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                                                                   Exhibit 10.13

                                                                  EXECUTION COPY



                                 PROMISSORY NOTE

January 10, 2002                                                      $34,650.00

         Steve Hanau ("MAKER"), hereby promises to pay to the order of
DigitalNet Holdings, Inc. (the "Company"), the principal amount of $34,650.00
together with interest thereon calculated from the date hereof in accordance
with the provisions of this Note.

         This Note is the promissory note referred to in the Consulting
Agreement, dated as of January 10, 2002, by and among the Company, Maker and
DigitalNet, Inc., a Delaware Corporation and a wholly-owned subsidiary of the
Company (the "CONSULTING AGREEMENT"). Section 2(a) of the Consulting Agreement
contains provisions for the issuance of this Note upon the terms and conditions
specified therein. Capitalized terms used herein and not otherwise defined shall
have the meanings given to them in the Consulting Agreement.

         1. PAYMENT OF INTEREST. Interest shall accrue on the outstanding
principal amount of this Note at a rate equal to the lesser of (i) 5.00% per
annum and (ii) the highest rate permitted by applicable law, compounded
annually. Accrued interest shall be payable at such time as the principal of
this Note becomes due and payable.

         2. PAYMENT OF PRINCIPAL ON NOTE.

         (a) In the event Maker receives any net cash proceeds in connection
with his ownership of the Executive Stock, Maker shall prepay any amounts owed
pursuant to this Note by applying all of such proceeds FIRST, to any accrued
interest and SECOND, to any principal then outstanding. In addition, if Maker
ceases to be employed by the Company and its Subsidiaries for any reason, Maker
shall pay the entire principal amount then outstanding and any accrued interest
to the Company. For purposes hereof, "EXECUTIVE STOCK" shall have the meaning
set forth in the Management Agreement. The entire unpaid principal balance,
together with any accrued but unpaid interest shall be due and payable in full
on December 10, 2010.

         (b) OPTIONAL PREPAYMENTS. Maker may, at any time and from time to time
without premium or penalty, prepay all of the outstanding principal amount of
the Note; provided that any prepayment will be accompanied by a payment of
accrued interest on the portion being prepaid. A prepayment of less than all of
the outstanding principal amount of the Note shall not relieve Maker of his
obligation to make the payments on the Note pursuant to paragraph 2(a) above.

         (c) RIGHT OF OFFSET. The Maker shall be entitled to offset any amounts
owed to the Maker by the Company, now existing or hereinafter arising, pursuant
to and as set forth in Section 3 of the Management Agreement between the Company
and the Maker, against any amounts payable under this Note. The Company shall be
entitled to offset any amounts owed to the Company by the Maker, now existing or
hereinafter arising, pursuant to this Note against any


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amounts payable by the Company to the Maker pursuant to and as set forth in
the Management Agreement between the Company and the Maker.

         3. SECURITY.

         (a) PLEDGE. The amounts due under this Note are secured by a pledge of
350,000 shares of the Company's Common Stock under the terms of the Executive
Stock Pledge Agreement of even date herewith between Maker and the Company, and
the payment of the principal amount and accrued interest under this Note is
subject to certain offset rights under the Management Agreement.

         (b) RECOURSE. Notwithstanding anything herein or in any other
agreement, instrument or other document to the contrary, the Maker shall be
personally liable for 100% of the repayment of the indebtedness evidenced by
this Note or for any claim of any kind based thereon.

         4. EVENTS OF DEFAULT.

         (a) DEFINITION. For purposes of this Note, an Event of Default shall be
deemed to have occurred if:

                  (i) Maker fails to pay when due, the full amount of any
         principal or interest payment; or

                  (ii) Maker makes an assignment for the benefit of creditors or
         admits in writing his inability to pay his debts generally as they
         become due; or an order, judgment or decree is entered adjudicating
         Maker bankrupt or insolvent; or any order for relief with respect to
         Maker is entered under the Federal Bankruptcy Code; or Maker petitions
         or applies to any tribunal for the appointment of a custodian, trustee,
         receiver or liquidator of any substantial part of Maker's assets, or
         commences any proceeding relating to Maker under any bankruptcy,
         reorganization, arrangement, insolvency, readjustment of debt,
         dissolution or liquidation law of any jurisdiction; or any such
         petition or application is filed, or any such proceeding is commenced,
         against Maker and either (A) Maker by any act indicates its approval
         thereof, consent thereto or acquiescence therein or (B) such petition,
         application or proceeding is not dismissed within 60 days.

         (b) CONSEQUENCES OF EVENTS OF DEFAULT. If an Event of Default has
occurred the aggregate principal amount of the Note (together with all accrued
interest thereon and all other amounts payable in connection therewith) shall
become immediately due and payable without any action on the part of the
Company, and Maker shall immediately pay to the Company all amounts due and
payable with respect to the Note.

         Maker, or his successors and assigns, hereby waives diligence,
presentment, protest and demand and notice of protest and demand, dishonor and
nonpayment of this Note, and expressly agrees that this Note, or any payment
hereunder, may be extended from time to time and that the


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Company may accept security for this Note or release security for this Note, all
without in any way affecting the liability of Maker hereunder.

         In the event that Maker fails to pay any amounts due hereunder when
due, Maker shall pay to the Company, in addition to such amounts due, all costs
of collection, including reasonable attorneys fees.

         5. AMENDMENT AND WAIVER. Except as otherwise expressly provided herein,
the provisions of the Note may be amended and Maker may take any action herein
prohibited, or omit to perform any act herein required to be performed by it,
only if Maker has obtained the written consent of the Company.

         6. CANCELLATION. After all principal and accrued interest at any time
owed on this Note has been paid in full, this Note shall be surrendered to Maker
for cancellation and shall not be reissued.

         7. PLACE OF PAYMENT. Payments of principal and interest are to be
delivered to the Company at the following address:

                              DigitalNet Holdings, Inc.
                              6700A Rockledge Drive
                              Suite 525
                              Bethesda, MD 20817
                              Attention: President

or to such other address or to the attention of such other person as specified
by prior written notice to Maker.

         8. USURY LAWS. It is the intention of the Company and Maker to conform
strictly to all applicable usury laws now or hereafter in force, and any
interest payable under this Note shall be subject to reduction to the amount not
in excess of the maximum legal amount allowed under the applicable usury laws as
now or hereafter construed by the courts having jurisdiction over such matters.
If the maturity of this Note is accelerated by reason of an election by the
Company resulting from an Event of Default, voluntary prepayment by Maker or
otherwise, then earned interest may never include more than the maximum amount
permitted by law, computed from the date hereof until payment, and any interest
in excess of the maximum amount permitted by law shall be canceled automatically
and, if theretofore paid, shall at the option of the Company either be rebated
to Maker or credited on the principal amount of this Note, or if this Note has
been paid, then the excess shall be rebated to Maker. The aggregate of all
interest (whether designated as interest, service charges, points or otherwise)
contracted for, chargeable, or receivable under this Note shall under no
circumstances exceed the maximum legal rate upon the unpaid principal balance of
this Note remaining unpaid from time to time. If such interest does exceed the
maximum legal rate, it shall be deemed a mistake and such excess shall be
canceled automatically and, if theretofore paid, rebated to Maker or credited on
the principal amount of this Note, or if this Note has been repaid, then such
excess shall be rebated to Maker.


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         9. GOVERNING LAW. This Note is made under and governed by the internal
law, not the laws of conflicts, of the State of Maryland.

         IN WITNESS WHEREOF, Maker has executed and delivered this Note as of
the date above.




                                               /s/ STEVEN HANAU
                                               ---------------------------------
                                               Steven Hanau





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