Exhibit 10.4

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LEHMAN BROTHERS       

GUARANTEE OF LEHMAN BROTHERS HOLDINGS INC.
 
LEHMAN BROTHERS SPECIAL FINANCING INC. (“Party A”) and THE BANK OF NEW YORK, not
in its individual or corporate capacity but solely as Swap Contract
Administrator Administrator for Alternative Loan Trust 2007-0H2 (“Party B”) have
entered into a Master Agreement dated as of June 29, 2007, as amended from time
to time (the “Master Agreement”), pursuant to which Party A and Party B have
entered and/or anticipate entering into one or more transactions (each a
“Transaction”), the Confirmation of each of which supplements, forms part of,
and will be read and construed as one with, the Master Agreement (collectively
referred to as the “Agreement”). This Guarantee is a Credit Support Document as
contemplated in the Agreement. For value received, and in consideration of the
financial accommodation accorded to Party A by Party B under the Agreement,
LEHMAN BROTHERS HOLDINGS INC., a corporation organized and existing under the
laws of the State of Delaware (“Guarantor”), hereby agrees to the following:
 
(a)           Guarantor hereby unconditionally guarantees to Party B the due and
punctual payment of all amounts payable by Party A in connection with each
Transaction when and as Party A’s obligations thereunder shall become due and
payable in accordance with the terms of the Agreement (whether at maturity, by
acceleration or otherwise). Guarantor hereby agrees, upon written demand by
Party B, to pay or cause to be paid any such amounts punctually when and as the
same shall become due and payable.
 
(b)           Guarantor hereby agrees that its obligations under this Guarantee
constitute a guarantee of payment when due and not of collection.
 
(c)           Guarantor hereby agrees that its obligations under this Guarantee
shall be unconditional, irrespective of the validity, regularity or
enforceability of the Agreement against Party A (other than as a result of the
unenforceability thereof against Party B), the absence of any action to enforce
Party A’s obligations under the Agreement, any waiver or consent by Party B with
respect to any provisions thereof, the entry by Party A and Party B into any
amendments to the Agreement, additional Transactions under the Agreement or any
other circumstance which might otherwise constitute a legal or equitable
discharge or defense of a guarantor (excluding the defense of payment or statute
of limitations, neither of which is waived) provided, however, that Guarantor
shall be entitled to exercise any right that Party A could have exercised under
the Agreement to cure any default in respect of its obligations under the
Agreement or to setoff, counterclaim or withhold payment in respect of any Event
of Default or Potential Event of Default in respect of Party B or any Affiliate,
but only to the extent such right is provided to Party A under the Agreement.
The Guarantor acknowledges that Party A and Party B may from time to time enter
into one or more Transactions pursuant to the Agreement and agrees that the
obligations of the Guarantor under this Guarantee will upon the execution of any
such Transaction by Party A and Party B extend to all such Transactions without
the taking of further action by the Guarantor.
 
(d)           This Guarantee shall remain in full force and effect until the
first to occur of (i) receipt by Party B of a written notice of termination from
Guarantor or (ii) none of the obligations of Party A remain outstanding.
Termination of this Guarantee shall not affect Guarantor’s liability hereunder
as to obligations incurred or arising out of Transactions entered into prior to
the termination hereof.
 

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(e)           Guarantor further agrees that this Guarantee shall continue to be
effective or be reinstated, as the case may be, if at any time, payment, or any
part thereof, of any obligation or interest thereon is rescinded or must
otherwise be restored by Party B upon an Event of Default as set forth in
Section 5(a)(vii) of the Master Agreement affecting Party A or Guarantor.
 
(f)           Guarantor hereby waives (i) promptness, diligence, presentment,
demand of payment, protest, order and, except as set forth in paragraph (a)
hereof, notice of any kind in connection with the Agreement and this Guarantee,
or (ii) any requirement that Party B exhaust any right to take any action
against Party A or any other person prior to or contemporaneously with
proceeding to exercise any right against Guarantor under this Guarantee.
 
This Guarantee shall be governed by and construed in accordance with the laws of
the State of New York without regard to conflicts of laws principles. All
capitalized terms not defined in this Guarantee, but defined in the Agreement,
shall have the meanings assigned thereto in the Agreement.
 
IN WITNESS WHEREOF, Guarantor has caused this Guarantee to be executed by its
duly authorized officer as of the date of the Agreement.
 

 
LEHMAN BROTHERS HOLDINGS INC.
         
By:
/s/ James J. Killerlane III
 
Name:
James J. Killerlane III
 
Title:
Vice President
 
Date:
June 28, 2007