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                                                                    EXHIBIT 10.9

                           THIRD AMENDED AND RESTATED
                         REGISTRATION RIGHTS AGREEMENT

      This THIRD AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT, dated as of
December 20, 2004 (this "AGREEMENT"), is entered into by and among Vocus, Inc.,
a Delaware corporation (the "COMPANY"), the persons listed on Schedule A
attached hereto as owners of shares of the Company's Series A Convertible
Preferred Stock (the "SERIES A INVESTORS"), the persons listed on Schedule A
attached hereto as owners of shares of the Company's Series B Convertible
Preferred Stock (the "SERIES B INVESTORS") and the persons listed on Schedule A
attached hereto as owners of shares of the Company's Series C Convertible
Preferred Stock (the "SERIES C INVESTORS," and collectively with the Series A
Investors and Series B Investors, the "INVESTORS" and each an "INVESTOR").

      WHEREAS, pursuant to that certain Series A Convertible Preferred Stock
Purchase Agreement, dated as of January 14, 2000, the Series A Investors
purchased, and the Company issued and sold, 5,158,628 shares of the Company's
Series A Convertible Preferred Stock, par value $.01 per share ("SERIES A
PREFERRED STOCK");

      WHEREAS, pursuant to that certain Series B Convertible Preferred Stock
Purchase Agreement, dated as of October 20, 2000, as amended by that certain
Amendment No. 1 and Joinder to the Series B Convertible Preferred Stock Purchase
Agreement, dated as of June 18, 2001, and that certain Second Amendment to the
Series B Convertible Preferred Stock Purchase Agreement, dated as of January 31,
2003, the Series B Investors purchased an aggregate of 10,135,973 shares of the
Company's Series B Convertible Preferred Stock, par value $.01 per share
("SERIES B PREFERRED STOCK");

      WHEREAS, the Series A and B Investors are parties to that certain Second
Amended and Restated Registration Rights Agreement, dated as of June 18, 2001
(the "PRIOR AGREEMENT"), setting forth certain demand and incidental
registration rights for such Investors;

      WHEREAS, the Company and the Series C Investors are parties to the Series
C Convertible Preferred Stock Purchase Agreement, dated as of the date hereof
(the "PURCHASE AGREEMENT"), pursuant to which the Series C Investors will buy,
and the Company will issue and sell, the Company's Series C Convertible
Preferred Stock, par value $.01 per share (the "SERIES C PREFERRED STOCK");

      WHEREAS, the obligations of the Company and the Series C Investors under
the Purchase Agreement are conditioned, among other things, upon the execution
and delivery of this Agreement by the Company and the Investors; and

      WHEREAS, the parties hereto desire to amend and supersede the Prior
Agreement in its entirety.

      NOW, THEREFORE, in consideration of these premises and intending to be
legally bound, the parties hereto agree as follows:

      1.    Certain Definitions. As used in this Agreement, the following terms
shall have the following respective meanings:

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      "AFFILIATE" means an "affiliate" as defined in Rule 12b-2 of the General
Rules and Regulations under the Exchange Act.

      "COMMISSION" means the U.S. Securities and Exchange Commission, or any
other federal agency at the time administering the federal securities laws,
rules and regulations.

      "COMMON STOCK" means the Company's common stock, $.01 par value per share.

      "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended, or
any successor federal statute, and the rules and regulations of the Commission
issued under such Act, as they each may, from time to time, be in effect.

      "PREFERRED STOCK" means the Series A, B and C Preferred Stock.

      "QUALIFIED PUBLIC OFFERING" means the first underwritten public offering
of Common Stock pursuant to a Registration Statement.

      "REGISTRABLE SHARES" means (i) the Series A Conversion Shares, (ii) the
Series B Conversion Shares, (iii) the Series C Conversion Shares, (iv) any
shares of Common Stock purchased or acquired by the Investors subsequent to the
date hereof and (v) any other shares of Common Stock of the Company issued in
respect of the shares described in clauses (i), (ii), (iii) and (iv) above (as a
result of stock splits, stock dividends, reclassifications, recapitalizations,
or similar events); provided, however, that shares of Common Stock that are
Registrable Shares shall cease to be Registrable Shares (x) upon any sale of
such shares pursuant to a Registration Statement or any open market sale of such
shares pursuant to Section 4(1) of the Securities Act or Rule 144 under the
Securities Act, (y) upon any sale of such shares in any manner to a person or
entity which, by virtue of Section 15 of this Agreement, is not entitled to the
rights provided by this Agreement or (z) with respect to any Investor, when such
Investor is eligible to sell, transfer or otherwise convey all of such
Investor's Registrable Shares pursuant to Rule 144 under the Securities Act in
any three-month period. Wherever reference is made in this Agreement to a
request or consent of holders of a certain percentage of Registrable Shares, the
determination of such percentage shall include shares of Common Stock issuable
upon conversion of Preferred Stock even if such conversion has not yet been
effected.

      "REGISTRATION STATEMENT" means a registration statement filed by the
Company with the Commission for a public offering and sale of securities of the
Company (other than a registration statement on Form S-8 or Form S-4, or their
successors, or any other form for a limited purpose, or any registration
statement covering only securities proposed to be issued in exchange for
securities or assets of another corporation).

      "SECURITIES ACT" means the Securities Act of 1933, as amended, or any
successor federal statute, and the rules and regulations of the Commission
issued under such Act, as they each may, from time to time, be in effect.

      "SERIES A, B OR C CONVERSION SHARES" means the shares of Common Stock into
which each share of Series A, B or C Preferred Stock, respectively, has been
converted or is then convertible.

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      "STOCKHOLDERS" means the Investors and any persons or entities to whom the
rights granted under this Agreement are properly transferred by the Investors,
their successors or assigns pursuant to Section 15 hereof.

      2.    Sale or Transfer of Preferred Stock; Legend.

            2.1.  Transfer Restrictions. The Preferred Stock and Registrable
Shares and shares issued in respect of shares of Preferred Stock or Registrable
Shares shall not be sold or transferred unless either (i) they first shall have
been registered under the Securities Act or (ii) the Company first shall have
been furnished with an opinion of legal counsel, reasonably satisfactory to the
Company, to the effect that such sale or transfer is exempt from the
registration requirements of the Securities Act. In no event may shares of
Series A Preferred Stock or Series A Conversion Shares be transferred to any
actual or potential competitor of the Company, as determined in good faith by
the Board of Directors.

            2.2.  Permitted Transfers. Notwithstanding anything to the contrary
contained in the foregoing Section 2.1, no registration or opinion of counsel
shall be required for either (i) a transfer pursuant to Section 15 hereof and,
subject to an exemption under state and federal securities laws, by an Investor
to an Affiliate of the Investor, or a partner of such Investor or a retired
partner of such Investor who retires after the date hereof, or to the estate of
any such partner or retired partner, if the transferee agrees in writing to be
subject to the terms of this Agreement to the same extent as if he were an
original Investor hereunder, or (ii) a transfer made in accordance with Rule 144
under the Securities Act.

            2.3.  Legends.

                  (a)   Each certificate representing Preferred Stock or
Registrable Shares and shares issued in respect of Preferred Stock and
Registrable Shares shall bear a legend substantially in the following form:

      THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
      UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT") OR THE SECURITIES
      LAWS OF ANY STATE. THE SECURITIES MAY NOT BE TRANSFERRED EXCEPT PURSUANT
      TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT AND APPLICABLE STATE
      SECURITIES LAWS OR PURSUANT TO AN APPLICABLE EXEMPTION FROM THE
      REGISTRATION REQUIREMENTS OF SUCH ACT AND SUCH LAWS OR PURSUANT TO A
      WRITTEN OPINION OF COUNSEL FOR THE COMPANY THAT SUCH REGISTRATION IS NOT
      REQUIRED.

                  (b)   In addition to the legend set forth in Section 2.3(a),
each certificate representing Preferred Stock and shares issued in respect of
Preferred Stock shall bear a legend substantially in the following form:

      THE SHARES OF STOCK REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE
      TERMS OF A REGISTRATION RIGHTS AGREEMENT, AS AMENDED FROM TIME TO TIME,
      BETWEEN THE COMPANY AND

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      THE REGISTERED OWNER OF THIS CERTIFICATE (OR THE REGISTERED OWNER'S
      PREDECESSOR IN INTEREST), AND SUCH AGREEMENT IS AVAILABLE FOR INSPECTION
      WITHOUT CHARGE AT THE OFFICE OF THE SECRETARY OF THE COMPANY.

                  (c)   The foregoing legends shall be removed from the
certificates representing any Registrable Shares at such time as they are sold
pursuant to Rule 144 under the Securities Act.

            2.4.  Rule 144 Information. The Company agrees, upon the request of
an Investor, to make available to such Investor and to any prospective permitted
transferee of any Preferred Stock or Registrable Shares of such Investor the
information concerning the Company described in Rule 144A(d)(4) under the
Securities Act.

      3.    Demand Registrations.

            3.1.  Series A Demand Registration Rights. At any time after the
closing of the Qualified Public Offering, the Series A Investors or any
permitted transferee of the Series A Investors holding in the aggregate at least
40% of the Registrable Shares collectively held by the Series A Investors and
any permitted transferees of the Series A Investors may request, in writing,
that the Company effect a registration on Form S-1 (or any successor form) of
Registrable Shares owned by such Stockholder or Stockholders covering shares of
Common Stock having an aggregate offering price of at least $3,000,000 (based on
the then current market price or fair value); provided, however, that the
Company shall not be required to effect any registration (other than on Form S-2
or S-3 or any successor form relating to secondary offerings) within six months
after the effective date of any other Registration Statement of the Company. If
the holders initiating the registration intend to distribute Registrable Shares
by means of an underwriting, they shall so advise the Company in their request.
In the event such registration is underwritten, the right of other Stockholders
to participate shall be conditioned on such Stockholders' participation in such
underwriting. Upon receipt of any such request, the Company shall promptly give
written notice of such proposed registration to all Stockholders. Such
Stockholders shall have the right, by giving written notice to the Company
within 30 days after the Company provides its notice, to elect to have included
in such registration such of their Registrable Shares as such Stockholders may
request in such notice of election, subject to the approval of the underwriter
managing the offering. If, in the opinion of the underwriter managing the
offering, the registration of all, or part of, the Registrable Shares that such
Stockholders have requested to be included in the offering would materially and
adversely affect such offering, then each Stockholder shall have the right to
participate with respect to its Registrable Shares pro rata based upon the
number of Registrable Shares then held by such Stockholder compared to the total
number of Registrable Shares then held by all of the participating Stockholders.
Thereupon, the Company shall, as expeditiously as possible, use its best efforts
to effect the registration, on Form S-1 (or any successor form), of all
Registrable Shares that the Company has been requested so to register.

            3.2.  Series B Demand Registration Rights. At any time after the
date hereof, the Series B Investors or any permitted transferee of the Series B
Investors holding in the aggregate at least 51% of the Registrable Shares
collectively held by the Series B Investors

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(excluding any Series A Conversion Shares and any other shares of Common Stock
of the Company issued in respect of the Series A Preferred Stock or the Series A
Conversion Shares (because of stock splits, stock dividends, reclassifications,
recapitalizations and the like)) and any permitted transferees of the Series B
Investors may request, in writing, that the Company effect a registration on
Form S-l (or any successor form) of Registrable Shares owned by such Stockholder
or Stockholders covering shares of Common Stock having an aggregate offering
price of at least $3,000,000 (based on the then current market price or fair
value); provided, however, that the Company shall not be required to effect any
registration (other than on Form S-2 or S-3 or any successor form relating to
secondary offerings) within six months after the effective date of any other
Registration Statement of the Company. If the holders initiating the
registration intend to distribute the Registrable Shares by means of an
underwriting, they shall so advise the Company in their request. In the event
such registration is underwritten, the right of other Stockholders to
participate shall be conditioned on such Stockholders' participation in such
underwriting. Upon receipt of any such request, the Company shall promptly give
written notice of such proposed registration to all Stockholders. Such
Stockholders shall have the right, by giving written notice to the Company
within 30 days after the Company provides its notice, to elect to have included
in such registration such of their Registrable Shares as such Stockholders may
request in such notice of election, subject to the approval of the underwriter
managing the offering. If, in the opinion of the underwriter managing the
offering, the registration of all, or part of, the Registrable Shares that such
Stockholders have requested to be included in the offering would materially and
adversely affect such offering, then each Stockholder shall have the right to
participate with respect to its Registrable Shares pro rata based upon the
number of Registrable Shares then held by such Stockholder compared to the total
number of Registrable Shares then held by all of the participating Stockholders.
Thereupon, the Company shall, as expeditiously as possible, use its best efforts
to effect the registration, on Form S-l (or any successor form), of all
Registrable Shares that the Company has been requested so to register.

            3.3.  Series C Demand Registration Rights. At any time after the
earlier of (a) October 29, 2009 or (b) the closing of the Qualified Public
Offering, the Series C Investors or any permitted transferee of the Series C
Investors holding in the aggregate at least 51% of the Registrable Shares
collectively held by the Series C Investors (excluding any Series A Conversion
Shares and any other shares of Common Stock of the Company issued in respect of
the Series A Preferred Stock or the Series A Conversion Shares (because of stock
splits, stock dividends, reclassifications, recapitalizations and the like)) and
any permitted transferees of the Series C Investors may request, in writing,
that the Company effect a registration on Form S-l (or any successor form) of
Registrable Shares owned by such Stockholder or Stockholders covering at least
20% of the Series C Conversion Shares (or any lesser percentage, if the
anticipated aggregate offering price of the Series C Conversion Shares proposed
to be registered is at least $3,000,000 (based on the then current market price
or fair value)); provided, however, that the Company shall not be required to
effect any registration (other than on Form S-2 or S-3 or any successor form
relating to secondary offerings) within six months after the effective date of
any other Registration Statement of the Company. If the holders initiating the
registration intend to distribute the Registrable Shares by means of an
underwriting, they shall so advise the Company in their request. In the event
such registration is underwritten, the right of other Stockholders to
participate shall be conditioned on such Stockholders' participation in such
underwriting. Upon receipt of any such request, the Company shall promptly give
written notice of such proposed registration to all Stockholders. Such
Stockholders shall have the right, by giving written notice

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to the Company within 30 days after the Company provides its notice, to elect to
have included in such registration such of their Registrable Shares as such
Stockholders may request in such notice of election, subject to the approval of
the underwriter managing the offering. If, in the opinion of the underwriter
managing the offering, the registration of all, or part of, the Registrable
Shares that such Stockholders have requested to be included in the offering
would materially and adversely affect such offering, then each Stockholder shall
have the right to participate with respect to its Registrable Shares pro rata
based upon the number of Registrable Shares then held by such Stockholder
compared to the total number of Registrable Shares then held by all of the
participating Stockholders. Thereupon, the Company shall, as expeditiously as
possible, use its best efforts to effect the registration, on Form S-l (or any
successor form), of all Registrable Shares that the Company has been requested
so to register.

            3.4.  Form S-3 Registration. To the extent that the Company is
eligible to file a Registration Statement on Form S-3 (or any successor form
relating to secondary offerings), holders of Registrable Shares will have the
right to require the Company to effect an unlimited number of Registration
Statements on Form S-3 (or any successor form), of Registrable Shares having an
aggregate offering price in each registration on Form S-3 in excess of
$1,000,000 (based on the then current public market price), each such request
for registration to be made by written notice to the Company. Upon receipt of
any such request, the Company shall promptly give written notice of such
proposed registration to all Stockholders. Such Stockholders shall have the
right, by giving written notice to the Company within 30 days after the Company
provides its notice, to elect to have included in such registration such of
their Registrable Shares as such Stockholders may request in such notice of
election. Thereupon, the Company shall, as expeditiously as possible, use its
best efforts to effect the registration on Form S-3 (or any successor form) of
all Registrable Shares that the Company has been requested to register. If the
registration involves an underwritten offering and, if in the opinion of the
underwriter managing the offering, the registration of all, or part of, the
Registrable Shares that such Stockholders have requested to be included in the
offering would materially and adversely affect such offering, then each
Stockholder shall have the right to participate in such offering pro rata based
upon the number of Registrable Shares then held by such Stockholder compared to
the total number of Registrable Shares then held by all of the participating
Stockholders.

            3.5.  Number of Registrations; Restriction Period. The Company shall
be required to effect not more than two registrations pursuant to each of
Section 3.1, 3.2 and 3.3 above; provided, however, that the Company shall not be
required to take any action to effect any registration pursuant to any of
Sections 3.1, 3.2 or 3.3 during the period commencing on the date on which any
Registration Statement (other than on Form S-2 or S-3 or any successor form
relating to secondary offerings), including, without limitation, any
Registration Statement filed pursuant to Section 3.1, 3.2 and 3.3, has been
declared or ordered effective and ending six months after such date. A
registration pursuant to Section 3.2 will not be included for purposes of this
Section 3.5 unless all Registrable Shares requested to be registered in such
registration are, in fact, registered in such registration.

            3.6.  Registration Delay. If at the time of any request to register
Registrable Shares pursuant to this Section 3, the Company is engaged or has
fixed plans to engage within 60 days of the time of the request in a registered
public offering as to which the Stockholders may include Registrable Shares
pursuant to Section 4 or is engaged in any other activity that, in the

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good faith determination of the Company's Board of Directors, would be adversely
affected by the requested registration to the material detriment of the Company,
then the Company may at its option direct that such request be delayed for a
period not in excess of 120 days from the effective date of such offering or the
date of commencement of such other material activity, as the case may be, such
right to delay a request to be exercised by the Company not more than once in
any one-year period.

      4.    Incidental Registration.

            4.1.  Notice. Whenever the Company proposes to file a Registration
Statement at any time and from time to time, it will, prior to such filing, give
written notice to all Stockholders of its intention to do so and, upon the
written request of a Stockholder or Stockholders given within 20 days after the
Company provides such notice (which request shall state the intended method of
disposition of such Registrable Shares), the Company shall use its best efforts
to cause all Registrable Shares that the Company has been requested by such
Stockholder or Stockholders to register to be registered under the Securities
Act to the extent necessary to permit their sale or other disposition in
accordance with the intended methods of distribution specified in the request of
such Stockholder or Stockholders; provided that the Company shall have the right
to postpone or withdraw any registration effected pursuant to this Section 4
without obligation to any Stockholder.

            4.2.  Limitations. In connection with any offering under this
Section 4 involving an underwriting, the Company shall not be required to
include any Registrable Shares in such underwriting unless the holders thereof
accept the terms of the underwriting as agreed upon between the Company and the
underwriters selected by it, and then only in such quantity as will not, in the
opinion of the underwriters, jeopardize the success of the offering by the
Company. If, in the opinion of the managing underwriter, the registration of
all, or part of, the Registrable Shares that the holders have requested to be
included would materially and adversely affect such public offering, then the
Company shall be required to include in the underwriting only that number of
Registrable Shares, if any, that the managing underwriter believes may be sold
without causing such adverse effect; provided that (i) in no event shall the
amount of Registrable Shares included in the offering be reduced below 25% of
the total number of shares of Common Stock (giving effect to the conversion into
Common Stock of all securities convertible thereto) included in the offering,
unless the offering is the Company's first underwritten public offering or the
shares being offered are solely for the Company's own account, in which case the
amount of Registrable Shares included in the offering may be reduced to zero,
and (ii) no persons or entities other than the Company, the Stockholders and
persons or entities holding registration rights granted in accordance with
Section 11 hereof shall be permitted to include securities in the offering. If
the number of Registrable Shares to be included in the underwriting in
accordance with the foregoing is less than the total number of shares that the
holders of Registrable Shares have requested to be included, then the holders of
Registrable Shares who have requested registration and other holders of shares
of Common Stock entitled to include shares of Common Stock in such registration
shall participate in the underwriting pro rata based upon their total ownership
of shares of Common Stock (giving effect to the conversion into Common Stock of
all securities convertible thereto). If any holder would thus be entitled to
include more shares than such holder requested to be registered, the excess
shall be

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allocated among other requesting holders pro rata based upon their total
ownership of Registrable Shares.

      5.    Registration Procedures. If and whenever the Company is required by
the provisions of this Agreement to use its best efforts to effect the
registration of any Registrable Shares under the Securities Act, the Company
shall:

                  (a)   file with the Commission a Registration Statement with
respect to such Registrable Shares and use its best efforts to cause that
Registration Statement to become and remain effective until the completion of
the distribution;

                  (b)   as expeditiously as possible prepare and file with the
Commission any amendments and supplements to the Registration Statement and the
prospectus included in the Registration Statement as may be necessary to keep
the Registration Statement effective, in the case of a firm commitment
underwritten public offering, until each underwriter has completed the
distribution of all securities purchased by it and, in the case of any other
offering, until the earlier of the sale of all Registrable Shares covered
thereby or 120 days after the effective date thereof;

                  (c)   as expeditiously as possible furnish to each selling
Stockholder such reasonable number of copies of the prospectus, including a
preliminary prospectus, in conformity with the requirements of the Securities
Act, and such other documents as the selling Stockholder may reasonably request
in order to facilitate the public sale or other disposition of the Registrable
Shares owned by the selling Stockholder;

                  (d)   as expeditiously as possible use its best efforts to
register or qualify the Registrable Shares covered by the Registration Statement
under the securities or Blue Sky laws of such states as the selling Stockholders
shall reasonably request, and do any and all other acts and things that may be
reasonably necessary to enable the selling Stockholders to consummate the public
sale or other disposition in such states of the Registrable Shares owned by the
selling Stockholder; provided, however, that the Company shall not be required
in connection with this Section 5(d) to qualify as a foreign corporation in any
jurisdiction;

                  (e)   in the event of any underwritten public offering, enter
into and perform its obligations under an underwriting agreement, in usual and
customary form, with the managing underwriter(s) of such offering; each
Stockholder participating in such underwriting shall also enter into and perform
its obligations under such an agreement;

                  (f)   notify each holder of Registrable Shares covered by such
Registration Statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act of the happening of any event
as a result of which the prospectus included in such Registration Statement, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading in the light of the circumstances then
existing, and supply or cause to be supplied to each such holder of Registrable
Shares a reasonable number of prospectus supplements or amended prospectuses
correcting any such errors;

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                  (g)   use its best efforts to furnish, on the date that such
Registrable Shares are delivered to the underwriters for sale, if such
securities are being sold through underwriters, (i) an opinion, dated as of such
date, of the counsel representing the Company for the purposes of such
registration, in form and substance as is customarily given to underwriters in
an underwritten public offering, addressed to the underwriters, if any, and (ii)
a letter dated as of such date, from the independent certified public
accountants of the Company, in form and substance as is customarily given by
independent certified public accountants to underwriters in an underwritten
public offering addressed to the underwriters; and

                  (h)   use its best efforts to have any Registrable Shares
listed for trading on the exchange or market on which the Company's Common Stock
is then admitted for trading.

      If the Company has delivered preliminary or final prospectuses to the
selling Stockholders and after having done so the prospectus is amended to
comply with the requirements of the Securities Act, the Company shall promptly
notify the selling Stockholders and, if requested, the selling Stockholders
shall immediately cease making offers of Registrable Shares and return all
prospectuses to the Company. The Company shall promptly provide the selling
Stockholders with revised prospectuses and, following receipt of the revised
prospectuses, the selling Stockholders shall be free to resume making offers of
the Registrable Shares.

      6.    Allocation of Expenses. The Company will pay all Registration
Expenses (as defined below) of all registrations under this Agreement; provided,
however, that if a registration under Section 3 is withdrawn at the request of
the Stockholders requesting such registration (other than as a result of
information concerning the business or financial condition of the Company that
is made known to the Stockholders after the date on which such registration was
requested) and if the requesting Stockholders elect not to have such
registration counted as a registration requested under Section 3, the requesting
Stockholders shall pay the Registration Expenses of such registration pro rata
in accordance with the number of their Registrable Shares included in such
registration. For purposes of this Section, the term "REGISTRATION EXPENSES"
shall mean all expenses incurred by the Company in complying with this Agreement
including, without limitation, all registration and filing fees, exchange
listing fees, printing expenses, fees and disbursements of counsel for the
Company and the reasonable and customary fees and expenses of one counsel
selected by the selling Stockholders to represent the selling Stockholders,
state Blue Sky fees and expenses, and the expense of any special audits incident
to or required by any such registration (such expenses of a special audit not to
exceed $15,000 in the case of a registration pursuant to Section 3 hereof), but
excluding underwriting discounts, selling commissions and the fees and expenses
of selling Stockholders' own counsel (other than the counsel selected to
represent all selling Stockholders). Any expenses in excess of $15,000 incident
to a special audit in connection with a registration pursuant to Section 3
hereof shall be borne ratably by the selling Stockholders.

      7.    Indemnification and Contribution.

            7.1.  Company Indemnification and Contribution. In the event of any
registration of any of the Registrable Shares under the Securities Act pursuant
to this Agreement, the Company will indemnify and hold harmless the seller of
such Registrable Shares, each

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underwriter of such Registrable Shares, and each other person, if any, who
controls such seller or underwriter within the meaning of the Securities Act or
the Exchange Act against any losses, claims, damages or liabilities, joint or
several, to which such seller, underwriter or controlling person may become
subject under the Securities Act, the Exchange Act, state securities or Blue Sky
laws or otherwise, insofar as such losses, claims, damages or liabilities (or
actions in respect thereof) arise out of or are based upon any untrue statement
or alleged untrue statement of any material fact contained in any Registration
Statement under which such Registrable Shares were registered under the
Securities Act, any preliminary prospectus or final prospectus contained in the
Registration Statement, or any amendment or supplement to such Registration
Statement, or arise out of or are based upon the omission or alleged omission to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading; and the Company will reimburse such seller,
underwriter and each such controlling person for any legal or any other expenses
reasonably incurred by such seller, underwriter or controlling person in
connection with investigating or defending any such loss, claim, damage,
liability or action promptly as such expenses are incurred; provided, however,
that the Company will not be liable in any such case to the extent that any such
loss, claim, damage or liability arises out of or is based upon any untrue
statement or omission made in such Registration Statement, preliminary
prospectus or prospectus, or any such amendment or supplement, in reliance upon
and in conformity with information furnished to the Company, in writing, by or
on behalf of such seller, underwriter or controlling person specifically for use
in the preparation thereof.

            7.2.  Holder Indemnification. In the event of any registration of
any of the Registrable Shares under the Securities Act pursuant to this
Agreement, each seller of Registrable Shares, severally and not jointly, will
indemnify and hold harmless the Company, each of its directors and officers and
each underwriter (if any) and each person, if any, who controls the Company or
any such underwriter within the meaning of the Securities Act or the Exchange
Act, against any losses, claims, damages or liabilities, joint or several, to
which the Company, such directors and officers, underwriter or controlling
person may become subject under the Securities Act, the Exchange Act, state
securities or Blue Sky laws or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon any untrue statement or alleged untrue statement of a material fact
contained in any Registration Statement under which such Registrable Shares were
registered under the Securities Act, any preliminary prospectus or final
prospectus contained in the Registration Statement, or any amendment or
supplement to the Registration Statement, or arise out of or are based upon any
omission or alleged omission to state a material fact required to be stated
therein or necessary to make the statements therein not misleading, if the
statement or omission was made in reliance upon and in conformity with
information furnished in writing to the Company by or on behalf of such seller,
specifically for use in connection with the preparation of such Registration
Statement, prospectus, amendment or supplement; provided, however, that the
obligations of a Stockholder hereunder shall be limited to an amount equal to
the net proceeds to such Stockholder of Registrable Shares sold as contemplated
herein. Subject to the limitations set forth in the preceding sentence, such
seller will reimburse the Company, such directors and officers, underwriter or
controlling person for any legal or any other expenses reasonably incurred by
such person in connection with investigating or defending any such loss, claim,
damage, liability or action promptly as such expenses are incurred.

                                       10
<PAGE>

            7.3.  Notice. Each party entitled to indemnification under this
Section 7 (the "INDEMNIFIED PARTY") shall give notice to the party required to
provide indemnification (the "INDEMNIFYING PARTY") promptly after such
Indemnified Party has actual knowledge of any claim as to which indemnity may be
sought, and shall permit the Indemnifying Party to assume the defense of any
such claim or any litigation resulting therefrom; provided that counsel for the
Indemnifying Party, who shall conduct the defense of such claim or litigation,
shall be approved by the Indemnified Party (whose approval shall not be
unreasonably withheld); and provided, further, that the failure of any
Indemnified Party to give notice as provided herein shall relieve the
Indemnifying Party of its obligations under this Agreement to the extent that
the Indemnifying Party was materially prejudiced by such failure. The
Indemnified Party may participate in such defense at such party's expense;
provided, however, that the Indemnifying Party shall pay such expense if
representation of such Indemnified Party by the counsel retained by the
Indemnifying Party would, in the reasonable opinion of such counsel, be
inappropriate due to actual differing interests between the Indemnified Party
and any other party represented by such counsel in such proceeding. No
Indemnifying Party in the defense of any such claim or litigation shall, except
with the consent of each Indemnified Party, consent to entry of any judgment or
enter into any settlement that does not include as an unconditional term thereof
the giving by the claimant or plaintiff to such Indemnified Party of a release
from all liability in respect of such claim or litigation, and no Indemnified
Party shall consent to entry of any judgment or settle such claim or litigation
without the prior written consent of the Indemnifying Party.

            7.4.  Contribution. In order to provide for just and equitable
contribution in circumstances in which the indemnification provided for in this
Section 7 is due in accordance with its terms but for any reason is held to be
unavailable to an Indemnified Party in respect to any losses, claims, damages
and liabilities referred to herein, then the Indemnifying Party shall, in lieu
of indemnifying such Indemnified Party, contribute to the amount paid or payable
by such Indemnified Party as a result of such losses, claims, damages or
liabilities to which such party may be subject in proportion as is appropriate
to reflect the relative fault of the Indemnifying Party on the one hand and the
Indemnified Party on the other in connection with the statements or omissions
that resulted in such losses, claims, damages or liabilities, as well as any
other relevant equitable considerations. The relative fault of the Indemnifying
Party and the Indemnified Party shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of material fact related
to information supplied by the Indemnifying Party or the Indemnified Party and
the parties' relative intent, knowledge, access to information and opportunity
to correct or prevent such statement or omission. The parties agree that it
would not be just and equitable if contribution pursuant to this Section 7 were
determined by pro rata allocation or by any other method of allocation that does
not take account of the equitable considerations referred to above.
Notwithstanding the provisions of this paragraph of Section 7, (a) in no case
shall any Stockholder who may be an Indemnifying Party be liable or responsible
for any amount in excess of the net proceeds received by such Stockholder from
the offering of Registrable Shares, and (b) the Company shall be liable and
responsible for any amount in excess of such proceeds to all participating
Stockholders who may be Indemnifying Parties; provided, however, that no person
guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of
the Securities Act) shall be entitled to contribution from any person who was
not guilty of such fraudulent misrepresentation. Any party entitled to
contribution will, promptly after receipt of notice of commencement of any
action, suit or proceeding against such party or parties

                                       11
<PAGE>

under this Section 7, notify such party or parties from whom such contribution
may be sought, but the omission so to notify such party or parties from whom
contribution may be sought shall not relieve such party from any other
obligation it or they may have thereunder or otherwise under this Section 7. No
party shall be liable for contribution with respect to any action, suit,
proceeding or claim settled without its prior written consent, which consent
shall not be unreasonably withheld; provided, however, that it shall not be
unreasonable to withhold such consent if no release is granted in connection
therewith or if such consent would constitute an admission of guilt.

      8.    Indemnification with Respect to Underwritten Offering. In the event
that Registrable Shares are sold pursuant to a Registration Statement in an
underwritten offering pursuant to Section 3, the Company agrees to enter into an
underwriting agreement containing customary representations and warranties with
respect to the business and operations of an issuer of the securities being
registered and customary covenants and agreements to be performed by such issuer
including, without limitation, customary provisions with respect to
indemnification by the Company of the underwriters of such offering.

      9.    Information by Holder. Each holder of Registrable Shares included in
any registration shall furnish to the Company such information regarding such
holder and the distribution proposed by such holder as the Company may request
in writing and as shall be required in connection with any registration,
qualification or compliance referred to in this Agreement.

      10.   "Market Stand-off" Agreement. Each Stockholder, if requested by the
Company and an underwriter of Common Stock or other securities of the Company,
hereby agrees not to sell, loan, pledge, hypothecate, encumber or otherwise
transfer or dispose of any Registrable Shares or other securities of the Company
held by such Stockholder for a specified period of time (not to exceed 180 days
in the case of the first such Registration Statement covering Common Stock of
the Company to be sold on its behalf to the public in an underwritten offering,
and not to exceed 90 days in the case of all other Registration Statements)
following the effective date of a Registration Statement; provided, however,
that all Stockholders holding not less than 5% of the Common Stock outstanding
(including shares of Common Stock issuable upon the conversion of Preferred
Stock or other convertible securities, or upon the exercise of options, warrants
or rights) and all officers and directors of the Company shall enter into
similar agreements. Such agreement shall be in writing in a form satisfactory to
the Company and such underwriter. The Company may impose stop-transfer
instructions with respect to the Registrable Shares or other securities subject
to the foregoing restriction until the end of the stand-off period.

      11.   Limitations on Subsequent Registration Rights. The Company shall
not, without the prior written consent of Stockholders holding at least 60% of
the Registrable Shares, enter into any agreement (other than this Agreement)
with any holder or prospective holder of any securities of the Company that
would allow such holder or prospective holder either (a) to include securities
of the Company in any registration filed under Section 3 or 4, or (b) to make a
demand registration that could result in such Registration Statement being
declared effective prior to the Qualified Public Offering. Additionally, the
Company shall not, without the prior written consent of the holders of at least
60% of the Series C Conversion Shares, enter into any agreement or otherwise
grant rights to any holder or prospective holder of any securities of the

                                       12
<PAGE>

Company that would allow such holder or prospective holder to include securities
of the Company in any registration filed under Section 3 or 4, unless such
agreement, instrument or arrangement granting such rights expressly states that
the rights of such holder or prospective holder to include any securities in any
such registration are subordinate to the rights of the holders of Series B and C
Conversion Shares hereunder and any securities requested by such holders to be
registered in any such offering shall be reduced to zero before the Registrable
Shares held by the holders of Series B and C Conversion Shares will be reduced
pursuant to Section 4.2 hereof.

      12.   Rule 144 Requirements. After the earliest of (i) the closing of the
sale of securities of the Company pursuant to a Registration Statement, (ii) the
registration by the Company of a class of securities under Section 12 of the
Exchange Act or (iii) the issuance by the Company of an offering circular
pursuant to Regulation A under the Securities Act, the Company agrees to:

                  (a)   comply with the requirements of Rule 144(c) under the
Securities Act with respect to current public information about the Company;

                  (b)   use its best efforts to file with the Commission in a
timely manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act (at any time after it has become subject to
such reporting requirements); and

                  (c)   furnish to any holder of Registrable Shares upon request
(i) a written statement by the Company as to its compliance with the
requirements of said Rule 144(c), and the reporting requirements of the
Securities Act and the Exchange Act (at any time after it has become subject to
such reporting requirements), (ii) a copy of the most recent annual or quarterly
report of the Company, and (iii) such other reports and documents of the Company
as such holder may reasonably request to avail itself of any similar rule or
regulation of the Commission allowing it to sell any such securities without
registration.

      13.   Selection of Underwriter. In the case of any registration effected
pursuant to this Agreement, the Company shall have the right to designate the
managing underwriter in any underwritten offering, subject to the approval of
the holders of a majority of the Registrable Shares requested to be included in
such offering, which approval shall not be unreasonably withheld.

      14.   Successors and Assigns. Except as provided in Section 15, the
provisions of this agreement shall be binding upon, and inure to the benefit of,
the respective successors, assigns, heirs, executors and administrators of the
parties hereto.

      15.   Transfers of Certain Rights.

            15.1. Amount. The rights granted to each Investor under this
Agreement may be transferred only to a transferee who is an Affiliate of the
Investor or who acquires at least 20% of the Preferred Stock or Registrable
Shares held by such transferring Investor and its Affiliates.

                                       13
<PAGE>

            15.2. Transferees. Any transferee (other than an Affiliate) to whom
rights under this Agreement are transferred shall, as a condition to such
transfer, deliver to the Company a written instrument by which such transferee
agrees to be bound by the obligations imposed upon the Investors under this
Agreement to the same extent as if such transferee were an Investor hereunder.

            15.3. Subsequent Transferees. A transferee to whom rights are
transferred pursuant to this Agreement may not again transfer such rights to any
other person or entity, other than as provided in Sections 15.1 or 15.2 above.

            15.4. Partners and Affiliates. Notwithstanding anything to the
contrary herein, an Investor may transfer rights granted to it under this
Agreement to any Affiliate or partner of such Investor to whom shares of
Preferred Stock are transferred pursuant to Section 2 and who delivers to the
Company a written instrument in accordance with Section 15.2 above and
containing the representation that the transfer is exempt from registration
under the Securities Act. In the event of such transfer, such Affiliate or
partner shall be deemed to be an Investor for purposes of this Section 15 and
may again transfer such rights to any other person or entity that acquires
shares of Preferred Stock from such Affiliate or partner, in accordance with,
and subject to, the provisions of Section 15.1, 15.2 and 15.3 above; provided,
however, that if an Investor transfers rights under this Agreement to its
partners at any time prior to the completion of the Qualified Public Offering,
the general partner of the Investor shall be deemed the sole recipient of
notices for all of such Investor's partners for the purposes of Section 16.6 of
this Agreement.

      16.   Miscellaneous.

            16.1. No Inconsistent Agreements. The Company will not hereafter
enter into any agreement with respect to its securities that is inconsistent
with or violates the rights granted to the holders of Registrable Shares in this
Agreement.

            16.2. Adjustments Affecting Registrable Shares. The Company will not
take any action, or permit any change to occur, with respect to its securities
that would adversely affect the ability of the holders of Registrable Shares to
include such Registrable Shares in a registration undertaken pursuant to this
Agreement or that would adversely affect the marketability of such Registrable
Shares in any such registration.

            16.3. Remedies. Any person having rights under any provision of this
Agreement will be entitled to enforce such rights specifically (without posting
any bond or other security), to recover damages caused by reason of any breach
of any provision of this Agreement and to exercise all other rights granted by
law.

            16.4. Amendments and Waivers. No term of this Agreement that inures
to the benefit of the Company may be amended, nor the observance of any term of
this Agreement waived (either generally or in a particular instance, and either
retroactively or prospectively), without the written consent of the Company. No
term of this Agreement that inures to the benefit of the holders of Series A
Conversion Shares may be amended, nor the observance of any term of this
Agreement waived (either generally or in a particular instance, and either
retroactively or prospectively), without the written consent of the holders of
all of the Series A

                                       14
<PAGE>

Conversion Shares then in existence; provided, however, that any such term may
be amended or any such observance waived with respect to all holders of Series A
Conversion Shares by written consent of the holders at least 60% of the Series A
Conversion Shares then in existence, if the amendment or waiver affects all such
holders in the same fashion, based on each such holder's proportionate ownership
of shares of Series A Preferred Stock. No term of this Agreement that inures to
the benefit of the holders of Series B Conversion Shares may be amended, nor the
observance of any term of this Agreement waived (either generally or in a
particular instance, and either retroactively or prospectively), without the
written consent of the holders of all of the Series B Conversion Shares then in
existence; provided, however, that any such term may be amended or any such
observance waived with respect to all holders of Series B Conversion Shares by
written consent of the holders at least 75% of the Series B Conversion Shares
then in existence, if the amendment or waiver affects all such holders in the
same fashion based on each such holder's proportionate ownership of shares of
Series B Preferred Stock. No term of this Agreement that inures to the benefit
of the holders of Series C Conversion Shares maybe amended, nor the observance
of any term of this Agreement waived (either generally or in a particular
instance, and either retroactively or prospectively), without the written
consent of the holders of all of the Series C Conversion Shares then in
existence; provided, however, that any such term may be amended or any such
observance waived with respect to all holders of Series C Conversion Shares by
written consent of the holders at least 75% of the Series C Conversion Shares
then in existence, if the amendment or waiver affects all such holders in the
same fashion based on each such holder's proportionate ownership of shares of
Series C Preferred Stock. Any such amendment or waiver effected in accordance
with this Section 16.4 shall be binding on all parties hereto, even if they do
not execute such consent. No waivers of or exceptions to any term, condition or
provision of this Agreement, in any one or more instances, shall be deemed to
be, or construed as, a further or continuing waiver of any such term, condition
or provision. This Agreement amends and restates in its entirety the Prior
Agreement, which agreement is hereby terminated and of no further force or
effect.

            16.5. Governing Law. This Agreement shall be governed by and
construed under the laws of the State of Delaware, without reference to the
conflict of laws provisions thereof.

            16.6. Notices. All notices, requests, consents, and other
communications under this Agreement shall be in writing and shall be deemed
delivered (i) two business days after being sent by registered or certified
mail, return receipt requested, postage prepaid or (ii) one business day after
being sent via a reputable nationwide overnight courier service guaranteeing
next business day delivery, in each case to the intended recipient as set forth
below:

          If to the Company:

                Vocus, Inc.
                4296 Forbes Boulevard
                Lanham, Maryland 20706
                Fax: (301) 459-2827
                Attention: Richard Rudman, President

                                       15
<PAGE>

          with a copy to:

                Greenberg Traurig, LLP
                1750 Tysons Boulevard, Suite 1200
                McLean, Virginia 22102
                Fax:(703) 749-1301
                Attention: Richard Melnick, Esq.

or at such other address or addresses as may have been furnished in writing by
such parties to the Investors.

      If to the Investors, at the addresses set forth on the signature pages
hereto, or at such other address or addresses as may have been furnished to the
Company in writing by such Investor.

      Any party may give any notice, request, consent or other communication
under this Agreement using any other means (including, without limitation,
personal delivery, messenger service, telecopy, first class mail or electronic
mail), but no such notice, request, consent or other communication shall be
deemed to have been duly given unless and until it is actually received by the
party for whom it is intended. Any party may change the address to which
notices, requests, consents or other communications hereunder are to be
delivered by giving the other parties notice in the manner set forth in this
Section.

            16.7. Severability. In case any provision of this Agreement shall be
invalid, illegal or unenforceable, as determined by a court of competent
jurisdiction, the validity, legality and enforceability of the remaining
provisions of this Agreement or any provision of the other Agreements shall not
in any way be affected or impaired thereby.

            16.8. Titles and Subtitles. The titles of the sections of this
Agreement are for convenience of reference only and are not to be considered in
construing this Agreement.

            16.9. No Registration of Preferred Stock. The registration rights
contained herein apply only to the Common Stock, and the Company shall never be
obligated to register any of the Preferred Stock.

                            [SIGNATURE PAGE FOLLOWS]

                                       16
<PAGE>

      IN WITNESS WHEREOF, the parties have executed this Third Amended and
Restated Registration Rights Agreement as of the date first written above.

                                         VOCUS, INC.

                                         By: /s/ Richard Rudman
                                             -----------------------------------
                                             Richard Rudman, President and
                                             Chief Executive Officer

INVESTORS:

EDISON VENTURE FUND IV, L.P.                LAZARD TECHNOLOGY PARTNERS
                                            II LP

By: Edison Partners IV, L.P., its General   By: LTP II LP, its General Partner
    Partner                                 By: LTP II GenPar LLC, its General
                                                Partner

By: /s/ Gary P. Golding                     By: /s/ Kevin Burns
    ----------------------------------          -------------------------------
    Gary P. Golding, General Partner            Kevin Burns, Managing Principal

1420 Spring Hill Road, Suite 420            5335 Wisconsin Avenue, NW, Suite 410
McLean, Virginia 22102                      Washington, D.C. 20015

STERLING VENTURE PARTNERS, LP

By: Sterling Venture Partners, LLC, its
    General Partner

By: /s/ Michael Bronfein
    ------------------------------------
    Michael Bronfein, Managing Member

6225 Smith Avenue, Suite 210
Baltimore, Maryland 21209

                                       19
<PAGE>

                                   SCHEDULE A

                                   INVESTORS

Series A Investors

Edison Venture Fund IV, L.P.
Carmel Investments, LLP

Series B Investors

Lazard Technology Partners II LP
Edison Venture Fund IV, L.P.
Sterling Venture Partners, LP

Series C Investors

Lazard Technology Partners II LP
Edison Venture Fund IV, L.P.
Sterling Venture Partners, LP<PAGE>

                                                                   EXHIBIT 10.10

                               AGREEMENT OF LEASE
                                 by and between
                                 MOR FORBES LLLP
                                   (Landlord)
                                      and
                               VOCUS, INC.(Tenant)

<TABLE>
<CAPTION>
                                                               Page
<S>                                                            <C>
1.  Leased Premises ........................................     1

2.  Term ...................................................     2

3.  Security Deposit .......................................     4

4.  Use ....................................................     5

5.  Basic Annual Rent ......................................     6

    5.1. Definitions .......................................     6
    5.2. Rent Adjustment ...................................     8
    5.3. Tax Adjustment ....................................     9
    5.5. Utilities .........................................    10
    5.6. Payments ..........................................    10

6.  Requirements of Law ....................................    11

7.  Tenant's Improvements ..................................    11

8.  Condition of Premises ..................................    11

9.  Conduct on Premises ....................................    13

10. Insurance ..............................................    13

11. Mechanics' and Materialmen's Liens and Other Liens .....    13

12. Tenant's Failure to Perform ............................    13

13. Loss, Damage, Injury ...................................    13

14. Destruction -- Fire or Other Casualty ..................    14

15. Eminent Domain .........................................    14

16. Environmental Assurances ...............................    15

    (a) Covenants ..........................................    15
    (b) Indemnification by Tenant ..........................    15
    (b) Indemnification by Landlord ........................    15
    (c) Definitions ........................................    16

17. Assignment/Subletting ..................................    16

18. Defaults ...............................................    17

19. Acceptance of Leased Premises ..........................    20

20. Access to Premises and Change in Services ..............    20

21. Estoppel Certificates ..................................    20

22. Subordination ..........................................    20

23. Attornment .............................................    21

24. Notices ................................................    21

25. Landlord's Liability ...................................    21
</TABLE>

<PAGE>

<TABLE>
<S>                                                            <C>
26. Separability, Enforceability ............................    21

27. Captions ................................................    22

28. Recordation .............................................    22

29. Successors and Assigns ..................................    22

30. Holding Over ...........................................     22

31. Commissions ............................................     22

32. Waiver of Jury Trial ...................................     22

33. Miscellaneous ..........................................     23

34. Authority ..............................................     24

35. Riders .................................................     24
</TABLE>

Rider No. 1 - Right of First Offer
Rider No. 2 - Renewal Option

EXHIBIT A - Site Plan and Leased Premises
EXHIBIT B - Plans and Specifications
EXHIBIT C - Lease Commencement Agreement
EXHIBIT D - Rules and Regulations
EXHIBIT E - HVAC Contract Specifications
EXHIBIT F - HVAC Certification

<PAGE>

                                 MOR FORBES LLLP

                                 LEASE AGREEMENT

      THIS AGREEMENT OF LEASE is made this 21st day of December, 2000, by and
between MOR FORBES LLLP, a limited liability limited partnership formed under
the laws of the state of Maryland (hereinafter referred to as "Landlord"), and
VOCUS, INC., a corporation duly formed under the laws of the State of Delaware
(hereinafter referred to as "Tenant").

      WITNESSETH, that the parties hereby covenant, promise and agree as
follows:

      1. Leased Premises.

            (a) Landlord is the developer of the building to be constructed at
4260 Forbes Boulevard, known as Building A (hereinafter referred to as the
"Building"), in the Forbes 50 Business Center, Prince George's County, Maryland.
The Building is located in a project which, upon completion, is expected to be
comprised of two one-story research and development buildings (the "Project").
Landlord does hereby lease unto Tenant and Tenant does hereby rent from
Landlord, that portion of the Building containing approximately 22,488 square
feet (hereinafter referred to as the "Leased Premises") as more particularly
shown on "Exhibit A" attached hereto, incorporated by reference herein and
initialled by the parties, together with the non-exclusive right to use the
designated parking areas, driveways and sidewalks. See Rider No.1 - Right of
First Offer.

            (b) The Leased Premises will be finished (the "Tenant Improvements")
by Landlord (through its general contractor, Manekin, LLC), in accordance with
plans and specifications to be prepared by Tenant's space planner/architect (the
"Architect") on or before January 16, 2001, and approved by Landlord and Tenant.
The Architect shall additionally provide to Landlord from time to time during
the design process schematic and design development drawings of the proposed
Tenant Improvements. The selection of Tenant's Architect shall be subject to
Landlord's approval, such approval not to be unreasonably withheld, conditioned
or delayed. GHK is hereby approved by Landlord as Tenant's Architect. At such
time as the plans and specifications for the Tenant Improvements are finalized
and approved by Landlord and Tenant, they shall be attached hereto as Exhibit B
and made a part hereof (the "Plans and Specifications"). All fees and expenses
payable to Tenant's Architect shall be paid by Tenant, but Tenant shall have the
right, to apply Landlord's Contribution, defined below, toward payment of such
expenses. Tenant agrees that Tenant shall bear full responsibility for the Plans
and Specifications, and the Leased Premises, as improved in accordance with the
Plans and Specifications, as being in compliance with all applicable
requirements of law, including without limitation, the Americans With
Disabilities Act, as amended. Tenant releases Landlord from any claim by Tenant
arising out of failure of the Leased Premises to be in compliance with all
applicable requirements of law, except to the extent that Landlord, or its
general contractor, fails to finish the Leased Premises in accordance with the
Plans and Specifications. Except to the extent that Tenant is responsible for
assuring that the Leased Premises comply with all applicable laws, and except to
the further extent that any legal requirements are attributable to Tenant's
particular use of the Leased Premises, and are not applicable to the building
generally, Landlord, at its expense, shall be responsible for assuring that the
Building and the Project are constructed in accordance with all applicable laws,
codes and ordinances,

<PAGE>

including the Americans With Disabilities Act, as such laws exist on the
Commencement Date.

            (c) Landlord shall contribute up to Twenty Dollars ($20.00)
multiplied by the Rentable Area of the Leased Premises, as hereinafter defined,
toward the cost of the Tenant Improvements ("Landlord's Contribution"). In
addition to Landlord's Contribution, at Tenant's option, Landlord shall
contribute an additional allowance of up to Ten Dollars ($10.00) multiplied by
the Rentable Area of the Leased Premises toward the cost of the Tenant
Improvements ("Landlord's Additional Contribution"). To the extent Landlord's
Additional Contribution is utilized by Tenant, the Basic Annual Rent described
below shall be increased by an amount sufficient to amortize Landlord's
Additional Contribution over the initial Lease Term, with interest at a rate of
twelve percent (12%) per annum. All charges and expenses incurred for work and
material respecting the finishing of the Leased Premises which are in excess of
Landlord's Contribution and Landlord's Additional Contribution and approved by
Tenant as set forth below, shall be deemed additional rent and shall be paid by
Tenant upon receipt of an invoice from Landlord therefor. All charges and
expenses incurred in connection with any change orders will be paid by Tenant at
the time it executes such change order.

            (d) The cost of the work to be performed by Landlord shall include
the general contractor's fee of 5% of all construction costs, excluding soft
costs (the "Hard Costs"), plus an additional 5% of all Hard Costs for general
conditions. After the Plans and Specifications are finalized, Landlord or its
general contractor shall obtain, for each of the major trades, competitive bids
from at least three reputable subcontractors acceptable to Landlord. Tenant
shall have the right to select one subcontractor to bid on each of such
subcontracts, subject to Landlord's prior approval. The selection of such
subcontractors from the bidding process shall be made by mutual agreement of
Landlord and Tenant.

            (e) After the major trades are bid and selected as aforesaid,
Landlord shall prepare and deliver to Tenant a budget for the cost of
constructing the Tenant Improvements (the "Budget"). To the extent that the
Budget includes any costs in excess of the amount of Landlord's Contribution
(which excess costs are hereinafter referred to as the "Tenant Costs"), Tenant
shall have the right to approve same; provided, however, the cost of all
subcontracts approved by Tenant and the fees payable to the general contractor
pursuant to subparagraph (d) above, are hereby deemed approved by Tenant. In the
event that the Budget includes Tenant Costs not otherwise approved or deemed
approved by Tenant and Tenant fails to approve or disapprove same in writing
within three (3) business days after receipt of the Budget from Landlord, then
the Budget and such Tenant Costs shall be deemed approved by Tenant. In the
event that Tenant disapproves same in writing within said three (3) business day
period, then Tenant, Landlord and Tenant's Architect shall endeavor in a prompt
and cooperative manner to reduce or eliminate the Tenant Costs to Tenant's
reasonable satisfaction by revising the Plans and Specifications, reducing the
scope of the work or otherwise. Any delays in the Commencement Date, as
hereinafter defined, resulting from Tenant's failure to approve the original
Budget shall be deemed a "Tenant Delay" for purposes of Section 2 below, it
being understood and agreed, however, that both parties will endeavor in good
faith to avoid unnecessary delays so as to enable construction to proceed
timely.

      2. Term. This Lease shall be for a term of approximately ten (10) years
(the Lease Term) commencing on the "Commencement Date", as hereinafter defined,
and terminating at

                                      -2-

<PAGE>

11:59 p.m. on the last day of the tenth (10th) full lease year, unless otherwise
terminated or extended in accordance with the provisions hereof. Each respective
period of twelve (12) successive calendar months during the Lease Term or any
renewals thereof commencing with the first full calendar month during the Lease
Term shall be hereinafter referred to as the "lease year". If the Commencement
Date does not occur on the first day of a month, the first lease year shall
include the twelve (12) calendar months and the period from the Commencement
Date until the first day of the following month. See Rider No. 2 - Renewal
Option.

            The Commencement Date will be the latest to occur of the following:
(a) the date on which Landlord's construction of the Tenant Improvements in
accordance with the Plans and Specifications is substantially complete and
certified as such to Landlord and Tenant by Landlord's architect; and (b) the
date on which Landlord obtains a temporary use and occupancy permit or other
applicable governmental approval which permits Tenant's occupancy of the Leased
Premises. Landlord estimates that the Commencement Date will occur on or about
May 1, 2001 (the "Estimated Commencement Date), so long as this Lease is
executed and delivered by Tenant on or before December 21, 2000, and the Plans
and Specifications are finalized and approved by Landlord and Tenant on or
before January 16, 2001 (collectively, "Tenant's Deadlines"). The Estimated
Commencement Date of May 1, 2001 will be postponed by one day for each day
Tenant is late in meeting either or both of Tenant's Deadlines, and for the
period of any other Tenant Delay hereunder. The Estimated Commencement Date
shall be further post-poned as reasonably required by Landlord if the Tenant
Improvements, as shown on the Plans and Specifications, require laboratory space
or any other specialty construction.

      Notwithstanding any language in this Lease to the contrary, in the event
that the Commencement Date fails to occur by May 1, 2001, then, to the extent
caused by Tenant's failure to meet either or both of Tenant's Deadlines, or as a
result of any Tenant Delay, or any other delay attributable to Tenant, then
Tenant's obligation to pay Basic Annual Rent shall nevertheless commence as of
May 1, 2001 (or such later date the Commencement Date would have occurred if not
for Tenant's delay), which date shall be deemed the Commencement Date for all
purposes of this Lease. In the event that the Commencement Date fails to occur
within thirty (30) days after the Estimated Commencement Date (as the same may
be postponed in accordance with the terms of this Lease)[that date which, is
thirty (30) days after the Estimated Commencement Date being referred to herein
as the "Final Delivery Date"], then the Basic Annual Rent payable by Tenant
hereunder shall be abated by one day for each day after the Final Delivery Date
that the actual Commencement Date occurs.

            In the event that Landlord shall be unable, by reason of
construction delays or otherwise, to deliver possession of the Leased Premises
on the Estimated Commencement Date (as the same may be postponed in accordance
with the terms of this Lease), then this Lease shall nevertheless continue in
full force and effect, and Tenant shall have no right to rescind, cancel or
terminate the same if possession is given within one hundred twenty (120) days
thereafter. If Landlord fails to deliver the Leased Premises within one hundred
twenty (120) days after the Estimated Commencement Date (as the same may be
postponed in accordance with the terms of this Lease) then Tenant may terminate
this Lease by giving written notice to Landlord of such termination within ten
(10) days after the expiration of such 120-day period (so long as Landlord does
not deliver possession within such 10-day period), which remedy, if exercised by
Tenant, shall be Tenant's sole and exclusive remedy for Landlord's

                                      -3-

<PAGE>

failure to deliver possession hereunder. In the event of such termination,
Landlord shall promptly return to Tenant all deposits and/or letters of credit
previously delivered to Landlord hereunder, and the parties shall not have any
further obligations under this Lease, other than the indemnification obligations
set forth in Section 31 below which shall survive such termination. Whether or
not Landlord shall deliver possession of the Leased Premises on the Estimated
Commencement Date, or within such additional 120-day period, Tenant agrees that
in no event shall Landlord be liable for damages, if any, sustained by Tenant as
a result of Landlord's failure to deliver possession.

            After Landlord delivers possession of the Leased Premises, Landlord
will remain responsible for the completion of those "punchlist" items, if any,
to which Landlord and Tenant have agreed in writing within fifteen (15) days
after the date Tenant occupies the Leased Premises. Landlord shall endeavor in
good faith to cause its general contractor to complete all punchlist items
within thirty (30) days following the preparation of a list of the agreed
punchlist items.

            Landlord shall use its reasonable efforts to notify Tenant fifteen
(15) days prior to the date on which the Leased Premises will be ready for
Tenant's occupancy, and Tenant shall have the right to enter the Leased Premises
at that time for the installation of its telephones, cabling, wiring, furniture
and equipment, provided that such work is done under the general supervision of
Landlord and does not interfere with Landlord's work. Such entry shall be at
Tenant's sole risk and expense. Commencing on the first day of such early
access, Tenant agrees that all the terms and provisions of this Lease shall be
in full force and effect except that Tenant shall have no obligation to pay rent
during such early access period. Tenant agrees to indemnify and hold harmless
landlord for any damage or personal injury which may occur as a result of
Tenant's entry into the Leased Premises prior to the Commencement Date. Tenant
shall deliver to Landlord evidence of the insurance required to be maintained by
Tenant pursuant to Section 10 of this Lease prior to Tenant's entry into the
Leased Premises.

            On the Commencement Date or such later date as Landlord may request,
Tenant shall promptly enter into a supplementary written agreement (the "Lease
Commencement Agreement") in substantially the form attached hereto as "Exhibit
C," thereby specifying, among other things, the date as of which the Lease Term
shall have begun and as of which the Lease Term shall end, the amount of Basic
Annual Rent payable by Tenant hereunder, and the principal amount of the Letter
of Credit, defined below.

      3. Security Deposit.

            (a) Cash. Tenant, contemporaneously with the execution of this
Lease, shall deposit with Landlord the sum of Twenty-Two Thousand Three Hundred
Dollars and Sixty Cents ($22,300.60) as a security deposit (the "Deposit").
Landlord's receipt of the Deposit shall be confirmed by Landlord in the Lease
Commencement Agreement. To the extent the Deposit has not been applied or
exhausted pursuant to the further terms hereof, ninety percent (90%) thereof
shall be returned by Landlord to Tenant within thirty (30) days following the
expiration of the Lease Term, and the balance within ninety (90) days after the
end of the Operating Year in which the Lease expiration date occurs. Landlord
shall have the right to apply the Deposit to cure any breach by Tenant beyond
the applicable cure period, if any, of any of Tenant's obligations or duties
pursuant to this Lease, and upon any such application of the Deposit by
Landlord, Tenant

                                      -4-

<PAGE>

shall immediately restore the same to the dollar amount set forth in this
Section. Landlord shall be entitled to the full use of the Deposit, shall not be
required to escrow or otherwise segregate the Deposit, and no interest shall
accrue thereon or be paid or payable by Landlord with respect to the Deposit.

            (b) Letter of Credit. In addition to the Deposit, Tenant shall
deposit with Landlord a clean, non-contingent irrevocable Letter of Credit (the
"Letter of Credit"), in form and substance and issued by a financial institution
reasonably acceptable to Landlord, in an amount equal to the cost of all Tenant
Improvements to be performed by Landlord hereunder, the total cost of which is
expected to exceed $18.00 multiplied by the Rentable Area of the Leased Premises
(the "Excess Costs"). The Letter of Credit shall be freely assignable to any
lender of Landlord, and to any successor or assign of Landlord's interest under
the Lease. The Letter of Credit shall be deposited with Landlord within five (5)
calendar days after the date the Budget is delivered to Tenant or, if the Budget
requires Tenant's approval, within five (5) calendar days after the date the
Budget is approved (or deemed approved) by Tenant. If from time to time, during
the course of construction or upon completion thereof, the Excess Costs are
reasonably expected to or actually exceed the original amount of the Letter of
Credit, then within five (5) days of Landlord's request, the principal amount of
the Letter of Credit shall be increased by Tenant accordingly. Landlord's
receipt of the Letter of Credit shall be confirmed in the Lease Commencement
Agreement. To the extent the same has not been applied or exhausted pursuant to
the further terms hereof, the Letter of Credit shall be returned by Landlord to
Tenant following the expiration of the Lease Term. In addition to any and all
other remedies available to Landlord under this Lease, Landlord shall have the
right to draw upon the Letter of Credit to cure any breach by Tenant of any of
Tenant's obligations or duties pursuant to the Lease, if such breach is not
cured beyond the applicable cure period, if any. Any demand by Landlord for a
draw upon the Letter of Credit shall be accompanied by a statement to the issuer
thereof purportedly signed by an authorized representative of Landlord
certifying that Tenant is in breach of its obligations under the Lease beyond
the expiration of applicable grace and cure periods, if any, and that Landlord
is entitled to draw upon the Letter of Credit in accordance with the terms of
the Lease. Upon any such draw, Tenant shall immediately restore the same to its
original amount. No interest shall accrue thereon or be paid or payable with
respect to the Letter of Credit.

            (c) Waiver of Letter of Credit. So long as Tenant is not then in
default of this Lease and has not been in default beyond the applicable grace
and cure periods, if any, more than once during any lease year of the term
hereof, Tenant's obligation to maintain the Letter of Credit shall be waived and
the Letter of Credit shall be returned to Tenant if Tenant has achieved either
of the following: (a) a credit rating of BBB or better as reported by a
national, reputable credit reporting agency acceptable to Landlord, and such
rating has continued for no less than three (3) consecutive quarters during the
term of this Lease, or (b) profitability in four (4) consecutive quarters during
the term of this Lease, as evidenced by Tenant's unaudited financial statements,
certified to be true and correct by Tenant's chief financial officer.

      4. Use. Landlord and Tenant expressly agree that the Leased Premises shall
be used or occupied by Tenant for general office and administrative purposes,
and for no other purposes whatsoever.

                                      -5-

<PAGE>
      5. Basic Annual Rent. Subject to adjustment pursuant to Section l(c)
above, Tenant shall pay to Landlord during the Lease Term "Basic Annual Rent" in
an amount equal to the per square foot amount set forth below, multiplied by the
Rentable Area of the Leased Premises:

<TABLE>
<CAPTION>
LEASE   BASIC ANNUAL      MONTHLY
 YEAR       RENT        INSTALLMENT   PER SQUARE FOOT
-----   -------------   -----------   ---------------
<S>     <C>             <C>           <C>
  1     $  267,607.20   $ 22,300.60       $11.90
  2     $  274,353.60   $ 22,862.80       $12.20
  3     $  281,324.88   $ 23,443.74       $12.51
  4     $  288,296.16   $ 24,024.68       $12.82
  5     $  295,492.32   $ 24,624.36       $13.14
  6     $  302,913.36   $ 25,242.78       $13.47
  7     $  310,559.28   $ 25,879.94       $13.81
  8     $  318,430.08   $ 26,535.84       $14.16
  9     $  326,300.88   $ 27,191.74       $14.51
 10     $  334,396.56   $ 27,866.38       $14.87
</TABLE>

Basic Annual Rent shall be payable in equal monthly installments as set forth
above, without any deductions or set-offs, and without demand, in advance on the
first day of each and every month for which payment is due, and the first such
monthly installment shall be due and payable simultaneously with Tenant's
execution of this Lease. If the Lease Term shall commence on a day other than
the first day of a month, then the Basic Annual Rent for the fractional part of
a month at the beginning of the term shall be pro-rated accordingly.

            5.1. Definitions. For purposes of this Lease, the following meanings
or definitions shall apply:

                  (a) "Rentable Area of the Building" shall, for all purposes of
this Lease, be deemed to be 54,692 square feet. The "Rentable Area of the
Project" shall be deemed to be 54,692 square feet until such time as "Building
B", to be located at 4230 Forbes Blvd., is substantially completed. Upon
substantial completion of Building B, the Rentable Area of the Project will
thereafter comprise both buildings on the Real Property with which Tenant shares
certain expenses, which shall be deemed to be 110,449 square feet. Landlord's
architect will certify to Landlord and Tenant that, if built in accordance with
the drawings of the Project previously provided to Tenant, the rentable area of
the finished Project will be 110,449 square feet.

                  (b) "Rentable Area of the Leased Premises" is hereby deemed to
be 22,488 square feet, which amount shall be certified to Landlord and Tenant by
Landlord's architect after the Plans and Specifications are finalized. The
Rentable Area of the Leased Premises has been determined in accordance with the
"industrial" standard (i.e., measured to the outside face of exterior walls and
the middle of interior demising walls). Tenant's pro rata portion of those
expenses applicable to the Project ("Tenant's Portion") shall be a fraction, the
numerator of which shall be the Rentable Area of the Leased Premises, and the
denominator of which shall be the Rentable Area of the Project, as it exists
from time to time. As of the Commencement Date, Tenant's Portion shall be
forty-one and twelve hundredths percent (41.12%). Notwithstanding the foregoing
figures and expectations, Landlord reserves the right to change the total number
and square footage of the buildings comprising the Project prior to completion
of construction thereof, in which event the number and percentages set forth
herein will be revised by Landlord accordingly.

                  (c) The term "Common Area Expenses" shall mean all reasonable
and customary expenses paid or incurred by

                                      -6-

<PAGE>

Landlord in connection with Landlord's management of the Real Property and the
management, maintenance, operation and repair of the common areas of the Real
Property, including, but not limited to, (i) keeping the driveways, parking
areas, sidewalks and steps free and clear of ice, snow and debris; (ii)
maintaining all grass and landscaping on the Real Property; (iii) maintaining
the common areas of the buildings of the Real Property (including the Building),
including the utility rooms and security systems, if any, and repair of normal
wear and tear of the roof and caulking; (iv) trash removal from dumpsters on the
Real Property, if any and pick-up for paper recycling; (v) monitoring, repairing
and payment of all common utilities, including water, sewerage, unmetered or
metered sprinkler and exterior electrical utilities on the Real Property; (vi)
management fees not to exceed those customarily charged for buildings comparable
to the Building in the general vicinity of the Project; and (vii) the cost of
maintaining Insurance, as defined below. "Common Area Expenses" does not include
(1) the costs of work Landlord performs for, and/or at the expense of, any
particular tenant (including Tenant), which costs will be billed directly to
Tenant or such other tenant, as the case may be, (2) any expenses incurred in
connection with capital improvements, other than as expressly permitted herein,
(3) costs of repairs and replacements occasioned by casualty or condemnation and
payable by insurance proceeds, (4) any cost that is reimbursed to Landlord by
insurance carriers, or is separately charged to and payable by tenants, (5) all
ownership costs not allocable to actual management, repair, maintenance or
operation of the Building, including, without limitation, leasing commissions,
advertising and other direct expenses or procuring tenants, including lease
concessions, (6) depreciation of the Building and other depreciable property
within the Real Property, (7) interest on and amortization of any debt or any
costs of financing, refinancing, constructing or purchasing the Leased Premises,
(8) interest and penalties for late payment of Taxes provided Tenant has
deposited with Landlord the amount necessary to pay such Taxes in accordance
with this Lease and any fines or penalties incurred by Landlord due to violation
by Landlord of any rule of a governmental authority other than those arising
from tenant's use or occupancy, (9) wages, salaries and benefits of employees
over the rank of property manager except to the extent those employees are
directly involved in the day to day management and operation of the Building,
(10) costs of correcting initial construction defects for work performed by
Landlord or any affiliate of Landlord, (11) costs of repairs caused by
Landlord's gross negligence, (12) any rent under any ground or underlying lease,
(13) costs incurred due to Landlord's negligence or willful misconduct or due to
violation by Landlord of the terms or conditions of this Lease on its part to be
performed, and (14) general overhead of Landlord except as set forth in (9)
above. Notwithstanding the foregoing, Landlord will be allowed reasonably to
allocate the costs of trash removal based on actual use of such service.

                  (d) "Taxes" shall mean any present or future federal, state,
municipal, local and/or any other taxes, assessments, levies, benefit charges,
and/or other governmental and/or private impositions (including business park
charges and dues), levied, assessed and/or agreed to be imposed upon the Real
Property of which the Leased Premises are a part or any part or parts of said
Real Property, or upon the rent due and payable hereunder, whether or not now
customary or within the contemplation of the parties hereto and regardless of
whether the same shall be extraordinary or ordinary, general or special,
foreseen or unforeseen, or similar or dissimilar to any of the foregoing but
shall not include any inheritance, estate, succession, income, profits or
franchise tax, provided, however, if at any time during the Lease Term or any
extension thereof the method of taxation prevailing at the commencement of the
Term

                                      -7-

<PAGE>

shall be altered or eliminated so as to cause the whole or any part of the items
defined as Taxes above to be replaced by a levy, assessment or imposition,
wholly or partly as a capital levy, or otherwise, on the rents or income
(provided the tax on such income is not a tax levied on taxable income
generally) received from the buildings, wholly or partly in place of an
imposition on or as a substitute for, or an increase of, taxes in the nature of
real estate taxes issued against the Real Property, then the charge to Landlord
resulting from such altered or replacement method of taxation shall be deemed to
be within the definition of "Taxes". All reasonable expenses incurred by
Landlord (including attorneys' fees and costs) in contesting any increase in
Taxes or any increase in the assessment of the Real Property shall be included
as an item of Taxes for the purpose of computing additional rent due hereunder.
Notwithstanding the foregoing, until Building B is constructed by Landlord,
Parcel L shall be excluded from the Real Property for purposes of determining
Taxes hereunder.

                  (e) "Real Property" shall mean the Lots, the two buildings on
the Lots, and all fixtures, equipment and other improvements in or upon said
Lots, and shall include the sidewalks, areaways, parking areas, loading areas,
gardens and lawns.

                  (f) "Insurance" shall mean all insurance of whatsoever nature
kept or caused to be kept by Landlord out of or in connection with its ownership
of the Real Property, the buildings, equipment, fixtures and other improvements
installed and/or owned by Landlord and used in connection with the buildings
and/or the Real Property and/or all alterations, rebuildings, replacements and
additions thereto, including, but not limited to, insurance insuring the same
against loss or damage by, or abatement of rental income resulting from fire,
and other such hazards, casualties and contingencies (including, but not limited
to, war risk insurance, if available), liability and indemnity insurance.

                  (g) "Lots" shall mean Parcels J, K, and L in Block A of the
Hanson-Palmer Business Park, Prince George's County, Maryland, upon which
Buildings A and B are or will be situated. Building A will be located on Parcel
J and a portion of Parcel K, and Building B will be located on Parcel L and a
portion of Parcel K.

                  (h) The term "Operating Year" shall mean: (i) when used in
context with Common Area Expenses, such applicable fiscal year as Landlord may
adopt from time to time during the Lease Term provided same is consistent with
the fiscal year Landlord uses for all other tenants in the Project and is not
changed more than one (1) time in any calendar year, and (ii) when used in
context with Taxes, each respective tax year (i.e., the fiscal year beginning
July 1) during the Lease Term, or such other fiscal year as the applicable
authorities may select.

            5.2. Rent Adjustment. Tenant agrees to pay to Landlord monthly, as
additional rent, with and at the same time as the payments of Basic Annual Rent,
the following amounts:

                  (a) One-twelfth of Tenant's estimated Portion of Common Area
Expenses, which estimated Portion shall be calculated on the basis of One Dollar
and Seventy Cents ($1.70) per square foot, resulting in a monthly installment of
Three Thousand One Hundred Eighty-Five Dollars and Eighty Cents ($3,185.80); and

                  (b) One-twelfth of Tenant's estimated Portion of Taxes, which
estimated Portion shall be calculated on

                                      -8-

<PAGE>

the basis of Eighty Cents ($.80) per square foot, resulting in a monthly
installment of One Thousand Four Hundred Ninety-Nine Dollars and Twenty Cents
($1,499.20).

            At any time during a lease year, but not more than one (1) time in
such year, Landlord may revise its estimate of Tenant's Portion of Common Area
Expenses and Taxes (collectively, the "Expenses") as set forth above and adjust
Tenant's monthly installments to reflect the revised estimates. Landlord will
give Tenant prior written notice of the revised estimates and the amount by
which Tenant's monthly installments will be adjusted, and Tenant will pay the
adjusted installments with each payment of the rent, beginning with the first
payment of the Basic Annual Rent to come due after Tenant's receipt of such
notice.

            Landlord will deliver to Tenant, within one hundred twenty (120)
days (or such longer time as is reasonable under the circumstances) after the
end of each applicable Operating Year for the Expenses, a statement for such
Operating year (the "Statement"), showing Tenant's Portion of such Expenses.
Tenant will pay Landlord within thirty (30) days of the receipt of the
Statement, such amounts as may be necessary to adjust Tenant's estimated
payments for such preceding Operating Year so that such payments will equal
Tenant's Portion of the actual Expenses for such Operating Year. If the actual
amount of Tenant's Portion of such Expenses is less than the amounts paid by
Tenant as installments of its applicable portion of such Expenses, then Landlord
will credit Tenant's account by the amount of the excess or, if at the end of
the Lease Term, promptly refund to Tenant the amount of the excess. Unless
Tenant gives Landlord written notice of its exception to any Statement for such
preceding Operating Year within thirty (30) days after delivery thereof, the
same shall be conclusive and binding on Tenant; provided, however, that in the
event that Tenant shall give Landlord written notice of its exception to such
Statement within such thirty (30) day period, Tenant shall nevertheless be
obligated to pay the additional rent.

            At Tenant's sole cost and expense and without unreasonable
interference with Landlord's business operations or waiving Tenant's obligation
to pay the amount shown on such Statement, Tenant shall have the right, upon at
least ten (10) business days' prior written notice given to Landlord within
sixty (60) days after its receipt of a Statement, to examine the books, records
and other papers of Landlord used to compute the Expenses reflected on such
Statement (the "Audit"). Any overpayment by Tenant reflected by the Audit shall
be promptly corrected. Any such examination shall be conducted only during
Landlord's regular business hours, and all information examined shall be kept by
Tenant in the strictest confidence.

            Failure of Landlord to provide any Statement within the time
prescribed will not relieve Tenant of its obligations under this Section 5.2.

            5.3. Tax Adjustment. Tenant acknowledges that Landlord must pay the
Taxes for an entire tax year (i.e., July 1 - June 30) in advance. Therefore,
within thirty (30) days after the Commencement Date, Tenant shall pay to
Landlord a sum equal to Tenant's Portion of the pre-paid Taxes paid by Landlord
for the tax year in which the Commencement Date occurs (the "Commencement Tax
Year"), pro-rated from the Commencement Date to the end of the Commencement Tax
Year. During the tax year immediately following the Commencement Tax Year (the
"Second Tax Year"), Tenant shall reimburse Landlord, upon receipt of an invoice
therefor, for Tenant's Portion of any pre-paid Taxes paid by Landlord with
respect to the Second Tax Year, after subtracting therefrom the amount of any
estimated payments made

                                      -9-

<PAGE>

by Tenant pursuant to Section 5.2(b) above with respect to such Second fax Year.
Thereafter, Tenant's estimated monthly amount of Tenant's Portion of Taxes as
set forth in Section 5.2(b) above shall be adjusted to reflect its Portion of
such actual Taxes, which monthly amounts shall be applied to the tax years
immediately following the Second Tax Year and succeeding tax years, subject to
further adjustment. Following termination of the Lease Term by passage of time
or for any reason other than Tenant's default of this Lease (the "Termination
Date"), Tenant shall be reimbursed by Landlord to the extent of any Portion of
Taxes which it has pre-paid as of such Termination Date for the period beyond
such Termination Date.

            5.4. Summary of Payments. The following is a list of the various
payments and installments of Basic Annual Rent and additional rent pursuant to
this Section 5 as of the Commencement Date. Some of these amounts will change
during the Lease Term.

<TABLE>
<CAPTION>
                          Monthly
                       Installments   P.S.F.
                       ------------   ------
<S>                    <C>            <C>
Basic Annual Rent       $22,300.60    $11.90
(1st lease year)

Common Area Expenses    $ 3,185.80    $ 1.70
(estimate)

Taxes (estimate)        $ 1,499.20    $  .80
                        ----------    ------

     TOTAL              $26,985.60    $14.40
                        ==========    ======
</TABLE>

            5.5. Utilities.

                  (a) Notwithstanding that certain utilities are commonly
metered on the Real Property and the costs of such utilities are included within
the Common Area Expenses set forth above, if Tenant's use of water or any other
commonly metered utility is disproportionate to that of other tenants in the
Building or Project, Landlord or Tenant shall have the right, at Tenant's sole
cost and expense, to have a meter installed upon the Leased Premises and
thereafter to pay to Landlord or the applicable utility provider all charges
respecting the Leased Premises based upon readings of said meter. In such event,
those costs which are separately metered shall be excluded from Tenant's Portion
of Common Area Expenses.

                  (b) Except to the extent included in Common Area Expenses,
Tenant shall pay on a timely basis to the appropriate utility or other supplier,
all charges for gas, steam, electricity, light, heat, power, telephone and all
other utility and communication services, used, rendered and/or supplied upon or
in connection with the Leased Premises.

            5.6. Payments. All payments or installments of any rent hereunder,
other than Basic Annual Rent, and all sums whatsoever due under this Lease
(including attorneys' fees) shall he deemed additional rent and shall be paid to
Landlord at the address designated for notice to Landlord herein, or as
otherwise designated by Landlord, If any rent or additional rent is not paid
within five days of when due, Tenant shall pay a late charge equal to five
percent (5%) of the arrearage. In addition, the arrearage shall bear interest
calculated at the rate of eighteen percent (18%) per annum for each day such sum
is in arrears in consideration of Landlord's additional expense caused by such
failure to pay. Such late charges shall be payable simultaneously with the
arrearage payment, without demand. Time is of the essence with respect to
Tenant's monetary obligations in this Lease. Unless otherwise stated, any such
additional rent shall be due within thirty (30) days after the Landlord has

                                      -10-

<PAGE>

submitted a written statement to Tenant showing the amount due, and Tenant's
obligation to pay any such additional rent which applies to the period prior to
the termination of the Lease shall survive the termination of this Lease.

      6. Requirements of Law. Tenant shall, at the sole cost and expense of
Tenant, observe and comply with all laws, requirements, rules, orders,
ordinances and regulations applicable to the Leased Premises, the Real Property
or the Building. Tenant shall comply with Landlord's rules and regulations for
the Project, a copy of which is attached hereto as Exhibit D, as the same may be
amended, modified or supplemented from time to time by Landlord, provided same
are generally enforced uniformly and non-discriminatorily and do not increase
Tenant's monetary obligations under the Lease.

      7. Tenant's Improvements. Tenant shall not make any alterations,
decorations, installations, additions and/or improvements to the Leased
Premises, including, but not limited to, the installation of any fixtures,
amenities, equipment, appliances or other apparatus (collectively, the "Work"),
without Landlord's prior written consent which shall not be unreasonably
withheld, conditioned or delayed, and then only by contractors or mechanics
approved by Landlord. Notwithstanding the foregoing, Tenant shall have the
right, without Landlord's consent, to make non-structural repairs to the Leased
Premises which do not affect the roof, mechanical, electrical or plumbing
systems of the Building, and which do not, in any lease year, cost more than Ten
Thousand Dollars ($10,000) in the aggregate. All such Work shall be done at
Tenant's sole cost and expense and at such times and in such manner as Landlord
may from time to time reasonably designate. All such Work shall be done under
the general supervision of Landlord to assure standard quality improvements on
the Real Property for which Landlord shall be paid a reasonable supervisory fee,
not to exceed seven percent (7%) of the cost of the Work. All such Work done by
either of the parties hereto upon the Leased Premises, except movable furniture,
equipment and trade fixtures put in at the expense of Tenant, shall be the
property of Landlord and shall remain upon and be surrendered with the Leased
Premises at the termination of this Lease without molestation or injury;
provided, however, that Landlord may elect to require Tenant to remove all or
any part of said work at the expiration of this Lease, in which event such
removal shall be done at Tenant's sole cost and expense. At Tenant's request,
Landlord will inform Tenant at the time it grants its consent to any proposed
Work, of whether the Work must be removed by Tenant at the expiration of the
Lease Term. Tenant shall, at its sole cost and expense, repair any damage to the
Leased Premises and/or the Building caused by such removal or by the removal of
its personalty.

      8. Condition of Premises. (a) Landlord hereby agrees to and will assign
to Tenant at the termination of Landlord's Warranty Period (as defined below),
to the extent they are assignable, any and all written warranties and guarantees
from Landlord's contractors, subcontractors and suppliers of any materials and
labor to the Leased Premises for that portion, if any, of the Lease Term that
such warranties and guarantees are in effect. With regard to any new
construction performed by Landlord for the benefit of Tenant pursuant to Section
1(b) of this Lease, Landlord hereby warrants ("Landlord's Warranty") to Tenant
that Landlord will be responsible for a period ("Landlord's Warranty Period") of
one (1) year from the Commencement Date to repair or to have repaired all
defects in such construction, to the extent such defects are not caused by the
negligence of Tenant or any of its agents, servants, employees or contractors
(in which event such defects will be repaired at Tenant's sole cost). To the
extent that Landlord is obligated to make repairs pursuant to

                                      -11-

<PAGE>

Landlord's Warranty, Tenant will be relieved during Landlord's Warranty Period
of the obligations imposed upon it pursuant to this Lease to make or pay for
such repairs to the Leased Premises. Tenant agrees to and will give Landlord
prompt notice of the need for any such repairs.

            (b) Subject to Landlord's Warranty, Tenant shall at all times during
the Lease Term take good care of and keep the Leased Premises and the
improvements, fixtures, equipment and appurtenances therein and thereto
(including, but not limited to, interior and exterior windows, interior and
exterior doors, including locks and hardware, pipes, plumbing, water and sewer
connections within or exclusively serving the Leased Premises, and light
fixtures) in good order and condition and, at Tenant's sole cost and expense,
shall make all necessary repairs thereto, which repairs shall be in quality and
class at least equal to the original work. Tenant shall not commit or suffer any
waste of the Leased Premises and will assume responsibility for all maintenance
and repair, regardless of the nature, pertaining to the heating and/or air
conditioning equipment. Tenant will secure and maintain during the Lease Term, a
full service contract on such mechanical equipment with a company reasonably
acceptable to Landlord and providing at least the services outlined on the
attached Exhibit E. Tenant must deliver a copy of such service contract to
Landlord upon the commencement of the term of this Lease and whenever a change
of company or a change in such contract occurs. At the expiration of the Lease
Term, Tenant must also deliver to Landlord a certification from the company
regularly maintaining the mechanical systems in the Leased Premises, which
certification must be based on an inspection conducted within thirty (30) days
of the termination date of the Lease and which must state that all such systems
are in good operating order and be in substantially the form attached as Exhibit
F. Landlord or Landlord's representatives may enter the Leased Premises at any
reasonable time upon at least twenty-four (24) hours' prior notice which may be
verbal to verify Tenant's compliance with this Lease. In the event Tenant fails
to maintain the mechanical equipment as provided in this Section 8, Tenant will
be liable to Landlord for any costs incurred by Landlord in maintaining or
repairing such mechanical equipment.

            (c) Landlord shall maintain in good order, condition and repair, the
exterior walls (excluding windows), downspouts, foundation and the roof, along
with the common areas of the Project, the cost of which shall be included in the
Common Area Expenses, so long as such maintenance is not required as a result of
any acts of Tenant, or Tenant's agents, employees or visitors, in which event
the same shall be repaired by Landlord at the sole cost and expense of Tenant
(to the extent not covered by insurance).

            (d) At the expiration of the Lease Term, or at the sooner
termination of this Lease as herein provided, Tenant shall deliver up the Leased
Premises in the same good order and condition, reasonable wear and tear and
damage from casualty or condemnation excepted, as at the beginning of the
tenancy, broom clean and (subject to the provisions of the preceding Section
hereof) Tenant shall remove all of its property and/or property maintained
and/or stored for or on the account of others therefrom prior to such
termination. Any items of Tenant's personalty remaining in the Leased Premises
after the termination of the Lease shall be deemed abandoned by Tenant and
become the sole property of Landlord. Notwithstanding the foregoing, any costs
incurred by Landlord in storing and/or disposing of such abandoned property
shall remain the sole obligation of Tenant, which obligation shall survive the
termination of this Lease.

                                      -12-

<PAGE>

      9. Conduct on Premises. Tenant shall not do, or permit anything to be done
in the Leased Premises, or bring or keep anything therein which will, in any way
invalidate or conflict with the fire insurance policies on the Real Property;
obstruct or interfere with the rights of Landlord or other tenants; or interfere
with the good order of the Building. Tenant agrees that any increase in fire or
other insurance premiums on the Real Property and/or the contents thereof to the
extent caused by the use or occupancy of Tenant shall, as they occur or accrue,
be added to the rent heretofore reserved and be paid as a part thereof; and
Landlord shall have all the rights and remedies for the collection of same as
are conferred upon Landlord for the collection of rent provided to be paid
pursuant to the terms of this Lease.

      10. Insurance. At all times during the Lease Term, Tenant, at its sole
cost and expense shall provide and keep in full force and effect a policy of
public liability insurance, naming Landlord and Manekin, LLC as additional
insureds, as their interests may appear, with respect to the Leased Premises and
the business of Tenant in, on, within, from or connected with the Leased
Premises, pursuant to which the limits of liability shall be at least
$1,000,000.00 in respect to any one occurrence, and at least $2,000,000.00 in
respect to the aggregate limit of liability. Said insurance policy shall contain
a clause that the insurer will not cancel or change the insurance without first
giving Landlord thirty (30) days prior written notice. Said insurance policy
shall be carried with an insurance company approved by Landlord, and a
certificate of insurance shall be delivered to Landlord at the inception of each
policy and renewal thereof.

      11. Mechanics' and Materialmen's Liens and Other Liens. Tenant shall not
do or suffer to be done any act, matter or thing whereby the Leased Premises (or
Tenant's interest therein), or any part thereof, may be encumbered by any
mechanics' or materialmen's lien and/or any other lien or encumbrance. Tenant
shall discharge or bond off, within ten (10) business days after notice of
filing, any mechanics' or materialmen's liens filed against the Leased Premises
(or Tenant's interest therein), or any part thereof, purporting to be for work
or material furnished or to be furnished to Tenant.

      12. Tenant's Failure to Perform. In the event that Tenant shall fail,
after fifteen (15) days written notice from Landlord, to keep the Leased
Premises in the state of condition and repair required by this Lease; to do any
act; make any payment; and/or perform any term or covenant on Tenant's part
required under this Lease, Landlord may (at its option, but without being
required to do so) immediately, or at any time thereafter and without notice,
perform the same for the account of Tenant (including, but not limited to,
entering upon the Leased Premises at any time to make repairs). Any costs
incurred by Landlord in so performing Tenant's obligations, together with a
reasonable rate of interest on such sums shall be deemed additional rent and
shall be due within fifteen (15) days of receipt of a statement therefor from
Landlord. All rights given to Landlord in this Section shall be in addition to
any other right or remedy of Landlord herein contained.

      13. Loss, Damage, Injury. Landlord and Tenant agree that each will
indemnify and hold harmless the other for all losses, damages, liabilities,
costs, payments, expenses and fines incurred by Landlord or Tenant, or
Landlord's manager and agents (as applicable, the "Indemnitee") as a result of
any claim or action (whether or not such claim or action proceeds to final
judgment) brought or threatened for any of the following acts or omissions of
the other party (the "Indemnitor"), and/or of the

                                      -13-

<PAGE>

Indemnitor's servants, employees, agents, licensees or invitees: (1) any breach,
violation and/or nonperformance of any covenant or provision of this Lease
applicable to the Indemnitor and/or (2) negligence or any willful misconduct of
the Indemnitor. This indemnification will remain in effect after the termination
or expiration of this Lease.

      14. Destruction -- Fire or Other Casualty. (a) In the event of partial or
total damage or destruction to the Leased Premises by fire, other casualty, or
any other cause whatsoever (except condemnation), Tenant shall give immediate
notice thereof to Landlord and: (a) this Lease shall continue in full force and
effect, and (b) Landlord, to the extent that insurance proceeds respecting such
damage or destruction are subject to being utilized for and, in fact, may be
utilized by Landlord therefor, shall thereupon cause such damage or destruction
to property owned by Landlord to be repaired with reasonable speed at the
expense of Landlord, due allowance being made for reasonable delay which may
arise by reason of adjustment of loss under insurance policies on the part of
Landlord and/or Tenant, and for reasonable delay on account of "labor troubles"
or any other cause beyond Landlord's control. To the extent that the Leased
Premises are rendered untenable, the rent shall proportionately abate. In the
event the damage or destruction shall be so extensive to the Building as to
render it uneconomical, in Landlord's opinion, to restore the Leased Premises
for the use of Tenant as specified herein or Landlord shall decide not to repair
or rebuild the Building, this Lease, at the option of Landlord, shall be
terminated upon written notice to Tenant and the rent shall, in such event, be
paid to or adjusted as of the date of such damage, and the terms of this Lease
shall expire by lapse of time upon the third day after such notice is mailed.
Tenant shall thereupon vacate the Leased Premises and surrender the same to
Landlord, but no such termination shall release Tenant from any liability to
Landlord arising from such damage or from any of the obligations or duties
imposed on Tenant hereunder prior to such termination.

            (b) Notwithstanding the provisions of Section 14, within sixty (60)
days after the date of material destruction of the Leased Premises, Landlord
shall obtain from Landlord's architect or contractor an estimate of the time
which will be required to repair the Leased Premises. Landlord shall promptly
communicate said estimate to Tenant. In the event that said estimate of time
exceeds one hundred eighty (180) days from the date of such destruction, then
Tenant shall have the right, within ten (10) days after receipt of said
estimate, to terminate this Lease without any further liability or obligation on
the part of the parties hereto for obligations thereafter accruing, provided
that Tenant shall give written notice to Landlord within said ten (10) days and
shall not be in breach or default of any covenant or condition by which Tenant
is obligated under this Lease.

      15. Eminent Domain. If the entire Leased Premises shall be substantially
taken (either temporarily or permanently) for public purposes, or in the event
Landlord shall convey or lease the Real Property to any public authority in
settlement of a threat of condemnation or taking, the rent shall be adjusted to
the date of such taking or leasing or conveyance, and this Lease shall thereupon
terminate. If only a portion of the Leased Premises shall be so taken, leased or
condemned, and as a result of such partial taking, in Tenant's reasonable
judgment, Tenant is reasonably able to use the remainder of the Leased Premises
for the purposes intended hereunder, then this Lease shall not terminate but,
effective as of the date of such taking, leasing or condemnation, the rent
hereunder shall be abated in an amount thereof proportionate to the area of the
Leased Premises so taken, leased or condemned. If, following such partial taking

                                      -14-

<PAGE>

Tenant shall not be reasonably able to use the remainder of the Leased Premises
for the purposes intended hereunder, then this Lease shall terminate as if the
entire leased Premises had been taken, leased or condemned. In the event of a
taking, leasing or condemnation as described in this Section, whether or not
there is a termination hereunder, Tenant shall have no claim against Landlord,
other than an adjustment of rent, to the date of taking, leasing or
condemnation, and Tenant shall not be entitled to any portion of any amount that
may be awarded as damages or paid as a result or in settlement of such
proceedings or threat, but will have the right to pursue a separate claim
against the condemnation authority for its own loss of business and moving
expenses.

      16. Environmental Assurances.

            (a) Covenants. Tenant covenants with Landlord:

                  (1) that it shall not Generate Hazardous Substances at, to or
from the Leased Premises unless the same is specifically approved in advance by
Landlord in writing;

                  (2) to comply with all obligations imposed by applicable law,
and regulations promulgated thereunder, and all other restrictions and
regulations upon the Generation of Hazardous Substances (whether or not at, to
or from the Leased Premises);

                  (3) to deliver promptly to Landlord true and complete copies
of all notices received by Tenant from any governmental authority with respect
to the Generation by Tenant of Hazardous Substances (whether or not at, to or
from the Leased Premises);

                  (4) to complete fully, truthfully and promptly any
questionnaires sent by Landlord with respect to Tenant's use of the Leased
Premises and Generation of Hazardous Substances;

                  (5) upon reasonable notice, to permit entry onto the Leased
Premises by Landlord or Landlord's representatives at any reasonable time to
verify and monitor Tenant's compliance with its representations, warranties and
covenants set forth in this Section; and

                  (6) to pay to Landlord, as additional rent, the costs incurred
by Landlord hereunder, including the costs of such monitoring and verification.

            (b) Indemnification by Tenant. Tenant agrees to indemnify and defend
Landlord, and its managers and agents (with legal counsel reasonably acceptable
to Landlord) from and against any costs, fees or expenses (including, without
limitation, environmental assessment, investigation and environmental
remediation expenses, third party claims and environmental impairment expenses
and reasonable attorneys' fees and expenses) incurred by Landlord or its
managers and agents, as the case may be, in connection with Tenant's Generation
of Hazardous Substances at, to or from the Leased Premises or in connection with
Tenant's failure to comply with its representations, warranties and covenants
set forth in this Section. This indemnification by Tenant will remain in effect
after the termination or expiration of this Lease.

            (c) Indemnification by Landlord. Landlord represents and warrants to
Tenant that, to Landlord's actual knowledge, without independent verification,
as of the date the Leased Premises are delivered to Tenant, the Leased Premises

                                      -15-

<PAGE>

shall be free and clear of any Hazardous Substance. Landlord agrees to indemnify
and defend Tenant (with legal counsel reasonably acceptable to Tenant) from and
against any costs, fees or expenses (including without limitation environmental
assessment, investigation and environmental remediation expenses, third party
claims and environmental impairment expenses and reasonable attorneys' fees and
expenses) incurred by Tenant in connection with the Landlord's Generation of
Hazardous Substances, to or from the Leased Premises, the Building and the
Project or in connection with Landlord's failure to comply with its
representations set forth in this Section. This indemnification by Landlord will
remain in effect after the termination or expiration of this Lease.

            (d) Definitions. The term "Hazardous Substance" means (i) any
"hazardous waste" as defined by the Resource Conservation and Recovery Act of
1976 (42 U.S.C. Section 6901 et seq.), as amended from time to time, and
regulations promulgated thereunder; (ii) any "hazardous substance" as defined by
the Comprehensive Environmental Response, Compensation and Liability Act of 1980
(42 U.S.C. Section 9601 et seq.), as amended from time to time, and regulations
promulgated thereunder; (iii) any "oil", "petroleum" products or their
by-products as defined by the Maryland Environment Code Ann. Section 4-401(g),
as amended from time to time, and regulations promulgated thereunder; (iv) any
"controlled hazardous substance" or "hazardous substance" as defined by the
Maryland Environment Code Ann., Section 7-201, as amended from time, and
regulations promulgated thereunder; (v) any "infectious waste" as defined by
the Maryland Environment Code Ann. Section 9-227, as amended from time to time,
and regulations promulgated thereunder; (vi) any substance the presence of which
on the Property is prohibited, regulated or restricted by any local law or
regulation or any other law or regulation similar to those set forth in this
definition; and (vii) any other substance which by law or regulation requires
special handling in its Generation. The term "To Generate" means to use,
collect, generate, store, transport, treat or dispose of.

      17. Assignment/Subletting. No Assignment of this Lease (as defined below)
is permitted without the prior written consent of Landlord. The granting or
withholding of such consent will be solely within the discretion of Landlord.
Notwithstanding the foregoing, Landlord's consent to an Assignment of the types
described in clauses (1), (2) and (6) of the following paragraph shall not be
unreasonably withheld, delayed or conditioned so long as the proposed assignee
is no less creditworthy than Tenant as of the date thereof or as of the
Commencement Date of the Lease, whichever is greater, and the proposed use is
acceptable to Landlord, in each instance as determined by Landlord in its sole,
but reasonable, discretion.

            The foregoing restriction will include, but not be limited to, the
following (all of which will be deemed to be an "Assignment"): (1) any
assignment of this Lease or a subletting of the Leased Premises; (2) any
permission to a third party to use all or part of the Leased Premises; (3) any
mortgage or other encumbrance of this Lease or of the Leased Premises; (4) the
appointment of a receiver or trustee of any of the Tenant's property; (5) any
assignment or sale in bankruptcy or insolvency; and (6) the transfer of majority
control of Tenant by any means, including operation of law, to parties other
than those maintaining majority control on the date on which the last party
executes this Lease.

            Notwithstanding the foregoing, the transfer of majority control of
Tenant due to an initial public offering of the Tenant's capital stock, or
because of the death of a majority stockholder, shall not require the consent of
Landlord so long as

                                      -16-

<PAGE>

Landlord is promptly notified of the transfer, Tenant is no less creditworthy as
a result thereof, the assignee resulting from the death of a majority
stockholder has sufficient business experience and acumen to carry on the
business of Tenant, but all of the other provisions of this Section 17 shall be
applicable to such assignment. Additionally, although an Assignment includes an
assignment or sublease or usage of the Leased Premises in whole or in part to or
by an affiliate of Tenant (a "Related Party"), Landlord's consent to such
Related Party Assignment shall not be required but all other provisions of this
Section 17 shall be applicable to such Related Party Assignment.

            Even if Landlord consents to an Assignment, Tenant will remain
primarily liable under this Lease. Also, Tenant will bear all reasonable legal
costs incurred by Landlord in connection with Landlord's review of documents
concerning an Assignment, whether or not Landlord consents to it. Landlord's
consent to a specific Assignment does not waive Landlord's right to withhold
consent to any future or additional Assignment. If Tenant intends to Assign this
Lease and Landlord's consent thereto is required pursuant to this Section 17,
Tenant must give Landlord notice of its intention to make an Assignment at least
thirty (30)days prior to the anticipated effective date of such Assignment,
which notice will contain such details as Landlord may reasonably request (the
"Assignment Notice"). Landlord may terminate this Lease by giving at least
fifteen (15) days' prior written notice to Tenant after Landlord has received
the Assignment Notice from Tenant. In the event Tenant receives a termination
notice from Landlord in accordance with this provision, Tenant may rescind its
Assignment Notice by giving notice to Landlord of such rescission within ten
(10) days after receipt of the termination notice, and therefore rescind
Landlord's termination notice.

            If the amount of rent and other sums received by Tenant under any
Assignment is more than the Rent due from Tenant under this Lease, then Tenant
will pay one-half (1/2) of the excess to Landlord on a monthly basis and
promptly upon Tenant's receipt of such excess amounts, after deducting from the
excess all of Tenant's reasonable expenses incurred in connection with such
Assignment (including, without limitation, brokers' commissions, leasehold
improvements, architectural fees, and reasonable attorneys' fees).

            If, without Landlord's consent, this Lease is Assigned, or if the
Leased Premises are occupied or used by any party other than Tenant, then all
resulting expenses (including reasonable attorneys' and brokerage fees) incurred
by Landlord will be immediately due and payable by Tenant upon receipt of an
invoice. If Tenant defaults, Landlord may collect rent from the assignee,
subtenant, occupant or user (the "Assignee") of the Leased Premises and apply it
towards the Rent due under this Lease. Such collection will not be deemed an
acceptance of the Assignee as tenant, will not waive or prejudice Landlord's
right to initiate legal action against Tenant to enforce Tenant's fulfillment of
its obligations under this Lease and will not release Tenant from such
obligations.

      18. Defaults.

            (a) Each of the following shall be deemed a material default by
Tenant under this Lease and a substantial breach of this Lease:

                  (1) The filing of a petition by or against Tenant for debtor
relief as defined under the Federal Bankruptcy Code, as now or hereafter amended
or supplemented, or for reorganization, arrangement or other rehabilitation
within the

                                      -17-

<PAGE>

meaning of the Bankruptcy Code, or the commencement of any action or proceeding
for the dissolution or liquidation of Tenant, whether instituted by or against
Tenant, or for the appointment of a receiver or trustee of the property of
Tenant, in each case filed by a party other than Tenant, if not bonded or
discharged within thirty (30) days of the date of filing; for purposes of this
subsection, the word "Tenant" shall include any guarantor of Tenant's
obligations under this Lease;

                  (2) The making by Tenant of an assignment for the benefit of
creditors;

                  (3) The suspension of business by Tenant;

                  (4) The filing of a tax lien against any property of Tenant
located at the Leased Premises;

                  (5) Tenant's causing or permitting the Leased Premises to be
vacant, the abandonment of the Leased Premises by Tenant and/or the cessation by
Tenant of active use of the Leased Premises for the purpose specified herein for
a period in excess of five (5) days; provided, however, that Tenant's vacating
the Leased Premises shall not be deemed an event of default so long as Tenant
(i) continues to pay all sums payable by Tenant hereunder when due; (ii)
continues to perform all other obligations of Tenant hereunder when the same are
required to be performed; (iii) provides Landlord at least 30 days' prior
written notice of the date of Tenant's vacating, the reason for Tenant's
vacating and Tenant's updated address for notices in Maryland; and (iv) Tenant
maintains a temperature of at least 50 degrees Fahrenheit in the Leased Premises
at all times during the heating season;

                  (6) Failure of Tenant to make payment of the rent herein
reserved, or any part thereof, or any other sum required by the terms of this
Lease (including late charges on the foregoing as provided herein) within ten
(10) days after Landlord has given Tenant notice that such payment is due,
provided, however, that no notice shall be required to be given to Tenant, and
Tenant shall be in immediate default as a result of any such failure, if
Landlord has given such notice to Tenant two (2) times in the preceding twelve
months;

                  (7) A breach by Tenant in the performance of any other term,
covenant, agreement or condition of this Lease, on the part of Tenant to be
performed, for a period of thirty (30) days after service of notice by Landlord
upon Tenant; provided, however, if cure of such breach cannot reasonably be
completed within such thirty (30) day period, then the thirty (30) day period
shall be extended for the period of time reasonably required to complete such
cure, up to a maximum of sixty (60) days, so long as Tenant commences such cure
within such thirty (30) day period and diligently pursues such cure to
completion.

            (b) All rights and remedies of Landlord in this Lease enumerated
shall be cumulative, and none shall exclude any other right or remedy, now or
hereafter allowed by or available under any statute, ordinance, rule of court,
or the common law, either at law or in equity or both. For the purposes of any
suit brought or based hereon, this Lease shall be construed to be a divisible
contract, to the end that successive actions may be maintained on this Lease as
successive periodic sums shall mature hereunder. The failure of Landlord to
insist, in any one or more instances, upon a strict performance of any of the
covenants, terms and conditions of this Lease, or to exercise any right or
option herein contained, shall not be construed as a waiver, or a relinquishment
for the future, of such covenant, term, condition, right or option, but the same
shall continue and remain in full

                                      -18-

<PAGE>

force and effect unless the contrary is expressed by Landlord in writing. The
receipt by Landlord of rent, with knowledge of the breach of any covenant
hereof, shall not be deemed a waiver of such breach, and no waiver by Landlord
of any provision hereof shall be deemed to have been made unless expressed in
writing and signed by Landlord.

            (c) In the event of a default of the nature set forth above,
Landlord may, at any time thereafter, at its election, without further notice to
Tenant, terminate this Lease and Tenant's right to possession of the Leased
Premises, and take possession of the Leased Premises, and remove Tenant, any
occupant, and any property therefrom, without relinquishing any rights of
Landlord against Tenant.

            (d) Tenant shall be obligated to, and shall pay to Landlord as
damages, upon demand, and Landlord shall be entitled to recover of and from
Tenant at the election of Landlord all expenses which shall have been incurred
in connection with such breach including the expenses (such as real estate
brokerage commissions and retrofit costs) of rerenting the Leased Premises
together with court costs and attorneys' fees and expenses at such attorneys'
customary hourly rates. In addition to the damages set forth in the preceding
sentences of this Section 18(d), if Landlord terminates this Lease as set forth
in Section 18(c) above, Landlord will also be entitled to either:

                  (1) liquidated damages, in an amount which, at the time of
such termination is equal to the installments of Basic Annual Rent and the
aggregate of all sums payable hereunder as additional rental (the "Additional
Rental") (for such purpose considering the annual amount of such Additional
Rental to be equal to the amount thereof due during the twelve months preceding
such default, or if less than twelve months have elapsed at such time, such
amounts as would have been due on an annual basis) reserved hereunder, for the
period which would otherwise have constituted the unexpired portion of the then
current term of this Lease, said amount to be discounted at the discount rate
then in effect at the Federal Reserve Bank in Baltimore; or

                  (2) damages (payable in monthly installments, in advance, on
the first day of each calendar month following such termination and continuing
until the date originally fixed herein for the expiration of the then current
term of this Lease) in an amount or amounts equal to the excess, if any, of the
sum of (i) the aggregate expenses (other than Additional Rental) paid by
Landlord during the month immediately preceding such calendar month for all such
items as, by the terms of this Lease, are required to be paid by Tenant, plus
(ii) an amount equal to the amount of the installment of Basic Annual Rent which
would have been payable by Tenant hereunder in respect of such calendar month
had this Lease and the Lease Term not been so terminated, and (iii) the monthly
average of the Additional Rental payable in the twelve months immediately
preceding such default, over the rents, if any, in fact, collected by Landlord
in respect of such calendar month pursuant to either rerenting, or from any
existing permitted subleases. Any suit, action or proceeding brought to collect
the amount of the deficiency for any calendar month shall not prejudice in any
way the rights of Landlord to collect the deficiency for any subsequent month by
a similar proceeding.

            (e) Notwithstanding anything herein to the contrary, upon the
occurrence of any breach by Tenant that is not cured within any applicable grace
period, Landlord shall use its reasonable efforts to mitigate its damages,
including using reasonable efforts to relet the Leased Premises so long as there

                                      -19-

<PAGE>

is no other space then available for leasing within the Project. If all amounts
required to be paid by Tenant under this Lease as damages and liquidated damages
are actually paid to and collected by Landlord, then any rent collected by
Landlord with regard to the Leased Premises from a subsequent tenant and
attributable to the period for which Tenant has paid liquidated damages, up to a
maximum amount equal to the amount of rental paid by Tenant as liquidated
damages for such period, shall be rebated to Tenant as and when such amounts are
actually collected by Landlord.

            (f) No act or thing done by Landlord shall be deemed to be an
acceptance of a surrender of the Leased Premises, unless Landlord shall execute
a written release of Tenant. Tenant's liability hereunder shall not be
terminated by the execution of a new lease of the Leased Premises by Landlord,
regardless of the term of such new lease. Separate actions may be maintained
each month by Landlord against Tenant to recover the damages then due, without
waiting until the end of the Term of this Lease to determine the aggregate
amount of such damages.

      19. Acceptance of Leased Premises. Tenant's occupancy of the Leased
Premises shall constitute acceptance thereof as complying with all requirements
of Tenant and Landlord with respect to the condition, order and repair thereof,
subject, however, to Landlord's Warranty and Landlord's liability described
above for punchlist items.

      20. Access to Premises and Change in Services. Landlord and/or the
authorized representative of Landlord or any mortgagee or deed of trust holder
shall have the right, without abatement of rent, to enter the Leased Premises at
any reasonable hour after at least twenty-four (24) hours' prior notice, which
may be verbal (or at any time and without notice in the event of an emergency)
to examine the same and/or to make such repairs, improvements and alterations as
Landlord and/or such authorized representatives shall deem necessary (but
Landlord shall not be obligated to do so) for the safety and preservation of the
Building, or for any other reasonable purpose whatsoever, including, but not
limited to, showing the Leased Premises to prospective tenants during the last
six (6) months of the Lease Term.

      21. Estoppel Certificates. Tenant agrees at any time and from time to time
upon not less than five (5) business days prior notice by Landlord to execute,
acknowledge and deliver to Landlord a statement in writing certifying, among
other matters, that this Lease is unmodified and in full force and effect (or if
there have been modifications, that the same is in full force and effect as
modified and stating the modifications) and the dates to which the rent and
other charges have been paid in advance, if any, and stating whether or not, to
the best knowledge of the signer of such certificate, Landlord is in breach
and/or default in performance of any covenant, agreement or condition contained
in this Lease and, if so, specifying each such breach, and/or default of which
the signer may have knowledge, and any other matters reasonably requested in
such estoppel certificate, it being intended that any such statement delivered
hereunder may be relied upon by any party not a party to this Lease. Tenant's
failure to deliver such estoppel certificate within said 5-business day period
shall be deemed a material default by Tenant under this Lease.

      22. Subordination. Tenant accepts this Lease, and the tenancy created
hereunder, subject and subordinate to any ground leases, security interests,
mortgages, deeds of trust or other financing arrangements now or hereafter a
lien upon or affecting the Building or any part or parts thereof and to any
extensions, modifications or amendments thereof. Subject to Tenant's receipt

                                      -20-

<PAGE>

of a non-disturbance agreement on Landlord's lender's standard form (so long as
such form does not modify any of the economic terms of this Lease), Tenant
shall, at any time hereafter, on request, execute any instruments which may be
required to subordinate, or render prior, Tenant's interest hereunder to such
lien and the failure of Tenant to execute any such instruments shall constitute
a default hereunder.

      23. Attornment. Tenant agrees that upon any termination of Landlord's
interest in the Leased Premises, and provided Tenant's rights and privileges
under this Lease are recognized in writing by such Successor, Tenant shall, upon
request, attorn to the person or entity then holding title to the reversion of
the Leased Premises (the "Successor") and to all subsequent Successors, and
shall pay to the Successor all rents and other monies required to be paid by the
Tenant, hereunder and perform all or the other covenants, agreements,
provisions, conditions, obligations and/or duties of Tenant in this Lease
contained.

      24. Notices. Except as otherwise provided in this Lease, any requirement
for a notice, demand or request under this Lease will be satisfied by a writing
(a) hand delivered with receipt; (b) mailed by United States registered or
certified mail or Express Mail, return receipt requested, postage prepaid; or
(c) sent by Federal Express or any other nationally recognized overnight courier
service, and addressed: (i) if to Landlord, c/o Manekin, LLC, 7061 Columbia
Gateway Drive, Columbia, Maryland 21046, Attention: General Counsel, with a copy
to Ann Clary Gordon, Esquire c/o Shapiro Sher & Guinot, 36 South Charles Street,
Baltimore, Maryland 21201; and (ii) if to Tenant, at the Leased Premises, with a
copy to: Richard J. Melnick, Esquire, Greenberg Traurig, LLP, 1750 Tysons
Boulevard, Suite 1200, Tysons Corner, Virginia 22102. All notices that are sent
in accordance with this Section 24 will be deemed received by the other party on
the earliest of the following applicable time periods: (a) three business days
after being mailed in the aforesaid manner; (b) the date the return receipt is
executed; or (c) the date delivered as documented by the overnight courier
service or the hand delivery receipt. All rental payments and other charges
payable by Tenant under this Lease will be delivered to Landlord at Landlord's
address set forth above: Attention: Accounting Department. Either party may
designate a change of address by written notice to the other party.

      25. Landlord's Liability. The term "Landlord" as used in this Lease means
only the owner, the mortgagee, or the trustee or the beneficiary under a deed of
trust, as the case may be, for the time being, of the Building, so that in the
event of any transfer of title to the Building, the transferring entity shall be
and hereby is entirely freed and relieved of all covenants and obligations of
Landlord hereunder accruing after such transfer. It is understood that Landlord
on the date hereof is a Maryland limited liability limited partnership, and that
no partner, general or limited, of said limited liability limited partnership,
as it may now or hereafter be constituted, shall have any personal liability to
Tenant and/or any person or entity claiming under, by or through Tenant upon any
action, claim, suit or demand brought under or pursuant to the terms and
conditions of this Lease and/or arising out of the use or occupancy by Tenant of
the Leased Premises, and as to Landlord, recourse shall be had only to the
extent of Landlord's interest in the Building.

      26. Separability, Enforceability. If any term or provision of this Lease
or the application thereof to any person or circumstances shall, to any extent,
be invalid or unenforceable, the remainder of this Lease or the application of
such term or provision to persons or circumstances other than

                                      -21-
<PAGE>

those as to which it is held invalid or unenforceable, shall not be affected
thereby, and each term and provision of this Lease shall be valid and
enforceable to the fullest extent permitted by law. Notwithstanding any language
in this Lease to the contrary, if the Lease Term does not commence by January 1,
2010, this Lease shall terminate automatically and neither party shall have any
further liability to the other.

            27.   Captions. All headings anywhere contained in this Lease are
intended for convenience of reference only and are not to be deemed or taken as
a summary of the provisions to which they pertain or as a construction thereof.

            28.   Recordation. Tenant covenants that if at any time any
mortgagee of Landlord's interest in the Leased Premises, any trustee or
beneficiary under a deed of trust constituting a lien upon the Building of which
deed of trust Landlord is grantor, or a landlord of Landlord in respect of the
real property upon which the Building is situate, shall require the recordation
of this Lease or a short form memorandum thereof, or if the recordation of this
Lease shall be required by any valid governmental order, or if any governmental
authority having jurisdiction in the matter shall assess and be entitled to
collect transfer taxes or documentary stamp taxes, or both such taxes on this
Lease, Tenant shall execute such acknowledgements as may be necessary to effect
such recordations and whichever party requires such recordation shall pay the
cost of all recording fees, transfer taxes and/or documentary stamp taxes
payable on, and/or in connection with this Lease and/or such recordation.

            29.   Successors and Assigns. The covenants, conditions and
agreements contained in this Lease shall bind and inure to the benefit of
Landlord and Tenant, and their respective heirs, distributees, executors,
administrators, successors, personal and legal representatives and their
permitted assigns.

            30.   Holding Over. If Tenant holds possession of the Leased
Premises after the termination of this Lease without Landlord's written consent,
Tenant shall become a tenant from month to month at one hundred fifty percent
(150%) the rent during the last year of the Lease Term and upon all other terms
herein specified and shall continue to be such tenant from month to month until
such tenancy shall be terminated by either party giving the other a written
notice of at least thirty (30) days of its intention to terminate such tenancy.
Nothing contained in this Lease shall be construed as a consent by Landlord to
the occupancy or possession of the Leased Premises by Tenant after termination
of this Lease. Upon the termination of this Lease, Landlord shall be entitled to
the benefit of all public general or public local laws relating to the speedy
recovery of the possession of lands and tenements held over by tenants, that may
now or hereafter be in force.

            31.   Commissions. Landlord and Tenant represent that each has dealt
directly with, and only with, THE MICHAEL COMPANIES, INC. and JOLIEN J. STUDLEY,
INC. as brokers in connection with this Lease, and that insofar as each party
knows, no other broker negotiated this Lease or is entitled to any commissions
in connection with it. Landlord and Tenant shall each hold the other harmless
from and indemnify the other for any costs incurred by such party arising out of
any other broker's claim that such other broker has assisted the indemnifying
party with respect to this Lease.

            32.   Waiver of Jury Trial. Landlord and Tenant desire a prompt
resolution of any litigation between them with respect to this Lease. To that
end, Landlord and Tenant waive trial by jury in any action, suit, proceeding
and/or counterclaim brought

                                      -22-
<PAGE>

by either against the other on any matters whatsoever arising out of or in any
way connected with this Lease, the relationship of Landlord and Tenant, Tenant's
use or occupancy of the Leased Premises, any claim of injury or damage and/or
any statutory remedy. This waiver is knowingly, intentionally and voluntarily
made by the parties. Each acknowledges that neither the other party nor any
person acting on behalf of such party has made any representations of fact to
induce this waiver of trial by jury or in any way to modify or nullify its
effect. Each further acknowledges that it has been represented (or has had the
opportunity to be represented) in the signing of this Lease and the making of
this waiver by independent legal counsel, selected of its own free will, and
that it has had the opportunity to discuss this waiver with counsel. Each party
further acknowledges that it has read and understands the meaning and
ramifications of this waiver of jury trial.

            33.   Miscellaneous.

                  (a)   As used in this Lease, and where the context requires:
(1) the masculine shall be deemed to include the feminine and neuter and
vice-versa; and (2) the singular shall be deemed to include the plural and
vice-versa.

                  (b)   This Lease was made in the State of Maryland and shall
be governed by and construed in all respects in accordance with the laws of the
State of Maryland.

                  (c)   Except as otherwise specifically provided in this Lease,
no abatement, refund, offset, counter-claim, recoupment, diminution or any
reduction of rent, charges or other compensation shall be claimed by or allowed
to Tenant, or any person claiming under it, under any circumstances, whether for
inconvenience, discomfort, interruption of business, or otherwise, arising from
the making of alterations, changes, additions, improvements or repairs to the
Building or the Leased Premises, by virtue or because of any present or future
governmental laws, ordinances, or for any other cause or reason.

                  (d)   Intentionally deleted.

                  (e)   All plats, exhibits, riders or other attachments to this
Lease shall be deemed a part hereof and incorporated by reference herein.

                  (f)   This Lease contains the entire agreement among the
parties regarding the subject matter of this Lease. There are no promises,
agreements, conditions, undertakings, warranties or representations, oral or
written, express or implied, among them, relating to this subject matter, other
than as herein set forth. This Lease is intended by the parties to be an
integration of all prior or contemporaneous promises, agreements, conditions,
negotiations and undertakings between them. This Lease may not be modified
orally or in any other manner than by an agreement in writing signed by all the
parties or their respective successors in interest. This Lease may be executed
in several counterparts, each of which shall be an original, but all of which
shall constitute one and the same instrument.

                  (g)   Landlord and Tenant hereby mutually waive all claims for
recovery from the other for any loss or damage to any of Landlord's property or
Tenant's property insured under valid and collectible insurance policies to the
extent of any recovery for loss insured thereunder and, to that end, the parties
agree to a mutual subrogation clause to be inserted or endorsed on each policy
setting forth that the insurance shall not be invalidated in the event that the
insured should waive in writing prior to

                                      -23-
<PAGE>

any loss, any or all right of recovery against the other party for any insured
loss.

                  (h)   In the event that Tenant or Landlord is delayed,
hindered or prevented, by reason of strikes, lock-outs, labor troubles,
inability to produce materials, delays in transportation, failure of power,
riots, insurrection, war, fire or other casualties, acts of God, rain or other
weather conditions or any other reason not reasonably within the control of such
party, from performing work or doing any act required under the terms of this
Lease (other than performance of any monetary obligation hereunder), then
performance of such act will be excused for the period of the delay, and the
period of the performance of any such act will be extended for a period equal to
the period of such delay.

                  (i)   Tenant shall have the right, at its sole cost and
expense, to erect an identification sign on the exterior of the Building facing
Route 50, subject, however, to Tenant's obtaining the prior written approval of
such sign from Landlord and as well as any other required governmental entities.
Such sign shall be installed by a reputable contractor reasonably acceptable to
Landlord. Tenant shall hold Landlord harmless from any damage caused to the
Building as a result of the installation of such sign. Upon termination of the
Lease, it shall be Tenant's obligation, at its sole expense, to remove such sign
and to restore the exterior face of the Building to its condition prior to
erecting such sign, normal wear and tear excepted. Landlord shall additionally
provide Tenant with suite-entry signage consistent with the suite-entry signage
criteria established by Landlord for the Project, the cost of which shall be
deducted from Landlord's Contribution described above.

                  (j)   Landlord covenants and agrees that, upon the payment of
the rent herein provided and the performance by Tenant of all the covenants,
agreements and provisions hereof on Tenant's part to be kept and performed,
Tenant shall have, hold and enjoy the Leased Premises free from any interference
whatsoever, by, from and through Landlord or anyone claiming by, from or through
Landlord, except as may be otherwise expressly provided herein.

            34.   Authority. Tenant warrants to Landlord that Tenant is a
corporation organized and validly existing in good standing under the laws of
the State of Delaware and qualified to transact business in the State of
Maryland. In addition, Tenant warrants to Landlord that this Lease has been
properly authorized and executed by Tenant and is binding upon Tenant in
accordance with its terms. Tenant's resident agent's name and address in the
State of Maryland are The Corporation Trust Incorporated, 300 East Lombard
Street, Baltimore, Maryland 21202. Tenant agrees to notify Landlord in writing
of any change with respect to its resident agent.

            35.   Riders. Riders, numbered 1-2, are attached hereto and
incorporated by reference herein.

                                      -24-
<PAGE>

            IN WITNESS WHEREOF, Landlord and Tenant have respectively signed
this Lease under seal as of the day and year first above written.

ATTEST:                                       MOR FORBES LLLP

                                              By: RA & DM, Inc., general partner

/s/ [ILLEGIBLE]                               By: /s/ [ILLEGIBLE]         (SEAL)
------------------------                          ------------------------------
                                                  Name: [ILLEGIBLE]
                                                  Title: Vice President
                                                                        Landlord

WITNESS/ATTEST:                               VOCUS, INC.

/s/ [ILLEGIBLE]                               By: /s/ Richard E. Rudman   (SEAL)
------------------------                          ------------------------------
                                                  Name: Richard E. Rudman
                                                  Title: President & CEO
                                                                          Tenant

STATE OF MARYLAND, CITY/COUNTY OF BALTIMORE, TO WIT:

            I HEREBY CERTIFY that on this 21st day of December, 2000, before me,
the subscriber, a Notary Public of the State of Maryland and City/County of
Baltimore, personally appeared [ILLEGIBLE] of RA & DM, Inc., general partner of
MOR FORBES LLLP, Landlord, and he acknowledged the foregoing Lease Agreement to
be the act and deed of said limited liability limited partnership.

            WITNESS my hand and Notarial Seal.

My Commission Expires:-
M.F. GRIMMEL, NOTARY PUBLIC
CITY OF BALTIMORE
STATE OF MARYLAND
MY COMMISSION EXPIRES 04/01/04                                  /s/ M.F. Grimmel
                                                                ----------------
                                                                Notary Public

STATE OF MARYLAND, CITY/COUNTY OF ANNE ARUNDEL, TO WIT:

            I HEREBY CERTIFY that on this 20th day of December, 2000, before me,
the subscriber, a Notary Public of the State of Maryland and City/County of Anne
Arundel, personally appeared Richard Rudman, of VOCUS, INC., Tenant, and she/he
acknowledged the foregoing Lease Agreement to be the act and deed of said body
corporate.

            WITNESS my hand and Notarial Seal.

My Commission Expires:

2/01/01                                                     /s/ Elinor J. Harvey
                                                            --------------------
                                                            Notary Public

                                      -25-
<PAGE>

                                   RIDER NO. 1

                              RIGHT OF FIRST OFFER

      A.    (1)   Tenant shall have the right of first offer (the "First Offer
Right"), on the terms and conditions hereinafter set forth, at any time during
the term of this Lease, to lease that portion of the Building which is at such
time contiguous to the Leased Premises (the "First Offer Space"), at such time
as such space becomes available after its initial leasing or occupancy by
another tenant. Tenant shall have the right to lease the First Offer Space upon
the same terms and conditions as such space is sought to be leased by a bona
fide prospective tenant and acceptable to Landlord, or, if there is no third
party offer to lease such space, upon such terms and conditions as Landlord
intends to market such space.

            (2)   Tenant's exercise of its First Offer Right shall be effective
only upon written notification by Tenant to Landlord of Tenant's exercise of the
First Offer Right (the "Notice") and its acceptance of the terms set forth in
the written notification of Landlord referred to in the next sentence of this
paragraph. Such notification must be given to Landlord before the close of
business on the fourth full business day after Landlord's written notification
to Tenant ("Landlord's Offer") of a bona fide offer for rental of the First
Offer Space or of the vacancy or termination of a lease for the First Offer
Space (a bona fide offer shall not include the exercise by another tenant of its
right of refusal or expansion). Landlord's Offer shall set forth the rental
terms of such third party offer or which Landlord is willing to accept. Time is
of the essence with respect to Tenant's exercise of its rights under this Rider,
and Tenant acknowledges that Landlord requires strict adherence to the
requirement that the Notice be timely made and in writing.

            (3)   In the event Tenant fails to so notify Landlord within said
four (4) business day period, Landlord shall be free to offer said First Offer
Space to a third party on any terms whatsoever, and this First Offer Right shall
be null and void and of no further force and effect, except as set forth in the
following sentence. In the event that Tenant fails to timely notify Landlord
within said four (4) business days of its exercise of the First Offer Right and
Landlord subsequently leases the First Offer Space to a third party (the "Third
Party Lease"), then, if the First Offer Space subsequently becomes again
available for lease, subject to any renewals or extensions of the Third Party
Lease, then Landlord shall be obligated to again offer the First Offer Space to
Tenant and Tenant shall have four (4) business days to accept said offer, all
upon the same terms and conditions as are set forth herein.

            (4)   In the event that the First Offer Right is exercised by
Tenant, the rent applicable to the First Offer Space shall be payable in equal
monthly installments (and, where applicable, fractions thereof), at the times
and in the manner as provided with respect to, and in addition to, the monthly
installments of the Basic Annual Rent as set forth in Section 4 of this Lease.

            (5)   This First Offer Right is personal to Tenant and shall not be
separated from the Lease or transferred by Tenant independently of the leasehold
interest without the prior written consent of Landlord, which consent of
Landlord will be given solely within the discretion of Landlord.

      B.    Notwithstanding any other provision of this Rider Number 1, the
following provisions shall apply to the First Offer

<PAGE>

Right and to Tenant's lease, if any, of the First Offer Space:

            (1)   Tenant shall not be entitled to exercise the rights accorded
to Tenant in paragraph (A), unless on the date Tenant gives Landlord its Notice
and on the First Offer Space Commencement Date, as hereinafter defined, Tenant
is in possession of the Leased Premises and Tenant is not in default of this
Lease.

            (2)   The lease by Tenant of the First Offer Space, if any, shall
commence on the date set forth in Landlord's Offer (the "First Offer Space
Commencement Date") and shall terminate on the date three (3) years after the
First Offer Space Commencement Date or the date Tenant's lease of the original
Leased Premises terminates, whichever later occurs, under and subject to the
terms of this Lease, except to the extent modified by Landlord's Offer, with the
same force and effect as though this Lease had originally provided for the
rental of the Leased Premises and the first Offer Space, except that, unless
otherwise provided in the Offer, the Basic Annual Rent applicable to the First
Offer Space shall be adjusted during any renewal term in accordance with the
provisions of Rider No. 2 below.

            (3)   The First Offer Space shall be delivered to Tenant in "AS IS"
condition, unless otherwise set forth in Landlord's Offer.

            (4)   From and after the First Offer Space Commencement Date, all
references in the Lease to the Leased Premises shall refer to both the area of
the original Leased Premises and of the First Offer Space. Tenant's Portion
shall be adjusted accordingly to reflect the leasing of the First Offer Space.

<PAGE>

                                  RIDER NO. 2

                                 RENEWAL OPTION

      Provided (i) this Lease is then in full force and effect, (ii) Tenant is
not in default respecting any provision or condition of this Lease either on the
date Tenant elects to renew or on the date the renewal term commences, and,
(iii) Tenant has not failed more than two times in any lease year during the
original term of this Lease to pay any payments called for by this Lease on the
date such payment is due, then Tenant shall have the right to renew this Lease
for one (1) renewal term of five (5) years immediately following the expiration
of the original term on the same terms, conditions, and provisions as are set
forth in this Lease with the same force and effect as though this Lease had
originally provided for a fifteen (15) year term, save that:

            (i)   there shall be no further right of renewal, after the renewal
term, and

            (ii)  the Basic Annual Rent payable with respect to the Leased
Premises shall be adjusted to reflect the prevailing rental rate for comparable
space within a two (2) mile radius of the Building as of the commencement of the
renewal term (as determined below) and subject to annual market increases
thereafter, but in no event less than 2.5% per year.

      Tenant shall be deemed to have waived the right to exercise this renewal
option unless not less than one hundred eighty (180) days prior to the date of
termination of the original term, Tenant shall have notified Landlord in writing
of Tenant's election to renew (the "Renewal Notice"). Landlord shall give Tenant
written notice of its good faith determination of the prevailing rental rate
within thirty (30) days after Landlord's receipt of the Renewal Notice (the
"Rent Notice"). Tenant may withdraw its Renewal Notice by giving Landlord
written notice within ten (10) days after Tenant's receipt of the Rent Notice
(the "Withdrawal Notice").

      Time is of the essence with respect to Tenant's exercise of its rights
under this Rider and Tenant acknowledges that Landlord requires strict adherence
to the requirement that the Renewal Notice and the Withdrawal Notice be timely
made and in writing.

<PAGE>

                                    EXHIBIT A

                         Site Plan and Leased Premises

                     [Identify location of Leased Premises
                          and permitted parking areas]

<PAGE>

                                    EXHIBIT B

                            Plans and Specifications

                         [To be attached when finalized]

<PAGE>

                                    EXHIBIT C

                          LEASE COMMENCEMENT AGREEMENT

THIS LEASE COMMENCEMENT AGREEMENT, made this __ day of _________, 2001, by and
between MOR FORBES LLLP ("Landlord") and VOCUS, INC.("Tenant").

                                   WITNESSETH:

WHEREAS, Landlord and Tenant have entered into that certain Lease Agreement
dated November ____, 2000 (the "Lease") for the premises located at 4260 Forbes
Boulevard, Prince George's County, Maryland (the "Leased Premises"); and

WHEREAS, Landlord and Tenant wish to set forth their agreements as to the term
of the Lease, as well as certain other matters, all as more particularly set
forth below.

NOW, THEREFORE, in consideration of the Leased Premises as described in the
Lease and the covenants set forth, therein, Landlord and Tenant agree as
follows:

      1.    The "Commencement Date" for all purposes of the Lease is
_____________, 2001.

      2.    The initial Lease Term shall expire on ___________, 2011.

      3.    The Rentable Area of the Leased Premises is 22,488 square feet.

      4.    The amount of Landlord's Additional Contribution utilized by Tenant
is $___________.

      5.    The Basic Annual Rent, increased by an amount sufficient to amortize
Landlord's Additional Contribution with interest of 12% per annum, is as
follows:

<TABLE>
<CAPTION>
Lease Year    Basic Annual Rent    Monthly Installment
----------    -----------------    -------------------
<S>           <C>                  <C>
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
</TABLE>

      6.    A cash security deposit was received from Tenant by Landlord in the
amount of $22,300.60.

      7.    A letter of credit was received from Tenant by Landlord in the
original principal amount of $________.

      8.    [Other provisions, as applicable]

<PAGE>

                                    EXHIBIT D

                             Rules and Regulations

            1.    The delivery, shipping, loading and unloading of goods, wares,
merchandise, equipment, supplies, fixtures and all other items to and from the
Leased Premises will be subject to the rules and regulations Landlord may
promulgate from time to time with respect to deliveries and shipments.

            2.    All garbage and refuse will be kept in the kind of container
specified by Landlord, and will be placed outside of the Building for collection
in the manner, in such containers and at the times and places reasonably
specified by Landlord. Tenant will not burn any trash or garbage of any kind in
or around the Leased Premises.

            3.    No radio, speakers, television, phonograph or other sound or
similar device will be installed or operated in the Leased Premises without
Landlord's prior written approval, not to be unreasonably withheld. Tenant will
prevent sounds emanating from the Leased Premises from being heard outside the
Leased Premises or otherwise unreasonably disturbing or annoying other tenants.

            4.    The plumbing facilities will not be used for any purpose other
than that for which they are constructed. No foreign substance of any kind will
be thrown into the plumbing facilities. The expense of any breakage, stoppage or
damage resulting from a violation of this provision by Tenant or any of its
servants, agents, invitees, employees and/or licensees will be borne solely by
Tenant.

            5.    Tenant will not place a load upon the floor of the Leased
Premises exceeding the floor load per square foot area which the floor of the
Leased Premises has been designed to carry.

            6.    Tenant will not permit anyone to lodge, sleep or cook in the
Leased Premises. Tenant is responsible for all persons whom it invites and/or
admits to the Leased Premises and will be liable to Landlord for all acts of
such persons.

            7.    Landlord reserves to itself all rights not granted to Tenant
under this Lease, including, but not limited to, the following: (a) the right to
change the address of the Building, without liability to Tenant for so doing,
but in such event, if the change is initiated by Landlord and not any
governmental or quasi-governmental entity, Landlord shall reimburse Tenant the
reasonable cost of replacing Tenant's stationary on hand; (b) the right to
install and maintain signs on the exterior of the Building; (c) the exclusive
right to use or dispose of the use of the roof of the Building; and (d) the
right to grant to anyone the right to conduct any particular business or
undertaking in the Building.

            8.    Tenant will not attach or place awnings, antennas or other
projections to the outside walls or any exterior portion of the Building,
without the prior written consent of Landlord. No curtains, blinds, shades or
screens shall be attached to or hung in, or used in connection with, any window
or door of the Leased Premises, without the prior written consent of Landlord.

            9.    Tenant will not pile or place or permit to be placed any goods
on the sidewalks or parking lots in the front, rear or sides of the Building or
in a place in any manner so as to block said sidewalks, parking lots and loading
areas and/or

<PAGE>

not to do anything that directly or indirectly will take away any of the rights
of ingress or egress or of light from any other tenant of Landlord in the
Project.

            10.   Tenant, Tenant's servants, agents, invitees, employees and/or
licensees shall not park on, store on, or otherwise utilize any parking or
loading areas on the Real Property, except as shown on Exhibit A, and then only
in the parking places designated by Landlord for such parking and in accordance
with such rules and regulations as Landlord may from time to time promulgate
with respect thereto. Upon completion of the Project, non-exclusive parking will
be available on the Real Property at the ratio of 3 parking spaces for each
1,000 square feet of rentable area. Landlord shall provide Tenant with five
parking spaces in close proximity to Tenant's suite entrance which shall be
identified for Tenant's exclusive use, but Landlord will have no obligation to
enforce Tenant's parking rights against any other tenant of the Project.

            11.   No animals of any kind (other than seeing eye dogs) shall be
brought into or kept in or about the Project.

            12.   Tenant covenants and agrees that it shall not inscribe, affix,
or otherwise display signs, advertisements or notices in, on, upon or behind any
windows or on any door, partition or other part of the interior or exterior of
the Building without the prior written consent of Landlord. If such consent be
given by Landlord, any such sign, advertisement, or notice shall be inscribed,
painted or affixed by Landlord, or a company approved by Landlord, but the cost
of the same shall be charged to and be paid by Tenant, and Tenant agrees to pay
the same promptly, on demand.

<PAGE>

                                    EXHIBIT E

                       MINIMUM CONTRACT SPECIFICATIONS FOR
                                   HVAC SYSTEM
                            PREVENTATIVE MAINTENANCE
                                      AND
                         FULL PARTS AND LABOR SERVICING

      Full Parts & Labor

      A.    This contract is meant to be a full parts and labor contract on the
            installed equipment as detailed on a separate sheet. It includes all
            repairs resulting from malfunctions discovered during inspections
            and emergency service requests.

      B.    Components under this agreement that may be obsolete will be
            repaired until such time as they are no longer repairable and the
            equipment must be replaced.

I.    Quarterly Inspections Shall be Provided as Follows;

      A.    General: Performed at all quarterly inspections

            1.    Replace all filters as required

            2.    Lubricate all motors and bearings

            3.    Adjust and/or replace all fan belts

            4.    Clean grilles, etc., as required

      B.    Spring and Summer;

            1.    Check refrigerant charge and/or temperature difference across
                  evaporator coil

            2.    Check refrigerant piping for leaks with electronic leak
                  detector

            3.    Check all operating and safety controls for cooling

            4.    Check system operation - (operating pressures, super heat,
                  compressor running current, condensate removal, etc.)

            5.    Clean condenser and/or evaporator coil as required

            6.    Check and tighten all electrical connections at unit as
                  required

      C.    Fall and Winter:

            1.    Check system operation - (operating pressures, etc.)

            2.    Check all operating and safety controls for heating

            3.    Check and tighten all electrical connections at unit as
                  required

II.   Qualifications of Contractors

      All contractors providing the services described above shall be qualified
      and certified by an EPA-approved testing organization to work with
      refrigerants and other chemicals.
<PAGE>

                                    EXHIBIT F

                          CERTIFICATION OF HVAC SYSTEM
                              BY LICENSED MECHANIC

4260 Forbes Boulevard

TO WHOM IT MAY CONCERN:

The heating and cooling equipment that conditions the air in the subject space
has been thoroughly inspected. All necessary repairs, replacements and services
have been performed to insure that the system operates properly in the following
aspects:

      1.    All electrical circuitry and all components function properly.

      2.    Refrigerant charge is correct, and no refrigerant leaks or
            discharges are apparent.

      3.    Evaporator and condenser coils are clean.

      4.    Belts are in good condition and all new filters installed.

      5.    All bearings are in good order and properly greased.

      6.    All wiring is in order and properly secured.

      7.    All access panels are in place.

      8.    All air diffusers include operational dampering devices.

      9.    All oil-heating appliances are clean and properly adjusted.

      10.   Components requiring clear and unobstructed condition for proper
            operation are in order.

      11.   All safety devices are operational.

      12.   Thermostats are operational, calibrated and in proper condition.

                                   NAME OF CERTIFYING CONTRACTOR:

                                   By:
                                   (NAME OF COMPANY REPRESENTATIVE):

                                   LICENSE NO.:

                                   DATE OF CERTIFICATION:

<PAGE>

                       FIRST AMENDMENT OF LEASE AGREEMENT

      THIS FIRST AMENDMENT OF LEASE AGREEMENT (this "Amendment") is made this 19
day of FEBRUARY, 2003, but is made effective as of the Effective Date (as
hereinafter defined), by and between FORBES BOULEVARD, LLC, a Maryland limited
liability company ("Landlord"), and VOCUS, INC., a Delaware corporation
("Tenant").

                              Explanatory Statement

      A. MOR FORBES LLC, a Maryland limited liability company (formerly known,
prior to its conversion to a limited liability company, as MOR FORBES LLLP, a
Maryland limited liability limited partnership) ("Original Landlord") and Tenant
entered into an Agreement of Lease dated December 21, 2000 (the "Original
Lease"), whereby Tenant leased from Original Landlord certain premises
originally anticipated by the parties to be comprised of twenty-two thousand
four hundred eighty-eight (22,488) square feet (the "Leased Premises") in the
building known as Building A (the "Building"), located at 4260 Forbes Boulevard,
Prince George's County, Maryland.

      B. The Original Lease was amended by a letter agreement dated March 23,
2001 (the "Letter Agreement") pursuant to which Original Landlord and Tenant,
among other matters, confirmed certain matters regarding Original Landlord's
construction of the Leased Premises, all as more particularly set forth therein.

      C. Pursuant to a Lease Commencement Agreement dated June 20, 2001 (the
"Commencement Agreement"), Original Landlord and Tenant, among other matters,
confirmed: (i) the Rentable Area of the Leased Premises to be twenty-three
thousand five hundred sixty (23,560) square feet; and (ii) the amounts of
Landlord's Contribution and Basic Annual Rent, all as more particularly set
forth therein. The Original Lease, as amended by the Commencement Agreement and
the Letter Agreement, is referred to herein as the "Lease".

      D. Original Landlord subsequently subdivided the Lots (the "Subdivision")
into two parcels, known respectively as Parcel V ("Parcel V") containing
approximately 5.3555 acres, on which the Building is located, and Parcel W
("Parcel W") containing approximately 4.5370 acres, all as more particularly
shown on that certain subdivision plat entitled "Parcels 'V' & 'W', Block "A"
(Being a Resubdivision of the Residue of Parcels J, K, & L, Block "A")
Hanson-Palmer Business Park, Kent Election District No. 13, Prince George's
County, Maryland", recorded December 9, 2002, among the Plat Records of Prince
George's County, Maryland, in Plat Book REP 195, as Plat No. 46.

      E. On December 24, 2002 (the "Effective Date"), Original Landlord
transferred ownership (the "Transfer") of Parcel V, together with the Building
and all appurtenances thereto to Landlord.

      F. As a result of the Subdivision and the Transfer, Parcels V and W are
owned by two different owners and will no longer share expenses (except as
otherwise agreed by such

<PAGE>

owners). Thus, certain terms of the Lease concerning (i) the development of the
Project (including, but not limited to the construction of Building B), and (ii)
the manner in which Tenant's Portion is calculated, are no longer accurate.

      G. Landlord and Tenant desire to confirm and/or amend certain matters
respecting the Leased Premises and Tenant's obligation under the Lease, and to
amend the Lease to reflect the Subdivision and the Transfer, on the terms set
forth below.

      H. Unless otherwise defined herein or unless the context requires a
contrary meaning, all capitalized terms in this Amendment shall have the
meanings ascribed to them in the Lease.

      NOW, THEREFORE, in consideration of the Explanatory Statement, which is
deemed a substantive part of this Amendment, the covenants of the parties herein
and in the Lease and other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, Landlord and Tenant hereby agree as
follows:

      1. Lease Amendments. From and after the Effective Date (or such earlier
date as is indicated), and notwithstanding any other provision of the Lease, as
amended by this Amendment, to the contrary, the Lease shall be amended as
follows:

            A. In Section 5.1.(a), the "Rentable Area of the Project" shall be
conclusively deemed to be fifty-four thousand six hundred ninety-two (54,692)
square feet.

            B. From and after the Commencement Date, in Section 5.1.(b): (i) the
"Rentable Area of the Leased Premises" shall be conclusively deemed to be
twenty-three thousand five hundred sixty (23,560) square feet; and (ii) the
"Tenant's Portion" shall be conclusively deemed to forty-three and eight
hundredths percent (43.08%) (23,560/54,692).

            C. From and after the Commencement Date, the chart in Section 5
setting forth the amounts of Basic Annual Rent payable by Tenant during the
Lease Term shall be deleted in its entirety and replaced by the following new
chart:

<TABLE>
<CAPTION>
                                                       Total Monthly
                                                       Payment (Basic
                                                        Annual Rent
Lease    Basic Annual    Per Square       Monthly      plus Monthly TI
 Year         Rent          Foot        Installment        Payment)
-----    ------------    ----------     -----------    ---------------
<S>      <C>             <C>            <C>            <C>
  1      $ 280,364.00     $ 11.90       $ 23,363.67      $26,740.60
  2      $ 287,432.00     $ 12.20       $ 23,952.67      $27,329.60
  3      $ 294,735.60     $ 12.51       $ 24,561.30      $27,938.23
  4      $ 302,039.20     $ 12.82       $ 25,169.93      $28,546.87
  5      $ 309,578.40     $ 13.14       $ 25,798.20      $29,175.13
  6      $ 317,353.20     $ 13.47       $ 26,446.10      $29,823.03
  7      $ 325,363.60     $ 13.81       $ 27,113.63      $30,490.57
  8      $ 333,609.60     $ 14.16       $ 27,800.80      $31,177.73
  9      $ 341,855.60     $ 14.51       $ 28,487.97      $31,864.90
  10     $ 350,337.20     $ 14.87       $ 29,194.77      $32,571.70
</TABLE>

                                       2
<PAGE>

            D. Section 5.l.(e) shall be deleted in its entirety and replaced by
the following new Section 5.l,(e):

            (e) "Real Property" shall mean Parcel V, the Building, and all
            fixtures, equipment and other improvements in or upon said Parcel V,
            and shall include the sidewalks, areaways, parking areas, loading
            areas, gardens and lawns,

            E. Section 5.l.(g) shall be deleted in its entirety and replaced by
the following new Section 5.1.(g):

            (g) "Parcel V" shall mean Parcel V, containing approximately 5.3555
            acres, as more particularly shown on that certain subdivision plat
            entitled "Parcels 'V' & 'W', Block "A" (Being a Resubdivision of the
            Residue of Parcels J,K, & L, Block "A") Hanson-Palmer Business Park,
            Kent Election District No. 13, Prince George's County, Maryland",
            recorded December 9, 2002, among the Plat Records of Prince George's
            County, Maryland, in Plat Book REP 195, as Plat No. 46.

            F. From and after the Commencement Date, Section 5.2(a) shall be
deleted in its entirety and replaced by the following new Section 5.2(a):

            (a) One-twelfth of Tenant's estimated Portion of Common Area
            Expenses, which estimated Portion shall be calculated on the basis
            of One Dollar and Seventy Cents ($1.12) per square foot, resulting
            in a monthly installment of Two Thousand One Hundred Ninety-Four
            Dollars and Eight Cents ($2,194.08).

            G. From and after the Commencement Date, Section 5.2(b) shall be
deleted in its entirety and replaced by the following new Section 5.2(b):

            (b) One-twelfth of Tenant's estimated Portion of Taxes, which
            estimated Portion shall be calculated on the basis of Eighty Cents
            (S.80) per square foot, resulting in a monthly installment of One
            Thousand Five Hundred Seventy Dollars and Sixty-Seven Cents
            ($1,570.67).

            H. From and after the Commencement Date, Section 5.4 shall be
deleted in its entirety and replaced by the following new Section 5.4:

            5.4 The following is a list of the various payments and installments
            of Basic Annual Rent and additional rent pursuant to this Section
            5.4 as of the Commencement Date. Some of these amounts will change
            during the Lease Term.

                                       3
<PAGE>

<TABLE>
<CAPTION>
                                         Monthly
                                       Installments              P.S.F.
                                       ------------              ------
<S>                                    <C>                       <C>
Basic Annual Rent (1st lease year)      $23,363.67               $11.90

Monthly Tenant Improvement Payment      $ 3,376.93               $ 1.72

Common Area Expenses(estimate)          $ 3,337.67               $ 1.70

Taxes (estimate)                        $ 1,570.67               $  .80
                                        ----------               ------

    TOTAL                               $31,648.94               $16.12
                                        ==========               ======
</TABLE>

            I. The term, the "Project", as defined in Section l.(a), shall be
redefined to refer only to the Building, and any references in the Lease to the
term, the "Project", where the context denotes the development by Landlord of a
building other than the Building (i.e., the anticipated development by Landlord
of Building B, prior to the Subdivision and the Transfer, as, for example, in
Section 5.1(a)) shall be nugatory.

      3. Authority. Tenant represents and warrants to Landlord that Tenant is a
corporation duly organized and validly existing and in good standing under the
laws of the State of Delaware and qualified to transact business and in good
standing in the State of Maryland; that the Lease and this Amendment were
approved by all necessary parties, were validly executed by all necessary
officers of Tenant, and are and remain binding upon and enforceable against
Tenant in accordance with their terms.

      4. Successors and Assigns. The terms, covenants, conditions, and
agreements contained in this Amendment shall bind and inure to the benefit of
Landlord and Tenant, and their respective successors and permitted assigns.

      5. Governing Law. This Amendment is made in the State of Maryland and
shall be governed by and construed in all respects in accordance with the laws
of the State of Maryland.

      6. Effect of Agreement. From and after the date hereof, the Lease shall be
amended and in full force and effect in such respects as are set forth in this
Amendment, and all other provisions, terms, conditions and riders of and to the
Lease shall in all respects remain as set forth in the Lease, in full force and
effect.

                        [SIGNATURES APPEAR ON NEXT PAGE]

                                       4
<PAGE>

      IN WITNESS WHEREOF, Landlord and Tenant have respectively signed and
sealed this First Amendment of Lease Agreement as of the day and year first
above written, intending to be bound as of the Effective Date.

ATTEST:                                FORBES BOULEVARD, LLC

/s/ [ILLEGIBLE]                        By: /s/ Mark D. Knobloch   (SEAL)
---------------------                      --------------------
                                       Name: Mark D. Knobloch
                                       Title: Authorized Signatory
                                                                        Landlord

WITNESS/ATTEST:                        VOCUS, INC.

/s/ [ILLEGIBLE]                        By: /s/ Stephen Vintz   (SEAL)
-------------------                        -----------------
                                       Name: Stephen Vintz
                                       Title: CFO
                                                                          Tenant

STATE OF MARYLAND, SET
CITY/COUNTY OF BALTIMORE, TO WIT:

      I HEREBY CERTIFY that on this 20th day of February, 2003, before me, the
subscriber, a Notary Public of the State aforesaid and County/City of Baltimore,
personally appeared before me Mark Knobloch, known to me or satisfactorily
proven to be the person whose name is subscribed to the foregoing instrument,
who acknowledged himself to be the Authorized Signatory of FORBES BOULEVARD,
LLC, Landlord, and he acknowledged the foregoing First Amendment of Lease
Agreement to be the act and deed of said limited liability company.

      WITNESS my hand and notarial seal.

                                           /s/ [ILLEGIBLE]
                                       ------------------------
                                           Notary Public

My Commission expires: 6/1/05

                        [NOTARIES CONTINUED ON NEXT PAGE]

                                       5
<PAGE>

STATE OF MARYLAND,
CITY/COUNTY OF PRINCE GEORGE'S TO WIT:

      I HEREBY CERTIFY that on this 11 day of February, 2003, before me, the
subscriber, a Notary Public of the State aforesaid and County/City of Prince
George's, personally appeared before me Stephen Vintz, known to me or
satisfactorily proven to be the person whose name is subscribed to the foregoing
instrument, who acknowledged herself/himself to be the CFO of VOCUS, INC.,
Tenant, and she/he acknowledged the foregoing First Amendment of Lease Agreement
to be the act and deed of said corporation.

      WITNESS my hand and notarial seal.

                                         /s/ Laura E. Tavacol
                                       ------------------------
                                            Notary Public

My Commission expires: 7/3/06

         LAURA E. TAVACOL
   NOTARY PUBLIC STATE OF MARYLAND
 My Commission Expires July  3, 2006

                                        6

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