone equipment, and wiring, and
office equipment, shall be furnished and installed by Tenant entirely at
Tenant's expense. Tenant shall be entitled to begin installing its wiring sixty
(60) days prior to completion of the Tenant Improvements. Tenant shall adopt a
schedule for performing such additional work consistent with the schedule of
Landlord's Contractor and shall see that such work is conducted in such a
manner as to maintain harmonious labor relations and as not to interfere
unreasonably with or to delay the work of constructing or installing the Tenant
Improvements. Landlord shall give access and entry to the Premises to Tenant
and its contract parties performing such additional work and reasonable
opportunity and time to enable Tenant and such contract parties to perform and
complete such work provided such additional work does not interfere with or
otherwise encumber Landlord's work or construction progress. All of such
additional work and Tenant's use (and the use by its contract parties) of the
Premises for such purposes shall be entirely in accordance with the Lease,
including without limitation this Work Letter.
<PAGE>   54

SECTION 6. TIME IS OF THE ESSENCE.

         Time is of the essence of this Agreement. Unless specifically provided
otherwise, all reference to days or months shall be construed as references to
calendar days or months, respectively. In the event of Tenant Delay, then the
date for completion by Landlord of Tenant Improvements shall be extended for
the period of such delay, but the Commencement Date of Tenant's payment
obligations hereunder, including, without limitation, Base Monthly Rental,
shall not be extended and shall commence as scheduled under this Lease without
regard to non-completion of Tenant Improvements.

SECTION 7. APPROVAL OF PLANS.

         Any approval by Landlord of or consent by Landlord to any plans,
specifications or other items to be submitted to and/or reviewed by Landlord
pursuant to this Lease shall be deemed to be strictly limited to an
acknowledgment of approval or consent by Landlord thereto and, whether or not
the work is performed by Landlord or by Tenant's contractor, such approval or
consent shall not constitute the assumption by Landlord of any responsibility
for the accuracy, sufficiency or feasibility of any plans, specifications or
other such items and shall not imply any acknowledgment, representation or
warranty by Landlord that the design is safe, feasible, structurally sound or
will comply with any legal or governmental requirements, and Tenant shall be
responsible for all of the same.
<PAGE>   55

                               MOUNT VERNON PLACE

                        OPERATING EXPENSES - DEFINITIONS

"Operating Expenses" for or attributable to the Premises shall mean the
operating costs and expenses for the Property and the Building, including all
expenses, costs and disbursements of every kind and nature, which Landlord
shall (i) pay and/or; (ii) become obligated to pay, including, but not limited
to, the following:

      -     Wages and salaries of all employees engaged in the operation and
            maintenance of the Property and Building, including, but not
            limited to, taxes, insurance and benefits relating thereto;

      -     All supplies and materials used in the operation and maintenance of
            the Property and Building;

      -     Cost of all service agreements and maintenance for the Property and
            Building and the equipment therein, including, but not limited to,
            trash removal, alarm services, window cleaning, janitorial service,
            HVAC maintenance, elevator maintenance and grounds maintenance;

      -     Cost of all insurance relating to the Property and Building,
            including, but not limited to, the cost of casualty and liability
            insurance applicable to the Property and Building and Landlord's
            personal property used in connection therewith;

      -     All taxes (ad valorem and otherwise), assessments and governmental
            charges, whether federal, state, county or municipal, and whether
            by taxing districts or authorities presently taxing the Property
            and Building, or by others, subsequently created or otherwise, and
            any other taxes (other than federal and state income taxes) and
            assessments attributable to the Property and Building or its
            operation and any reasonable consultants' fees incurred with
            respect to issues or concerns involving the taxes of the Building,
            the Property, or both;

      -     Cost of repairs and general maintenance of the interior and
            exterior of the Property and Building (including, but not limited
            to, glass breakage), parking areas and landscaping;

      -     A management fee for general operation and management of the
            Property and Building, such management fee to be no greater than
            three percent (3%) of Base Monthly Rental net of electricity for
            the Term of this Lease; and

      -     An amortization cost due to any capital expenditures incurred (i)
            which reduce or limit Operating Costs of the Property and Building,
            if such reduction or limitation


                                  EXHIBIT "E"
<PAGE>   56

OPERATING EXPENSE EXCLUSIONS - CONTINUED

            inures to Tenant's benefit (but only to the extent and in the
            amount that such Operating Costs of the Property and Building are
            reduced); (ii) which may be required by governmental authority or
            by Landlord's insurance carrier; or (iii) which are designed to
            protect or enhance the health, safety or welfare of the tenants in
            the Building or their invitees.
<PAGE>   57

OPERATING EXPENSE EXCLUSIONS - CONTINUED


                               MOUNT VERNON PLACE

                          OPERATING EXPENSE EXCLUSIONS

1.    Franchise, income, transfer, inheritance, capital stock taxes or taxes
      imposed upon or measured by the income of the Landlord;

2.    Depreciation of the Building, amortization and other non-cash charges;

3.    The cost of any alteration, additions, changes or decorations which are
      made in order to prepare space (including Premises) for Tenant's
      occupancy;

4.    The cost of performing work or furnishing services to or for any Tenant,
      other than Tenant, at Landlord's expense, to the extent that such work or
      service exceeds or is more favorable than comparable work or service
      provided to Tenant at Landlord's expense;

5.    The cost (including, without limitation, attorney's fees and
      disbursements) of any judgement, settlement or arbitration award
      resulting from any tort liability;

6.    The general overhead of Landlord and labor costs and all other
      compensation of all administrative personnel, officers, executives and
      staff members of Landlord or Landlord's agents above the grade of
      building manager or engineer.

7.    The cost of installing, operating and maintaining any specialty service
      such as an observatory, broadcasting facility, luncheon club, athletic or
      recreational club;

8.    The costs of defects in the construction, design or equipping of the
      Building with respect to the mechanical systems of the Building or with
      respect to any of the structural components of the Building;

9.    Any cost or expense incurred in connection with correcting latent defects
      or inadequacies in the Building;

10.   The cost of any special heating, ventilating, air-conditioning,
      janitorial or other special or extra services provided to tenants during
      other than regular business hours;

11.   Legal or auditing fees, other than those reasonably incurred in
      connection with the maintenance and operation of the Land and Building or
      in connection with the preparation of statements required pursuant to
      Additional Rent or lease escalation provisions;

12.   Any rent, additional rent or any other charge under any lease or sublease
      to or assumed directly or indirectly by Landlord;
<PAGE>   58

OPERATING EXPENSE EXCLUSIONS - CONTINUED


13.   Expenditure on account of Landlord acquisition of air rights;

14.   Any Operating Expenses related exclusively to any retail or storage space
      in, on or about the Property or appurtenant or adjacent thereto;

15.   Any accrued and unfunded pension or other benefits of any personnel;

16.   Any amount paid to any affiliate of Landlord to the extent such amount is
      in excess of the amount which would be paid in the absence of such
      relationship;

17.   Advertising, marketing or promotional expenditures;

18.   Any costs incurred in the removal, containment, encapsulation, or
      disposal of or repair or cleaning or monitoring of areas affected by any
      hazardous material including without limitation, asbestos;

19.   Costs incurred to correct any misrepresentation by Landlord expressly
      made herein;

20.   The value or loss of income to Landlord of any space in the Building
      which is utilized for the management of the Building;

21.   Any compensation paid to clerks, attendants or other persons in
      commercial concessions operated by Landlord or any affiliate of Landlord;

22.   Late fees, penalties, interest charges or similar costs incurred by
      Landlord;

23.   Costs associated with the operation of the business of the legal entity
      that constitute Landlord as the same is separate and apart from the costs
      of the operation of the Building, including the legal entity formation,
      internal accounting and legal matters;

24.   Unrecovered expenses resulting directly from the negligence of the
      Landlord, its agents, servants or employees;

25.   Costs incurred due to the violation by Landlord or any tenant of the
      Building of the terms of any lease or any laws, rules, regulations or
      ordinances applicable to the Building; and

26.   Brokerage commissions paid by Landlord in its leasing of the Building.
<PAGE>   59

                               MOUNT VERNON PLACE


                       PROJECTED 2000 OPERATING EXPENSES
                               (Per Square Foot)


<TABLE>
<S>                                          <C>
Building Maintenance                         .71

Janitorial Maintenance                       .85

Grounds Maintenance                          .33

Administrative                               .52

Property Tax                                1.50

Insurance                                    .13

Management Fee                               .63

Reserves                                     .20
------------------------------------------------

TOTAL PROJECTED 2000 OPERATING EXPENSES    $4.87
                                           =====
</TABLE>


                    EXHIBIT "E"
<PAGE>   60

                               MOUNT VERNON PLACE

                             RULES AND REGULATIONS

Tenant shall observe the following Rules and Regulations (as amended, modified
or supplemented from time to time by Landlord as provided in this Lease):

1.    The following provisions of this Rule and Regulation No. 1 shall be
      applicable only in the event Landlord determines to invoke such rule and
      regulation in the event of multiple tenants of the Building which could
      result in the event Landlord approves partial assignments and/or
      subletting by Tenant. So long as Tenant is the single tenant of the
      Building, the parties acknowledge that Landlord will not provide security
      services and that Tenant will be responsible for the same, and that as
      such, the provisions of the following Rule and Regulation No. 1 shall be
      inapplicable: "Normal business hours" shall mean the days Monday through
      Friday, inclusive, except legal holidays, during the hours from 8:00 a.m.
      to 6:00 p.m., and Saturdays, except legal holidays, from 8:00 a.m. to
      1:00 p.m. At all other times every person, including Tenant, Tenant's
      employees, agents clients, customers, invitees and guests entering and
      leaving the Building may be questioned by a security guard as to that
      person's business therein, and may be required to sign such person's name
      on a form for registering such person. Landlord reserves the right to
      exclude from the Building between the hours of 6:00 p.m. and 8:00 a.m.
      and at all hours on Saturdays, Sundays, and holidays all persons who are
      not occupants or their accompanied guests. Tenant shall be responsible
      for all persons for whom it allows to enter the Building and shall be
      liable to Landlord for all acts of such persons. Landlord reserves the
      right to exclude or expel from the Building any persons who, in the
      opinion of Landlord, are or appear to be intoxicated or under the
      influence of liquor or drugs or who is in violation of any of the rules
      and regulations of the Building. Landlord shall in no case be liable for
      damages for error with regard to the admission to or exclusion from the
      Building of any person. During the continuance of any invasion, mob,
      riot, public excitement or other circumstances rendering such action
      advisable in the opinion of Landlord, Landlord reserves the right to
      prevent access to the Building by closing the doors, or otherwise, for
      the safety of the occupants and protection of the Building and property
      in the Building.

2.    Subject to Section 42 of the Lease which shall be controlling, no sign,
      advertisement, notice or other lettering shall be exhibited, inscribed,
      painted or affixed by Tenant on any part of the Building.

3.    The sidewalks, entry passages, corridors, halls, elevators and stairways
      shall not be obstructed by Tenant, or used for any purpose other than for
      ingress and egress. Tenant will insure that movers take necessary
      measures required by Landlord to protect Building (e.g., windows,
      carpets, walls, doors and elevator cabs) from damage. The halls,
      passages, exits, entrances, elevators and stairways are for the use of
      Tenant and Tenant shall in all cases retain the right to control and
      prevent access thereto by all persons whose presence, in the judgment of
      Tenant, shall be prejudicial to the safety, character, reputation and
      interests of the Building and its occupants. The toilet rooms, toilets,
      urinals, wash bowls and other apparatus shall not be used


                                  EXHIBIT "F"
<PAGE>   61

MOUNT VERNON PLACE - RULES AND REGULATIONS (CONTINUED)


      for any purpose other than that for which they were constructed and no
      foreign substance of any kind whatsoever, including, but not limited to,
      coffee grounds shall be thrown therein, and the expense of any breakage,
      stoppage or damage resulting from the violation of this rule shall be
      borne by the Tenant, if Tenant's employees, agents, clients, customers,
      invitees and guests, shall have caused it.

4.    No curtains, draperies, blinds, shutters, shades, screens or other
      coverings, awnings, hangings or decorations shall be attached to, hung or
      placed in, or used in connection with, any window or door of the Premises
      without the prior written consent of Landlord. In any event with the
      prior written consent of Landlord, all such items shall be installed
      inboard of the Building standard window blinds and shall in no way be
      visible from the exterior of the Building. Tenant shall not remove the
      Building standard window blinds installed in the Premises. No articles
      shall be placed or kept on the window sills so as to be visible from the
      exterior of the Building.

5.    Tenant, Tenant's employees, agents, clients, customers, invitees and
      guests shall maintain order in the Building, shall not make or permit any
      improper noise in the Building or interfere in any way with other
      occupants or those having business with them. Nothing shall be thrown by
      Tenant, Tenant's employees, agents, clients, customers, invitees and
      guests out of the windows or doors, or down the passages or atrium of the
      Building. No rooms shall be occupied or used as sleeping or lodging
      apartments at any time. No part of the Building shall be used or in any
      way appropriated for gambling, immoral or other unlawful practices, and
      no intoxicating liquor or liquors shall be sold in the Premises or
      Building without the written consent of Landlord.

6.    Tenant shall not, without the written consent of Landlord, put up or
      operate any machinery or stove upon the Premises, or carry on any
      mechanical business thereon, or use or allow to be used upon the
      Premises, oil, burning fluids, camphene, gasoline or kerosene for
      heating, warming or lighting. No cooking shall be done or permitted by
      Tenant on the Premises except in conformity with law and then only in the
      utility kitchen, if any, as set forth in Tenant's layout, which is to be
      primarily used by Tenant's employees for heating beverages and light
      snacks. No article deemed extra hazardous on account of fire and no
      explosives shall be brought into the Premises. No offensive gases or
      liquids will be permitted.

7.    No sunscreen or other films shall be applied to the interior or exterior
      surface of any window glass. All glass, locks and trimmings in or upon
      the doors and windows of the Building shall be kept whole and, when any
      part shall be broken, the same shall be immediately replaced or repaired
      and put in order under the direction and to the satisfaction of Landlord,
      and shall be left whole and in good repair. Tenant shall not injure,
      overload or deface the Building.

8.    Upon commencement of this Lease, Landlord shall provide, at no expense to
      Tenant, two entrance door keys. The cost of providing additional keys to
      Tenant shall be borne by Tenant. At the termination of this Lease, Tenant
      shall return to Landlord all keys to doors in the
<PAGE>   62

MOUNT VERNON PLACE - RULES AND REGULATIONS (CONTINUED)


      Building and all plastic cards for parking and entry to Building
      furnished to Tenant by Landlord and those keys otherwise procured by
      Tenant.

9.    Tenant assumes any and all responsibility for protecting Premises from
      theft, robbery and pilferage, which includes keeping doors locked and
      other means of entry to the Premises closed.

10.   Tenant shall not place a load upon any floor of the Premises which
      exceeds the load per square foot which such floor was designed to carry
      (i.e. fifty (50) pounds per square foot of live load) and which is
      allowed by law. Tenant, Tenant's employees, agents, clients, customers,
      invitees and guests, shall not bring in or take out, position, construct,
      install or move any safe, business machine or other heavy office
      equipment without first obtaining the consent of the Landlord. In giving
      such consent, Landlord shall have the right, in its sole discretion, to
      prescribe the weight permitted and the position thereof, and the use and
      design of planks, skids or platforms to distribute the weight thereof.
      All damage done to the Building by moving or using any such heavy
      equipment or other office equipment or furniture shall be repaired at the
      expense of Tenant. Safes and other heavy office equipment will be moved
      through the halls and corridors only upon steel bearing plates.

11.   There shall not be used in any space, or in the public areas of the
      Building, either by Tenant or others, any hand trucks except those
      equipped with rubber tires and side guards or such other
      material-handling equipment as Landlord may approve.

12.   Tenant shall not cause any unnecessary labor by reason of such Tenant's
      carelessness or indifference in the preservation of good order and
      cleanliness of the Premises. Landlord shall in no way be responsible to
      Tenant for any loss of property on the Premises however occurring, or for
      any damage done to the effects of Tenant by the janitor or any other
      employee or any other person. Tenant shall at the end of each business
      day leave the Premises in a reasonably tidy condition for the purpose of
      the performance of cleaning.

13.   Landlord and its respective agents, employees and contractors shall have
      the right to enter the Premises upon one day (1) prior notice to Tenant
      (except in the event of emergency in which event no notice shall be
      required) at all reasonable hours for the purpose of making any repairs,
      alterations, or additions which it shall deem necessary for the safety,
      preservation, or improvement of the Building; and Landlord, its
      respective agents, employees and contractors shall be allowed to take all
      material into and upon said Premises that may be required to make such
      repairs, improvements, and additions, or any alterations for the benefit
      of the Tenant without in any way being deemed or held guilty of an
      eviction of the Tenant; and the rent reserved shall be in no way abate
      while said repairs, alterations, or additions are being made; and the
      Tenant shall not be entitled to maintain a setoff or counterclaim for
      damages against Landlord and its respective agents, employees and
      contractors by reason of loss or interruption to the business of the
      Tenant because of the prosecution of any such work. All such repairs,
<PAGE>   63

MOUNT VERNON PLACE - RULES AND REGULATIONS (CONTINUED)


      decorations, additions, and improvements shall be done during normal
      business hours, or, if any such work is at the request of the Tenant to
      be done during any other hours, the Tenant shall pay for all overtime
      costs.

14.   Tenant shall observe and obey all parking and traffic regulations as
      imposed by Landlord. The parking facilities shall be used by vehicles
      that may occupy a standard parking area only.

15.   Canvassing, soliciting, distributing of handbills or any other written
      material, and peddling in the Building are prohibited and Tenant shall
      cooperate to prevent the same. Tenant shall not make room-to-room
      solicitation of business from other occupants in the Building.

16.   Tenant will observe strict care and caution that all water faucets or
      water apparatus are entirely shut off before the Tenant, Tenant's
      employees, agents, clients, customers, invitees and guests leave the
      Premises, and that all utilities shall likewise be carefully shut off so
      as to prevent waste or damage, and for any default or carelessness, the
      Tenant shall make good all injuries sustained by other occupants of the
      Building. Tenant will comply with all energy conservation, safety, fire
      protection and evacuation procedures and regulations established by
      Landlord or any governmental agency.

17.   Tenant shall store all trash and garbage within the interior of the
      Premises. No materials shall be placed in the trash boxes or receptacles
      if such materials is of such nature that it may not be disposed of in the
      ordinary and customary manner of removing and disposing of trash and
      garbage in this area without violation of any law or ordinance governing
      such disposal. All trash, garbage and refuse disposal shall be made only
      through entryways and elevators provided for such purposes and at such
      times as Landlord may designate.

18.   Tenant shall give prompt notice to Landlord of any accidents to or
      defects in plumbing, electrical fixtures, or heating apparatus so that
      such accidents or defects may be attended to properly.

19.   Tenant shall be responsible for the observance of all of the foregoing
      Rules and Regulations by Tenant's employees, agents, clients, customers,
      invitees and guests. These Rules and Regulations are in addition to and
      as a supplement of, and shall not be construed to in any way otherwise
      modify, alter or amend, in whole or in part, the terms, covenants,
      agreements and conditions of the Lease Agreement.