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                                 LEASE AGREEMENT

        THIS LEASE AGREEMENT ("Lease") is entered into the 12th day of December,
1997, by and between FACILITY PROPERTIES, L.L.C., a Kansas limited liability
corporation ("Lessor"), and ILLUMINET, INC., a Delaware corporation ("Lessee").

        WITNESSETH:

        1. LEASE OF PREMISES: For and in consideration of the rents reserved
herein and the covenants and undertakings contained herein, Lessor hereby leases
to Lessee, and Lessee hereby leases from Lessor, upon the terms and conditions
herein set forth, those certain premises (hereinafter called the "Premises")
consisting of the area outlined in red on the plans and specifications to be
attached hereto and marked Exhibit A, which shall be a part of Lessor's building
(the "Building") to be constructed upon that certain real property situated in
Overland Park, Johnson County, Kansas, more particularly described in Exhibit B
attached hereto. Exhibit A and Exhibit B are each incorporated herein by this
reference. This Lease and the rents reserved herein also cover Lessee's right to
use the common areas and the parking spaces in the parking areas designated by
Lessor for parking by Lessee and Lessee's employees and visitors.

        2. CONSTRUCTION: Lessor shall construct the Building and Premises in
accordance with Exhibit C attached hereto and incorporated herein by reference.

        3. LEASE TERM: This Lease shall be for a term of five (5) years
commencing on the "Commencement Date," which is defined to be the first day of
the month immediately following the "Completion Date" (as defined in Exhibit C),
and ending at midnight on the last day of the month that is five years from the
month in which the Commencement Date occurs (the "Expiration Date"), unless
earlier terminated in accordance with the terms of this Lease. Upon the request
by either party, the parties shall execute an acknowledgment letter confirming
the actual Commencement Date and Expiration Date. Lessee will have thirty (30)
days access to fixture the space prior to the Completion Date. If such access or
ability to fixture the space is not available from the Lessor, the Commencement
Date will be adjusted accordingly.

        4. OPTION TO EXTEND: Lessee shall have the option to extend the term of
this Lease for an additional five (5) year term (the "Option Period") commencing
immediately after the Expiration Date by notifying Lessor in writing one hundred
and eighty (180) days prior to the Expiration Date ("the Option Renewal Date").
All terms and provisions of this Lease shall govern during the Option Period,
except that the rent shall be adjusted per Section 6: Rent Adjustments.

In addition, Lessee shall pay as additional rent the pro rata costs associated
with Lessor's refinance of its then existing mortgage of the Building (the "Loan
Refinance Costs") which shall include, without limitation, interest rate
increases over Lessor's then current loan, loan origination fees, title
insurance and property appraisal fees. Such pro rata share is based on the ratio
of the floor area of the Premises (23,000 square feet including a proportionate
part of the Common Areas and any expansion space occupied by the Lessee which
have been allocated to all rentable areas in Lessor's building) to the total
rentable floor area in Lessor's building. On or before the Option Renewal Date,
Lessor shall submit its estimate of the Loan Refinance Costs to


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Lessee. The proposed Loan Refinance Costs submitted to Lessee must be consistent
with then prevailing market rates and costs in the Overland Park, Kansas area
for comparable loans. If Lessee exercises its options to renew the lease, Lessee
shall notify Lessor on or before the Option Renewal Date that Lessee intends to
pay the Loan Refinance Costs as follows: (i) the portion of the Loan Refinance
Costs relating to the interest rate increase shall be payable monthly with the
payment of Rent, and (ii) the remainder of the Loan Refinance Costs shall be
payable (a) in one lump sum payment on or before the tenth day of the first
month of the Option Period, (b) in equal monthly installments, or (c) some
combination thereof, to be determined by Lessee. If the actual Loan Refinance
Costs differ from the estimated Loan Refinance Costs previously submitted to
Lessee, Lessee shall pay an amount equal to the actual Loan Refinance Costs;
provided, however, that Lessee shall not pay the portion of the Loan Refinance
Costs that exceeds ten percent of the estimated Loan Refinance Costs.

        5. RENT: Lessee promises to pay to Lessor, as rent for the Premises, the
sum of Fifteen and 38/100 Dollars ($15.38) per rentable square foot in the
Premises per annum, payable in equal monthly installments in advance on the
first day of each and every calendar month during the term of this Lease,
commencing on the Commencement Date. Lessee agrees to pay the rent payable for
each and every month of the term of this Lease without deduction or setoff
except as set forth herein. All references to square footage in this lease shall
mean rentable square feet as defined and agreed upon by Lessee and Lessor in the
Standard Method of Floor Measurement prepared by the Building Owners' and
Managers' Association International ANSI Z 65.1-1996 Method dated June 7, 1996.
The rent for any partial month shall be prorated.

        All rent payable pursuant to this Lease during the term hereof shall be
paid to Lessor at such place as Lessor may, from time to time, designate in
writing and until any further such designation, such place shall be the business
office of Lessor at 8500 W. 110th Street, Suite 525, Overland Park, Kansas
66210. In the event Lessee fails to pay any rent or other payment owed to Lessor
pursuant to this lease within five (5) days after such payment is due, Lessor
will notify Lessee of payment due. Lessee will have five (5) days after such
notice to make payment. If payment is not received after ten (10) days such
payment was due, the Lessee agrees to pay to Lessor, as additional rent, a sum
equal to five percent (5%) of each such delinquent payment.

        6. RENT ADJUSTMENTS: Lessee agrees that the monthly rent payable in each
of the succeeding years of the term of this Lease as provided in Paragraph 5
herein above shall be increased or decreased effective on each twelve (12) month
anniversary of the Commencement Date, as follows:

               (a) For Real Property Tax and for Fire and Casualty Insurance
Premium Changes during years one (1) through (5): By one-twelfth (1/12) of the
amount by which the ad valorem real property taxes and Fire and Casualty
Insurance premium payable by Lessor for the Premises changed during the
preceding calendar year;

               For any lease extension beyond the initial five-year term, the
following rent adjustments 6(b) and 6(c) will also apply:

               (b) For all Operating Expense changes, except electricity, during
years six (6) through (10): by one twelfth (1/12) of the amount by which the
operating expenses payable by


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Lessor changed from the base year except that such adjustments will not exceed
the aggregate average annual percentage price changes as measured by the
Consumer Price Index for Overland Park, Kansas of the preceding three (3)
calendar years.

               (c) For all Loan Finance Cost changes during years six (6)
through ten (10): By 1/12 the amount by which the bona fide loan financing costs
payable by Lessor changed from the Base Year. On or before the Option Renewal
Date, Lessor shall submit its estimate of the Loan Refinance Costs to Lessee.
The proposed Loan Refinance Costs submitted to Lessee must be consistent with
then prevailing market rates and costs in the Overland Park, Kansas area for
comparable loans. If Lessee exercises its options to renew the lease, Lessee
shall notify Lessor on or before the Option Renewal Date that Lessee intends to
pay the Loan Refinance Costs as follows: (i) the portion of the Loan Refinance
Costs relating to the interest rate increase shall be payable monthly with the
payment of Rent, and (ii) the remainder of the Loan Refinance Costs shall be
payable (a) in one lump sum payment on or before the tenth day of the first
month of the Option Period, (b) in equal monthly installments, or (c) some
combination thereof, to be determined by Lessee. If the actual Loan Refinance
Costs differ from the estimated Loan Refinance Costs previously submitted to
Lessee, Lessee shall pay an amount equal to the actual Loan Refinance Costs;
provided, however, that Lessee shall not pay the portion of the Loan Refinance
Costs that exceeds ten percent of the estimated Loan Refinance Costs.

        The parties acknowledge and agree that for the purposes of the
computations contemplated by subparagraphs 6(a), 6(b) and 6(c) herein above, the
property taxes insurance premiums, operating expenses and loan finance cost for
the Premises referenced in those subparagraphs shall be the pro rata share of
the total ad valorem real property taxes, fire and casualty insurance premiums
and operating expenses payable by Lessor for the entire property of which the
premises are a part, and that such prorata share is based on the ratio of the
floor area of the Premises (23,000 square feet and any expansion space occupied
by the Lessee including a proportionate part of the Common Areas which have been
allocated to all rentable areas in Lessor's building) to the total rentable
floor area in Lessor's building.

        Base Year is defined as the calendar year ending December 31, 1999.

        Consumer Price Index is defined as the Overland Park, Kansas - All Urban
Consumers published by the United States Government. In the event the United
States Government shall revise or discontinue publication of the Consumer Price
Index, the parties agree to use in its place the government index or computation
which may replace the Consumer Price Index or such other reasonable comparable
economic index that would yield substantially the same result.

        Operating Expenses are defined as all reasonable and appropriate
expenses paid or incurred by the Lessor for maintaining, operating and repairing
the building, the land, the parking facilities on the land, including but not
limited to all expenses paid or incurred by lessor for heating, cooling, water,
gas, sewers, refuse collection, telephone charges not chargeable to Lessee and
similar utility services; the cost of supplies, janitorial and cleaning
services, window washing, the cost of complying with any governmental rules,
regulations, requirements or orders (except that Lessor is responsible for any
capital items for American Disabilities Act compliance), cost of independent
contractors, the cost of compensation (including employment taxes and fringe
benefits) of all persons who perform duties in connection with such operating


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costs and any other reasonable and appropriate expense or charge which, in
accordance with generally accepted accounting principles, would be considered an
expense of operating or repairing the building. Operating expenses shall not
include capital expenditures, Lessor's income taxes or any expenses paid by the
Lessee directly to third parties, or as to which Lessor is otherwise reimbursed
by a third party or by any insurance proceeds.

        7. OPTION TO EXPAND: During the period that commences on the
Commencement Date and terminates six months prior to the Expiration Date (or
expiration of the Option Period, if applicable), Lessee shall have the right to
expand into additional space of up to 4,000 square feet in the Building not then
occupied by Lessee by delivering one hundred twenty (120) days prior written
notice to Lessor. Such notice shall specify the date Lessee desires to expand
and the area subject to Lessee's desired expansion (the "Expansion Space").
Additionally, for any space in the Building vacated by the Lessor or a third
party tenant, Lessee shall have the first right of refusal to expand into part
or all of that space. Lessee will have ten (10) business days from receipt of
Lessor's written notice of such space availability to exercise the option to
expand into part or all the available space. Lessor (or the possessor of the
Expansion Space at such time) shall surrender the Expansion Space on or before
the date specified in the notice in good condition and in a condition compatible
with Lessee's use and occupancy, reasonable wear and tear excepted. The rent
payable by Lessee shall be adjusted to reflect Lessee's increased square
footage, as certified by Lessee or Lessee's agent, effective the date Expansion
Space is made available to Lessee. All other terms and conditions will remain
the same for the Expansion Space.

        8. COMMON AREAS: PARKING: Common areas include parking areas, entrances
and exits thereto, driveways, sidewalks, landscaped areas, lavatories, and other
areas and facilities which are provided and designated by Lessor for the common
or joint use and benefit of occupants of the Building, and their respective
employees, agents, customers and invitees. Lessor shall provide at no cost
Lessee parking spaces in size, number, and type sufficient to comply with
federal, state, and local statutes, ordinances, and regulations, and in no event
shall Lessor provide Lessee with fewer than 108 parking spaces for the use by
Lessee, its employees, and visitors. If Lessee exercises option to expand,
Lessor will provide additional parking spaces in size, number and type
sufficient to comply with federal, state and local statutes, ordinances and
regulations and in no event fewer than 3.1 spaces per each one thousand (1,000)
square feet of Expansion Space exercised.

        9. AUTHORIZED USE: Lessee shall use and occupy the Premises during the
entire Lease term for a business office and for no other purpose without the
prior written consent of Lessor. No use shall be made of the Premises nor any
act done in or about the Premises which is unlawful. Lessee agrees to observe
the rules and regulations set forth on Exhibit D attached hereto and
incorporated herein and such additional reasonable and nondiscriminatory rules
and regulations as may be mutually adopted and published by Lessor and Lessee
from time to time for the safety, care and cleanliness of the Premises. Written
notice of changes will be provided to each party five (5) days before effective
date to allow time for conformance except that rules and regulations addressing
issues of immediate high risk safety and security matters will be effective
immediately.


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        10. POSSESSION: So long as Lessee shall fully comply with and promptly
perform all of the terms, covenants and conditions of this Lease and the rules
and regulations on its part to be complied with and performed, Lessee shall have
and quietly enjoy possession of the Premises for the term set forth herein.
Lessee's occupation and continued possession of the Premises shall be deemed
Lessee's agreement and acknowledgement that the Premises are then in a
tenantable and good condition, except for latent defects or defects which Lessee
has given Lessor written notice to correct.

        11. SECURITY: Lessor acknowledges that access to the Premises is limited
and strictly controlled. Lessor agrees to cause all of its employees, agents,
customers and invitees to comply with any and all rules and regulations
established by Lessee and agreed to in writing by Lessor to assure the security
of its premises. Lessor shall be granted access, which will not be unreasonably
withheld, to the building for the purpose of inspection, repair, remodeling and
operation of the Building under security procedures established by Lessee;
provided, however, that Lessor, its employees, or any other party acting on
Lessor's behalf or at Lessor's request shall not disclose to any third party
information about Lessee or Lessee's customers or operations obtained by Lessor
or such other party while in the Premises, and Lessor shall indemnify Lessee
from and against all damages, losses, liabilities, and expenses (including
reasonable attorneys' fees) incurred by Lessee as a result of a breach or
violation of the non-disclosure obligation set forth in this Paragraph.

        12. MAINTENANCE AND SERVICES PROVIDED BY LESSOR: Lessor shall maintain
the roof, exterior walls and structural members of the Building, in good order
and condition, except for damage occasioned by the acts of Lessee or Lessee's
officers, employees and agents.

        Lessor shall provide lighting, electrical power, air conditioning,
water, sewer service, refuse disposal service, janitorial service and other such
utility and maintenance services, all within the normal requirements of such
utilities and services for which the occupancy of Lessee under this Lease is
contemplated. Lessor shall also provide the security alarm system and the
security monitoring service for the Building, which shall be subject to Lessee's
written approval. Electrical power shall be separately metered for Lessee's use.
Lessor shall pay for all utilities and services set forth in this paragraph
except electricity separately metered for Lessee's use. Lessee's primary
business hours will be 7 a.m. to 6 p.m. Monday through Friday and the Premises
will be occupied twenty four hours a day, seven days a week by customer service
and network monitoring personnel.

        Lessor shall maintain the Building, the common areas, and the parking
areas in good order and condition, except for damage occasioned thereto by the
acts of Lessee or Lessee's officers, employees and agents, and Lessor shall
furnish such areas with required utility services, snow and ice removal, and
shall provide lighting replacement for such areas.

        Lessor will sufficiently notify Lessee of utility service repairs,
especially those services that would impact the Lessee's operations. Following
sufficient notice to the Lessee, Lessor shall not be liable to Lessee for any
loss or damage caused by our resulting from any variation, interruption or
failure of utility services to be provided by Lessor pursuant to this Lease, due
to any cause except for Lessee's negligence or willful acts and no temporary
interruption or failure


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<PAGE>   6
of such services incidental to the making of repairs, alterations or
improvements, or due to accident or strike or conditions or events not under
Lessor's control, shall be deemed as an eviction of Lessee or release Lessee
from any of Lessee's obligations hereunder.

        13. CARE OF PREMISES, REPAIRS AND ALTERATIONS: Lessee shall take good
care of the Premises. Lessee shall be responsible for timely payment of all
utility and other services furnished to or provided for the Premises which are
not to be provided by Lessor as specifically set forth hereinabove.

        Lessee shall, upon termination of this Lease by the expiration of time
or as otherwise provided herein, promptly and peacefully yield and surrender the
Premises to Lessor in as good condition as when received by Lessee from Lessor
or as hereafter improved, reasonable use, wear and damage by fire or other
casualty excepted.

        Lessee shall not make any alterations, additions or improvements in or
to the Premises, or make changes to locks on doors except for emergency security
or safety purposes, or add, disturb or in any other way change any plumbing or
wiring without first obtaining the written consent of Lessor. Lessor will be
notified as soon as practical regarding any changes due to emergency security or
safety requirements. All damage or injury done to the Premises by Lessee, or by
any person who may be in or upon the Premises with the consent of Lessee, shall
be paid for by Lessee, and Lessee shall pay for all damage to the Building
caused by Lessee's misuse of the same or the appurtenances thereto.

        Lessor may make any alterations, repairs or improvements, which Lessor
may deem necessary or advisable for the security, preservation, safety or
improvement of the Building, subject to Lessee's prior written approval. Such
alterations, repairs or improvements shall be made at times convenient to
Lessee. Lessor will make best efforts to limit disruption of Lessee's business
operations. All alterations, additions and improvements to the building
structure during the term of this Lease, shall be and become the property of
Lessor. All equipment and trade fixtures installed by Lessee shall remain the
property of Lessee. If Lessee shall damage the Premises in removing any
equipment or trade fixtures, Lessee shall promptly cause such damage to be
repaired and shall be fully responsible for the cost thereof.

        Lessee may install antennas and satellite dishes on the roof of the
Building in accordance with local codes and regulations.

        14. ENTRY AND INSPECTION: Subject to Paragraph 10 above, Lessee agrees
to permit Lessor and Lessor's agents to enter the Premises at reasonable times
and upon reasonable notice (except in the case of emergency), for the purpose of
inspecting the same or for the purpose of cleaning, repairing, altering or
improving the Premises. Nothing contained in this paragraph shall be deemed to
impose any obligation upon Lessor not expressly set forth elsewhere in this
Lease. Lessor shall have the right to enter the Premises at reasonable times,
and with reasonable notice, for the purpose of showing the same to prospective
tenants during a period of one hundred and eighty (180) days prior to the
expiration of the term of this Lease, if Lessee has not extended lease. Due to
Lessee's business security reasons, any Lessor entry and inspection will require
an escort provided by the Lessee except in emergency situations.


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<PAGE>   7
        15. TAXES AND LICENSEE FEES: Lessee shall be liable for and pay,
throughout the term of this Lease, any and all license fees, excise taxes and
occupation taxes applicable to the business conducted by Lessee on the Premises,
and all applicable ad valorem taxes levied and assessed upon the personal
property of Lessee maintained on the Premises.

        Lessor shall be liable for and pay all real property ad valorem taxes
levied and assessed upon the land and improvements of which the Premises are a
part.

        The parties acknowledge and agree that the rent provided in Paragraph 5
hereof are exclusive of any sales, use, business and occupation or other similar
taxes, based upon or measured by rents payable to Lessor hereunder. If during
the term of this Lease any such taxes shall become payable by Lessor to any
governmental authority, the rent hereunder shall be deemed increased to net
Lessor the same revenue after Lessor's payment of any such tax, as would have
been payable to Lessor prior to the imposition of any such tax. The foregoing
provision does not include, and shall not be construed to impose on Lessee, any
liability to pay any income taxes payable by Lessor.

        16. LIABILITY AND INDEMNIFICATION: Lessor shall not be liable for any
injury to or the death of any person, or for any loss of or damage to any
property (including the property of Lessee) occurring in or about the Premises
of any cause whatsoever, save the except that caused by the negligence and/or
willful misconduct of Lessor; provided, however, Lessor shall not in any event
be liable to Lessee, or any person or entity claiming by, through or under
Lessee, for any incidental or consequential damages.

        Lessee shall defend and indemnify Lessor and save Lessor harmless, from
and against any and all loss, damage, liability or expense (including attorney's
fees and other expenses of litigation) incurred by Lessor arising or resulting
from any actual or alleged injury or death to any person occurring upon the
Premises or from any actual or alleged loss of or damage to any property upon or
about the Premises, caused by or resulting from any act or omission of Lessee or
any officer, employee, contractor, licensee, agent, servant, guest, invitee or
visitor of Lessee, in or about the Premises; provided, however, that the
foregoing provisions shall not be construed to make Lessee responsible for any
loss, damage, liability or expense resulting from injuries to third parties
caused by the negligence or willful misconduct of Lessor, or any officer,
employee, contractor, licensee, business invitee or visitor of Lessor. Lessee
shall not in any event be liable for any indirect, incidental, or consequential
damages to Lessor or any person or entity making such claim by, through or under
Lessor.

        17. LIABILITY INSURANCE: Throughout the term of this Lease, and any and
all extensions of such term, Lessee and Lessor shall each maintain, with
insurers authorized to do business in the State of Kansas that are well rated by
any recognized national rating organization, a policy or policies of commercial
general liability insurance providing coverage against claims for bodily injury,
death or property damage arising out of the use or occupancy of the Premises by
Lessee and Lessor, in a combined single limit amount of not less than
$1,000,000.00. The policies of insurance required to be maintained by Lessee and
Lessor pursuant to this paragraph shall name the Lessee and Lessor as insured
parties such that both parties are named in both policies and may be carried
under blanket policies maintained by Lessee and Lessor if such policies comply
with the provisions of this Lease. The policy or policies of insurance required
to


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<PAGE>   8
be maintained by Lessee and Lessor pursuant to this paragraph shall each provide
that not less than thirty (30) days prior written notice of any cancellation,
termination, modification or lapse of coverage shall be given to Lessor and
Lessee, and any holder or holders of a first lien mortgage or deed of trust
covering the Building, and such insurance policy or policies shall not contain
any provision relieving the insurers thereunder of liability for any loss by
reason of the existence of other policies of insurance covering the Premises
against the perils involved, whether collectible or not.

        Lessor shall acquire builder's risk insurance prior to the start of
construction of the Building.

        Lessee and Lessor shall deliver to the other before the Commencement
Date certificates evidencing all of the insurance which is required to be
maintained by Lessee and Lessor hereunder, and, within five (5) working days
following policy expiration of any such insurance, other certificates evidencing
the renewal of such insurance.

        18. PROPERTY INSURANCE: DAMAGE OR DESTRUCTION BY FIRE OR OTHER CASUALTY:
Lessor shall carry all-risk property damage insurance effective as of the
Commencement Date in an amount equal to the full replacement cost of the
Building, and Lessor shall deliver to Lessee certificates evidencing such
insurance. The policy shall provide a minimum of thirty (30) days' written
notice to Lessee prior to the expiration or any cancellation or modification of
such policy. In the event Lessor shall fail to maintain the insurance required
by this section, Lessee may, but shall not be so obligated, to procure such
insurance, and any amount so expended by Lessee shall be reimbursed to Lessee by
Lessor within ten days of Lessee's written demand. If Lessor fails to reimburse
Lessee within such time period, Lessee may abate rent in the amount of such cost
to Lessee.

        In the event the Premises shall be destroyed or rendered untenantable,
either wholly or in part, by fire or other unavoidable casualty, Lessor shall
restore the Premises to the same condition that existed prior to such casualty,
and during the time the premises or any portion thereof shall be so rendered
untenantable, the rent shall be abated in the same proportion as the
untenantable portion of the Premises bears to the whole thereof; provided,
however, that during the last six months of the term of the Lease (or Option
Period, if applicable), either Lessor or Lessee may terminate the Lease by
delivering written notice to the other within thirty (30) days after the
happening of any such casualty.

        19. WAIVER OF SUBROGATION: In the event of any loss or damage referred
to in this Lease, whether such loss or damage is due to the negligence of either
of the parties hereto or their respective agents or employees, or any other
cause, Lessor and Lessee do each herewith and hereby release and relieve the
other from responsibility for, and waive the entire claim of recovery for (a)
any loss or damage to the Premises and other parts of the Building, or any
personal property of either located anywhere in said building, arising out of or
incident to the occurrence of any of the perils which may be covered by any fire
and casualty insurance policy with extended coverage endorsement in common use
in the Overland Park, Kansas area; or (b) any loss resulting from business
interruption at or upon the Premises or loss of rental income, arising out of or
incident to the occurrence of any of the perils which may be covered by any


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<PAGE>   9
such insurance, and each party shall cause its insurance carrier to consent to
such waiver and to waive any and all rights of subrogation against the other
party.

        20. EMINENT DOMAIN: If the whole of the Premises, or if such portion of
the Premises as may be required for the reasonable use of the same, shall be
taken by virtue of any condemnation or eminent domain proceeding, this Lease
shall automatically terminate as of the date of such condemnation, or as of the
date possession is taken by the condemning authority, whichever date is earlier.
Current rent shall be apportioned as of the date of such termination on a thirty
(30) day month basis. In the case of a taking of only a portion of the Premises
not required for the reasonable use thereof, then Lessor shall restore the
Premises as nearly as practicable to the condition prior to such taking, and
this Lease shall continue in full force and effect and the rental shall be
equitably reduced based upon the proportion by which the Premises are reduced,
such rent reduction to be effective on the date of such partial taking. No award
for any partial or entire taking shall be apportioned, and Lessee hereby assigns
to Lessor any award which may be made in such taking or condemnation, together
with any and all rights of Lessee now or hereafter arising in or to the same or
any part thereof; provided, however, that nothing herein shall be deemed to give
Lessor any interest in, or to require Lessee to assign to Lessor, any award made
to Lessee for the interruption of or damage to Lessee's business or for Lessee's
moving expenses.

        21. ASSIGNMENT AND SUBLETTING: Lessee shall not assign this Lease or
sublet the Premises, or any part thereof, without first obtaining Lessor's
written consent which shall not be unreasonably withheld; provided, however,
that Lessee is not required to obtain Lessor's prior written consent if Lessee
is not released from its obligations under this Lease. The Lessee shall be
released from its obligations hereunder to an assignee subject to approval of
Lessor, which approval will not be unreasonably withheld if the assignee has a
net worth in equal to or in excess of Lessee's net worth, equal or better credit
rating of Lessee and assignee assumes all obligations set forth hereunder.
Lessor's consent, which will not be unreasonably withheld, to any assignment or
subletting which requires Lessor's consent shall not operate as a waiver of the
necessity for a consent to any subsequent assignment or subletting which
requires Lessor's consent. The terms of this paragraph shall be binding upon any
person by, under or through Lessee.

        Lessor may assign this Lease at any time without obtaining Lessee's
consent provided the assignee agrees to abide by and is bound by the terms and
conditions of this Lease Agreement; and provided further, however, that Lessor
shall not assign this Lease prior to the Completion Date without first obtaining
Lessee's written consent. Lessee hereby consents to Lessor assigning the Lease
to any entity be wholly owned by Lessor, and/or individuals or entities related
to Facility Design, Inc. or Rolly McNutt that are acceptable to Lessee. In the
event of such assignment, Facility Design, Inc. shall not be released from its
obligations to perform Lessor's obligation to construct the Building and the
Premises set forth herein.

        22. APPROVAL OF THIRD PARTY TENANTS: Because of the nature of Lessee's
business requiring security and privacy from competitors, Lessee shall approve
any third party tenant proposed by the Lessor. The Lessee will not unreasonably
withhold such approval.


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<PAGE>   10
        23. LIENS AND INSOLVENCY: Lessee shall keep the Premises free from any
and all liens arising out of any work performed, materials ordered or
obligations incurred by Lessee.

        24. DEFAULT AND TERMINATION: If Lessee fails to pay any installment of
rent within ten (10) days after the due date, or to perform any other covenant
under this Lease within thirty (30) days after written notice from Lessor
stating the nature of such default, Lessor may cancel this Lease and re-enter
and take possession of the Premises using all necessary force to do so;
provided, however, that if the nature of such default (other than for nonpayment
of rent) is such that the same cannot reasonably be cured within such thirty-day
period, Lessee shall not be deemed to be in default if Lessee shall, within such
period, commence such cure and thereafter diligently pursue the same to
completion. Notwithstanding such retaking of possession by Lessor, Lessee's
liability for the rent provided herein shall not be extinguished for the balance
of the term of this Lease. Upon such re-entry, Lessor may, without terminating
this Lease, relet or attempt to relet, all or any part of the Premises upon such
terms and conditions as Lessor may deem advisable, in which event the rents
received in connection with such reletting shall be applied first to the
expenses of reletting and collection, including any necessary renovations and
thereafter to payment of all sums due to or become due Lessor pursuant to the
terms of this Lease, and if a sufficient amount shall not be thus realized to
pay such charges, Lessee shall pay Lessor any deficiency monthly, and Lessor may
bring an action for any and all such monthly deficiencies as the same shall
arise. Lessee hereby waives any and all claims for damages that may be caused by
Lessor's re-entering and taking possession of the Premises or removing and
storing the property of Lessee as provided in this Lease, and Lessee will save
Lessor harmless from any loss, costs or damages occasioned Lessor thereby, and
no such re-entry shall be considered or construed to be a forcible entry.

        25. REMOVAL OF PROPERTY: If Lessee shall fail to remove any of its
property of any nature whatsoever from the Premises after termination of this
Lease or when Lessor has the right of reentry, Lessor may, at Lessor's option,
remove and store such property without liability for loss thereof or damage
thereto, such storage to be for the account and at the expense of Lessee. If
Lessee shall not pay the cost of storing any such property after the same has
been stored for a period of (30) days or more, Lessor may, at Lessor's option,
sell or permit to be sold, any or all of such property at public or private
sale, in such manner and at such times and places as Lessor, in Lessor's sole
discretion, may deem proper, without notice to Lessee, and Lessor shall apply
the proceeds of such sale first to the cost and expenses of such sale, including
reasonable attorney's fees actually incurred; second, to the payment of the
costs of storing any such property; third, to the payment any other obligations
which may then be or thereafter become due Lessor from Lessee pursuant to the
terms hereof; and fourth, the balance, if any, to Lessee.

        26. NON-WAIVER: A waiver by either party of any breach of any term,
covenant or condition herein contained shall not be deemed to be a waiver of
such term, covenant or condition or of any subsequent breach of the same or any
other term, covenant or condition herein contained.

        27. HOLDOVER: If Lessee shall, with the consent of Lessor, continue to
occupy the Premises after the expiration of the term of this Lease, such tenancy
shall be for an indefinite period of time on a month-to-month tenancy, which
tenancy may be terminated as provided by


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<PAGE>   11
the laws of the State of Kansas. During such tenancy, Lessee agrees to pay to
Lessor the rent then determined payable as provided herein unless a different
rate be agreed upon at such time, and to be bound by all the terms, covenants
and conditions herein set forth insofar as applicable.

        28. SUBORDINATION TO MORTGAGE: Lessee agrees to subordinate this Lease
to any mortgage covering property which includes the Premises that may hereafter
be placed by Lessor upon such property and all renewals, replacements and
extensions of such existing mortgage or any such subsequent security instrument,
provided that the secured party under any such subsequent security instrument
agrees not to disturb the leasehold interest of Lessee in the event of
foreclosure if Lessee is not in default hereunder. If any existing secured party
desires to have this Lease a prior lien to its security interest, then in such
event and upon such secured party notifying Lessee to that effect, this Lease
shall be deemed prior to the lien of such security interest. Within fifteen (15)
days of presentation, Lessee shall execute any and all documents which any such
secured party may require to effectuate the provisions of this paragraph, and
Lessee shall execute certificates as to the status of rental payments and
Lessee's compliance as required by Lessor from time to time in the standard form
of any such security party.

        29. RIGHT OF FIRST REFUSAL TO PURCHASE THE BUILDING AND REAL PROPERTY:
During the term of the lease the Lessee shall have the right of first refusal to
purchase the building and the real property described in Exhibit B prior to the
Lessor seeking third party buyers. The purchase price will be determined by a
joint agreement of a qualified appraiser selected by the Lessor and a qualified
appraiser selected by the Lessee. A qualified appraiser shall be an appraiser
who is independent, licensed, and a member of the American Institute of Real
Estate Appraisers or its successor organization. If the two appraisers are
unable to agree upon a purchase price, the two appraisers will each submit their
latest proposed purchase price to a third appraiser who will select one of the
two submitted purchase prices. Each party will be responsible for their
respective expenses except in the case of utilizing a third appraiser wherein
those costs will be shared equally. Lessee will have ten (10) business days to
respond from the date upon receiving written notice of the pending sale from the
Lessor.

        In addition, if the Lessee exercises the option, Lessor will furnish
Lessee an ALTA Survey and Title Commitment, as well as any and all additional
documents and materials relating to the building and the property, including,
without limitation, copies of environmental studies, engineering studies, and
plans and specifications. Lessor and Lessee will share equally in the costs of
obtaining such surveys, commitments and studies. Lessee shall have at least ten
days to object to the items set forth therein prior to closing. If Lessor fails
to cure such objections, Lessee shall be able to waive its objections or shall
terminate the sale and continue as a tenant under the Lease. The closing date
should occur on the later of the following two dates: (i) the date that is sixty
(60) days from the day Lessee affirmatively responds to the notice of Lessor's
desire to sell, or (ii) the date that is twenty (20) days beyond Lessee's
receipt of all due diligence materials. Lessor will furnish Lessee a Title
Policy at its own cost.

        30. TRANSFER OF LESSOR'S INTEREST: In the event of sale or conveyance by
Lessor of Lessor's interest in the premises, this Lease shall not be affected by
any such sale and the Lessor will provide for the assumption of all Lessor
obligations under this lease in writing by the transferee. Lessor agrees not to
sell or convey Lessor's interest in the premises without consent from the
Lessee. Lessee's consent will not be unreasonably withheld.


                                       11


<PAGE>   12
        31. NOTICES: All notices required to be made and given under this Lease
shall be in writing and delivered in person or sent by certified mail to Lessor
at the same place rent payments are made hereunder, and to Lessee at the
Premises or to such other addresses as may hereafter be designated by either
party to the other in writing.

        32. COSTS AND ATTORNEY'S FEES: In the event of any action at law or in
equity between the Lessor and Lessee to enforce any of the terms and provisions
of this Lease or the rights of either party hereunder, the parties each agree
that the unsuccessful party to such litigation shall pay to the successful party
all costs and expenses, including reasonable attorney's fees, incurred therein
by such successful party, and if such successful party shall recover judgment in
any such action or proceeding, such costs and expenses, including attorney's
fees, shall be included in and made a part of such judgment.

        33. CAPTIONS AND CONSTRUCTIONS: Paragraph titles of this Lease are not a
part of this Lease and shall have no effect upon the construction or
interpretation of any part hereof. This Lease shall be construed in accordance
with and governed by the laws of the State of Kansas.

        34. SUCCESSORS: Subject to and consistent with the limitations on
assignments and subletting as provided in Paragraph 20 hereinabove, all of the
covenants, agreements, terms and conditions contained in this Lease shall apply
to and be binding upon Lessor and Lessee and their respective successors and
assigns.

        35. SEVERABILITY: In the event any part of this Lease is held to be
unenforceable or invalid for any reason, by any court of competent jurisdiction
and if such invalidity or unenforceability shall materially impair achieving the
purpose and intent of this Lease, then this entire Lease shall be invalid and
unenforceable. Otherwise, this Lease shall be construed as if not containing the
particular provision or provisions hereof held to be invalid or unenforceable,
and the rights and obligations of the parties shall be construed and enforced
accordingly.

        36. LESSEE'S APPROVALS: All approvals required by Lessee hereunder and
in the Exhibits attached hereto shall be exercisable in Lessee's sole
discretion.

        IN WITNESS WHEREOF, Lessor and Lessee have executed this Lease effective
as of the day and year first above written.


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<PAGE>   13
                          FACILITY PROPERTIES, L.L.C.


                          By:______________________________________________
                          Name:____________________________________________
                          Title:___________________________________________

                                                                    "Lessor"

                          ILLUMINET, INC., a Delaware corporation


                          By:______________________________________________
                                 Roger H. Moore
                                 President and CEO

                                                                    "Lessee"


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