Exhibit 10.3 


 


STOCK ESCROW AGREEMENT


 


This
STOCK ESCROW AGREEMENT, dated as of October 4, 2021 (“Agreement”), by and among MOUNT RAINIER ACQUISITION CORP.,
a Delaware corporation (“Company”) and the initial stockholders listed on the signature pages hereto (collectively, the
 “Initial Stockholders”) and AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC, a New York limited liability trust company
(“Escrow Agent”).


 


WHEREAS,
the Company has entered into an Underwriting Agreement, dated as of October 4, 2021 (“Underwriting Agreement”),
with A.G.P./Alliance Global Partners, as representative of the underwriters 
( the “Underwriters”), pursuant to which, among other matters, the Underwriters have agreed to purchase 15,000,000
units (“Units”) of the Company, plus an additional 2,250,000
Units if the Underwriters exercise their over-allotment option in full. Each Unit consists of one share of common stock of the Company,
par value $0.0001 per share (the “Common Stock”), and one warrant, with each warrant entitling the holder thereof to purchase
three-fourths of one share of the Common Stock at an exercise price of $11.50 per whole share, all as more fully described in the Company’s
final Prospectus, dated October 4, 2021 (“Prospectus”), comprising part of the Company’s Registration Statement
on Form S-1 (File No. 333-256816) under the Securities Act of 1933, as amended (“Registration Statement”), declared
effective on October 4, 2021 (“Effective Date”).


 


WHEREAS, the Initial Stockholders
have agreed as a condition of the sale of the Units to deposit their “founder shares” (as defined in the Prospectus), as set
forth opposite their respective names on Exhibit A attached hereto (collectively “Escrow Shares”), in escrow as
hereinafter provided.


 


WHEREAS, the Company and the
Initial Stockholders desire that the Escrow Agent accept the Escrow Shares, in escrow, to be held and disbursed as hereinafter provided.


 


IT IS AGREED:


 


1. Appointment of Escrow
Agent. The Company and the Initial Stockholders hereby appoint the Escrow Agent to act in accordance with and subject to the terms
of this Agreement and the Escrow Agent hereby accepts such appointment and agrees to act in accordance with and subject to such terms.


 


2. Deposit of Escrow Shares.
On or prior to the date hereof, each of the Initial Stockholders delivered to the Escrow Agent certificates representing such Initial
Stockholder’s respective Escrow Shares, together with applicable share powers, to be held and disbursed subject to the terms and
conditions of this Agreement. Each of the Initial Stockholders acknowledges that the certificate representing such Initial Stockholder’s
Escrow Shares is legended to reflect the deposit of such Escrow Shares under this Agreement.


 


3. Disbursement of the
Escrow Shares.


 


3.1 The Escrow Agent shall hold
the Escrow Shares during the period (the “Escrow Period”) commencing on the date hereof ending on the earlier of (i) one
year after the date of the consummation of the Company’s initial business combination (as described in the Registration Statement,
hereinafter a “Business Combination”) and (ii) the date on which the closing price of the Common Stock equals or exceeds
$12.00 per share (as adjusted for stock splits, stock dividends, stock capitalizations, reorganizations and recapitalizations) for any
20 trading days within any 30-trading day period commencing at least 150 following the closing of the Company’s initial Business
Combination. The Company shall promptly provide notice of the consummation of a Business Combination to the Escrow Agent. Upon completion
of the Escrow Period, the Escrow Agent shall disburse such amount of each Initial Stockholder’s Escrow Shares (and any applicable
share power) to such Initial Stockholder; provided, however, that if the Escrow Agent is notified by the Company pursuant to Section 6.7
hereof that the Company is being liquidated at any time during the Escrow Period, then the Escrow Agent shall promptly destroy the certificates
representing the Escrow Shares; provided further, however, that if, after the Company consummates an initial Business Combination, the
Company (or the surviving entity) subsequently consummates a liquidation, merger, stock exchange or other similar transaction which results
in all of the stockholders of such entity having the right to exchange their shares of Common Stock for cash, securities or other property,
then the Escrow Agent will, upon receipt of a notice executed by the Chairman of the Board, Chief Executive Officer or other authorized
officer of the Company, in form reasonably acceptable to the Escrow Agent, certifying that such transaction is then being consummated
or such conditions have been achieved, as applicable, release the Escrow Shares to the Initial Stockholders. The Escrow Agent shall have
no further duties hereunder after the disbursement or destruction of the Escrow Shares in accordance with this Section 3.1.


 






     


     


    

 


3.2
Notwithstanding Section 3.1, if the Underwriters do not exercise their over-allotment option to purchase an additional 2,250,000
Units of the Company in full within 45 days of the date of the Prospectus (as described in the Underwriting Agreement), the Initial Stockholders
agree that the Escrow Agent shall return to the Company for cancellation, at no cost, the number of Escrow Shares held by the Initial
Stockholders listed on Exhibit B determined by multiplying (a) the product of (i) 562,500
multiplied by (ii) a fraction, (x) the numerator of which is the number of Escrow Shares held by each such holder, and (y) the
denominator of which is the total number of Escrow Shares, by (b) a fraction, (i) the numerator of which is 2,250,000
minus the number of Units purchased by the Underwriters upon the exercise of their over-allotment option, and (ii) the denominator
of which is 2,250,000, without taking into account the transfer of an
aggregate amount of 350,000 representative shares (400,000 shares if the over-allotment option is exercised in full) from A.G.P./Alliance
Global Partners to the sponsor that took place pursuant to the side letters dates as of September 27, 2021 and September 30,
2021. The Company shall promptly provide notice to the Escrow Agent of the expiration or termination of the Underwriters’ over-allotment
option and the number of Units, if any, purchased by the Underwriters in connection with their exercise thereof.


 


4. Rights of Initial Stockholders
in Escrow Shares.


 


4.1 Voting Rights as a Stockholder.
Subject to the terms of the Insider Letters (as defined below) described in Section 4.4 hereof and except as herein provided, the
Initial Stockholders shall retain all of their rights as stockholders of the Company during the Escrow Period, including, without limitation,
the right to vote such shares.


 


4.2 Dividends and Other Distributions
in Respect of the Escrow Shares. During the Escrow Period, all dividends payable in cash with respect to the Escrow Shares shall be
paid to the Initial Stockholders, but all dividends payable in stock or other non-cash property (“Non-Cash Dividends”) shall
be delivered to the Escrow Agent to hold in accordance with the terms hereof. As used herein, the term “Escrow Shares” shall
be deemed to include the Non-Cash Dividends distributed thereon, if any.


 


4.3
Restrictions on Transfer. During the Escrow Period, the only permitted transfers of the Escrow Shares will be (1) to any persons
or entities (including their affiliates and stockholders) participating in the private placement of the “private warrants”
(as defined in the Prospectus), and officers, directors, stockholders, employees and members of the Initial Stockholders and their respective
affiliates, (2) amongst the Initial Stockholders (including, to the extent the Initial Stockholders are entities, to such entity’s
members, partners, stockholders or other equity holders) or to the Company’s officers, directors and employees, (3) if any
Initial Stockholder is an entity, as a distribution to its partners, stockholders, or members upon its liquidation, (4) by bona fide
gift to a member of the Initial Stockholder’s (or its permitted transferee’s) immediate family or to a trust, the beneficiary
of which is the Initial Stockholder (or its permitted transferee) or a member of the Initial Stockholder’s (or its permitted transferee’s)
immediate family, for estate planning purposes, (5) by virtue of the laws of descent and distribution upon death, (6) pursuant
to a qualified domestic relations order, (7) by certain pledges to secure obligations incurred in connection with purchases of the
Company’s securities, (8) by private sales at prices no greater than the price at which the founder shares were originally
purchased or (9) for the cancellation of up to 562,500 shares
of Common Stock subject to forfeiture to the extent that the Underwriters’ over-allotment is not exercised in full or in part or
in connection with the consummation of the Company’s initial business combination, in each case (except for clause 9 or with the
Company’s prior consent) where such permitted transferee agrees to the terms of this Agreement and the Insider Letter (as defined
below).


 


4.4 Insider Letters.
Each of the Initial Stockholders has executed a letter agreement with the Representatives and the Company, dated as indicated on Exhibit C
hereto, and the form of which is filed as an exhibit to the Registration Statement (“Insider Letter”), respecting the rights
and obligations of such Initial Stockholder in certain events, including but not limited to the liquidation of the Company.


 






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5. Concerning the Escrow
Agent.


 


5.1 Good Faith Reliance.
The Escrow Agent shall not be liable for any action taken or omitted by it in good faith and in the exercise of its own best judgment,
and may rely conclusively and shall be protected in acting upon any order, notice, demand, certificate, opinion or advice of counsel (including
counsel chosen by the Escrow Agent), statement, instrument, report or other paper or document (not only as to its due execution and the
validity and effectiveness of its provisions, but also as to the truth and acceptability of any information therein contained) which is
believed by the Escrow Agent to be genuine and to be signed or presented by the proper person or persons. The Escrow Agent shall not be
bound by any notice or demand, or any waiver, modification, termination or rescission of this Agreement unless evidenced by a writing
delivered to the Escrow Agent signed by the proper party or parties and, if the duties or rights of the Escrow Agent are affected, unless
it shall have given its prior written consent thereto.


 


5.2 Indemnification.
The Escrow Agent shall be indemnified and held harmless by the Company from and against any expenses, including reasonable counsel fees
and disbursements, or loss suffered by the Escrow Agent in connection with any action, suit or other proceeding involving any claim which
in any way, directly or indirectly, arises out of or relates to this Agreement, the services of the Escrow Agent hereunder, or the Escrow
Shares held by it hereunder, other than expenses or losses arising from the gross negligence or willful misconduct of the Escrow Agent
(as determined by a court of competent jurisdiction in a final and non-appealable decision). Promptly after the receipt by the Escrow
Agent of notice of any demand or claim or the commencement of any action, suit or proceeding, the Escrow Agent shall notify the other
parties hereto in writing. In the event of the receipt of such notice, the Escrow Agent, in its sole discretion, may commence an action
in the nature of interpleader in an appropriate court to determine ownership or disposition of the Escrow Shares or it may deposit the
Escrow Shares with the clerk of any appropriate court or it may retain the Escrow Shares pending receipt of a final, non-appealable order
of a court having jurisdiction over all of the parties hereto directing to whom and under what circumstances the Escrow Shares are to
be disbursed and delivered. The provisions of this Section 5.2 shall survive in the event the Escrow Agent resigns or is discharged
pursuant to Sections 5.5 or 5.6 below.


 


5.3 Compensation. The
Escrow Agent shall be entitled to reasonable compensation from the Company for all services rendered by it hereunder. The Escrow Agent
shall also be entitled to reimbursement from the Company for all expenses paid or incurred by it in the administration of its duties hereunder
including, but not limited to, all counsel, advisors’ and agents’ fees and disbursements and all taxes or other governmental
charges.


 


5.4 Further Assurances.
From time to time on and after the date hereof, the Company and the Initial Stockholders shall deliver or cause to be delivered to the
Escrow Agent such further documents and instruments and shall do or cause to be done such further acts as the Escrow Agent shall reasonably
request to carry out more effectively the provisions and purposes of this Agreement, to evidence compliance herewith or to assure itself
that it is protected in acting hereunder.


 


5.5 Resignation. The
Escrow Agent may resign at any time and be discharged from its duties as escrow agent hereunder by its giving the other parties hereto
written notice and such resignation shall become effective as hereinafter provided. Such resignation shall become effective at such time
that the Escrow Agent shall turn over to a successor escrow agent appointed by the Company, the Escrow Shares held hereunder. If no new
escrow agent is so appointed within the 90 day period following the giving of such notice of resignation, the Escrow Agent may deposit
the Escrow Shares with any court it reasonably deems appropriate.


 


5.6 Discharge of Escrow Agent.
The Escrow Agent shall resign and be discharged from its duties as escrow agent hereunder if so requested in writing at any time by the
other parties hereto, jointly, provided, however, that such resignation shall become effective only upon acceptance of appointment by
a successor escrow agent as provided in Section 5.5.


 


5.7 Liability. Notwithstanding
anything herein to the contrary, the Escrow Agent shall not be relieved from liability hereunder for its own gross negligence or its own
willful misconduct (as determined by a court of competent jurisdiction in a final and non-appealable decision).


 






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5.8 Waiver. The Escrow
Agent hereby waives any right of set-off or any other right, title, interest or claim of any kind (“Claim”) in, or to any
distribution of, the Trust Account (as defined in that certain Investment Management Trust Agreement, dated as of the date hereof, by
and between the Company and the Escrow Agent as trustee thereunder) and hereby agrees not to seek recourse, reimbursement, payment or
satisfaction for any Claim against the Trust Account for any reason whatsoever.


 


6. Miscellaneous.


 


6.1 Governing Law. This
Agreement shall for all purposes be deemed to be made under and shall be construed in accordance with the laws of the State of New York,
without giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction.


 


6.2 Third Party Beneficiaries.
Each of the Initial Stockholders hereby acknowledges that each of the Representatives is a third party beneficiary of this Agreement and
this Agreement may not be modified or changed without the prior written consent of the Representatives.


 


6.3 Entire Agreement.
This Agreement contains the entire agreement of the parties hereto with respect to the subject matter hereof and, except as expressly
provided herein, may not be changed or modified except by an instrument in writing signed by the party to the charged.


 


6.4 Headings. The headings
contained in this Agreement are for reference purposes only and shall not affect in any way the meaning or interpretation thereof.


 


6.5 Binding Effect. This
Agreement shall be binding upon and inure to the benefit of the respective parties hereto and their legal representatives, successors
and assigns; provided, that the Escrow Agent may not assign this Agreement without the prior written consent of the Company.


 


6.6 Notices. Any notice
or other communication required or which may be given hereunder shall be in writing and either be delivered personally or be mailed, certified
or registered mail, or by private national courier service, return receipt requested, postage prepaid, or by e-mail as described below,
and shall be deemed given when so delivered personally or by e-mail or, if mailed or sent by private national courier service, two days
after the date of mailing or the date of delivery to the private national courier service, as follows:


 


If to the Company or a Stockholder,
to: 


 


Mount Rainier Acquisition Corp.


256 W. 38th Street, 15th Floor


New York, NY 10018


Attn:
Matthew Kearney


 


Copy (which copy
shall not constitute notice) to:


 


Loeb & Loeb LLP

345 Park Avenue

New York, New York 10154


Attn: Mitchell Nussbaum, Esq.

Email:


 


and if to the Escrow Agent, to:


 


American Stock Transfer &
Trust Company, LLC


201 15th Avenue


Brooklyn, NY 11219


Attn: Reorg Department


 






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A copy (which copy shall not constitute
notice) sent hereunder shall be sent to:


 


A.G.P./Alliance
Global Partners

590 Madison Avenue, 28th Floor


New
York, NY 10022

Attn: Thomas J. Higgins

Email:


 


and:  Manatt,
Phelps & Phillips LLP


695 Town Center Drive, 14th Floor


Costa Mesa, California 92626


Attn: Thomas J. Poletti


Email:


 


The parties hereto consent
to the delivery of notices or other communication by electronic transmission at the e-mail address set forth below the respective party’s
name in Section 6.6 hereto. To the extent that any notice given by means of electronic transmission is returned or undeliverable
for any reason, the foregoing consent shall be deemed to have been revoked until a new or corrected e-mail address has been provided,
and such attempted electronic notice shall be ineffective and deemed to not have been given. Each party agrees to promptly notify the
other parties of any change in its e-mail address, and that failure to do so shall not affect the foregoing. The parties may change the
persons and addresses to which the notices or other communications are to be sent by giving written notice to any such change in the manner
provided herein for giving notice.


 


6.7 Liquidation of the Company.
The Company shall give the Escrow Agent written notification of the liquidation and dissolution of the Company in the event that the Company
fails to consummate a Business Combination within the time period specified in the Prospectus.


 


[Signature Page Follows]


 






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WITNESS the execution of this
Agreement as of the date first above written.


 


	 	MOUNT RAINIER ACQUISITION CORP.
	 	 
	 	 
	 	By:	 /s/ Matthew Kearney
	 	 	Name: Matthew Kearney
	 	 	Title: Chief Executive Officer
	 	 	 
	 	 	 
	 	AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC
	 	 
	 	 
	 	By:	/s/ Michael A. Nespoli
	 	 	Name: 	Michael A. Nespoli
	 	 	Title:	 Vice President



 


 


	 	INITIAL STOCKHOLDERS:
	 	 
	 	
    DC RAINIER SPV LLC

    By: Dominion Capital LLC, its Manager

    By: Dominion Capital Holdings LLC, its Manager

	 	 	 
	 	 	 
	 	 	By: 	/s/ Mikhail Gurevich
	 	 	Name:	 Mikhail Gurevich
	 	 	Title:	 Managing Member
	 	 	 
	 	 	 
	 	 	A.G.P./Alliance
    Global Partners
	 	 	By:
	 	 	 
	 	 	By:	/s/ Thomas J. Higgins
	 	 	Name:	 Thomas J. Higgins
	 	 	Title:	Managing Director 



 


	 	 	/s/ Matthew Kearney
	 	 	Matthew Kearney 
	 	 	 
	 	 	/s/ Young Cho
	 	 	
    Young Cho

	 	 	 
	 	 	/s/ Otto Risbakk
	 	 	Otto Risbakk
	 	 	 
	 	 	/s/ Christina Favilla
	 	 	Christina Favilla
	 	 	 
	 	 	/s/ Jeffery Bistrong
	 	 	Jeffery Bistrong



 


[Signature Page to Escrow Agreement]


 






     


     


    


 


EXHIBIT A


 


Initial Stockholders; Escrow Shares


 


	Name of Initial Stockholders*	 	Number 
 of Shares	 	 	Date of 
 Insider Letter
	DC Rainier SPV LLC	 	 	2,901,919	 	 	October 4, 2021
	 	 	 	 	 	 	 
	A.G.P./Alliance Global Partners	 	 	915,000	 	 	October 4, 2021
	 	 	 	 	 	 	 
	Matthew Kearney	 	 	336,985	 	 	October 4, 2021
	 	 	 	 	 	 	 
	Young Cho	 	 	101,095	 	 	October 4, 2021
	 	 	 	 	 	 	 
	Otto Risbakk	 	 	19,167	 	 	October 4, 2021
	 	 	 	 	 	 	 
	Christina Favilla	 	 	19,167	 	 	October 4, 2021
	 	 	 	 	 	 	 
	Jeffery Bistrong	 	 	19,167	 	 	October 4, 2021





 






     


     


    

 


EXHIBIT B


 


Escrow Shares subject to cancellation


 


	DC Rainier SPV LLC	 	 	332,859	 
	A.G.P./Alliance Global Partners	 	 	165,000	 
	Matthew Kearney	 	 	43,955	 
	Young Cho	 	 	13,186	 
	Otto Risbakk	 	 	2,500	 
	Christina Favilla	 	 	2,500	 
	Jeffery Bistrong	 	 	2,500	 




 






     


     


    

 


EXHIBIT C


 


Insider Letter


 


Insider
Letter by and between the Company, DC Rainier SPV LLC, A.G.P./Alliance
Global Partners, Matthew Kearney, Young Cho, Otto Risbakk, Christina Favilla,
and Jeffery Bistrong, dated October 4, 2021.