Exhibit 10.13


Execution Version


 


OSIRIS ACQUISITION CORP.


95 5th Avenue, 6th
Floor


New York, NY 10003


May 13, 2021


 


Osiris Acquisition Corp.

95 5th Avenue, 6th Floor


New York, NY 10003


 


Re: Administrative Services Agreement


 


Ladies and Gentlemen:


 


This letter agreement by and between Osiris Acquisition Corp.,
a Delaware corporation (the “Company”) and Osiris Sponsor, LLC, a Delaware limited liability company
(the “Services Provider”), dated as of the date hereof, will confirm our agreement that, commencing on
the date that securities of the Company are first listed in connection with the Company’s initial public offering (the “Listing
Date”) and continuing until the earlier of the consummation by the Company of an initial business combination and
the Company’s liquidation (in each case as described in the Registration Statement on Form S-1 (File No. 333-254997) filed with
the Securities and Exchange Commission) (such earlier date hereinafter referred to as the “Termination Date”):


 


		1.	The Services Provider (and/or any of its affiliates designated by the Services Provider) shall make available to the Company,
at the address of the Services Provider referred to above (or any successor location or other existing office locations of the
Services Provider or any of its affiliates), office space, utilities and administrative and support services as may be reasonably
requested by the Company. In exchange therefor, the Company shall pay to the Services Provider, on the first day of each month,
the sum of $10,000 per month commencing on the Listing Date and continuing monthly thereafter until the Termination Date; and



 


		2.	The Services Provider hereby irrevocably waives any and all right, title, interest, causes of action and claims of any kind
or nature whatsoever (each, a “Claim”) in or to, and any and all right to seek payment of any amounts
due to it out of, the trust account established for the benefit of the public stockholders of the Company and into which substantially
all of the proceeds of the Company’s initial public offering will be deposited (the “Trust Account”),
and hereby irrevocably waives any Claim it presently has or may have in the future as a result of, or arising out of, this letter
agreement, which Claim would reduce, encumber or otherwise adversely affect the Trust Account or any monies or other assets in
the Trust Account, and further agrees not to seek recourse, reimbursement, payment or satisfaction of any Claim against the Trust
Account or any monies or other assets in the Trust Account for any reason whatsoever.



 






     


     


    

 


This letter agreement constitutes the entire agreement and understanding
of the parties hereto in respect of its subject matter and supersedes all prior understandings, agreements, or representations
by or among the parties hereto, written or oral, to the extent they relate in any way to the subject matter hereof or the transactions
contemplated hereby.


 


This letter agreement may not be amended, modified or waived
as to any particular provision, except by a written instrument executed by all parties hereto.


 


No party hereto may assign either this letter agreement or any
of its rights, interests, or obligations hereunder without the prior written approval of the other party, provided that the Services
Provider may assign this letter agreement or any of its rights, interests, or obligations hereunder to an affiliate without the
prior written approval of the Company. Any purported assignment in violation of this paragraph shall be void and ineffectual and
shall not operate to transfer or assign any interest or title to the purported assignee.


 


This letter agreement constitutes the entire relationship of
the parties hereto with respect to the subject matter described herein and any litigation between the parties (whether grounded
in contract, tort, statute, law or equity) shall be governed by and construed in accordance with the laws of the State of New York.


 


This letter agreement may be executed in one or more counterparts,
each of which shall for all purposes be deemed to be an original but all of which together shall constitute one and the same letter
agreement.


 


[Signature page follows]


 






    2


     


    

 


	 	Very truly yours,
	 	 
	 	 
	 	OSIRIS acquisition corp.
	 	 	 
	 	By:	/s/ Benjamin E. Black
	 	 	Name: Benjamin E. Black
 Title: Chief Executive Officer




 


AGREED TO AND ACCEPTED BY:


 


	OSIRIS SPONSOR, LLC	 
	 	 	 
	By: Fortinbras SPAC Holdings, LLC,	 
	 	 	 
	its  managing member	 
	 	 	 
	 	 	 
	By:	/s/ Benjamin E. Black	 
	 	Name: Benjamin E. Black
 Title: Managing Partner	 




 


[Signature Page
to Administrative Services Agreement]