<PAGE>

________________________________________________________________________________


                            LEASE AGREEMENT BETWEEN


                    W9/CGN REAL ESTATE LIMITED PARTNERSHIP,


                               AS LANDLORD, AND


                             TENFOLD CORPORATION,


                                   AS TENANT


                            DATED FEBRUARY 4, 2000



                           600 LAS COLINAS BOULEVARD
                                 IRVING, TEXAS


________________________________________________________________________________
<PAGE>

                            BASIC LEASE INFORMATION
                            -----------------------

Lease Date:         February 4, 2000

Landlord:           W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a Delaware limited
                    partnership

Tenant:             TENFOLD CORPORATION, a Delaware corporation

Premises:           Suite No. 600, containing 23,386 rentable square feet, in
                    the office building commonly known as 600 Las Colinas
                    Boulevard (the "Building"), and whose street address is 600
                                    --------
                    East Las Colinas Boulevard, Irving, Texas 75039. The
                    Premises are outlined on the plan attached to the Lease as
                    Exhibit A-1. The land on which the Building is located (the
                    -----------
                    "Land") is described on Exhibit B. The term "Building"
                     ----                   ---------
                    includes the related land, driveways, parking facilities,
                    and similar improvements.

Term:               Approximately 60 months, commencing on the Commencement Date
                    and ending at 5:00 p.m. local time on the last day of the
                    60th full calendar month following the Commencement Date,
                    subject to adjustment and earlier termination as provided in
                    the Lease.

Commencement Date:  The earliest of (a) the date on which Tenant occupies any
                    portion of the Premises and begins conducting business
                    therein, (b) the date on which the Work (as defined in
                    Exhibit D hereto) in the Premises is Substantially Completed
                    ---------
                    (as defined in Exhibit D hereto), (c) the date on which the
                                   ---------
                    Work in the Premises would have been Substantially Completed
                    but for the occurrence of any Tenant Delay Days (as defined
                    in Exhibit D hereto), or (d) April 1, 2000.
                       ---------

Basic Rent:         Basic Rent shall be the following amounts for the following
                    periods of time:


                    ------------------------------------------------------------
                                     Monthly Basic Rent
                                     per Rentable Square
                       Lease Month          Foot           Monthly Basic Rent
                    ------------------------------------------------------------
                          1 - 24           $22.50               $43,848.75
                    ------------------------------------------------------------
                         25 - 36           $24.00               $46,772.00
                    ------------------------------------------------------------
                         37 - 60           $25.50               $49,695.25
                    ------------------------------------------------------------

                    As used herein, the term "Lease Month" shall mean each
                                              -----------
                    calendar month during the Term (and if the Commencement Date
                    does not occur on the first day of a calendar month, the
                    period from the Commencement Date to the first day of the
                    next calendar month shall be included in the first Lease
                    Month for purposes of determining the duration of the Term
                    and the monthly Basic Rent rate applicable for such partial
                    month).

                                       i
<PAGE>

Security Deposit:   [Intentionally deleted.]

Rent:               Basic Rent, Tenant's Proportionate Share of Taxes and
                    Electrical Costs, Tenant's share of Additional Rent, and all
                    other sums that Tenant may owe to Landlord or otherwise be
                    required to pay under the Lease.

Permitted Use:      General office use, including software development, training
                    and demonstrations.

Tenant's Proportionate Share:
                    4.589%, which is the percentage obtained by dividing (a) the
                    number of rentable square feet in the Premises as stated
                    above by (b) the 509,559 rentable square feet in the
                    Building. Landlord and Tenant stipulate that the number of
                    rentable square feet in the Premises and in the Building set
                    forth above shall be binding upon them.

Expense Stop:       Operating Costs per rentable square foot in the Building for
                    the calendar year 2000 (grossed up as provided in Section
                    4.(b)(6) of the Lease).

Base Tax Year:      The calendar year 2000.

Initial Liability Insurance Amount:
                    $3,000,000.


Tenant's        Tenfold Corporation             With a copy to:
Address:        180 West Election Road          --------------
                Suite 100                       Tenfold Corporation
                Draper, Utah 84020              100 Foster City Boulevard
                Attention: General Counsel      Suite 200
                Telephone: 801-495-1010         Foster City, California 94404
                Telecopy: 801-495-0353          Attention: Lease Administrator
                                                Telephone: 650-570-5711
                                                Telecopy: 650-570-5988


Landlord's      For all Notices:                With a copy to:
Address:        ---------------                 --------------
                W9/CGN Real Estate Limited      W9/CGN Real Estate Limited
                Partnership                     Partnership
                c/o Grubb & Ellis               c/o Archon Group, L.P.
                600 E. Las Colinas Boulevard,   600 East Las Colinas Blvd.,
                Suite 100                       Suite 400
                Irving, Texas 75039             Irving, Texas 75039
                Attention: Property Manager     Attention: General Counsel -
                Telephone: 972-869-0044         600 Las Colinas Blvd.
                Telecopy: 972-869-2043          Telephone: 972-368-2200
                                                Telecopy: 972-368-3199

                                      ii
<PAGE>

The foregoing Basic Lease Information is incorporated into and made a part of
the Lease identified above.  If any conflict exists between any Basic Lease
Information and the Lease, then the Lease shall control.


LANDLORD:                W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a Delaware
                         limited partnership
                         By: W9/CGN Gen-Par, Inc., a Delaware corporation, its
                             general partner


                             By: /s/ William G. Mundinger II
                                ----------------------------
                             Name: William G. Mundinger II
                                  --------------------------
                             Title: Assistant Vice President
                                   -------------------------


TENANT:                  TENFOLD CORPORATION, a Delaware corporation


                         By: /s/ Robert P. Hughes
                            --------------------------------
                         Name: Robert P. Hughes
                              ------------------------------
                         Title: Chief Financial Officer
                               -----------------------------

                                      iii
<PAGE>

                                     LEASE
                                     -----

     THIS LEASE AGREEMENT (this "Lease") is entered into as of February 4, 2000,
                                 -----
between W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a Delaware limited partnership
("Landlord"), and TENFOLD CORPORATION, a Delaware corporation ("Tenant").
  --------                                                      ------

     1.   Definitions and Basic Provisions.  The definitions and basic
          --------------------------------
provisions set forth in the Basic Lease Information (the "Basic Lease
                                                          -----------
Information") executed by Landlord and Tenant contemporaneously herewith are
-----------
incorporated herein by reference for all purposes.  Additionally, the following
terms shall have the following meanings when used in this Lease: "Affiliate"
                                                                  ---------
means any person or entity which, directly or indirectly, through one or more
intermediaries, controls, is controlled by, or is under common control with the
party in question; "Building's Structure" means the Building's exterior walls,
                    --------------------
roof, elevator shafts, footings, foundations, structural portions of load-
bearing walls, structural floors and subfloors, and structural columns and
beams; "Building's Systems" means the Building's HVAC, elevators, life-safety,
        ------------------
plumbing, electrical, and mechanical systems; "including" means including,
                                               ---------
without limitation; "Laws" means all federal, state, and local laws, rules and
                     ----
regulations, all court orders, governmental directives, and governmental orders,
and all restrictive covenants affecting the Building, and "Law" shall mean any
                                                           ---
of the foregoing; and "Tenant Party" means any of the following persons:
                       ------------
Tenant; any assignees claiming by, through, or under Tenant; any subtenants
claiming by, through, or under Tenant; and any of their respective agents,
contractors, employees, and invitees.

     2.   Lease Grant.  Subject to the terms of this Lease, Landlord leases to
          -----------
Tenant, and Tenant leases from Landlord, the Premises.

     3.   Tender of Possession. Landlord and Tenant presently anticipate that
          --------------------
possession of the Premises will be tendered to Tenant (with the Work to be
performed by Landlord therein, if any, Substantially Completed) on or about
March 15, 2000 (the "Estimated Delivery Date").  If Landlord is unable to tender
                     -----------------------
possession of the Premises in such condition to Tenant by the Estimated Delivery
Date, then (a) Landlord shall not be in default hereunder or be liable for
damages therefor, and (b) Tenant shall accept possession of the Premises when
Landlord tenders possession thereof to Tenant.  Notwithstanding the foregoing,
if the Work in the Premises is not Substantially Completed by the Completion
Termination Date, Tenant may terminate this Lease by delivering to Landlord
written notice thereof at any time before the earlier of (1) ten days following
the Completion Termination Date or (2) the date on which the Work in the
Premises is Substantially Completed.  The termination right afforded to Tenant
under this Section 3 shall be Tenant's sole remedy for Landlord's failure to
timely Substantially Complete the Work.  Time is of the essence for the delivery
of Tenant's termination notice under this Section 3; accordingly, if Tenant
fails timely to deliver any such notice, Tenant's right to terminate this Lease
under this Section 3 shall expire. As used herein, "Completion Termination Date"
                                                    ---------------------------
means 180 days after the Estimated Delivery Date, plus the number of Tenant
Delay Days and the number of Force Majeure Delay Days.  As used herein, "Force
                                                                         -----
Majeure Delay Days" means any delay in achieving Substantial Completion with
------------------
respect to the Work for the reasons specified in Section 25.(c) of this Lease.
By occupying the Premises, Tenant shall be deemed to have accepted the Premises
in their condition as of the date of such occupancy, subject to the performance
of punch-list items that remain to be performed by Landlord, if any.  Prior to
occupying the Premises, Tenant shall execute and deliver to Landlord a letter
substantially in the form of Exhibit E hereto confirming (A) the Commencement
                             ---------
Date and the expiration date of the initial Term, (B) that Tenant has accepted
the Premises, and (C) that Landlord has performed all of its obligations with
respect to the Premises (except for punch-list

                                       1
<PAGE>

items specified in such letter). Occupancy of the Premises by Tenant prior to
the Commencement Date shall be subject to all of the provisions of this Lease
excepting only those requiring the payment of Basic Rent, Additional Rent, Taxes
and Electrical Costs (each as defined herein).

     4.   Rent.
          ----

          (a)  Payment.  Tenant shall timely pay to Landlord Rent, without
               -------
notice, demand, deduction or set off (except as otherwise expressly provided
herein), at Landlord's address provided for in this Lease or as otherwise
specified by Landlord and shall be accompanied by all applicable state and local
sales or use taxes.  Basic Rent, adjusted as herein provided, shall be payable
monthly in advance.  The first monthly installment of Basic Rent shall be
payable contemporaneously with the execution of this Lease; thereafter, Basic
Rent shall be payable on the first day of each month beginning on the first day
of the second full calendar month of the Term.  The monthly Basic Rent for any
partial month at the beginning of the Term shall equal the product of 1/365 of
the annual Basic Rent in effect during the partial month and the number of days
in the partial month from and after the Commencement Date, and shall be due on
the Commencement Date.

          (b)  Operating Costs; Taxes; Electrical Costs.
               ----------------------------------------

               (1)  Tenant shall pay to Landlord the amount (per each rentable
     square foot in the Premises) ("Additional Rent") by which the annual
                                    ---------------
     Operating Costs (defined below) per rentable square foot in the Building
     exceed the Expense Stop (per rentable square foot in the Building).
     Landlord may make a good faith estimate of the Additional Rent to be due by
     Tenant for any calendar year or part thereof during the Term. During each
     calendar year or partial calendar year of the Term (after the base year, if
     the Expense Stop is calculated on a base year basis), Tenant shall pay to
     Landlord, in advance concurrently with each monthly installment of Basic
     Rent, an amount equal to the estimated Additional Rent for such calendar
     year or part thereof divided by the number of months therein. From time to
     time, Landlord may estimate and re-estimate the Additional Rent to be due
     by Tenant and deliver a copy of the estimate or re-estimate to Tenant.
     Thereafter, the monthly installments of Additional Rent payable by Tenant
     shall be appropriately adjusted in accordance with the estimations so that,
     by the end of the calendar year in question, Tenant shall have paid all of
     the Additional Rent as estimated by Landlord. Any amounts paid based on
     such an estimate shall be subject to adjustment as herein provided when
     actual Operating Costs are available for each calendar year.

          (2)  The term "Operating Costs" shall mean all expenses and
                         ---------------
     disbursements (subject to the limitations set forth below) that Landlord
     incurs in connection with the ownership, operation, and maintenance of the
     Building, determined in accordance with sound accounting principles
     consistently applied, including the following costs: (A) wages and salaries
     (including management fees consistent with other similar class A buildings
     in the Las Colinas Urban Center) of all on-site employees at or below the
     grade of senior building manager engaged in the operation, maintenance or
     security of the Building (together with Landlord's reasonable allocation of
     expenses of off-site employees at or below the grade of senior building
     manager who perform a portion of their services in connection with the
     operation, maintenance or security of the Building), including taxes,
     insurance and benefits relating thereto; (B) all supplies and materials
     used in the operation, maintenance, repair, replacement, and security of
     the Building; (C) costs for improvements made to the Building which,
     although capital in nature, are reasonably expected to reduce the normal

                                       2
<PAGE>

     operating costs (including all utility costs) of the Building, as amortized
     using a commercially reasonable interest rate over the time period
     reasonably estimated by Landlord to recover the costs thereof taking into
     consideration the anticipated cost savings, as determined by Landlord using
     its good faith, commercially reasonable judgment, as well as capital
     improvements made in order to comply with any Law hereafter promulgated by
     any governmental authority or any interpretation hereafter rendered with
     respect to any existing Law, as amortized using a commercially reasonable
     interest rate over the useful economic life of such improvements as
     determined by Landlord in its reasonable discretion; (D) cost of all
     utilities, except Electrical Costs and the cost of other utilities
     reimbursable to Landlord by the Building's tenants other than pursuant to a
     provision similar to this Section 4.(b); (E) insurance expenses; (F)
     repairs, replacements, and general maintenance of the Building except those
     repair and replacement costs that are reimbursed by warranties or insurance
     proceeds; and (G) service or maintenance contracts with independent
     contractors for the operation, maintenance, repair, replacement, or
     security of the Building (including alarm service, window cleaning, and
     elevator maintenance).

          Operating Costs shall not include costs for (i) capital improvements
     made to the Building, other than capital improvements described in Section
     4.(b)(2)(C) and except for items which are generally considered maintenance
     and repair items, such as painting of common areas, replacement of carpet
     in elevator lobbies, and the like; (ii) repair, replacements and general
     maintenance paid by proceeds of insurance or by Tenant or other third
     parties; (iii) interest, amortization or other payments on loans to
     Landlord; (iv) depreciation; (v) leasing commissions; (vi) legal expenses
     for services, other than those that benefit the Building tenants generally
     (e.g., tax disputes); (vii) renovating or otherwise improving space for
     occupants of the Building or vacant space in the Building; (viii) Taxes;
     (ix) federal income taxes imposed on or measured by the income of Landlord
     from the operation of the Building; (x) original construction costs of the
     Building; (xi) reserves for repairs, maintenance and replacements (as
     opposed to escrows for such things as taxes and insurance expenses, both of
     which may be included in Operating Costs); (xii) costs or expenses
     associated with leasing space in the Building or the sale of any interest
     in the Building, including advertising and marketing, commissions or any
     amounts paid for on behalf of a tenant such as space planning, moving
     costs, rental and other tenant concessions; (xiii) ground rents; (xiv)
     costs of electricity outside normal business hours sold to tenants of the
     Building by Landlord or any other special service to tenants or service in
     excess of that furnished to Tenant or which are over and above the rent and
     escalations payable under the lease agreement with that tenant (including
     after-hour HVAC costs); (xv) expenses for repairs, replacements or
     improvements arising from the initial construction of the Building to the
     extent such expenses are either a) reimbursed to Landlord by virtue of
     warranties from contractors or suppliers or b) result by reason of
     deficiencies in design or workmanship except conditions resulting from
     ordinary wear and tear; (xvi) the excess over competitive costs by
     independent suppliers and contractors, of the cost of supplies and services
     provided by subsidiaries and affiliates of Landlord; (xvii) Landlord's
     general overhead except to the extent it is expended in direct connection
     with management and operation of the Building; (xviii) accounting or legal
     fees incurred in tenant disputes, or in procuring tenants, or for fees not
     related to the operation and maintenance of the Building but personal to
     Landlord; (xix) all costs shall be "net" only and shall be reduced by the
     amount of insurance (or the amount of reimbursement if Landlord would have
     maintained insurance per Landlord's requirements in the Lease),
     condemnation awards or other reimbursement, recoupment, payment, discount,
     warrantee, guarantee or allowance received by Landlord; (xx) costs of
     renovating or otherwise improving space for new tenants or in renovating
     space vacated by any tenant or any other work which Landlord performs for

                                       3
<PAGE>

     any tenant; (xxi) costs relating to maintaining Landlord's existence,
     either as a corporation, partnership, or other entity, such as trustee's
     fees, annual fees, partnership organization or administration expenses,
     deed recordation expenses, legal and accounting fees (other than with
     respect to Building operations); (xxii) interest or penalties arising by
     reason of Landlord's failure to timely pay any Operating Costs or Taxes,
     provided such late payment was caused (in whole or in part) by a Tenant
     Party; (xxiii) costs incurred to contain, encapsulate, remove or remedy any
     hazardous or toxic wastes, materials or substances from either the Building
     or Land or any tests or surveys obtained in connection with the above,
     unless such incurred costs are caused, in whole or in part, by a Tenant
     Party; (xxiv) rental and other expenses incurred in leasing air condition
     systems, elevators or other equipment considered to be of a capital nature
     under generally accepted accounting principles, except equipment used in
     emergency situations or in providing janitorial services when such
     equipment is not affixed to the Building; (xxv) costs incurred because the
     Building or common areas violate any valid, applicable building code,
     regulation or law in effect and as interpreted by government authorities
     before the date on which this Lease is signed (including fines, penalties,
     interest and the costs of repairs, replacements, alterations or
     improvements necessary to make the Building or common areas comply with
     applicable past laws in effect and as interpreted by government authorities
     before the date on which this Lease is signed, such as sprinkler
     installation or requirements under the Americans With Disabilities Act of
     1990; (xxvi) costs for acquisitions of sculpture, paintings or other
     objects of art; (xxvii) title insurance, automobile insurance, key man and
     other life insurance, long-term disability insurance and health, accident
     and sickness insurance, excepting only group plans providing reasonable
     benefits to persons of the grade of building manager and below employed in
     the operation and management of the Building (provided that the cost of
     insurance with respect to any such employee dividing his or her time
     between the Building and any other buildings shall be apportioned pro rata
     among all such buildings); (xxviii) the cost of removal of halon or CFCs
     from the Building, unless the cost incurred is cause, in whole or in part,
     by a Tenant Party; and (xxix) costs of any items for which Landlord
     receives reimbursement from insurance proceeds (insurance proceeds shall be
     excluded from Operating Costs in the year in which they are received,
     except that any deductible amount under any insurance policy shall be
     included within Operating Costs). If the Expense Stop is calculated on a
     base year basis, Operating Costs for the base year only shall not include
     market-wide labor-rate increases due to extraordinary circumstances,
     including boycotts and strikes; utility rate increases due to extraordinary
     circumstances, including conservation surcharges, boycotts, embargos or
     other shortages; or amortized costs relating to capital improvements.

               (3)  Tenant shall also pay its Proportionate Share of any
     increase in Taxes for each year and partial year falling within the Term
     over the Taxes for the Base Tax Year. Tenant shall pay its Proportionate
     Share of Taxes in the same manner as provided above for Additional Rent
     with regard to Operating Costs. "Taxes" shall mean taxes, assessments, and
                                      -----
     governmental charges or fees whether federal, state, county or municipal,
     and whether they be by taxing districts or authorities presently taxing or
     by others, subsequently created or otherwise, and any other taxes and
     assessments (including non-governmental assessments for common charges
     under a restrictive covenant or other private agreement that are not
     treated as part of Operating Costs) now or hereafter attributable to the
     Building (or its operation), excluding, however, penalties and interest
     thereon and federal and state taxes on income (if the present method of
     taxation changes so that in lieu of the whole or any part of any Taxes,
     there is levied on Landlord a capital tax directly on the rents received
     therefrom or a franchise tax, assessment, or charge based, in whole or in
     part, upon such rents for the Building, then all such taxes, assessments,
     or charges, or the part thereof so based, shall

                                       4
<PAGE>

     be deemed to be included within the term "Taxes" for purposes hereof).
     Taxes shall include the actual and reasonable costs of consultants retained
     in an effort to lower taxes and all costs incurred in disputing any taxes
     or in seeking to lower the tax valuation of the Building. For property tax
     purposes, Tenant waives all rights to protest or appeal the appraised value
     of the Premises, as well as the Building, and all rights to receive notices
     of reappraisement as set forth in Sections 41.413 and 42.015 of the Texas
     Tax Code.

               (4)  Tenant shall also pay to Landlord Tenant's Proportionate
     Share of the cost of all electricity used by the Building ("Electrical
                                                                 ----------
     Costs"). Such amount shall be payable in monthly installments on the
     -----
     Commencement Date and on the first day of each calendar month thereafter.
     Each installment shall be based on Landlord's estimate of the amount due
     for each month. From time to time during any calendar year, Landlord may
     estimate or re-estimate the Electrical Costs to be due by Tenant for that
     calendar year and deliver a copy of the estimate or re-estimate to Tenant.
     Thereafter, the monthly installments of Electrical Costs payable by Tenant
     shall be appropriately adjusted in accordance with the estimations.
     Electrical Costs shall be billed at actual cost from the local utility
     without any markup or service charges. Landlord's reasonable estimate of
     calendar year 2000 Electrical Costs is $1.07 per rentable square foot in
     the Building; however, Landlord and Tenant agree that such figure shall not
     be interpreted as the maximum amount which may be charged to Tenant for
     Electrical Costs per rentable square foot during calendar year 2000.

               (5)  By April 1 of each calendar year, or as soon thereafter as
     practicable, Landlord shall furnish to Tenant a statement of Operating
     Costs and Electrical Costs for the previous year, in each case adjusted as
     provided in Section 4.(b)(6), and of the Taxes for the previous year (the
     "Operating Costs and Tax Statement").  If Tenant's estimated payments of
      ---------------------------------
     Operating Costs, Electrical Costs or Taxes under this Section 4.(b) for the
     year covered by the Operating Costs and Tax Statement exceed Tenant's share
     of such items as indicated in the Operating Costs and Tax Statement, then
     Landlord shall promptly credit or reimburse Tenant for such excess;
     likewise, if Tenant's estimated payments of Operating Costs, Electrical
     Costs or Taxes under this Section 4.(b) for such year are less than
     Tenant's share of such items as indicated in the Operating Costs and Tax
     Statement, then Tenant shall promptly pay Landlord such deficiency.

               (6)  With respect to any calendar year or partial calendar year
     in which the Building is not occupied to the extent of 100% of the rentable
     area thereof, the Operating Costs and Electrical Costs for such period
     shall, for the purposes hereof, be increased to the amount which would have
     been incurred had the Building been occupied to the extent of 100% of the
     rentable area thereof.

               (7)  Provided no Event of Default then exists, after receiving an
     annual Operating Costs and Tax Statement and giving Landlord 30-days' prior
     written notice thereof, Tenant may inspect or audit Landlord's records
     relating to Operating Costs for the period of time covered by such
     Operating Costs and Tax Statement in accordance with the following
     provisions. If Tenant fails to object to the calculation of Operating Costs
     on an annual Operating Costs and Tax Statement within 30 days after the
     statement has been delivered to Tenant, or if Tenant fails to conclude its
     audit or inspection within 90 days after the statement has been delivered
     to Tenant, then Tenant shall have waived its right to object to the
     calculation of Operating Costs for the year in question and the calculation
     of Operating Costs set forth on such statement shall be final. Tenant's
     audit or inspection shall be conducted where Landlord maintains its books
     and records, shall not unreasonably interfere

                                       5
<PAGE>

     with the conduct of Landlord's business, and shall be conducted only during
     business hours reasonably designated by Landlord. Tenant shall pay the cost
     of such audit or inspection, including $150 per hour of Landlord's or the
     building manager's employee time devoted to such inspection or audit in
     excess of the first four hours (Landlord shall provide the first four such
     hours to Tenant free of charge) to reimburse Landlord for its overhead
     costs allocable to the inspection or audit, unless the total Operating
     Costs for the period in question is determined to be in error by more than
     5% in the aggregate, and, as a result thereof, Tenant paid to Landlord
     $0.50 per square foot in the Premises more than the actual Operating Costs
     due for such period, in which case Landlord shall pay the audit cost (not
     to exceed the amount Tenant was overcharged for the period in question).
     Tenant may not conduct an inspection or have an audit performed more than
     once during any calendar year. Tenant or the accounting firm conducting
     such audit shall, at no charge to Landlord, submit its audit report in
     draft form to Landlord for Landlord's review and comment before the final
     approved audit report is submitted to Landlord, and any reasonable comments
     by Landlord shall be incorporated into the final audit report. If such
     inspection or audit reveals that an error was made in the Operating Costs
     previously charged to Tenant, then Landlord shall refund to Tenant any
     overpayment of any such costs, or Tenant shall pay to Landlord any
     underpayment of any such costs, as the case may be, within 30 days after
     notification thereof. Provided Landlord's accounting for Operating Costs is
     consistent with the terms of this Lease, Landlord's good faith judgment
     regarding the proper interpretation of this Lease and the proper accounting
     for Operating Costs shall be binding on Tenant in connection with any such
     audit or inspection. Tenant shall maintain the results of each such audit
     or inspection confidential and shall not be permitted to use any third
     party to perform such audit or inspection, other than a certified public
     accountant (A) reasonably acceptable to Landlord, (B) which is not
     compensated on a contingency fee basis or in any other manner which is
     dependent upon the results of such audit or inspection (and Tenant shall
     deliver the fee agreement or other similar evidence of such fee arrangement
     to Landlord upon request), and (C) which agrees with Landlord in writing to
     maintain the results of such audit or inspection confidential.
     Notwithstanding the foregoing, Tenant shall have no right to conduct an
     audit if Landlord furnishes to Tenant an audit report for the period of
     time in question prepared by an independent certified public accounting
     firm of recognized national standing (whether originally prepared for
     Landlord or another party). Nothing in this Section 4.(b)(7) shall be
     construed to limit, suspend or abate Tenant's obligation to pay Rent when
     due, including Additional Rent.

     5.   Delinquent Payment; Handling Charges.  All past due payments required
          ------------------------------------
of Tenant hereunder shall bear interest from the date due until paid at the
lesser of eighteen percent per annum or the maximum lawful rate of interest;
additionally, Landlord may charge Tenant a fee equal to five percent of the
delinquent payment to reimburse Landlord for its cost and inconvenience incurred
as a consequence of Tenant's delinquency.  In no event, however, shall the
charges permitted under this Section 5 or elsewhere in this Lease, to the extent
they are considered to be interest under applicable Law, exceed the maximum
lawful rate of interest.  Notwithstanding the foregoing, the late fee referenced
above shall not be charged with respect to the first two occurrences (but not
any subsequent occurrence) during any 12-month period that Tenant fails to make
payment when due, until five days after Landlord delivers written notice of such
delinquency to Tenant.

     6.   Security Deposit.  Landlord agrees to waive Tenant's payment of a
          ----------------
security deposit (the "Security Deposit") in connection with the execution of
                       ----------------
this Lease.  Notwithstanding the foregoing, if, during the three-month period
immediately preceding the leasing by Tenant during the initial Term of any
additional space in the Building (including under Tenant's Right of Opportunity
hereunder), Tenant's

                                       6
<PAGE>

Tangible Net Worth (defined below) decreases to a level below Tenant's Tangible
Net Worth for the third quarter of 1999 (which amount is stipulated by Landlord
and Tenant to be $57,671,000), Tenant shall deliver to Landlord a standby,
unconditional, irrevocable letter of credit (the "Letter of Credit") in the face
                                                  ----------------
amount of the construction allowance plus all commissions paid by Landlord for
leasing the space in question. The Letter of Credit shall be issued by any of
the five largest national banking associations with banking offices in Dallas,
Texas, shall permit partial draws thereon, and shall otherwise be in the form of
Exhibit J attached hereto or another form reasonably acceptable to Landlord.
---------
Tenant shall from time to time cause its letter of credit to be renewed no later
than 30 days prior to any expiration date thereof so that its letter of credit
remains in effect for 30 days after the scheduled expiration date of the Term or
any renewal Term; if Tenant fails timely to renew its letter of credit, then
Landlord shall have the right to draw thereon, and retain the amounts so drawn
as the Security Deposit. Landlord may draw upon the letter of credit and apply
the proceeds thereof to perform any of Tenant's unperformed obligations under
this Lease. After any such draw, Tenant shall pay to Landlord on demand the
amount so drawn to be held as part of the Security Deposit. Tenant hereby
irrevocably appoints Landlord its true and lawful attorney-in-fact, such power
of attorney being coupled with an interest, with full power of substitution, to
do any one or more of the following in its sole discretion upon the occurrence
of an Event of Default under the Lease: (1) demand, collect, receive, sue for,
compound and give acquittance for any and all amounts which may be or become due
or payable with respect to the letter of credit and all funds evidenced thereby,
(2) execute any and all withdrawal receipts or others orders for the payment of
money drawn from the letter of credit, (3) endorse the name of Tenant on all
commercial paper given in payment or in partial payment of the letter of credit,
(4) file any claim or institute any proceeding with respect to the letter of
credit, (5) transfer the letter of credit into the name of Landlord or its
nominee, and (6) take any other action which Landlord may deem necessary or
appropriate to protect and preserve the right, title, and interest of Landlord
under the Lease. To further secure Tenant's obligations under the Lease, Tenant
hereby pledges to Landlord, and grants to Landlord a security interest in, the
letter of credit, and all renewals and replacements thereof, and proceeds
therefrom. The Security Deposit is not an advance payment of Rent or a measure
or limit of Landlord's damages upon an Event of Default (as defined herein).
Landlord may, from time to time following an Event of Default and without
prejudice to any other remedy, use all or a part of the Security Deposit to
perform any obligation Tenant fails to perform hereunder. Following any such
application of the Security Deposit, Tenant shall pay to Landlord on demand the
amount so applied in order to restore the Security Deposit to its original
amount. Provided that Tenant has performed all of its obligations hereunder,
Landlord shall, within 30 days after the Term ends, return to Tenant the portion
of the Security Deposit which was not applied to satisfy Tenant's obligations.
The Security Deposit may be commingled with other funds, and no interest shall
be paid thereon. If Landlord transfers its interest in the Premises and the
transferee assumes Landlord's obligations under this Lease, then Landlord may
assign the Security Deposit to the transferee and Landlord thereafter shall have
no further liability for the return of the Security Deposit.

     7.   Landlord's Obligations.
          ----------------------

          (a)  Services.  Landlord shall furnish to Tenant (1) water at those
               --------
points of supply provided for general use of tenants of the Building; (2) heated
and refrigerated air conditioning ("HVAC") as appropriate, at such temperatures
                                    ----
and in such amounts as are consistent with other similar class A buildings in
the Las Colinas Urban Center; (3) janitorial service to the Premises on
weekdays, other than holidays, for Building-standard installations in accordance
with the janitorial specifications in Exhibit K hereto (Landlord reserves the
                                      ---------
right to modify and/or replace such specifications from time to time so long as
such modifications and/or replacement specifications are consistent with the
janitorial services provided in other similar class A buildings in the Las
Colinas Urban Center) and such window washing as may from

                                       7
<PAGE>

time to time be reasonably required; (4) elevators for ingress and egress to the
floor on which the Premises are located, in common with other tenants, provided
that Landlord may reasonably limit the number of operating elevators during non-
business hours and holidays; and (5) electrical current during normal business
hours for equipment that does not require more than 110 volts and whose
electrical energy consumption does not exceed normal office usage. Landlord
shall maintain the common areas of the Building in reasonably good order and
condition, except for damage caused by a Tenant Party. If Tenant desires any of
the services specified in Section 7.(a)(2): (A) at any time other than between
8:00 a.m. and 6:00 p.m. on weekdays and between 8:00 a.m. and 1:00 p.m. on
Saturday (in each case other than holidays), or (B) on Sunday or holidays, then
such services shall be supplied to Tenant upon the written request of Tenant
delivered to Landlord before 3:00 p.m. on the business day preceding such extra
usage, and Tenant shall pay to Landlord the cost of such services within 30 days
after Landlord has delivered to Tenant an invoice therefor. The costs incurred
by Landlord in providing after-hour HVAC service to Tenant shall include costs
for electricity, water, sewage, water treatment, labor, metering, filtering, and
maintenance reasonably allocated by Landlord to providing such service.
Landlord's reasonable estimate of calendar year 2000 after-normal-business-hours
charges for HVAC is $25 per hour per one-half floor of the Building (with a two-
hour minimum); however, Landlord and Tenant agree that such figure shall not be
interpreted as the maximum amount which may be charged to Tenant for such
services.

          (b)  Excess Utility Use.  Landlord shall not be required to furnish
               ------------------
electrical current  for equipment that requires more than 110 volts or other
equipment whose electrical energy consumption exceeds normal office usage.  If
Tenant's requirements for or consumption of electricity exceed the electricity
to be provided by Landlord as described in Section 7.(a), Landlord shall, at
Tenant's expense, make reasonable efforts to supply such service through the
then-existing feeders and risers serving the Building and the Premises, and
Tenant shall pay to Landlord the cost of such service within 30 days after
Landlord has delivered to Tenant an invoice therefor.  Landlord may determine
the amount of such additional consumption and potential consumption by any
verifiable method, including installation of a separate meter in the Premises
installed, maintained, and read by Landlord, at Tenant's expense.  Tenant shall
not install any electrical equipment requiring special wiring or requiring
voltage in excess of 110 volts or otherwise exceeding Building capacity unless
approved in advance by Landlord.  The use of electricity in the Premises shall
not exceed the capacity of existing feeders and risers to or wiring in the
Premises.  Any risers or wiring required to meet Tenant's excess electrical
requirements shall, upon Tenant's written request, be installed by Landlord, at
Tenant's cost, if, in Landlord's judgment, the same are necessary and shall not
cause permanent damage to the Building or the Premises, cause or create a
dangerous or hazardous condition, entail excessive or unreasonable alterations,
repairs, or expenses, or interfere with or disturb other tenants of the
Building. If Tenant uses machines or equipment in the Premises which affect the
temperature otherwise maintained by the air conditioning system or otherwise
overload any utility, Landlord may install supplemental air conditioning units
or other supplemental equipment in the Premises, and the cost thereof, including
the cost of installation, operation, use, and maintenance, shall be paid by
Tenant to Landlord within 30 days after Landlord has delivered to Tenant an
invoice therefor.

          (c)  Restoration of Services; Abatement.  Landlord shall use
               ----------------------------------
commercially reasonable efforts to restore any service required of it that
becomes unavailable; however, such unavailability shall not render Landlord
liable for any damages caused thereby, be a constructive eviction of Tenant,
constitute a breach of any implied warranty, or, except as provided in the next
sentence, entitle Tenant to any abatement of Tenant's obligations hereunder.
If, however, Tenant is prevented from using the Premises for more than 15
consecutive business days because of the unavailability of any such service (or
seven consecutive business days because of the unavailability and the
restoration of such services is within the reasonable control of

                                       8
<PAGE>


Landlord) and such unavailability was not caused by a Tenant Party, then Tenant
shall, as its exclusive remedy be entitled to a reasonable abatement of Rent for
each consecutive day (after such 15-day period [or after such seven-day period,
as applicable]) that Tenant is so prevented from using the Premises.



     8.   Improvements; Alterations; Repairs; Maintenance.
          -----------------------------------------------


          (a)  Improvements; Alterations.  Improvements to the Premises shall be
               -------------------------
installed at Tenant's expense only in accordance with plans and specifications
which have been previously submitted to and approved in writing by Landlord,
which approval shall be governed by standards in the following sentence.  No
alterations or physical additions in or to the Premises may be made without
Landlord's prior written consent, which shall not be unreasonably withheld,
conditioned or delayed; however, Landlord may withhold its consent to any
alteration or addition that would adversely affect (in the reasonable discretion
of Landlord) (1) the Building's Structure or the Building's Systems (including
the Building's restrooms or mechanical rooms), (2) the exterior appearance of
the Building, or (3) the appearance of the Building's common areas or elevator
lobby areas.  Tenant shall not paint or install lighting or decorations, signs,
window or door lettering, or advertising media of any type on or about the
Premises without the prior written consent of Landlord, which shall not be
unreasonably withheld, conditioned or delayed; however, Landlord may withhold
its consent to any such painting or installation which would affect the
appearance of the exterior of the Building or of any common areas of the
Building.  Notwithstanding the foregoing, Tenant shall not be required to obtain
Landlord's consent for repainting, recarpeting, or other alterations, tenant
improvements, alterations or physical additions to the Premises which are
cosmetic in nature totaling less than $10,000 in any single instance or series
of related alternations performed within a six-month period (provided that
Tenant shall not perform any improvements, alterations or additions to the
Premises in stages as a means to subvert this provision), in each case provided
that (A) Tenant delivers to Landlord written notice thereof, a list of
contractors and subcontractors to perform the work (and certificates of
insurance for each such party) and any plans and specifications therefor prior
to commencing any such alterations, additions, or improvements (for
informational purposes only so long as no consent is required by Landlord as
required by this Lease), (B) the installation thereof does not involve any core
drilling or the configuration or location of any exterior of interior walls of
the Building, and (C) such alterations, additions and improvements will not
affect (i) the Building's Structure or the Building's Systems, (ii) the
provision of services to other Building tenants, or (iii) the appearance of the
Building's common areas or the exterior of the Building.  All alterations,
additions, and improvements shall be constructed, maintained, and used by
Tenant, at its risk and expense, in accordance with all Laws; Landlord's consent
to or approval of any alterations, additions or improvements (or the plans
therefor) shall not constitute a representation or warranty by Landlord, nor
Landlord's acceptance, that the same comply with sound architectural and/or
engineering practices or with all applicable Laws, and Tenant shall be solely
responsible for ensuring all such compliance.


          (b)  Repairs; Maintenance.  Tenant shall maintain the Premises in a
               --------------------
clean, safe, and operable condition, and shall not permit or allow to remain any
waste or damage to any portion of the Premises.  Tenant shall repair or replace,
subject to Landlord's direction and supervision, any damage to the Building
caused by a Tenant Party.  If Tenant fails to make such repairs or replacements
within 15 business days after the occurrence of such damage, then Landlord may
make the same at Tenant's cost.  If any such damage occurs outside of the
Premises, then Landlord may elect to repair such damage at Tenant's expense,
rather than having Tenant repair such damage.  The cost of all repair or
replacement work performed by Landlord under this Section 8 shall be paid by
Tenant to Landlord within 30 days after Landlord has invoiced Tenant therefor.


          (c)  Performance of Work.  All work described in this Section 8 shall
               -------------------
be performed only by Landlord or by contractors and subcontractors approved in
writing by Landlord. Tenant shall cause all contractors and subcontractors to
procure and maintain insurance coverage naming Landlord as an additional insured
against such risks, in such amounts, and with such companies as Landlord may
reasonably require. All such work shall be performed in accordance with all Laws
and in a good and workmanlike manner so as not to damage the Building (including
the Premises, the Building's Structure and the Building's Systems). All such
work which may affect the Building's Structure or the Building's Systems must be
approved by the Building's engineer of record, at Tenant's expense and, at
Landlord's election, must be performed by Landlord's usual contractor for such
work.

                                       9










          (d)  Mechanic's Liens. Tenant shall not permit any mechanic's liens to
               ----------------
be filed against the Premises or the Building for any work performed, materials
furnished, or obligation incurred by or at the request of Tenant.  If such a
lien is filed, then Tenant shall, within ten business days after Landlord has
delivered notice of the filing thereof to Tenant (or such earlier time period as
may be necessary to prevent the forfeiture of the Building or any interest of
Landlord therein or the imposition of a civil or criminal fine with respect
thereto), either (1) pay the amount of the lien and cause the lien to be
released of record, or (2) diligently contest such lien and deliver to Landlord
a bond or other security reasonably satisfactory to Landlord.  If Tenant fails
to timely take either such action, then Landlord may pay the lien claim, and any
amounts so paid, including expenses and interest, shall be paid by Tenant to
Landlord within ten days after Landlord has invoiced Tenant therefor.  All
materialmen, contractors, artisans, mechanics, laborers and any other persons
now or hereafter contracting with Tenant or any contractor or subcontractor of
Tenant for the furnishing of any labor, services, materials, supplies or
equipment with respect to any portion of the Premises, at any time from the date
hereof until the end of the Term, are hereby charged with notice that they look
exclusively to Tenant to obtain payment for same.  Nothing herein shall be
deemed a consent by Landlord to any liens being placed upon the Building or
Landlord's interest therein due to any work performed by or for Tenant.


     9.   Use.  Tenant shall continuously occupy and use the Premises only for
          ---
the Permitted Use and shall comply with all Laws relating to the use, condition,
access to, and occupancy of the Premises.  The population density within the
Premises as a whole shall at no time exceed one person for each 200 rentable
square feet in the Premises.  Tenant shall not conduct second or third shift
operations within the Premises; however, Tenant may use the Premises after
normal business hours, so long as Tenant is not generally conducting business
from the Premises after normal business hours.  The Premises shall not be used
for any use which is disreputable, creates extraordinary fire hazards, or
results in an increased rate of insurance on the Building or its contents, or
for the storage of any Hazardous Materials (other than typical office supplies
[e.g., photocopier toner] and then only in compliance with all Laws).  Tenant
shall not use any substantial portion of the Premises for a "call center," any
other telemarketing use, or any credit processing use.  If, because of a Tenant
Party's acts, the rate of insurance on the Building or its contents increases,
then such acts shall be an Event of Default, Tenant shall pay to Landlord the
amount of such increase on demand, and acceptance of such payment shall not
waive any of Landlord's other rights.  Tenant shall conduct its business and
control each other Tenant Party so as not to create any nuisance or unreasonably
interfere with other tenants or Landlord in its management of the Building.


     10.  Assignment and Subletting.
          -------------------------


          (a)  Transfers.  Except as provided in Section 10.(g), Tenant shall
               ---------
not, without the prior written consent of Landlord, (1) assign, transfer, or
encumber this Lease or any estate or interest herein, whether directly or by
operation of law, (2) permit any other entity to become Tenant hereunder by
merger, consolidation, or other reorganization, (3) if Tenant is an entity other
than a corporation whose stock is publicly traded, permit the transfer of an
ownership interest in Tenant so as to result in a change in the current control
of Tenant, (4) sublet any portion of the Premises, (5) grant any license,
concession, or other right of occupancy of any portion of the Premises, or (6)
permit the use of the Premises by any parties other than Tenant (any of the
events listed in Section 10.(a)(1) through 10.(a)(6) being a "Transfer").
                                                              --------

          (b)  Consent Standards.  Landlord shall not unreasonably withhold or
               -----------------
delay its consent to any assignment or subletting of the Premises, provided that
the proposed transferee (1) is creditworthy, (2) has a reasonably good
reputation in the business community, (3) will use the Premises for the
Permitted Use (thus, excluding, without limitation, uses for credit processing
and telemarketing) and will not use the Premises in any manner that would
conflict with any exclusive use agreement or other similar agreement entered
into by Landlord with any other tenant of the Building, (4) is not a
governmental entity, or subdivision or agency thereof, (5) is not another
occupant of the Building, and (6) is not a person or entity with whom Landlord
is negotiating to lease space in the Building; otherwise, Landlord may withhold
its consent in its sole discretion.

                                      10

















          (c)  Request for Consent.  If Tenant requests Landlord's consent to a
               -------------------
Transfer, then, at least 15 business days prior to the effective date of the
proposed Transfer, Tenant shall provide Landlord with a written description of
all terms and conditions of the proposed Transfer, copies of the proposed
documentation, and the following information about the proposed transferee: name
and address; reasonably satisfactory information about its business and business
history; its proposed use of the Premises; banking, financial, and other credit
information; and general references sufficient to enable Landlord to determine
the proposed transferee's creditworthiness and character.  Concurrently with
Tenant's notice of any request for consent to a Transfer, Tenant shall pay to
Landlord a fee of $500 to defray Landlord's expenses in reviewing such request,
and Tenant shall also reimburse Landlord immediately upon request for its
reasonable attorneys' fees incurred in connection with considering any request
for consent to a Transfer.  If Landlord fails to notify Tenant that it approves
or disapproves the requested Transfer within 15 business days after submission
to Landlord of all of the items required under this Section 10 and the Tenant's
request for consent conspicuously states, "IF YOU DO NOT MAIL YOUR APPROVAL OR
DISAPPROVAL OF THE REQUESTED TRANSFER WITHIN 15 BUSINESS DAYS AFTER YOU RECEIVE
THIS REQUEST FOR CONSENT, YOUR APPROVAL OF THIS TRANSFER WILL BE DEEMED GIVEN,"
then Landlord shall be deemed to have approved such Transfer.


          (d)  Conditions to Consent.  If Landlord consents to a proposed
               ---------------------
Transfer, then the proposed transferee shall deliver to Landlord a written
agreement whereby it expressly assumes Tenant's obligations hereunder; however,
any transferee of less than all of the space in the Premises shall be liable
only for obligations under this Lease that are properly allocable to the space
subject to the Transfer for the period of the Transfer.  No Transfer shall
release Tenant from its obligations under this Lease, but rather Tenant and its
transferee shall be jointly and severally liable therefor.  Landlord's consent
to any Transfer shall not waive Landlord's rights as to any subsequent
Transfers.  If an Event of Default occurs while the Premises or any part thereof
are subject to a Transfer, then Landlord, in addition to its other remedies, may
collect directly from such transferee all rents becoming due to Tenant and apply
such rents against Rent.

                                      11
<PAGE>

Tenant authorizes its transferees to make payments of rent directly to Landlord
upon receipt of notice from Landlord to do so following the occurrence of an
Event of Default hereunder. Tenant shall pay for the cost of any demising walls
or other improvements necessitated by a proposed subletting or assignment.

          (e)  Cancellation.  Landlord may, within 20 business days after
               ------------
submission of Tenant's written request for Landlord's consent to an assignment
or subletting, cancel this Lease as to the portion of the Premises proposed to
be sublet or assigned as of the date the proposed Transfer is to be effective.
If Landlord cancels this Lease as to any portion of the Premises, then this
Lease shall cease for such portion of the Premises and Tenant shall pay to
Landlord all Rent accrued through the cancellation date relating to the portion
of the Premises covered by the proposed Transfer.  Thereafter, Landlord may
lease such portion of the Premises to the prospective transferee (or to any
other person) without liability to Tenant. Notwithstanding the foregoing, if
Landlord provides written notification to Tenant of its election to cancel this
Lease as to any portion of the Premises as provided above, Tenant may rescind
its proposed assignment or subletting of all or any portion of the Premises by
notifying Landlord in writing within three business days following Landlord's
written cancellation notice.

          (f)  Additional Compensation. While no Event of Default exists, Tenant
               -----------------------
shall pay to Landlord, immediately upon receipt thereof, 50% of the excess of
(1) all compensation received by Tenant for a Transfer less the costs reasonably
incurred by Tenant with unaffiliated third parties in connection with such
Transfer (i.e., brokerage commissions, tenant finish-work, and the like) over
(2) the Rent allocable to the portion of the Premises covered thereby.  While
any Event of Default exists, Tenant shall pay to Landlord, immediately upon
receipt thereof, 100% of the excess of (A) all compensation received by Tenant
for a Transfer over (B) the Rent allocable to the portion of the Premises
covered thereby.

          (g)  Permitted Transfers.  Notwithstanding Section 10.(a), Tenant may
               -------------------
Transfer all or part of its interest in this Lease or all or part of the
Premises (a "Permitted Transfer") to the following types of entities (a
             ------------------
"Permitted Transferee") without the written consent of Landlord:
 --------------------

               (1)  an Affiliate of Tenant;

               (2)  any corporation, limited partnership, limited liability
     partnership, limited liability company or other business entity in which or
     with which Tenant, or its corporate successors or assigns, is merged or
     consolidated, in accordance with applicable statutory provisions governing
     merger and consolidation of business entities, so long as (A) Tenant's
     obligations hereunder are assumed by the entity surviving such merger or
     created by such consolidation; and (B) the Tangible Net Worth of the
     surviving or created entity is not less than the Tangible Net Worth of
     Tenant as of the date hereof; or

               (3)  any corporation, limited partnership, limited liability
     partnership, limited liability company or other business entity acquiring
     all or substantially all of Tenant's assets if such entity's Tangible Net
     Worth after such acquisition is not less than the Tangible Net Worth of
     Tenant as of the date hereof.

Tenant shall promptly notify Landlord of any such Permitted Transfer.  Tenant
shall remain liable for the performance of all of the obligations of Tenant
hereunder, or if Tenant no longer exists because of a merger, consolidation, or
acquisition, the surviving or acquiring entity shall expressly assume in writing
the obligations of Tenant hereunder.  Additionally, the Permitted Transferee
shall comply with all of the terms

                                      12
<PAGE>

and conditions of this Lease, including the Permitted Use, and the use of the
Premises by the Permitted Transferee may not violate any other agreements
affecting the Premises, the Building, Landlord or other tenants of the Building.
At least 30 days after the effective date of any Permitted Transfer, Tenant
agrees to furnish Landlord with copies of the instrument effecting any of the
foregoing Transfers and documentation establishing Tenant's satisfaction of the
requirements set forth above applicable to any such Transfer. The occurrence of
a Permitted Transfer shall not waive Landlord's rights as to any subsequent
Transfers. "Tangible Net Worth" means the excess of total assets over total
            ------------------
liabilities, in each case as determined in accordance with generally accepted
accounting principles consistently applied ("GAAP"), excluding, however, from
                                             ----
the determination of total assets all assets which would be classified as
intangible assets under GAAP including goodwill, licenses, patents, trademarks,
trade names, copyrights, and franchises. Any subsequent Transfer by a Permitted
Transferee shall be subject to the terms of this Section 10.

     11.  Insurance; Waivers; Subrogation; Indemnity.
          ------------------------------------------

          (a)  Tenant's Insurance. Tenant shall maintain throughout the Term the
               ------------------
following insurance policies: (1) commercial general liability insurance in
amounts of $3,000,000 per occurrence or, following the expiration of the initial
Term, such other amounts as Landlord may from time to time reasonably require
(and, if the use and occupancy of the Premises include any activity or matter
that is or may be excluded from coverage under a commercial general liability
policy [e.g., the sale, service or consumption of alcoholic beverages], Tenant
shall obtain such endorsements to the commercial general liability policy or
otherwise obtain insurance to insure all liability arising from such activity or
matter [including liquor liability, if applicable] in such amounts as Landlord
may reasonably require), insuring Tenant, Landlord, Landlord's agents and their
respective Affiliates against all liability for injury to or death of a person
or persons or damage to property arising from the use and occupancy of the
Premises, (2) insurance covering the full value of Tenant's property and
improvements, and other property (including property of others) in the Premises,
(3) contractual liability insurance sufficient to cover Tenant's indemnity
obligations hereunder (but only if such contractual liability insurance is not
already included in Tenant's commercial general liability insurance policy), (4)
worker's compensation insurance, and (5) business interruption insurance.
Tenant's insurance shall provide primary coverage to Landlord when any policy
issued to Landlord provides duplicate or similar coverage, and in such
circumstance Landlord's policy will be excess over Tenant's policy.  Tenant
shall furnish to Landlord certificates of such insurance and such other evidence
satisfactory to Landlord of the maintenance of all insurance coverages required
hereunder, and Tenant shall obtain a written obligation on the part of each
insurance company to notify Landlord at least 30 days before cancellation or a
material change of any such insurance policies.  All such insurance policies
shall be in form, and issued by companies, reasonably satisfactory to Landlord.

          (b)  Landlord's Insurance. Throughout the Term of this Lease, Landlord
               --------------------
shall maintain, as a minimum, the following insurance policies:  (1) fire and
extended risk insurance for the Building's replacement value and (2) commercial
general liability insurance in an amount of not less than $3,000,000. The cost
of all insurance carried by Landlord with respect to the Building shall be
included in Operating Costs.  The foregoing insurance policies and any other
insurance carried by Landlord shall be for the sole benefit of Landlord and
under Landlord's sole control, and Tenant shall have no right or claim to any
proceeds thereof or any other rights thereunder.

          (c)  No Subrogation.  Landlord and Tenant each waives any claim it
               --------------
might have against the other for any injury to or death of any person or persons
or damage to or theft, destruction, loss, or loss of use of any property (a
"Loss"), to the extent the same is insured against under any insurance policy
 ----
that

                                      13
<PAGE>

covers the Building, the Premises, Landlord's or Tenant's fixtures, personal
property, leasehold improvements, or business, or is required to be insured
against under the terms hereof, regardless of whether the negligence of the
other party caused such Loss. Each party shall cause its insurance carrier to
endorse all applicable policies waiving the carrier's rights of recovery under
subrogation or otherwise against the other party.

          (d)  Indemnity.  Subject to Section 11.(c), Tenant shall defend,
               ---------
indemnify, and hold harmless Landlord and its representatives and agents from
and against all claims, demands, liabilities, causes of action, suits,
judgments, damages, and expenses (including attorneys' fees) arising from (1)
any Loss arising from any occurrence on the Premises or (2) Tenant's failure to
perform its obligations under this Lease, even though caused or alleged to be
caused by the negligence or fault of Landlord or its agents (other than a Loss
arising from the sole or gross negligence of Landlord or its agents), and even
though any such claim, cause of action, or suit is based upon or alleged to be
based upon the strict liability of Landlord or its agents.  This indemnity is
intended to indemnify Landlord and its agents against the consequences of their
own negligence or fault as provided above when Landlord or its agents are
jointly, comparatively, contributively, or concurrently negligent with Tenant.
Subject to Section 11.(c), Landlord shall defend, indemnify, and hold harmless
Tenant and its agents from and against all claims, demands, liabilities, causes
of action, suits, judgments, and expenses (including attorneys' fees) for any
Loss arising from any occurrence in the Building's common areas, even though
caused or alleged to be caused by the negligence or fault of Tenant or its
agents (other than a Loss arising from the sole or gross negligence of Tenant or
its agents), and even though any such claim, cause of action, or suit is based
upon or alleged to be based upon the strict liability of Tenant or its agents.
This indemnity is intended to indemnify Tenant and its agents against the
consequences of their own negligence or fault as provided above when Tenant or
its agents are jointly, comparatively, contributively, or concurrently negligent
with Landlord.  The indemnities set forth in this Section 11.(d) shall survive
termination or expiration of this Lease and shall not terminate or be waived,
diminished or affected in any manner by any abatement or apportionment of Rent
under any provision of this Lease.  If any proceeding is filed for which
indemnity is required hereunder, the indemnifying party agrees, upon request
therefor, to defend the indemnified party in such proceeding at its sole cost
utilizing counsel satisfactory to the indemnified party.

     12.  Subordination; Attornment; Notice to Landlord's Mortgagee.
          ---------------------------------------------------------

          (a)  Subordination.  This Lease shall be subordinate to any deed of
               -------------
trust, mortgage, or other security instrument (each, a "Mortgage"), or any
                                                        --------
ground lease, master lease, or primary lease (each, a "Primary Lease"), that now
                                                       -------------
or hereafter covers all or any part of the Premises (the mortgagee under any
such Mortgage, beneficiary under any such deed of trust, or the lessor under any
such Primary Lease is referred to herein as a "Landlord's Mortgagee").  Landlord
                                               --------------------
shall use reasonable efforts to obtain a subordination, non-disturbance and
attornment agreement from the current Landlord's Mortgagee in the form of
Exhibit L hereto within 60 days from the date hereof; however, Landlord's
---------
failure to deliver such agreement shall not constitute a default by Landlord
hereunder nor affect the subordination of the Lease as provided in this Section;
and further provided that any administration fee or other similar cost imposed
by Landlord's Mortgagee in connection with obtaining such subordination, non-
disturbance and attornment agreement shall be paid by Tenant within 15 days
after Landlord's written request therefor.  Any Landlord's Mortgagee may elect,
at any time, unilaterally, to make this Lease superior to its Mortgage, Primary
Lease, or other interest in the Premises by so notifying Tenant in writing.  The
provisions of this Section shall be self-operative and no further instrument of
subordination shall be required; however, in confirmation of such subordination,
Tenant shall execute and return to Landlord (or such other party designated by
Landlord)

                                      14
<PAGE>

within ten business days after written request therefor such documentation, in
recordable form if required, as a Landlord's Mortgagee may reasonably request to
evidence the subordination of this Lease to such Landlord's Mortgagee's Mortgage
or Primary Lease (including a subordination, non-disturbance and attornment
agreement) or, if the Landlord's Mortgagee so elects, the subordination of such
Landlord's Mortgagee's Mortgage or Primary Lease to this Lease.

          (b)  Attornment.  Tenant shall attorn to any party succeeding to
               ----------
Landlord's interest in the Premises, whether by purchase, foreclosure, deed in
lieu of foreclosure, power of sale, termination of lease, or otherwise, upon
such party's request, and shall execute such agreements confirming such
attornment as such party may reasonably request.

          (c)  Notice to Landlord's Mortgagee.  Tenant shall not seek to enforce
               ------------------------------
any remedy it may have for any default on the part of Landlord without first
giving written notice by certified mail, return receipt requested, specifying
the default in reasonable detail, to any Landlord's Mortgagee whose address has
been given to Tenant, and affording such Landlord's Mortgagee a reasonable
opportunity to perform Landlord's obligations hereunder.

          (d)  Landlord's Mortgagee's Protection Provisions.  If Landlord's
               --------------------------------------------
Mortgagee shall succeed to the interest of Landlord under this Lease, Landlord's
Mortgagee shall not be: (1) liable for any act or omission of any prior lessor
(including Landlord); (2) bound by any rent or additional rent or advance rent
which Tenant might have paid for more than the current month to any prior lessor
(including Landlord), and all such rent shall remain due and owing,
notwithstanding such advance payment; (3) bound by any security or advance
rental deposit made by Tenant which is not delivered or paid over to Landlord's
Mortgagee and with respect to which Tenant shall look solely to Landlord for
refund or reimbursement; (4) bound by any termination, amendment or modification
of this Lease made without Landlord's Mortgagee's consent and written approval,
except for those terminations, amendments and modifications permitted to be made
by Landlord without Landlord's Mortgagee's consent pursuant to the terms of the
loan documents between Landlord and Landlord's Mortgagee; (5) subject to the
defenses which Tenant might have against any prior lessor (including Landlord);
and (6) subject to the offsets which Tenant might have against any prior lessor
(including Landlord) except for those offset rights which (A) are expressly
provided in this Lease, (B) relate to periods of time following the acquisition
of the Building by Landlord's Mortgagee, and (C) Tenant has provided written
notice to Landlord's Mortgagee and provided Landlord's Mortgagee a reasonable
opportunity to cure the event giving rise to such offset event.  Landlord's
Mortgagee shall have no liability or responsibility under or pursuant to the
terms of this Lease or otherwise after it ceases to own an interest in the
Building.  Nothing in this Lease shall be construed to require Landlord's
Mortgagee to see to the application of the proceeds of any loan, and Tenant's
agreements set forth herein shall not be impaired on account of any modification
of the documents evidencing and securing any loan.

     13.  Rules and Regulations.  Tenant shall comply with the rules and
          ---------------------
regulations of the Building which are attached hereto as Exhibit C.  Landlord
                                                         ---------
may, from time to time, change such rules and regulations for the safety, care,
or cleanliness of the Building and related facilities, provided that such
changes are applicable to all tenants of the Building, will not unreasonably or
materially interfere with Tenant's use of the Premises and are enforced by
Landlord in a non-discriminatory manner.  Tenant shall be responsible for the
compliance with such rules and regulations by each Tenant Party.

                                      15
<PAGE>

     14.  Condemnation.
          ------------

          (a)  Total Taking.  If the entire Building or Premises are taken by
               ------------
right of eminent domain or conveyed in lieu thereof (a "Taking"), this Lease
                                                        ------
shall terminate as of the date of the Taking.

          (b)  Partial Taking - Tenant's Rights.  If any part of the Building
               --------------------------------
becomes subject to a Taking and such Taking will prevent Tenant from conducting
its business in the Premises in a manner reasonably comparable to that conducted
immediately before such Taking for a period of more than 180 days, then Tenant
may terminate this Lease as of the date of such Taking by giving written notice
to Landlord within 30 days after the Taking, and Basic Rent and Additional Rent
shall be apportioned as of the date of such Taking.  If Tenant does not
terminate this Lease, then Rent shall be abated on a reasonable basis as to that
portion of the Premises rendered untenantable by the Taking.

          (c)  Partial Taking - Landlord's Rights.  If any material portion, but
               ----------------------------------
less than all, of the Building becomes subject to a Taking, or if Landlord is
required to pay any of the proceeds arising from a Taking to a Landlord's
Mortgagee, then Landlord may terminate this Lease by delivering written notice
thereof to Tenant within 30 days after such Taking, and Basic Rent and
Additional Rent shall be apportioned as of the date of such Taking.  If Landlord
does not so terminate this Lease, then this Lease will continue, but if any
portion of the Premises has been taken, Rent shall abate as provided in the last
sentence of Section 14.(b).

          (d)  Award.  If any Taking occurs, then Landlord shall receive the
               -----
entire award or other compensation for the Land, the Building, and other
improvements taken; however, Tenant may separately pursue a claim (to the extent
it will not reduce Landlord's award) against the condemnor for the value of
Tenant's personal property which Tenant is entitled to remove under this Lease,
moving costs, loss of business, and other claims it may have.

     15.  Fire or Other Casualty.
          ----------------------

          (a)  Repair Estimate.  If the Premises or the Building are damaged by
               ---------------
fire or other casualty (a "Casualty"), Landlord shall, within 75 days after such
                           --------
Casualty, deliver to Tenant a good faith estimate (the "Damage Notice") of the
                                                        -------------
time needed to repair the damage caused by such Casualty.

          (b)  Tenant's Rights. If a material portion of the Premises is damaged
               ---------------
by Casualty such that Tenant is prevented from conducting its business in the
Premises in a manner reasonably comparable to that conducted immediately before
such Casualty and Landlord estimates that the damage caused thereby cannot be
repaired within 210 days after the Casualty (the "Repair Period"), then Tenant
                                                  -------------
may terminate this Lease by delivering written notice to Landlord of its
election to terminate within 30 days after the Damage Notice has been delivered
to Tenant.

          (c)  Landlord's Rights.  If a Casualty damages the Premises or a
               -----------------
material portion of the Building and (1) Landlord estimates that the damage to
the Premises cannot be repaired within the Repair Period, (2) the damage to the
Premises exceeds 50% of the replacement cost thereof (excluding foundations and
footings), as estimated by Landlord, and such damage occurs during the last two
years of the Term, (3) regardless of the extent of damage to the Premises,
Landlord makes a good faith determination that restoring the Building would be
uneconomical, or (4) Landlord is required to pay any insurance proceeds arising
out

                                      16
<PAGE>

of the Casualty to a Landlord's Mortgagee, then Landlord may terminate this
Lease by giving written notice of its election to terminate within 30 days after
the Damage Notice has been delivered to Tenant.

          (d)  Repair Obligation.  If neither party elects to terminate this
               -----------------
Lease following a Casualty, then Landlord shall, within a reasonable time after
such Casualty, begin to repair the Premises and shall proceed with reasonable
diligence to restore the Premises to substantially the same condition as they
existed immediately before such Casualty; however, Landlord shall only be
required to reconstruct the Premises to the extent of any improvements existing
therein on the date of the damage that were installed by Landlord as part of the
Work (if any) pursuant to Exhibit D ("Landlord's Contribution"), and Landlord's
                          ---------   -----------------------
obligation to repair or restore the Premises shall be limited to the extent of
the insurance proceeds (plus any applicable deductible amounts) actually
received by Landlord for the Casualty in question.  Tenant shall be responsible
for repairing or replacing its furniture, equipment, fixtures, alterations and
other improvements which Landlord is not obligated to restore, and shall use the
proceeds of its insurance for such purpose. Tenant shall pay the difference
between the total cost of reconstructing the Premises and Landlord's
Contribution ("Tenant's Contribution").
               ---------------------

          (e)  Abatement of Rent.  If the Premises are damaged by Casualty, Rent
               -----------------
for the portion of the Premises rendered untenantable by the damage shall be
abated from the date of damage until the completion of Landlord's repairs (or
until the date of termination of this Lease by Landlord or Tenant as provided
above, as the case may be), unless such damage was caused solely by a Tenant
Party, in which case, Tenant shall continue to pay Rent without abatement.

     16.  Personal Property Taxes.  Tenant shall be liable for all taxes levied
          -----------------------
or assessed against personal property, furniture, or fixtures placed by Tenant
in the Premises.  If any taxes for which Tenant is liable are levied or assessed
against Landlord or Landlord's property and Landlord elects to pay the same, or
if the assessed value of Landlord's property is increased by inclusion of such
personal property, furniture or fixtures and Landlord elects to pay the taxes
based on such increase, then Tenant shall pay to Landlord, within 30 days
following written request, the part of such taxes for which Tenant is primarily
liable hereunder; however, Landlord shall not pay such amount if Tenant notifies
Landlord that it will contest the validity or amount of such taxes before
Landlord makes such payment, and thereafter diligently proceeds with such
contest in accordance with Law and if the non-payment thereof does not pose a
threat of loss or seizure of the Building or interest of Landlord therein or
impose any fee or penalty against Landlord.

     17.  Events of Default.  Each of the following occurrences shall be an
          -----------------
"Event of Default":
 ----------------

          (a)  Payment Default.  Tenant's failure to pay Rent within five
               ---------------
business days after Landlord has delivered written notice to Tenant that the
same is due; however, an Event of Default shall occur hereunder without any
obligation of Landlord to give any notice if Tenant fails to pay Rent when due
and, during the 12 month interval preceding such failure, Landlord has given
Tenant written notice of failure to pay Rent on one or more occasions;

          (b)  Vacation.  Tenant vacates the Premises or any substantial portion
               --------
thereof;

          (c)  Estoppel.  Tenant fails to provide any estoppel certificate after
               --------
Landlord's written request therefor pursuant to Section 25.(e) and such failure
shall continue for five days after Landlord's second written notice thereof to
Tenant;

                                      17
<PAGE>

          (d)  Other Defaults.  Tenant's failure to perform, comply with, or
               --------------
observe any other agreement or obligation of Tenant under this Lease and the
continuance of such failure for a period of more than 30 days after Landlord has
delivered to Tenant written notice thereof; and

          (e)  Insolvency.  The filing of a petition by or against Tenant (the
               ----------
term "Tenant" shall include, for the purpose of this Section 17.(e), any
      ------
guarantor of Tenant's obligations hereunder) (1) in any bankruptcy or other
insolvency proceeding; (2) seeking any relief under any state or federal debtor
relief law; (3) for the appointment of a liquidator or receiver for all or
substantially all of Tenant's property or for Tenant's interest in this Lease;
or (4) for the reorganization or modification of Tenant's capital structure;
however, if such a petition is filed against Tenant, then such filing shall not
be an Event of Default unless Tenant fails to have the proceedings initiated by
such petition dismissed within 90 days after the filing thereof.

     18.  Remedies.  Upon any Event of Default, Landlord may, in addition to all
          --------
other rights and remedies afforded Landlord hereunder or by law or equity, take
any one or more of the following actions:

          (a)  Termination of Lease.  Terminate this Lease by giving Tenant
               --------------------
written notice thereof, in which event Tenant shall pay to Landlord the sum of
(1) all Rent accrued hereunder through the date of termination, (2) all amounts
due under Section 19.(a), and (3) an amount equal to (A) the total Rent that
Tenant would have been required to pay for the remainder of the Term discounted
to present value at a per annum rate equal to the "Prime Rate" as published on
the date this Lease is terminated by The Wall Street Journal, Southwest Edition,
in its listing of "Money Rates" minus one percent, minus (B) the then present
fair rental value of the Premises for such period, similarly discounted;

          (b)  Termination of Possession.  Terminate Tenant's right to possess
               -------------------------
the Premises without terminating this Lease by giving written notice thereof to
Tenant, in which event Tenant shall pay to Landlord (1) all Rent and other
amounts accrued hereunder to the date of termination of possession, (2) all
amounts due from time to time under Section 19.(a), and (3) all Rent and other
net sums required hereunder to be paid by Tenant during the remainder of the
Term, diminished by any net sums thereafter received by Landlord through
reletting the Premises during such period, after deducting all costs incurred by
Landlord in reletting the Premises.  If Landlord elects to proceed under this
Section 18.(b), Landlord may remove all of Tenant's property from the Premises
and store the same in a public warehouse or elsewhere at the cost of, and for
the account of, Tenant, without becoming liable for any loss or damage which may
be occasioned thereby.  Landlord shall use reasonable efforts to relet the
Premises on such terms as Landlord in its sole discretion may determine
(including a term different from the Term, rental concessions, and alterations
to, and improvement of, the Premises); however, Landlord shall not be obligated
to relet the Premises before leasing other portions of the Building.  Landlord
shall not be liable for, nor shall Tenant's obligations hereunder be diminished
because of, Landlord's failure to relet the Premises or to collect rent due for
such reletting.  Tenant shall not be entitled to the excess of any consideration
obtained by reletting over the Rent due hereunder.  Reentry by Landlord in the
Premises shall not affect Tenant's obligations hereunder for the unexpired Term;
rather, Landlord may, from time to time, bring an action against Tenant to
collect amounts due by Tenant, without the necessity of Landlord's waiting until
the expiration of the Term.  Unless Landlord delivers written notice to Tenant
expressly stating that it has elected to terminate this Lease, all actions taken
by Landlord to dispossess or exclude Tenant from the Premises shall be deemed to
be taken under this Section 18.(b).  If Landlord elects to proceed under this
Section 18.(b), it may at any time elect to terminate this Lease under Section
18.(a); or

                                      18
<PAGE>

          (c)  Alteration of Locks. Additionally, with or without notice, and to
               -------------------
the extent permitted by Law, Landlord may alter locks or other security devices
at the Premises to deprive Tenant of access thereto, and Landlord shall not be
required to provide a new key or right of access to Tenant.

     19.  Payment by Tenant; Non-Waiver; Cumulative Remedies.
          --------------------------------------------------

          (a)  Payment by Tenant. Upon any Event of Default, Tenant shall pay to
               -----------------
Landlord all costs incurred by Landlord (including court costs and reasonable
attorneys' fees and expenses) in (1) obtaining possession of the Premises, (2)
removing and storing Tenant's or any other occupant's property, (3) repairing,
restoring, altering, remodeling, or otherwise putting the Premises into
condition reasonably acceptable to a new tenant for similar space in the Las
Colinas Urban Center, (4) if Tenant is dispossessed of the Premises and this
Lease is not terminated, reletting all or any part of the Premises (including
brokerage commissions, cost of tenant finish work, and other costs incidental to
such reletting for similar space in the Las Colinas Urban Center), (5)
performing Tenant's obligations which Tenant failed to perform, and (6)
enforcing, or advising Landlord of, its rights, remedies, and recourses arising
out of the Event of Default. To the full extent permitted by law, Landlord and
Tenant agree the federal and state courts of the state in which the Premises are
located shall have exclusive jurisdiction over any matter relating to or arising
from this Lease and the parties' rights and obligations under this Lease.

          (b)  No Waiver.  Landlord's acceptance of Rent following an Event of
               ---------
Default shall not waive Landlord's rights regarding such Event of Default.  No
waiver by Landlord of any violation or breach of any of the terms contained
herein shall waive Landlord's rights regarding any future violation of such
term.  Landlord's acceptance of any partial payment of Rent shall not waive
Landlord's rights with regard to the remaining portion of the Rent that is due,
regardless of any endorsement or other statement on any instrument delivered in
payment of Rent or any writing delivered in connection therewith; accordingly,
Landlord's acceptance of a partial payment of Rent shall not constitute an
accord and satisfaction of the full amount of the Rent that is due.

          (c)  Cumulative Remedies.  Any and all remedies set forth in this
               -------------------
Lease:  (1) shall be in addition to any and all other remedies Landlord may have
at law or in equity, (2) shall be cumulative, and (3) may be pursued
successively or concurrently as Landlord may elect.  The exercise of any remedy
by Landlord shall not be deemed an election of remedies or preclude Landlord
from exercising any other remedies in the future.

     20.  Landlord's Lien.  [Intentionally Deleted].
          ---------------

     21.  Surrender of Premises.  No act by Landlord shall be deemed an
          ---------------------
acceptance of a surrender of the Premises, and no agreement to accept a
surrender of the Premises shall be valid unless it is in writing and signed by
Landlord.  At the expiration or termination of this Lease, Tenant shall deliver
to Landlord the Premises with all improvements located therein in good repair
and condition, free of Hazardous Materials placed on the Premises during the
Term, broom-clean, reasonable wear and tear (and condemnation and Casualty
damage not caused by Tenant, as to which Sections 14 and 15 shall control)
excepted, and shall deliver to Landlord all keys to the Premises.  Provided that
Tenant has performed all of its obligations hereunder, Tenant may remove all
unattached trade fixtures, furniture, and personal property placed in the
Premises or elsewhere in the Building by Tenant (but Tenant may not remove any
such item which was paid for, in whole or in part, by Landlord or any wiring or
cabling unless Landlord requires such removal). Additionally, at Landlord's
option, Tenant shall remove such alterations, additions, improvements, trade

                                      19
<PAGE>

fixtures, personal property, equipment, wiring, cabling, and furniture as
Landlord may request; however, Tenant shall not be required to remove any
addition or improvement to the Premises if Landlord has specifically agreed in
writing that the improvement or addition in question need not be removed.
Tenant shall repair all damage caused by such removal.  All items not so removed
shall, at Landlord's option, be deemed to have been abandoned by Tenant and may
be appropriated, sold, stored, destroyed, or otherwise disposed of by Landlord
without notice to Tenant and without any obligation to account for such items;
any such disposition shall not be considered a strict foreclosure or other
exercise of Landlord's rights in respect of the security interest granted under
Section 20.  The provisions of this Section 21 shall survive the end of the
Term.

     22.  Holding Over.  If Tenant fails to vacate the Premises at the end of
          ------------
the Term, then Tenant shall be a tenant at sufferance and, in addition to all
other damages and remedies to which Landlord may be entitled for such holding
over, (a) Tenant shall pay for the first 60 days of such holdover period, in
addition to the other Rent, Basic Rent equal to 150% of the Basic Rent payable
during the last month of the Term, and (b) Tenant shall otherwise continue to be
subject to all of Tenant's obligations under this Lease.  The provisions of this
Section 22 shall not be deemed to limit or constitute a waiver of any other
rights or remedies of Landlord provided herein or at law.  If Tenant fails to
surrender the Premises within 30 days following the termination or expiration of
this Lease, in addition to any other liabilities to Landlord accruing therefrom,
Tenant shall protect, defend, indemnify and hold Landlord harmless from all
loss, costs (including reasonable attorneys' fees) and direct liability
resulting from such failure.  If Tenant holds over in the Premises for more than
60 days following the end of the Term, then the holdover rental rate as stated
above shall increase from 150% of the Basic Rent payable during the last month
of the Term to 200% of the Basic Rent payable during the last term of the Term,
and in addition to all the liabilities described above, Tenant shall also be
liable for all liabilities (direct and indirect) resulting from Tenant's failure
to vacate the Premises at the end of the Term, including any claims made by any
succeeding tenant founded upon such failure to surrender, and any lost profits
to Landlord resulting therefrom.

     23.  Certain Rights Reserved by Landlord.  Provided that the exercise of
          -----------------------------------
such rights does not unreasonably interfere with Tenant's occupancy of the
Premises, Landlord shall have the following rights:

          (a)  Building Operations.  To decorate and to make inspections,
               -------------------
repairs, alterations, additions, changes, or improvements, whether structural or
otherwise, in and about the Building, or any part thereof; to enter upon the
Premises (after giving Tenant reasonable notice thereof, which may be oral
notice, except in cases of real or apparent emergency, in which case no notice
shall be required) and, during the continuance of any such work, to temporarily
close doors, entryways, public space, and corridors in the Building; to
interrupt or temporarily suspend Building services and facilities; to change the
name of the Building; and to change the arrangement and location of entrances or
passageways, doors, and doorways, corridors, elevators, stairs, restrooms, or
other public parts of the Building;

          (b)  Security.  To take such reasonable measures as Landlord deems
               --------
advisable for the security of the Building and its occupants; evacuating the
Building for cause, suspected cause, or for drill purposes; temporarily denying
access to the Building; and closing the Building after normal business hours and
on Sundays and holidays, subject, however, to Tenant's right to enter when the
Building is closed after normal business hours under such reasonable regulations
as Landlord may prescribe from time to time;

          (c)  Prospective Purchasers and Lenders.  To enter the Premises at all
               ----------------------------------
reasonable hours to show the Premises to prospective purchasers or lenders; and

                                      20
<PAGE>

          (d)  Prospective Tenants.  At any time during the last nine months of
               -------------------
the Term (or earlier if Tenant has notified Landlord in writing that it does not
desire to renew the Term) or at any time following the occurrence of an Event of
Default, to enter the Premises at all reasonable hours to show the Premises to
prospective tenants.

     Prior to Landlord exercising its rights under Sections 23.(c) and 23.(d),
Landlord shall provide Tenant with reasonable prior notice thereof (which notice
may be verbal) and allow Tenant the opportunity to provide an employee or other
representative of Tenant to accompany Landlord during such entries.

     24.  Substitution Space.  Landlord may, at Landlord's expense, relocate any
          ------------------
part of the Premises consisting of less than 10,000 rentable square feet and any
expansion areas on which tenant has a right to expand (including the Opportunity
Space [as defined below]) within the Building to space which is comparable in
size, utility and condition to the Premises. If Landlord relocates Tenant,
Landlord shall reimburse Tenant for Tenant's reasonable out-of-pocket expenses
for moving Tenant's furniture, equipment, cabling and supplies from the Premises
to the relocation space and for reprinting Tenant's stationery of the same
quality and quantity as Tenant's stationery supply on hand immediately before
Landlord's notice to Tenant of the exercise of this relocation right. Upon such
relocation, the relocation space shall be deemed to be the Premises and the
terms of the Lease shall remain in full force and shall apply to the relocation
space.

     25.  Miscellaneous.
          -------------

          (a)  Landlord Transfer.  Landlord may transfer any portion of the
               -----------------
Building and any of its rights under this Lease.  If Landlord assigns its rights
under this Lease, then Landlord shall thereby be released from any further
obligations hereunder arising after the date of transfer, provided that the
assignee assumes Landlord's obligations hereunder in writing.

          (b)  Landlord's Liability.  The liability of Landlord (and its
               --------------------
partners, shareholders or members) to Tenant (or any person or entity claiming
by, through or under Tenant) for any default by Landlord under the terms of this
Lease or any matter relating to or arising out of the occupancy or use of the
Premises and/or other areas of the Building shall be limited to Tenant's actual
direct, but not consequential, damages therefor and shall be recoverable only
from the interest of Landlord in the Building, and Landlord (and its partners,
shareholders or members) shall not be personally liable for any deficiency.
Additionally, Tenant hereby waives its statutory lien under Section 91.004 of
the Texas Property Code.

          (c)  Force Majeure.  Other than for Tenant's obligations under this
               -------------
Lease that can be performed by the payment of money (e.g., payment of Rent and
maintenance of insurance), whenever a period of time is herein prescribed for
action to be taken by either party hereto, such party shall not be liable or
responsible for, and there shall be excluded from the computation of any such
period of time, any delays due to strikes, riots, acts of God, shortages of
labor or materials, war, governmental laws, regulations, or restrictions, or any
other causes of any kind whatsoever which are beyond the control of such party.

          (d)  Brokerage.  Neither Landlord nor Tenant has dealt with any broker
               ---------
or agent in connection with the negotiation or execution of this Lease, other
than Grubb & Ellis Management Services, Inc. and Cushman & Wakefield of Texas,
Inc., whose commissions shall be paid by Landlord pursuant to separate written
agreements.  Tenant and Landlord shall each indemnify the other against all
costs, expenses,

                                      21
<PAGE>

attorneys' fees, liens and other liability for commissions or other compensation
claimed by any broker or agent claiming the same by, through, or under the
indemnifying party.

          (e)  Estoppel Certificates. From time to time, Tenant shall furnish to
               ---------------------
any party designated by Landlord, within ten days after Landlord has made a
request therefor, a certificate signed by Tenant confirming and containing such
factual certifications and representations as to this Lease as Landlord may
reasonably request.  Unless otherwise required by Landlord's Mortgagee or a
prospective purchaser or mortgagee of the Building, the initial form of estoppel
certificate to be signed by Tenant is attached hereto as Exhibit F.
                                                         ---------

          (f)  Notices.  All notices and other communications given pursuant to
               -------
this Lease shall be in writing and shall be (1) mailed by first class, United
States Mail, postage prepaid, certified, with return receipt requested, and
addressed to the parties hereto at the address specified in the Basic Lease
Information, (2) hand delivered to the intended address, (3) sent by a
nationally recognized overnight courier service, or (4) sent by facsimile
transmission during normal business hours followed on the same day by a
confirmatory letter sent in another manner permitted hereunder.  All notices
shall be effective upon delivery to the address of the addressee.  The parties
hereto may change their addresses by giving notice thereof to the other in
conformity with this provision.

          (g)  Separability.  If any clause or provision of this Lease is
               ------------
illegal, invalid, or unenforceable under present or future laws, then the
remainder of this Lease shall not be affected thereby and in lieu of such clause
or provision, there shall be added as a part of this Lease a clause or provision
as similar in terms to such illegal, invalid, or unenforceable clause or
provision as may be possible and be legal, valid, and enforceable.

          (h)  Amendments; Binding Effect.  This Lease may not be amended except
               --------------------------
by instrument in writing signed by Landlord and Tenant.  No provision of this
Lease shall be deemed to have been waived by Landlord unless such waiver is in
writing signed by Landlord, and no custom or practice which may evolve between
the parties in the administration of the terms hereof shall waive or diminish
the right of Landlord to insist upon the performance by Tenant in strict
accordance with the terms hereof.  The terms and conditions contained in this
Lease shall inure to the benefit of and be binding upon the parties hereto, and
upon their respective successors in interest and legal representatives, except
as otherwise herein expressly provided.  This Lease is for the sole benefit of
Landlord and Tenant, and, other than Landlord's Mortgagee, no third party shall
be deemed a third party beneficiary hereof.

          (i)  Quiet Enjoyment.  Provided Tenant has performed all of its
               ---------------
obligations hereunder, Tenant shall peaceably and quietly hold and enjoy the
Premises for the Term, without hindrance from Landlord or any party claiming by,
through, or under Landlord, but not otherwise, subject to the terms and
conditions of this Lease.

          (j)  No Merger.  There shall be no merger of the leasehold estate
               ---------
hereby created with the fee estate in the Premises or any part thereof if the
same person acquires or holds, directly or indirectly, this Lease or any
interest in this Lease and the fee estate in the leasehold Premises or any
interest in such fee estate.

                                      22
<PAGE>

          (k) No Offer.  The submission of this Lease to Tenant shall not be
              --------
construed as an offer, and Tenant shall not have any rights under this Lease
unless Landlord executes a copy of this Lease and delivers it to Tenant.

          (l) Entire Agreement.  This Lease constitutes the entire agreement
              ----------------
between Landlord and Tenant regarding the subject matter hereof and supersedes
all oral statements and prior writings relating thereto.  Except for those set
forth in this Lease, no representations, warranties, or agreements have been
made by Landlord or Tenant to the other with respect to this Lease or the
obligations of Landlord or Tenant in connection therewith.  The normal rule of
construction that any ambiguities be resolved against the drafting party shall
not apply to the interpretation of this Lease or any exhibits or amendments
hereto.

          (m) Waiver of Jury Trial.  To the maximum extent permitted by law,
              --------------------
Landlord and Tenant each waive right to trial by jury in any litigation arising
out of or with respect to this Lease.

          (n) Governing Law.  This Lease shall be governed by and construed in
              -------------
accordance with the laws of the state in which the Premises are located.

          (o) Recording.  Tenant shall not record this Lease or any memorandum
              ---------
of this Lease without the prior written consent of Landlord, which consent may
be withheld or denied in the sole and absolute discretion of Landlord.  Tenant
grants to Landlord a power of attorney to execute and record a release releasing
any such recorded instrument of record that was recorded without the prior
written consent of Landlord.

          (p) Joint and Several Liability.  If Tenant is comprised of more than
              ---------------------------
one party, each such party shall be jointly and severally liable for Tenant's
obligations under this Lease.  All unperformed obligations of Tenant at the end
of the Term shall survive.

          (q) Financial Reports.  Within 15 business days after Landlord's
              -----------------
request, Tenant will furnish Tenant's most recent audited financial statements
(including any notes to them) to Landlord, or, if no such audited statements
have been prepared, such other financial statements (and notes to them) as may
have been prepared by an independent certified public accountant or, failing
those, Tenant's internally prepared financial statements.  If Tenant is a
publicly traded corporation, Tenant may satisfy its obligations hereunder by
providing to Landlord Tenant's most recent annual and quarterly reports.  Tenant
will discuss its financial statements with Landlord and, following the
occurrence of an Event of Default hereunder, will give Landlord access to
Tenant's books and records in order to enable Landlord to verify the financial
statements.  Landlord will not disclose any aspect of Tenant's financial
statements that Tenant designates to Landlord as confidential except (1) to
Landlord's Mortgagee or prospective mortgagees or purchasers of the Building,
(2) in litigation between Landlord and Tenant, and (3) if required by court
order.  Tenant shall not be required to deliver the financial statements
required under this Section 25.(q) more than once in any 12-month period unless
requested by Landlord's Mortgagee or a prospective buyer or lender of the
Building or an Event of Default occurs.

          (r) Landlord's Fees.  Whenever Tenant requests Landlord to take any
              ---------------
action not required of it hereunder or give any consent required or permitted
under this Lease, Tenant will reimburse Landlord for Landlord's reasonable, out-
of-pocket costs payable to third parties and incurred by Landlord in reviewing
the proposed action or consent, including reasonable attorneys', engineers' or
architects' fees, within 30 days after Landlord's delivery to Tenant of an
invoice containing a statement of such costs.  Tenant

                                      23
<PAGE>

will be obligated to make such reimbursement without regard to whether Landlord
consents to any such proposed action.

          (s) Telecommunications.  Tenant and its telecommunications companies,
              ------------------
including local exchange telecommunications companies and alternative access
vendor services companies, shall have no right of access to and within the
Building, for the installation and operation of telecommunications systems,
including voice, video, data, Internet, and any other services provided over
wire, fiber optic, microwave, wireless, and any other transmission systems
("Telecommunications Services"), for part or all of Tenant's telecommunications
-----------------------------
within the Building and from the Building to any other location without
Landlord's prior written consent.  All providers of Telecommunications Services
shall be required to comply with the rules and regulations of the Building,
applicable Laws and Landlord's policies and practices for the Building. Tenant
acknowledges that Landlord shall not be required to provide or arrange for any
Telecommunications Services and that Landlord shall have no liability to any
Tenant Party in connection with the installation, operation or maintenance of
Telecommunications Services or any equipment or facilities relating thereto.
Tenant, at its cost and for its own account, shall be solely responsible for
obtaining all Telecommunications Services.

          (t) Confidentiality.  Both Landlord and Tenant acknowledge that the
              ---------------
terms and conditions of this Lease (other than the existence of this Lease and
the location of the Premises) are to remain confidential for both parties'
benefit, and may not be disclosed by either party to anyone, by any manner or
means, directly or indirectly, without the other party's prior written consent;
however, each party may disclose the terms and conditions of this Lease to their
respective attorneys, accountants, employees and existing or prospective
financial partners and Landlord may also disclose the terms and conditions
hereof to any existing, future or prospective Landlord's Mortgagee, prospective
purchasers of the Building, any necessary governmental agencies (including any
taxing authority), and internal and external auditors.  The consent by either
party to any disclosures shall not be deemed to be a waiver  on the part of such
party of any prohibition against any future disclosure.

          (u) Authority.  Tenant (if a corporation, partnership or other
              ---------
business entity) hereby represents and warrants to Landlord that Tenant is a
duly formed and existing entity qualified to do business in the state in which
the Premises are located, that Tenant has full right and authority to execute
and deliver this Lease, and that each person signing on behalf of Tenant is
authorized to do so.  Landlord hereby represents and warrants to Tenant that
Landlord is a duly formed and existing entity qualified to do business in the
state in which the Premises are located, that Landlord has full right and
authority to execute and deliver this Lease, and that each person signing on
behalf of Landlord is authorized to do so.

          (v) Hazardous Materials.
              -------------------

              (1) The term "Hazardous Materials" means any substance, material,
                            -------------------
     or waste which is now or hereafter classified or considered to be
     hazardous, toxic, or dangerous under any Law relating to pollution or the
     protection or regulation of human health, natural resources or the
     environment, or poses or threatens to pose a hazard to the health or safety
     of persons on the Premises or in the Building. Tenant shall not use,
     generate, store, or dispose of, or permit the use, generation, storage or
     disposal of Hazardous Materials on or about the Premises or the Building
     except in a manner and quantity necessary for the ordinary performance of
     Tenant's business, and then in compliance with all Laws. If Tenant breaches
     its obligations under this Section 25.(v), Landlord may immediately take
     any and all action reasonably appropriate to remedy the same, including
     taking

                                      24
<PAGE>

     all appropriate action to clean up or remediate any contamination resulting
     from Tenant's use, generation, storage or disposal of Hazardous Materials.
     Tenant shall defend, indemnify, and hold harmless Landlord and its
     representatives and agents from and against any and all claims, demands,
     liabilities, causes of action, suits, judgments, damages and expenses
     (including reasonable attorneys' fees and cost of clean up and remediation)
     arising from Tenant's failure to comply with the provisions of this Section
     25.(v). This indemnity provision shall survive termination or expiration of
     this Lease.

          (2) Landlord has provided to Tenant a copy of a Phase I Environmental
     Site Assessment (NOVA Project No. 976135) ("Report") with respect to the
                                                 ------
     Land, dated September 29, 1997, prepared by NOVA Consulting Services, Inc.
     ("Consultant"). Tenant agrees not to release the Report, or a copy of it,
       ----------
     or any part of it, or disclose any of the information contained in the
     Report to any third party (other than Tenant's counsel) without the express
     prior written consent of Landlord. Such consent shall not be unreasonably
     withheld as long as the proposed party to whom the report is given executes
     a letter agreement containing covenants similar to this Section 25.(v).
     Tenant releases Landlord for any inaccuracies, omissions, or errors
     contained in the Report. Tenant agrees that it will not rely on the Report
     and it will make whatever independent investigation it feels is necessary
     to investigate the environmental and other conditions of the Land. Tenant
     agrees that Landlord has no duty to provide it with the Report, to correct
     any inaccuracies, errors, or omission in the Report, to supplement the
     Report with any additional information, or to provide Tenant with any
     information concerning the environmental conditions of the Land. Tenant
     agrees that Landlord considers the Report to be confidential proprietary
     information and Tenant agrees to maintain the confidentiality and security
     of the Report information in accordance with the highest standards of
     confidentiality and security associated with the protection of "trade
     secrets." Landlord hereby expressly disclaims responsibility for the
     investigation of the Land by Tenant and further disclaims any
     responsibility for the contents of the Report. Tenant's obligations
     pursuant to this Section 25.(v) shall survive the expiration or termination
     of this Lease.

          (3) Landlord represents and warrants to Tenant that to the best of
     Landlord' s actual knowledge (not constructive), without any duty of
     inquiry, Landlord has not received written notice of any Hazardous
     Materials on the Land or the Premises in violation of any environmental
     Law. Landlord and Tenant each specifically acknowledge and agree that all
     references in this Lease to the phrase "to the best of Landlord's actual
     knowledge" (or other similar phrase) (1) shall mean the actual (not
     constructive) personal knowledge of Landlord' s individual asset manager,
     Paul Garancis ("Landlord's Personnel"); (2) shall in no case mean or refer
                     --------------------
     to the actual or constructive knowledge of any other employee, trustee,
     partner, agent or partner of a partner, officer, director or other
     representative of Landlord or any investment advisor, attorney, contractor
     or representative of Landlord (together with Landlord's Personnel,
     "Landlord's Representatives"); and (3) shall in no event or circumstance
      --------------------------
     impose upon Landlord or any of Landlord's Representatives any duty or
     obligation to verify, inquire or make any independent inquiry or
     investigation of any such representation, warranty or statement, or to
     otherwise investigate the facts or circumstances relating or otherwise
     pertinent thereto. Tenant further acknowledges and agrees that none of
     Landlord's Representatives shall be personally liable, or otherwise have
     any personal liability, under or in connection with this Lease, including
     without limitation, in connection with any of the representations,
     warranties or statements made in connection with, or pursuant to, this
     Lease.

                                      25
<PAGE>

          (w) List of Exhibits.  All exhibits and attachments attached hereto
              ----------------
are incorporated herein by this reference.

          Exhibit A-1 -  Outline of Premises
          Exhibit A-2 -  Outline of Opportunity Space
          Exhibit B -    Description of the Land
          Exhibit C -    Building Rules and Regulations
          Exhibit D -    Tenant Finish-Work:  Allowance
          Exhibit E -    Form of Confirmation of Commencement Date Letter
          Exhibit F -    Form of Tenant Estoppel Certificate
          Exhibit G -    Parking
          Exhibit H -    Renewal Option
          Exhibit I -    Right of First Opportunity
          Exhibit J -    Form of Letter of Credit
          Exhibit K -    Janitorial Specifications
          Exhibit L -    Form of Subordination, Non-Disturbance and Attornment
                         Agreement

     26.  Other Provisions.
          ----------------

          (a) Attorneys' Fees.  If there is any legal or arbitration action or
              ---------------
proceeding between Landlord and Tenant to enforce any provision of this Lease or
to protect or establish any right or remedy of either Landlord or Tenant
hereunder, the unsuccessful party to such action or proceeding will pay to the
prevailing party all reasonable, actual out-of-pocket costs and expenses paid or
payable to third parties, including reasonable attorneys' fees incurred by such
prevailing party in such action or proceeding and in any appeal in connection
therewith, and if such prevailing party recovers a judgment in any such action,
proceeding or appeal, such costs, expenses and attorneys' fees will be
determined by the court or arbitration panel handling the proceeding and will be
included in and as a part of such judgment.

          (b) Signage.  Following the leasing by Tenant of at least two full
              -------
floors in the Building and subject to (1) the rights of other tenants in the
Building and (2) Landlord's prior approval of the location, design, size, color,
material composition, and plans and specifications therefor, Tenant may, at its
sole risk and expense, install Tenant's trade name (the "Sign") on the black
                                                         ----
marble retaining wall adjacent to the main entrance of the Building.  If
Landlord grants its approval, Tenant shall erect the Sign in accordance with the
approved plans and specifications, in a good and workmanlike manner, in
accordance with all laws, regulations, restrictions (governmental or otherwise),
and architectural guidelines in effect for the area in which the Building is
located (including the Las Colinas Association) and has received all requisite
approvals thereunder (the "Sign Requirements"), and in a manner so as not to
                           -----------------
unreasonably interfere with the use of the Building grounds while such
construction is taking place; thereafter, Tenant shall maintain the Sign in a
good, clean, and safe condition in accordance with the Sign Requirements.  After
the end of the Term or after Tenant's right to possess the Premises has been
terminated, Landlord (A) may require that Tenant remove the Sign by delivering
to Tenant written notice thereof within 30 days after the end of the Term or (B)
may use the Sign, in which case the Sign shall become the property of Landlord
without compensation to Tenant.  If Landlord so requests, Tenant shall remove
the Sign, repair all damage caused thereby, and restore the black marble
retaining wall to its condition before the installation of the Sign within ten
business days after Landlord's request therefor.  If Tenant fails to timely do
so, Landlord may, without compensation to Tenant, (i) use the Sign or (ii) at
Tenant's expense, remove the Sign, perform the related restoration and repair
work and dispose of the Sign in any manner Landlord deems appropriate.
Notwithstanding

                                      26
<PAGE>

Landlord's indemnification contained in Section 11.(d), it is the intention of
the parties that Tenant bear all risks relating to the installation, use,
maintenance, operation, and removal of the Sign; therefore, Tenant shall defend,
indemnify, and hold harmless Landlord, its agents, and their respective
affiliates from all losses, claims, costs, and liabilities arising in connection
with or relating to the installation, maintenance, use, operation, and removal
of the Sign, including, without limitation, that arising from Landlord's
negligence (other than its sole or gross negligence). The rights granted to
Tenant under this Section 26.(b) are personal to Tenfold Corporation, may not be
assigned to any party, and may be revoked by Landlord if Tenant ceases to lease
at least two full floors in the Building or if Tenant ceases to occupy a portion
of the Premises.

           [THE REMAINDER OF THIS PAGE IS INTENTIONALLY LEFT BLANK]

                                      27
<PAGE>

LANDLORD AND TENANT EXPRESSLY DISCLAIM ANY IMPLIED WARRANTY THAT THE PREMISES
ARE SUITABLE FOR TENANT'S INTENDED COMMERCIAL PURPOSE, AND TENANT'S OBLIGATION
TO PAY RENT HEREUNDER IS NOT DEPENDENT UPON THE CONDITION OF THE PREMISES OR THE
PERFORMANCE BY LANDLORD OF ITS OBLIGATIONS HEREUNDER, AND, EXCEPT AS OTHERWISE
EXPRESSLY PROVIDED HEREIN, TENANT SHALL CONTINUE TO PAY THE RENT, WITHOUT
ABATEMENT, DEMAND, SETOFF OR DEDUCTION, NOTWITHSTANDING ANY BREACH BY LANDLORD
OF ITS DUTIES OR OBLIGATIONS HEREUNDER, WHETHER EXPRESS OR IMPLIED.

     Dated as of the date first above written.


LANDLORD:                     W9/CGN REAL ESTATE LIMITED PARTNERSHIP,
                              a Delaware limited partnership
                              By: W9/CGN Gen-Par, Inc., a Delaware corporation,
                                  its general partner

                                  By: /s/ William G. Mundinger II
                                     ----------------------------------------
                                  Name:  William G. Mundinger II
                                       --------------------------------------
                                  Title: Assistant Vice President
                                        -------------------------------------


TENANT:                       TENFOLD CORPORATION, a Delaware corporation


                              By: /s/ Robert P. Hughes
                                 --------------------------------------------
                              Name:  Robert P. Hughes
                                   ------------------------------------------
                              Title: Chief Financial Officer
                                    -----------------------------------------

                                      28
<PAGE>

                                  EXHIBIT A-1
                                  -----------

                              OUTLINE OF PREMISES
                              -------------------

                                     A-1-1
<PAGE>

                                  EXHIBIT A-2
                                  -----------

                         OUTLINE OF OPPORTUNITY SPACE
                         ----------------------------

                                     A-2-1
<PAGE>

                                   EXHIBIT B
                                   ---------


                            DESCRIPTION OF THE LAND
                            -----------------------

     Being a 4.982 acre tract of land situated in the S.A. & M.G.R.R. Survey,
     Abstract No. 1452, Dallas County, Texas, said 4.982 acre tract being all of
     Lot 1, Block A, Las Colinas Urban Center, Nineteenth Installment Revised,
     an addition to the City of Irving, Dallas County, Texas as recorded in
     Volume 88192, Page 2950, Plat Records, Dallas County, Texas, said 4.982
     acre tract being more particularly described as follows:

     BEGINNING at a set point on a corner cutoff line of the northeasterly
     right-of-way line on El Lago Boulevard (110' R.O.W.), said iron pin being
     the most easterly southeast corner of said El Lago Boulevard as recorded in
     Volume 80246, Page 2835, Deed Records of Dallas County, Texas;

     THENCE N 55 degrees 44'02" W, 60.66 feet along a corner cutoff line of said
     ------
     El Lago Boulevard to a set 'x' in concrete for an angle point;

     THENCE N 15 degrees 02'47" W, a distance of 385.46 feet along said
     ------
     northeasterly line to a set 'x' in concrete for an angle point;

     THENCE N 29 degrees 57'13" E, a distance of 56.57 feet along a corner
     ------
     cutoff line to a set 'x' in concrete for an angle point on the southerly
     right-of-way line of Las Colinas Boulevard (1100 R.O.W.);

     THENCE easterly along said southerly line of Las Colinas Boulevard as
     ------
     follows:

          N 74 degrees 57'13" E, a distance of 20.00 feet to a set 'x' in
          concrete for the beginning of a curve to the right having a central
          angle of 18 degree 50'41" and a radius of 765.51 feet and a chord
          bearing and distance of N 84 degrees 22'33" E, 251.63 feet;

          Easterly an arc distance of 252.76 feet to a set 'x' in concrete for
          an angle point said point being the common line of said Lot 1 and Lot
          2, Block A, Las Colinas Urban Center, Nineteenth Installment Revised,
          an addition to the City of Irving as recorded in Volume 88192, Page
          2950, Plat Records, Dallas County, Texas;

     THENCE continuing along said common line S 69E0401800 E, a distance of 5.49
     ------
     feet departing said southerly line of Las Colinas Boulevard to a set 'x' in
     concrete for corner, said 'x' being the beginning of a nontangent curve to
     the right having a central angle of 26 degrees 25'51", a radius of 265.00
     feet, and a long chord bearing of S 49 degrees 22'45" E, for a distance of
     121.17 feet;

     THENCE continuing along said common line southeasterly an arc distance of
     ------
     122.25 feet to a set 'x' in concrete, said 'x' being the beginning of a
     nontangent curve to the left having

                                      B-1
<PAGE>

     a central angle of 138 degrees 48' 01" and a radius of 61.30 feet and a
     long cord bearing and distance of N 62 degrees 22'18" W, 114.76 feet;

     THENCE continuing along said common line along said curve an arc distance
     ------
     of 148.50 feet to a set 'x' in concrete, said 'x' being the end of said
     curve;

     THENCE continuing along said common line, S 15 degrees 05'46" E, a portion
     ------
     of said line lying along the easterly face of a multi-story parking garage,
     a distance of 381.02 feet, to a set iron pin on the northerly right-of-way
     line of Rochelle Boulevard (110' R.O.W.);

     THENCE departing said common line westerly along said northerly line of
     ------
     said Rochelle Boulevard as follows:

          Westerly along a curve to the right having a central angle of 06
          degrees 08'07" and a radius of 1206.13 feet, and a long chord bearing
          and a distance of N 88 degrees 45'05" W, 129.09 feet, an arc being the
          end of said curve;

          N 85 degrees 41'02" W, a distance of 192.92 feet to a set iron pin,
          said iron pin being the beginning of a curve to the left having a
          central angle 9E1501500 and a radius of 771.20 feet and a long chord
          bearing and distance of S 89 degrees 41'16" W, 124.45 feet;

          Westerly, an arc distance of 124.60 feet to the POINT OF BEGINNING and
                                                          ------------------
          CONTAINING 4.982 acres of 217,008 square feet of land.
          ----------

                                      B-2
<PAGE>

                                   EXHIBIT C
                                   ---------


                        BUILDING RULES AND REGULATIONS
                        ------------------------------

     The following rules and regulations shall apply to the Premises, the
Building, the parking garage associated therewith, and the appurtenances
thereto:

     1.   Sidewalks, doorways, vestibules, halls, stairways, and other similar
areas shall not be obstructed by tenants or used by any tenant for purposes
other than ingress and egress to and from their respective leased premises and
for going from one to another part of the Building.

     2.   Plumbing, fixtures and appliances shall be used only for the purposes
for which designed, and no sweepings, rubbish, rags or other unsuitable material
shall be thrown or deposited therein.  Damage resulting to any such fixtures or
appliances from misuse by a tenant or its agents, employees or invitees, shall
be paid by such tenant.

     3.   No signs, advertisements or notices shall be painted or affixed on or
to any windows or doors or other part of the Building without the prior written
consent of Landlord. No nails, hooks or screws (other than those which are
necessary to hang paintings, prints, pictures, or other similar items on the
Premises' interior walls) shall be driven or inserted in any part of the
Building except by Building maintenance personnel. No curtains or other window
treatments shall be placed between the glass and the Building standard window
treatments.

     4.   Landlord shall provide and maintain an alphabetical directory for all
tenants in the main lobby of the Building.

     5.   Landlord shall provide all door locks in each tenant's leased
premises, at the cost of such tenant, and no tenant shall place any additional
door locks in its leased premises without Landlord's prior written consent.
Landlord shall furnish to each tenant a reasonable number of keys to such
tenant's leased premises, at such tenant's cost, and no tenant shall make a
duplicate thereof.

     6.   Movement in or out of the Building of furniture or office equipment,
or dispatch or receipt by tenants of any bulky material, merchandise or
materials which require use of elevators or stairways, or movement through the
Building entrances or lobby shall be conducted under Landlord's supervision at
such times and in such a manner as Landlord may reasonably require.  Each tenant
assumes all risks of and shall be liable for all damage to articles moved and
injury to persons or public engaged or not engaged in such movement, including
equipment, property and personnel of Landlord if damaged or injured as a result
of acts in connection with carrying out this service for such tenant.

     7.   Landlord may prescribe weight limitations and determine the locations
for safes and other heavy equipment or items, which shall in all cases be placed
in the Building so as to distribute weight in a manner acceptable to Landlord
which may include the use of such supporting devices as Landlord may require.
All damages to the Building caused by the installation or removal of any
property of a tenant, or done by a tenant's property while in the Building,
shall be repaired at the expense of such tenant.

                                      C-1
<PAGE>

     8.   Corridor doors, when not in use, shall be kept closed.  Nothing shall
be swept or thrown into the corridors, halls, elevator shafts or stairways.  No
birds or animals (other than seeing-eye dogs) shall be brought into or kept in,
on or about any tenant's leased premises. No portion of any tenant's leased
premises shall at any time be used or occupied as sleeping or lodging quarters.

     9.   Tenant shall cooperate with Landlord's employees in keeping its leased
premises neat and clean. Tenants shall not employ any person for the purpose of
such cleaning other than the Building's cleaning and maintenance personnel.

     10.  To ensure orderly operation of the Building, no ice, mineral or other
water, towels, newspapers, etc. shall be delivered to any leased area except by
persons approved by Landlord, which approval shall not be unreasonably withheld.

     11.  Tenant shall not make or permit any vibration or improper,
objectionable or unpleasant noises or odors in the Building or otherwise
interfere in any way with other tenants or persons having business with them.

     12.  No machinery of any kind (other than normal office equipment) shall be
operated by any tenant on its leased area without Landlord's prior written
consent, nor shall any tenant use or keep in the Building any flammable or
explosive fluid or substance (other than typical office supplies [e.g.,
photocopier toner] used in compliance with all Laws).

     13.  Landlord will not be responsible for lost or stolen personal property,
money or jewelry from tenant's leased premises or public or common areas
regardless of whether such loss occurs when the area is locked against entry or
not.

     14.  No vending or dispensing machines of any kind may be maintained in any
leased premises without the prior written permission of Landlord, which approval
shall not be unreasonably withheld.

     15.  Tenant shall not conduct any activity on or about the Premises or
Building which will draw pickets, demonstrators, or the like.

     16.  All vehicles are to be currently licensed, in good operating
condition, parked for business purposes having to do with Tenant's business
operated in the Premises, parked within designated parking spaces, one vehicle
to each space. No vehicle shall be parked as a "billboard" vehicle in the
parking lot. Any vehicle parked improperly may be towed away. Tenant, Tenant's
agents, employees, vendors and customers who do not operate or park their
vehicles as required shall subject the vehicle to being towed at the expense of
the owner or driver. Landlord may place a "boot" on the vehicle to immobilize it
and may levy a charge of $50.00 to remove the "boot." Tenant shall indemnify,
hold and save harmless Landlord of any liability arising from the towing or
booting of any vehicles belonging to a Tenant Party.

     17.  No tenant may enter into phone rooms, electrical rooms, mechanical
rooms, or other service areas of the Building unless accompanied by Landlord or
the Building manager.

                                      C-2
<PAGE>

                                   EXHIBIT D
                                   ---------


                         TENANT FINISH-WORK: ALLOWANCE
                         -----------------------------
                         (Landlord Performs the Work)

     1.   Acceptance of Premises.  Except as set forth in this Exhibit, Tenant
          ----------------------
accepts the Premises in their "AS-IS" condition on the date that this Lease is
                               -----
entered into.  Notwithstanding the foregoing, Landlord, shall, at its expense,
make such alterations to ensure that the drinking fountains currently located in
the Premises comply with the Americans With Disabilities Act.

     2.   Space Plans.
          -----------

          (a)  Preparation and Delivery.  Landlord and Tenant hereby approve the
               ------------------------
space plans dated December 23, 1999, prepared by da&a architects (the
"Architect") depicting improvements to be installed in the Premises (the "Space
 ---------                                                                -----
Plans").
-----

          (b)  Approval Process.  [Intentionally deleted.]
               ----------------

     3.   Working Drawings.
          ----------------

          (a)  Preparation and Delivery.  On or before February 4, 2000 (the
               ------------------------
"Working Drawings Delivery Deadline"), Tenant shall provide to Landlord for its
 ----------------------------------
approval final working drawings, prepared by the Architect, of all improvements
that Tenant proposes to install in the Premises; such working drawings shall
include the partition layout, ceiling plan, electrical outlets and switches,
telephone outlets, drawings for any modifications to the mechanical and plumbing
systems of the Building, and detailed plans and specifications for the
construction of the improvements called for under this Exhibit in accordance
with all applicable Laws. If Tenant fails to timely deliver such drawings, then
each day after the Working Drawings Delivery Deadline that such drawings are not
delivered to Landlord shall be a Tenant Delay Day.

          (b)  Approval Process. Landlord shall notify Tenant whether it
               ----------------
approves of the submitted working drawings within five business days after
Tenant's submission thereof. If Landlord disapproves of such working drawings,
then Landlord shall notify Tenant thereof specifying in reasonable detail the
reasons for such disapproval, in which case Tenant shall, within five business
days after such notice, revise such working drawings in accordance with
Landlord's objections and submit the revised working drawings to Landlord for
its review and approval. Landlord shall notify Tenant in writing whether it
approves of the resubmitted working drawings within three business days after
its receipt thereof. This process shall be repeated until the working drawings
have been finally approved by Tenant and Landlord. If Landlord fails to notify
Tenant that it disapproves of the initial working drawings within five business
days (or, in the case of resubmitted working drawings, within three business
days) after the submission thereof, then Landlord shall be deemed to have
approved the working drawings in question. If the working drawings are not fully
approved (or deemed approved) by both Landlord and Tenant by the 15th business
day after the delivery of the initial draft thereof to Landlord, then each day
after such time period that such working drawings are not fully approved (or
deemed approved) by both Landlord and Tenant shall constitute a Tenant Delay
Day.

                                      D-1
<PAGE>

          (c)  Landlord's Approval; Performance of Work.  If any of Tenant's
               ----------------------------------------
proposed construction work will affect the Building's Structure or the
Building's Systems, then the working drawings pertaining thereto must be
approved by the Building's engineer of record.  Landlord's approval of such
working drawings shall not be unreasonably withheld, provided that (1) they
comply with all Laws, (2) the improvements depicted thereon do not adversely
affect (in the reasonable discretion of Landlord) the Building's Structure or
the Building's Systems (including the Building's restrooms or mechanical rooms),
the exterior appearance of the Building, or the appearance of the Building's
common areas or elevator lobby areas, (3) such working drawings are sufficiently
detailed to allow construction of the improvements in a good and workmanlike
manner, and (4) the improvements depicted thereon conform to the rules and
regulations promulgated from time to time by Landlord for the construction of
tenant improvements (a copy of which has been delivered to Tenant).  As used
herein, "Working Drawings" shall mean the final working drawings approved by
         ----------------
Landlord, as amended from time to time by any approved changes thereto, and
"Work" shall mean all improvements to be constructed in accordance with and as
 ----
indicated on the Working Drawings, together with any work required by
governmental authorities to be made to other areas of the Building as a result
of the improvements indicated by the Working Drawings. Landlord's approval of
the Working Drawings shall not be a representation or warranty of Landlord that
such drawings are adequate for any use or comply with any Law, but shall merely
be the consent of Landlord thereto. Tenant shall, at Landlord's request, sign
the Working Drawings to evidence its review and approval thereof. After the
Working Drawings have been approved, Landlord shall cause the Work to be
performed in substantial accordance with the Working Drawings.

     4.   Bidding of Work.  Constructors & Associates, Inc. of Dallas, Texas, is
          ---------------
hereby deemed approved by Landlord. If Tenant elects to use a general contractor
other than Constructors & Associates, Inc., prior to commencing the Work,
Landlord shall competitively bid the Work to three contractors approved by
Landlord. If the estimated Total Construction Costs are expected to exceed the
Construction Allowance, Tenant shall be allowed to review the submitted bids
from such contractors to value engineer any of Tenant's requested alterations.
In such case, Tenant shall notify Landlord of any items in the Working Drawings
that Tenant desires to change within two business days after Landlord's
submission thereof to Tenant. If Tenant fails to notify Landlord of its election
within such two business day period, Tenant shall be deemed to have approved the
bids. Within five business days following Landlord's submission to Tenant of the
initial construction bids to Tenant under the foregoing provisions (if
applicable), Tenant shall have completed all of the following items: (a)
finalized with Landlord's representative and the proposed contractor, the
pricing of any requested revisions to the bids for the Work, and (b) approved in
writing any overage in the Total Construction Costs in excess of the
Construction Allowance, failing which each day after such five business day
period shall constitute a Tenant Delay Day.

     5.   Change Orders.  Tenant may initiate changes in the Work.  Each such
          -------------
change must receive the prior written approval of Landlord, such approval not to
be unreasonably withheld or delayed; however, (a) if such requested change would
adversely affect (in the reasonable discretion of Landlord) (1) the Building's
Structure or the Building's Systems (including the Building's restrooms or
mechanical rooms), (2) the exterior appearance of the Building, or (3) the
appearance of the Building's common areas or elevator lobby areas, or (b) if any
such requested change might delay the Commencement Date, Landlord may withhold
its consent in its sole and absolute discretion.  Tenant shall, upon completion
of the Work, furnish Landlord with an accurate architectural "as-built" plan of
the Work as constructed, which plan shall be incorporated into this Exhibit D by
                                                                    ---------
this reference for all purposes. If Tenant requests any changes to the Work
described in the Space Plans or the Working Drawings, then such increased costs
and any additional

                                      D-2
<PAGE>

design costs incurred in connection therewith as the result of any such change
shall be added to the Total Construction Costs.

     6.   Definitions.  As used herein, a "Tenant Delay Day" shall mean each
          -----------                      ----------------
day of delay in the performance of the Work that occurs (a) because of Tenant's
failure to timely deliver or approve any required documentation such as the
Space Plans or Working Drawings, (b) because of any change by Tenant to the
Space Plans or Working Drawings, (c) because of any specification by Tenant of
materials or installations in addition to or other than Landlord's standard
finish-out materials, or (d) because a Tenant Party otherwise delays completion
of the Work.  As used herein "Substantial Completion," "Substantially
                              ----------------------    -------------
Completed," and any derivations thereof mean (1) the Work in the Premises is
---------
substantially completed (as reasonably determined by Landlord) in substantial
accordance with the Working Drawings and (2) the applicable municipality has
issued and Tenant has received authorization from the City of Irving (as
evidenced by the issuance of so-called "green tag") to occupy the Premises.
Substantial Completion shall have occurred even though minor details of
construction, decoration, landscaping and mechanical adjustments remain to be
completed by Landlord.

     7.   Walk-Through; Punchlist.  When Landlord considers the Work in the
          -----------------------
Premises to be Substantially Completed, Landlord will notify Tenant and within
three business days thereafter, Landlord's representative and Tenant's
representative shall conduct a walk-through of the Premises and identify any
necessary touch-up work, repairs and minor completion items that are necessary
for final completion of the Work. Neither Landlord's representative nor Tenant's
representative shall unreasonably withhold his or her agreement on punchlist
items. Landlord shall use reasonable efforts to cause the contractor performing
the Work to complete all punchlist items within 30 days after agreement thereon;
however, Landlord shall not be obligated to engage overtime labor in order to
complete such items.

     8.   Excess Costs.  The entire cost of performing the Work (including
          ------------
design of the Work and preparation of the Working Drawings, costs of
construction labor and materials, additional janitorial services, general tenant
signage, related taxes and insurance costs, and the construction supervision fee
referenced in Section 10 of this Exhibit, all of which costs are herein
collectively called the "Total Construction Costs") in excess of the
                         ------------------------
Construction Allowance (hereinafter defined) shall be paid by Tenant. Upon
approval of the Working Drawings and selection of a contractor, Tenant shall
promptly (a) execute a work order agreement prepared by Landlord which
identifies such drawings and itemizes the Total Construction Costs and sets
forth the Construction Allowance, and (b) pay to Landlord 50% of the amount by
which Total Construction Costs exceed the Construction Allowance. Upon
Substantial Completion of the Work and before Tenant occupies the Premises to
conduct business therein, Tenant shall pay to Landlord an amount equal to the
Total Construction Costs (as adjusted for any approved changes to the Work),
less (1) the amount of the advance payment already made by Tenant, and (2) the
amount of the Construction Allowance. In the event of default of payment of such
excess costs, Landlord (in addition to all other remedies) shall have the same
rights as for an Event of Default under the Lease.

     9.   Construction Allowance.  Landlord shall provide to Tenant a
          ----------------------
construction allowance not to exceed $18.00 per rentable square foot in the
Premises (the "Construction Allowance") to be applied toward the Total
               ----------------------
Construction Costs, as adjusted for any changes to the Work. The Construction
Allowance shall not be disbursed to Tenant in cash, but shall be applied by
Landlord to the payment of the Total Construction Costs, if, as, and when the
cost of the Work is actually incurred and paid by Landlord. The Construction
Allowance must be used within six months following the Commencement Date or
shall be deemed forfeited with no further obligation by Landlord with respect
thereto. From the Construction

                                      D-3
<PAGE>

Allowance, Tenant may apply up to $1.00 per rentable square foot in the Premises
of such allowance to pay for the costs of Tenant's architectural and MEP fees.

     10.  Construction Management.  Landlord or its Affiliate or agent shall
          -----------------------
supervise the Work, make disbursements required to be made to the contractor,
and act as a liaison between the contractor and Tenant and coordinate the
relationship between the Work, the Building and the Building's Systems. In
consideration for Landlord's construction supervision services, Tenant shall pay
to Landlord a construction supervision fee equal to four percent of the Total
Construction Costs.

     11.  Construction Warranty.  As part of the construction contract with
          ---------------------
general contractor performing the Work in the Premises, Landlord shall obtain a
one-year construction warranty with respect to the Work therein, beginning on
the date of Substantial Completion (such time period is referred to herein as
the "Warranty Period"). During the Warranty Period, if Tenant notifies Landlord
     ---------------
of any defect in the workmanship or construction of the Work, then Landlord
shall enforce such construction warranty against the general contractor on
Tenant's behalf. Such construction warranty shall expire and be of no further
force or effect (and neither the general contractor nor Landlord shall have any
obligation of repair relative thereto), for any defect with respect to the Work
that Tenant fails to make a written claim to Landlord relative to such defect on
or before the expiration of the Warranty Period. Notwithstanding the foregoing,
in no event shall Landlord or the general contractor have any liability for any
defects in the Work caused by any deficiencies in the Working Drawings, and,
with respect to any such defects, Tenant shall rely solely on any warranties it
separately obtains from its Architect.

     12.  Early Entry by Tenant.  Tenant may enter the Premises before the
          ---------------------
Premises are in a substantially completed condition with Landlord's prior
consent (which shall not be unreasonably withheld) to perform work therein
(including data cabling, telephone and data equipment, security, audio/visual
equipment, white noise, and furniture systems), provided that (a) Landlord is
given prior written notice of any such entry, (b) such entry shall be
coordinated with Landlord and shall not interfere with Landlord's work, and (c)
Tenant shall deliver to Landlord evidence that the insurance required under
Section 11.(a) of this Lease has been obtained. Any such entry shall be on the
terms of this Lease, but no rent shall accrue in respect of Basic Rent or
Operating Costs, during the period that Tenant so enters the Premises prior to
the Commencement Date. Tenant shall conduct its activities therein so as not to
interfere with Landlord's construction activities, and shall do so at its risk
and expense. If, in Landlord's judgment, Tenant's activities therein interfere
with Landlord's construction activities, Landlord may terminate Tenant's right
to enter the Premises before the Commencement Date.

     13.  Construction Representatives.  Landlord's and Tenant's representatives
          ----------------------------
for coordination of construction and approval of change orders will be as
follows, provided that either party may change its representative upon written
notice to the other:

     Landlord's Representative:      Kathy Boop
                                     c/o Grubb & Ellis Management Services, Inc.
                                     14785 Preston Road, Suite 1000
                                     Dallas, Texas 75240
                                     Telephone: 972-450-3300
                                     Telecopy: 972-450-3239

                                      D-4
<PAGE>

     Tenant's Representative:        Gina Katigbak
                                     c/o Tenfold Corporation
                                     100 Foster City Boulevard
                                     Suite 200
                                     Foster City, California  94404
                                     Telephone: 650-570-5711
                                     Telecopy: 650-570-5988

     14.  Miscellaneous.  To the extent not inconsistent with this Exhibit,
          -------------
Sections 8.(a) and 21 of this Lease shall govern the performance of the Work and
Landlord's and Tenant's respective rights and obligations regarding the
improvements installed pursuant thereto.

                                      D-5
<PAGE>

                                   EXHIBIT E
                                   ---------

                       CONFIRMATION OF COMMENCEMENT DATE
                       ---------------------------------


                             ______________, 2000


Tenfold Corporation

__________________________
__________________________
__________________________

     Re:  Lease Agreement (the "Lease") dated February 4, 2000, between W9/CGN
                                -----
          Real Estate Limited Partnership, a Delaware limited partnership
          ("Landlord"), and Tenfold Corporation, a Delaware corporation
            --------
          ("Tenant"). Capitalized terms used herein but not defined shall be
            ------
          given the meanings assigned to them in the Lease.

Ladies and Gentlemen:

     Landlord and Tenant agree as follows:

     1.   Condition of Premises.  Tenant has accepted possession of the Premises
          ---------------------
pursuant to the Lease. Any improvements required by the terms of the Lease to be
made by Landlord have been completed to the full and complete satisfaction of
Tenant in all respects except for the punchlist items described on Exhibit A
                                                                   ---------
hereto (the "Punchlist Items"), and except for such Punchlist Items, Landlord
             ---------------
has fulfilled all of its duties under the Lease with respect to such initial
tenant improvements. Furthermore, Tenant acknowledges that the Premises are
suitable for the Permitted Use.

     2.   Commencement Date.  The Commencement Date of the Lease is __________,
          -----------------
2000.

     3.   Expiration Date.  The Term is scheduled to expire on the last day of
          ---------------
the 60th full calendar month of the Term, which date is ______________, 2005.

     4.   Contact Person.  Tenant's contact person in the Premises is:
          --------------

          Tenfold Corporation
          600 Las Colinas Boulevard, Suite 600
          Irving, Texas 75039
          Attention: ____________________
          Telephone:  ____- ___-_____
          Telecopy:  ____- ___-_____

     5.   Ratification.  Tenant hereby ratifies and confirms its obligations
          ------------
under the Lease, and represents and warrants to Landlord that it has no defenses
thereto.  Additionally, Tenant further confirms and ratifies that, as of the
date hereof, (a) the Lease is and remains in good standing and in full force and

                                      E-1
<PAGE>

effect, and (b) Tenant has no claims, counterclaims, set-offs or defenses
against Landlord arising out of the Lease or in any way relating thereto or
arising out of any other transaction between Landlord and Tenant.

     6.   Binding Effect; Governing Law.  Except as modified hereby, the Lease
          -----------------------------
shall remain in full effect and this letter shall be binding upon Landlord and
Tenant and their respective successors and assigns. If any inconsistency exists
or arises between the terms of this letter and the terms of the Lease, the terms
of this letter shall prevail.  This letter shall be governed by the laws of the
state in which the Premises are located.

     Please indicate your agreement to the above matters by signing this letter
in the space indicated below and returning an executed original to us.

                                        Sincerely,

                                        GRUBB & ELLIS MANAGEMENT SERVICES, INC.


                                        By:_____________________________________
                                        Name:___________________________________
                                        Title:__________________________________


Agreed and accepted:

TENFOLD CORPORATION, a Delaware corporation


By:________________________________
Name:______________________________
Title:_____________________________

                                      E-2
<PAGE>

                                   EXHIBIT A
                                   ---------


                                PUNCHLIST ITEMS
                                ---------------

Please insert any punchlist items that remain to be performed by Landlord. If no
items are listed below by Tenant, none shall be deemed to exist.

                                      E-3
<PAGE>

                                   EXHIBIT F
                                   ---------


                      FORM OF TENANT ESTOPPEL CERTIFICATE
                      -----------------------------------


     The undersigned is the Tenant under the Lease (defined below) between
_______________________, a ___________________, as Landlord, and the undersigned
as Tenant, for the Premises on the __________ floor(s) of the office building
located at _____________________, __________ and commonly known as
_______________________, and hereby certifies as follows:

     1.   The Lease consists of the original Lease Agreement dated as of
___________, 2000, between Tenant and Landlord ['s predecessor-in-interest] and
the following amendments or modifications thereto (if none, please state
"none"):________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________

The documents listed above are herein collectively referred to as the "Lease"
                                                                       -----
and represent the entire agreement between the parties with respect to the
Premises. All capitalized terms used herein but not defined shall be given the
meaning assigned to them in the Lease.

     2.   The Lease is in full force and effect and has not been modified,
supplemented or amended in any way except as provided in Section 1 above.

     3.   The Term commenced on __________________, 200__, and the Term expires,
excluding any renewal options, on _____________________, 200__, and Tenant has
no option to purchase all or any part of the Premises or the Building or, except
as expressly set forth in the Lease, any option to terminate or cancel the
Lease.

     4.   Tenant currently occupies the Premises described in the Lease and
Tenant has not transferred, assigned, or sublet any portion of the Premises nor
entered into any license or concession agreements with respect thereto except as
follows (if none, please state "none"):_________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________

     5.   All monthly installments of Basic Rent, all Additional Rent and all
monthly installments of estimated Additional Rent have been paid when due
through _____________. The current monthly installment of Basic Rent is
$__________.

     6.   All conditions of the Lease to be performed by Landlord necessary to
the enforceability of the Lease have been satisfied and Landlord is not in
default thereunder. In addition, Tenant has not delivered any notice to Landlord
regarding a default by Landlord thereunder.

     7.   As of the date hereof, there are no existing defenses or offsets, or,
to the undersigned's knowledge, claims or any basis for a claim, that the
undersigned has against Landlord and no event has

                                      F-1
<PAGE>

occurred and no condition exists, which, with the giving of notice or the
passage of time, or both, will constitute a default under the Lease.

     8.   No rental has been paid more than 30 days in advance and no security
deposit has been delivered to Landlord except as provided in the Lease.

     9.   If Tenant is a corporation, partnership or other business entity, each
individual executing this Estoppel Certificate on behalf of Tenant hereby
represents and warrants that Tenant is a duly formed and existing entity
qualified to do business in the state in which the Premises are located and that
Tenant has full right and authority to execute and deliver this Estoppel
Certificate and that each person signing on behalf of Tenant is authorized to do
so.

     10.  There are no actions pending against Tenant under any bankruptcy or
similar laws of the United States or any state.

     11.  Other than in compliance with all applicable laws and incidental to
the ordinary course of the use of the Premises, the undersigned has not used or
stored any hazardous substances in the Premises.

     12.  All tenant improvement work to be performed by Landlord under the
Lease has been completed in accordance with the Lease and has been accepted by
the undersigned and all reimbursements and allowances due to the undersigned
under the Lease in connection with any tenant improvement work have been paid in
full.

     Tenant acknowledges that this Estoppel Certificate may be delivered to
Landlord, Landlord's Mortgagee or to a prospective mortgagee or prospective
purchaser, and their respective successors and assigns, and acknowledges that
Landlord, Landlord's Mortgagee and/or such prospective mortgagee or prospective
purchaser will be relying upon the statements contained herein in disbursing
loan advances or making a new loan or acquiring the property of which the
Premises are a part and that receipt by it of this certificate is a condition of
disbursing loan advances or making such loan or acquiring such property.

Executed as of __________, 200_.


TENANT:                                 _______________________________________,
                                        a ______________________________________


                                        By:_____________________________________
                                        Name:___________________________________
                                        Title:__________________________________

                                      F-2
<PAGE>

                                   EXHIBIT G
                                   ---------


                                    PARKING
                                    -------

     Tenant may use up to 108 undesignated parking spaces and seven reserved
parking spaces in the parking garage/area associated with the Building (the
"Parking Area") during the initial Term subject to such terms, conditions and
 ------------
regulations as are from time to time applicable to patrons of the Parking Area.
Prior to April 1, 2003, the parking spaces granted to Tenant hereunder shall be
provided at no charge to Tenant. On and after April 1, 2003, and continuing
until the end of the initial Term, Tenant shall pay $40.00 per undesignated
parking space per month (plus any applicable taxes) for each undesignated
parking space leased hereunder and $125.00 (plus any applicable taxes) for each
of the reserved parking spaces leased hereunder, in each case, regardless of
whether Tenant elects to use such parking spaces. Following the expiration of
the initial Term, Tenant shall pay to Landlord for each parking space leased
hereunder, regardless of whether Tenant elects to use such parking space, the
amount charged to patrons of the Parking Area, as the same may change from time
to time. If, for any reason, Landlord is unable to provide Tenant the use of all
or any portion of the parking spaces to which it is entitled hereunder, then
Tenant's obligation to pay for such spaces shall be abated for so long as Tenant
does not have the use thereof; this abatement shall be in full settlement of all
claims that Tenant might otherwise have against Landlord because of Landlord's
failure or inability to provide Tenant with such parking spaces.

                                      G-1
<PAGE>

                                   EXHIBIT H
                                   ---------


                                RENEWAL OPTION
                                --------------

     Provided no Event of Default exists and Tenant is occupying the entire
Premises at the time of such election, Tenant may renew this Lease for one
additional period of five years, by delivering written notice of the exercise
thereof to Landlord not earlier than 12 months nor later than nine months before
the expiration of the Term. The Basic Rent payable for each month during such
extended Term shall be the prevailing rental rate (the "Prevailing Rental
                                                        -----------------
Rate"), at the commencement of such extended Term, for renewals of space in the
Building of equivalent quality, size, utility and location, with the length of
the extended Term and the credit standing of Tenant to be taken into account.
Within 30 days after receipt of Tenant's notice to renew, Landlord shall deliver
to Tenant written notice of the Prevailing Rental Rate and shall advise Tenant
of the required adjustment to Basic Rent, if any, and the other terms and
conditions offered. Tenant shall, within ten days after receipt of Landlord's
notice, notify Landlord in writing whether Tenant accepts or rejects Landlord's
determination of the Prevailing Rental Rate. If Tenant timely notifies Landlord
that Tenant accepts Landlord's determination of the Prevailing Rental Rate,
then, on or before the commencement date of the extended Term, Landlord and
Tenant shall execute an amendment to this Lease extending the Term on the same
terms provided in this Lease, except as follows:

          (a)  Basic Rent shall be adjusted to the Prevailing Rental Rate;

          (b)  Tenant shall have no further renewal option unless expressly
     granted by Landlord in writing;

          (c)  Landlord shall lease to Tenant the Premises in their then-current
     condition, and Landlord shall not provide to Tenant any allowances (e.g.,
     moving allowance, construction allowance, and the like) or other tenant
     inducements; and

          (d)  Tenant shall pay for the parking spaces which it is entitled to
     use at the rates from time to time charged to patrons of the Parking Area
     and/or any other parking area associated with the Building during the
     extended Term (plus all applicable taxes).

If Tenant rejects Landlord's determination of the Prevailing Rental Rate, and
timely notifies Landlord thereof, Tenant may, in its notice to Landlord, require
that the determination of the Prevailing Rental Rate be made by brokers (and if
Tenant makes such election, Tenant shall be deemed to have irrevocably renewed
the Term, subject only to the determination of the Prevailing Rental Rate as
provided below). In such event, within ten days thereafter, each party shall
select a qualified commercial real estate broker with at least ten years
experience in appraising property and buildings in the city or submarket in
which the Premises are located. The two brokers shall give their opinion of
prevailing rental rates within 20 days after their retention. In no event,
however, shall the Basic Rent in the renewal term be less than the then current
Basic Rent rate per rentable square foot in effect hereunder. In the event the
opinions of the two brokers differ and, after good faith efforts over the
succeeding 20 day period, they cannot mutually agree, the brokers shall
immediately and jointly appoint a third broker with the qualifications specified
above. This third broker shall immediately (within five days) choose either the
determination of Landlord's broker or Tenant's broker and such choice of this
third broker shall be final and binding on Landlord and Tenant. Each party shall
pay its own costs for its real estate broker. Following the determination of the
Prevailing Rental Rate by the brokers,

                                      H-1
<PAGE>

the parties shall equally share the costs of any third broker. The parties shall
immediately execute an amendment as set forth above. If Tenant fails to timely
notify Landlord in writing that Tenant accepts or rejects Landlord's
determination of the Prevailing Rental Rate, time being of the essence with
respect thereto, Tenant's rights under this Exhibit shall terminate and Tenant
shall have no right to renew this Lease.

     Tenant's rights under this Exhibit shall terminate if (1) this Lease or
Tenant's right to possession of the Premises is terminated, (2) Tenant assigns
any of its interest in this Lease or sublets any portion of the Premises, or (3)
Tenant fails to timely exercise its option under this Exhibit, time being of the
essence with respect to Tenant's exercise thereof.

                                      H-2
<PAGE>

                                   EXHIBIT I
                                   ---------


                          RIGHT OF FIRST OPPORTUNITY
                          --------------------------

     1.   Subject to then-existing renewal or expansion options of other
tenants, if Landlord has a bona fide prospect other than the then-current tenant
therein (the "Prospect") for any portion of the space on the fifth floor
              --------
designated on Exhibit A (the "Opportunity Space"), Landlord shall offer to lease
              ---------       -----------------
to Tenant the Opportunity Space on the same terms and conditions as offered to
the Prospect; such offer shall be in writing, specify the rent to be paid for
the Opportunity Space, contain the basic terms and conditions offered to the
Prospect and the date on which the Opportunity Space shall be included in the
Premises (the "Opportunity Notice"). Tenant shall notify Landlord in writing
               ------------------
whether Tenant elects to lease the entire portion of the Opportunity Space
subject to the same terms and conditions as offered to the Prospect as outlined
in the Opportunity Notice within five business days after Landlord delivers to
Tenant the Opportunity Notice. If Tenant timely elects to lease the Opportunity
Space within such five-business-day period, then Landlord and Tenant shall
execute an amendment to this Lease, effective as of the date the Opportunity
Space is to be included in the Premises, on the same terms as this Lease except
(a) the Basic Rent shall be the amount specified in the Offer Notice, (b) the
term for the Opportunity Space shall be that specified in the Offer Notice, (c)
Tenant shall lease the Opportunity Space in an "AS-IS" condition, Landlord shall
                                                -----
not be required to perform any work therein, and Landlord shall not provide to
Tenant any allowances other than those contained in the Opportunity Notice
(e.g., moving allowance, construction allowance, and the like) if any, and (d)
other matters set forth in the Lease which are inconsistent with the terms of
the Opportunity Notice shall be modified accordingly. Notwithstanding the
foregoing, if the Opportunity Notice includes space in excess of the Opportunity
Space, Tenant must exercise its right hereunder, if at all, as to all of the
space contained in the Opportunity Notice. If Tenant fails or is unable to
timely exercise its right hereunder, then such right shall lapse, time being of
the essence with respect to the exercise thereof (it being understood that
Tenant's right hereunder is a one-time right only), and Landlord may lease all
or a portion of the Opportunity Space to third parties on such terms as Landlord
may elect. Tenant may not exercise its rights under this Exhibit if an Event of
Default exists or Tenant is not then occupying the entire Premises. For purposes
hereof, if an Opportunity Notice is delivered for less than all of the
Opportunity Space but such notice provides for an expansion, right of first
refusal, or other preferential right to lease some of the remaining portion of
the Opportunity Space, then such remaining portion of the Opportunity Space
shall thereafter be excluded from the provisions of this Exhibit.

     2.   Prior to September 30, 2001, if Tenant is unable to exercise its
rights as provided hereunder as to the Opportunity Space due to the exercise by
JPI, Inc., a Texas corporation, of its right to renew its lease as to any
portion of the Opportunity Space, then, as soon as reasonably practicable,
Landlord shall designate as the Opportunity Space the next available space in
the Building that consists of between 15,000 rentable square feet of area and a
full floor of the Building, and Tenant's rights as provided hereunder shall
continue only as to such newly-designated Opportunity Space subject to the terms
and conditions of this Exhibit G.
                       ---------

     3.   Tenant's rights under this Exhibit shall terminate if (a) this Lease
or Tenant's right to possession of the Premises is terminated, (b) Tenant
assigns any of its interest in this Lease or sublets any portion of the Premises
other than to a Permitted Transferee, or (c) Tenant fails timely to exercise its
option as to any portion of the Opportunity Space; provided, however, that if
Landlord delivers to Tenant the Opportunity Notice before January 1, 2001 and
Tenant does not elect to lease the Opportunity Space as provided in paragraph 1
of this Exhibit G within five business days after Landlord delivers to Tenant
        ---------
the

                                      I-1
<PAGE>

Opportunity Notice, then, as soon as reasonably practicable, Landlord shall
designate as the Opportunity Space the next available space in the Building that
consists of between 15,000 rentable square feet of area and a full floor of the
Building, and Tenant's rights as provided hereunder shall not terminate but
shall continue only as to such newly-designated Opportunity Space subject to the
terms and conditions of this Exhibit G.
                             ---------

                                      I-2
<PAGE>

                             FORM OF OFFER NOTICE
                             --------------------

[Insert Date of Notice]



BY TELECOPY AND FEDERAL EXPRESS
-------------------------------
Tenfold Corporation

_________________________________
_________________________________
_________________________________


     Re:  Lease Agreement (the "Lease") dated February 4, 2000, between W9/CGN
                                -----
          Real Estate Limited Partnership, a Delaware limited partnership
          ("Landlord"), and Tenfold Corporation, a Delaware corporation
            --------                                      ------
          ("Tenant"). Capitalized terms used herein but not defined shall be
            ------
          given the meanings assigned to them in the Lease.

Ladies and Gentlemen:

     Pursuant to the Right of First Offer attached to the Lease, enclosed please
find an Offer Notice on Suite ______. The basic terms and conditions are as
follows:



LOCATION:           ____________________________________________

SIZE:               ___________ rentable square feet

BASIC RENT RATE:    $______ per month

TERM:               ____________________________________________

IMPROVEMENTS:       ____________________________________________

COMMENCEMENT:       ____________________________________________

PARKING TERMS:      ____________________________________________

OTHER MATERIAL TERMS: ___________________________________________

     Under the terms of the Right of First Offer, you must exercise your rights,
if at all, as to the Offer Space on the depiction attached to this Offer Notice
within ______ days after Landlord delivers such Offer Notice. Accordingly, you
have until 5:00 p.m. local time on _______________, 200__, to exercise your
rights under the Right of First Offer and accept the terms as contained herein,
failing which your rights under the Right of First Offer shall terminate and
Landlord shall be free to lease the Offer Space to any third party.

                                      I-3
<PAGE>

If possible, any earlier response would be appreciated. Please note that your
acceptance of this Offer Notice shall be irrevocable and may not be rescinded.

     Upon receipt of your acceptance herein, Landlord and Tenant shall execute
an amendment to the Lease memorializing the terms of this Offer Notice including
the inclusion of the Offer Space in the Premises; provided, however, that the
failure by Landlord and Tenant to execute such amendment shall not affect the
inclusion of such Offer Space in the Premises in accordance with this Offer
Notice.

     THE FAILURE TO ACCEPT THIS OFFER NOTICE BY (1) DESIGNATING THE "ACCEPTED"
BOX, AND (2) EXECUTING AND RETURNING THIS OFFER NOTICE TO LANDLORD WITHOUT
MODIFICATION WITHIN SUCH TIME PERIOD SHALL BE DEEMED A WAIVER OF TENANT'S RIGHTS
UNDER THE RIGHT OF FIRST OFFER, AND TENANT SHALL HAVE NO FURTHER RIGHTS TO THE
OFFER SPACE. THE FAILURE TO EXECUTE THIS LETTER WITHIN SUCH TIME PERIOD SHALL BE
DEEMED A WAIVER OF THIS OFFER NOTICE.

     Should you have any questions, do not hesitate to call.

Sincerely,

________________________________
________________________________
________________________________

[please check appropriate box]

ACCEPTED  [_]
REJECTED  [_]

TENFOLD CORPORATION, a Delaware corporation


By:    ____________________________
Name:  ____________________________
Title: ____________________________
Date:  ____________________________

Enclosure [attach depiction of Offer Space]

                                      I-4
<PAGE>

                                   EXHIBIT J
                                   ---------


                           FORM OF LETTER OF CREDIT
                           ------------------------


                            ________________, 200__


                IRREVOCABLE, UNCONDITIONAL LETTER OF CREDIT NO.____


W9/CGN Real Estate Limited Partnership
c/o Archon Group, L.P.
600 Las Colinas Boulevard, Suite 400
Irving, Texas 75039

Gentlemen:

     ________________________, a national banking association ("Bank"), of
                                                                ----
________, _______________ hereby issues its Irrevocable, Unconditional Letter of
Credit in favor of W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a Delaware limited
partnership, and/or its successors and assigns ("Landlord") for the account of
                                                 --------
TENFOLD CORPORATION, a Delaware corporation ("Tenant") up to the aggregate
                                              ------
amount of $__________, available at sight by the drafts of Landlord on the Bank.
Drafts drawn on this Letter of Credit will be honored when presented,
accompanied only by a letter or certificate executed by a representative of
Landlord stating that it is entitled to draw on this Letter of Credit under the
terms of the Lease Agreement, dated as of February 4, 2000, between Landlord and
Tenant. Partial draws shall be permitted hereunder. This Letter of Credit may be
assigned.

     The Bank shall be entitled (and required) to rely upon the statements
contained in the above-described letter or certificate and will have no
obligation to verify the truth of any statements set forth therein.

     The Bank hereby agrees with drawers, endorsers, and bona fide holders of
this Letter of Credit that all drafts drawn by reason of this Letter of Credit
and in accordance with the above conditions, will meet with due honor when
presented at the office of the Bank in _______________, _______________.

     The obligations of the Bank shall not be subject to any claim or defense by
reason of the invalidity, illegality, or inability to enforce any of the
agreement set forth in the Lease.

     This Letter of Credit is subject to the Uniform Customs and Practices for
Documentary Credits (1993 Revision) fixed by the International Chamber of
Commerce (publication 500) when not in conflict with the express terms of this
Letter of Credit or with the provisions of Article 5 of the Texas Business and
Commerce Code, as amended.

     This Letter of Credit shall terminate at 3:00 p.m. Central Daylight Savings
Time on the first anniversary date following the date hereof.

                                      J-1
<PAGE>

     Amounts drawn upon this Letter of Credit are to be endorsed on the reverse
side of this Letter of Credit by the negotiating bank.

     THIS WRITTEN LOAN AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE
PARTIES THAT MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR
SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL
AGREEMENTS BETWEEN THE PARTIES.

                              _____________________________________________


                              By:__________________________________________
                              Name:________________________________________
                              Title:_______________________________________


                                      J-2
<PAGE>

                                   EXHIBIT K
                                   ---------


                        SCHEDULE OF JANITORIAL SERVICES
                        -------------------------------

OFFICE AREAS:
------------

     1.   Empty, clean and damp dust all waste receptacles and remove waste
          paper and rubbish from the Premises nightly; wash receptacles as
          necessary.

     2.   Empty and clean all ash trays, screen all sand urns nightly and supply
          and replace sand as necessary.

     3.   Vacuum all rugs and carpeted areas in offices, lobbies and corridors
          nightly. Spot clean carpets as needed.

     4.   Hand dust and wipe clean with damp or treated cloth all office
          furniture, files, fixtures, paneling, window sills and other
          horizontal surfaces nightly; wash window sills when necessary.

     5.   Damp wipe and polish all glass furniture tops nightly.

     6.   Remove all finger marks and smudges from vertical surfaces, including
          doors, door frames, around light switches, private entrance glass and
          partitions nightly.

     7.   Wash clean all water coolers nightly.

     8.   Sweep all stairways nightly, vacuum if carpeted.

     9.   Police all stairwells throughout the entire building daily and keep in
          clean condition.

     10.  Damp mop spillage in office and public areas as required.

     11.  Damp dust all telephones as necessary.


WASHROOMS:
---------

     1.   Mop, rinse and dry floors nightly.

     2.   Scrub floors weekly.

     3.   Clean all mirrors, bright work and enameled surfaces nightly.

     4.   Wash and disinfect all basis, urinals and bowls nightly, using non-
          abrasive cleaners to remove stains and clean underside of rim on
          urinals and bowls nightly.


                                      K-1
<PAGE>

     5.   Wash both sides of all toilet seats with soap and water and disinfect
          nightly.

     6.   Damp wipe nightly, wash all partitions, tile walls and outside surface
          of all dispensers and receptacles.

     7.   Empty and sanitize all receptacles and sanitary disposals nightly;
          thoroughly clean and wash at least once per week.

     8.   Fill toilet tissue, soap, towel and sanitary napkin dispensers
          nightly.

     9.   Clean flushometers, piping, toilet seat hinges and other metal work
          nightly.

     10.  Wash and polish all wall, partitions, tile walls and enamel surfaces
          from trim to floor monthly or as needed.

     11.  Vacuum all louvers, ventilating grills, and dust light fixtures
          monthly.


FLOORS:
------

     1.   Ceramic tile, marble and terrazzo floors to be swept and buffed
          nightly and washed or scrubbed as necessary.

     2.   Vinyl asbestos, asphalt, vinyl, rubber or other composition floors and
          bases to be swept nightly; such floors in public areas on multiple
          tenancy floors to be waxed and buffed as needed.

     3.   Tile floors in office areas will be washed and buffed monthly.

     4.   All vinyl floors stripped and rewaxed as necessary.

     5.   All carpeted areas and rugs to be vacuumed clean nightly.

     6.   Detail vacuuming shall be performed as necessary.


RAISED COMPUTER FLOORS:
----------------------

     1.   Dry mop and spot clean all computer flooring nightly.

     2.   West mop all computer flooring at least once weekly. Mopping may be
          performed on separate sections of the computer flooring on successive
          nights, as long as entire raised flooring is mopped once during each
          one-week period.

     3.   Buff all computer flooring monthly.

     4.   Computer sub-flooring shall be cleaned annually by contractor, or as
          necessary.

                                      K-2
<PAGE>

GLASS:
-----

     1.   Clean glass entrance doors, adjacent glass panels, and any common area
          glass nightly.


HIGH DUSTING (as needed):
------------

     1.   Dust and wipe clean all closet shelving when empty and carpet sweep or
          dry mop all floors in closets if such are empty.

     2.   Dust all picture frames, charts, graphs, and similar wall hangings.

     3.   Dust clean all verticals such as walls, partitions, doors, door bucks,
          and other surfaces above shoulder height.

     4.   Damp dust all ceiling air conditions diffusers, wall grilles,
          registers and other ventilating louvers.

     5.   Dust the exterior surfaces of lighting fixtures, including glass and
          plastic enclosures.

     6.   Dust all mini blinds.


ELEVATORS:
---------

     1.   Carpets will be vacuumed daily and spot cleaned as necessary.

     2.   Exterior and interior doors and trim will be dusted nightly.

     3.   Cabinets will be dusted nightly.

     4.   Control and dispatch panels will be dusted and polished as necessary.

     5.   Elevator thresholds will be cleaned nightly.

     6.   Hardwood surfaces will be kept clean.

     7.   Telephones will be kept dust free.


GENERAL:
-------

     1.   Wipe all interior metal window frames, mullions, and other unpainted
          interior metal surfaces of the perimeter walls of the building each
          time the interior of the window is washed (as requested by the
          Manager).

                                      K-3
<PAGE>

     2.   Keep slopsink rooms in a clean, neat and orderly condition at all
          times.

     3.   Wipe clean and polish all metal hardware fixtures and other bright
          work nightly.

     4.   Dust and/or wash all directory boards as required, remove fingerprints
          and smudges nightly.

     5.   Maintain building lobby, corridors and other public areas in a clean
          condition.

     6.   Dust fire extinguishers and cabinets nightly (interior and exterior);
          wash as necessary.

     7.   All baseboards (resilient flooring and carpeted areas) will be washed
          and wiped clean as necessary.

     8.   Vacuum entrance mats nightly.

     9.   Perform special cleaning needs of individual tenants only as
          authorized and directed by the Manger.

     10.  Properly maintain exterior of building at ground level by ensuring
          that curtain wall, glass, marble, etc., is kept in a clean condition.
          Exterior stainless steel is to be cleaned or polished weekly.

     11.  Polish standpipes and sprinkler siamese connections as necessary.

                                      K-4
<PAGE>

                                   EXHIBIT L
                                   ---------

                 SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT
                 -------------------------------------------------------

     This Subordination, Non-Disturbance, and Attornment Agreement ("Agreement")
                                                                     ---------
is made as of February 4, 2000, by and among LaSALLE NATIONAL BANK, with a place
                       -
of business at 135 South LaSalle Street, Chicago, Illinois 60603 ("Collateral
                                                                   ----------
Agent"), W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a Delaware limited partnership
-----
("Landlord"), and TENFOLD CORPORATION, a Delaware corporation, with a place of
  --------
business as stated in the Lease (as defined below) ("Tenant").
                                                     ------

     A.   Tenant has entered into a certain lease dated February 4, 2000 (the
"Lease"), with Landlord covering certain premises (the "Premises") at the
 -----                                                  --------
property known as 600 Las Colinas Boulevard, Irving, Texas 75039 (the
"property").
 --------

     B.   The Collateral Agent is acting for the benefit of certain Lenders (the
"Lenders") in connection with a loan to Landlord (the "Loan") secured by a First
 -------                                               ----
Deed of Trust, Security Agreement and Fixture Filing (the "Mortgage") and by
                                                           --------
other security instruments (the Mortgage, such other security instruments and
the loan agreement, collectively, the "Loan Documents").
                                       --------------

     NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereby covenant and agree
as follows:

     1.   Subordination.  The Lease and all rights created thereby are and shall
          -------------
be subject and subordinate to the Loan Documents and to any and all renewals,
modifications, consolidations, replacements, and extensions thereof and all
advances made thereunder, to the full extent of all sums due to the Lenders. The
Loan Documents shall take priority over the Lease and shall be entitled to the
same rights and privileges, both at law and in equity, as the Loan Documents
would have had if they had been executed, delivered, and recorded prior to the
execution, delivery, or recording of the Lease.

     2.   Non-Disturbance.  If the Lenders or any of their agents succeed to the
          ---------------
interest of Landlord under the Lease and no event of default shall then be
continuing under the Lease, the Lenders or such agents shall not disturb
Tenant's possession of the Premises or its rights under the Lease, except in
accordance with the terms of the Lease and this Agreement, and the Lease shall
continue as a lease between Tenant and Lenders or such agents. Neither Lenders
nor their agents shall join Tenant in summary or foreclosure proceedings,
provided the Lease is then in full force and effect and Tenant is not in default
thereunder.

     3.   Attornment.  Tenant agrees that, following foreclosure or any deed in
          ----------
lieu of foreclosure, it will attorn to, and recognize as its landlord, the
Lenders or any agent acting on behalf of the Lenders or any purchaser at a
foreclosure sale and their respective successors and assigns (the "Successor
                                                                   ---------
Landlord") for the unexpired balance of the term of the Lease (and any
--------
extensions, if exercised) upon the same terms and conditions as are set forth in
the Lease. This agreement shall be effective without further written agreement,
but, on request of such Successor Landlord, Tenant agrees to execute and deliver
an agreement of attornment of similar import to this Agreement. Tenant agrees
that foreclosure of the Mortgage will not be a constructive eviction of Tenant.
Tenant shall not join, appear, or petition to become a party in any foreclosure
action.

                                      L-1
<PAGE>

     4.   Liability of Lenders.  If a Successor Landlord succeeds to the
          --------------------
interest of Landlord under the Lease, such Successor Landlord shall assume and
perform (but only while such Successor Landlord is the owner of the Property)
all of Landlord's obligations under the Lease, except that the Successor
Landlord shall not be:

          (a)  liable for any action or omission of any prior landlord,
including the present Landlord (the "Former Landlord");
                                     ---------------

          (b)  liable for the return of any security deposit not actually
received by such Successor Landlord;

          (c)  subject to any offsets or defenses which Tenant might have
against the Former Landlord (including any claim for damages of any kind
whatsoever as the result of any breach by a Former Landlord that occurred before
the date of attornment) (the "Offset Rights");
                              -------------

          (d)  bound by any rent or additional rent which Tenant might have paid
for more than the then current month to any Former Landlord;

          (e)  bound by any assignment, surrender, termination, cancellation,
amendment, or modification of the Lease made without its express written
consent;

          (f)  bound by any sum(s) that any Former Landlord owed to Tenant; or

          (g)  bound by any obligation of a Former Landlord under the Lease to
make, pay for, or reimburse Tenant for any alterations, demolition, or other
improvements or work (other than day-to-day maintenance and repairs).

     5.   Notice and Right to Cure.  Tenant agrees to give the Collateral Agent
          ------------------------
at the time given to Landlord a copy of any notice of default served upon
Landlord. If Landlord fails to cure such default within the time provided for in
the Lease, the Collateral Agent and the Lenders shall have the right, but not
the obligation, to cure such default within a reasonable time thereafter (but in
no event more than 60 days from the expiration of Landlord's cure period), or if
such default cannot be cured within such reasonable time then such additional
time as may be necessary to cure such default, provided the Collateral Agent
and/or the Lenders have commenced and are diligently pursuing the remedies
necessary to cure such default (including, without limitation, commencement of
foreclosure proceedings if necessary to effect such cure). In such event, the
Lease shall not be terminated or the rights of Landlord under the Lease
forfeited or adversely affected during such reasonable time or while the
Collateral Agent and/or the Lenders diligently pursue such remedies. Neither the
Collateral Agent nor any Lender shall have any obligation to cure, or liability
or obligation for not curing.

     6.   Assignment of Lease.  Tenant acknowledges that the Lease is being
          -------------------
assigned to the Collateral Agent under the Loan Documents. The interest of
Landlord in the Lease is being assigned to the Collateral Agent, but the
Collateral Agent assumes no duty, liability, or obligation whatever under the
Lease. Unless and until different written instructions from the Collateral Agent
are received by Tenant, all rent payments under the Lease shall be paid directly
to the Cash Receipts Account (as defined in the Loan Agreement) in accordance
with the terms of the tenant notice delivered to Tenant by Landlord pursuant to
the Loan Agreement, a copy of which is attached hereto.

                                     L-2
<PAGE>

     7.   Effect of Foreclosure.  Any right of Tenant to purchase the Property,
          ---------------------
including any right of first refusal, shall not apply to a foreclosure sale.

     8.   Exculpation of Successor Landlord.  Notwithstanding anything to the
          ---------------------------------
contrary in this Agreement or the Lease, upon any attornment pursuant to this
Agreement the Lease shall be deemed to have been automatically amended to
provide that Successor Landlord's obligations and liability under the Lease
shall never extend beyond Successor Landlord's (or its successors' or assigns')
interest, if any, in the premises covered by the Lease from time to time,
including insurance and condemnation proceeds and Successor Landlord's interest
in the Lease (collectively, "Successor Landlord's Interest"). Tenant shall look
                             -----------------------------
exclusively to Successor Landlord's Interest (or that of its successors and
assigns) for payment or discharge of any obligations of Successor Landlord under
the Lease as affected by this Agreement. If Tenant obtains any money judgment
against Successor Landlord with respect to the Lease or the relationship between
Successor Landlord and Tenant, then Tenant shall look solely to Successor
Landlord's Interest (or that of its successors and assigns) to collect such
judgment. Tenant shall not collect or attempt to collect any such judgment out
of any other assets of Successor Landlord.

     9.   Interpretation; Governing Law.  The interpretation, validity and
          -----------------------------
enforcement of this Agreement shall be governed by and construed under the
internal laws of the State of New York, excluding its principles of conflict of
laws.

     10.  Amendments.  No modification, amendment, waiver, or release of any
          ----------
provisions of this Agreement or of any right, obligation, claim or cause of
action arising hereunder shall be valid or binding for any purpose whatsoever
unless in writing and duly executed by the party against which the same is
sought to be asserted.

     11.  Notices.  All notices, directions, demands, requests, permissions,
          -------
approvals, consents, elections or other communications permitted or required to
be given hereunder (singly, a "notice" or collectively, "notices") shall be in
                               ------                    -------
writing, shall be effective for all purposes if hand delivered or sent by
expedited prepaid delivery service (either commercial or United States Postal
Service) with proof of delivery, and shall be deemed given on the date of actual
receipt by the entity to which it is directed, notwithstanding any further
direction to the attention of any individual or department. Notices shall be
addressed to any party hereto at its address first above written. Notices to the
Lenders shall be addressed to the Collateral Agent on the Lenders' behalf at the
address of the Collateral Agent first above written. Any address or name
specified above may be changed by a notice given in accordance with this
Section. The inability to deliver because of a changed address of which no
notice was given, rejection, or other refusal to accept any notice shall be
deemed to be the receipt of the notice as of the date of such inability to
deliver, rejection, or refusal to accept.

     12.  Successors and Assigns.  The terms of this Agreement shall be binding
          ----------------------
upon, inure to benefit of, and be enforceable by, the parties and their
respective successors and assigns.

                                      L-3
<PAGE>

     IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed as of the date first above written.

LENDER:                       LaSALLE NATIONAL BANK, as Collateral Agent


                              By:_________________________________________
                              Name:_______________________________________
                              Title:______________________________________

LANDLORD:                     W9/CGN REAL ESTATE LIMITED PARTNERSHIP, a
                              Delaware limited partnership

                              By:  W9/CGN Gen-Par, Inc., a Delaware corporation,
                                   its general partner


                                   By:____________________________________
                                   Name:__________________________________
                                   Title:_________________________________

TENANT:                       TENFOLD CORPORATION, a Delaware corporation


                              By:_________________________________________
                              Name:_______________________________________
                              Title:______________________________________


                                      L-4