FOURTH AMENDMENT TO PROMISSORY NOTE (SIX-MONTH)

THIS FOURTH AMENDMENT TO PROMISSORY NOTE (SIX-MONTH) (the “Fourth Amendment”) is made and entered into as of the 26^st day of July 2013 by Discovery Energy Corp. a Nevada corporation f/k/a “Santos Resource Corp.” (herein called “Maker”), and Liberty Petroleum Corporation, an Arizona corporation (herein called “Payee”).

RECITALS:

WHEREAS, Maker executed in favor of Payee a promissory note (the “Note”) dated October 26, 2012; and

WHEREAS, the parties amended the Note according to a First Amendment to Promissory Note (Six-Month) dated the 7^th day of March 2013 (the “First Amendment”); and

WHEREAS, pursuant to the First Amendment, Maker made a partial principal payment of $100,000 and thereby reduced the principal amount due Payee to $400,000; and

WHEREAS, the parties amended the Note according to a Second Amendment to Promissory Note (Six-Month) dated the 12^th day of June 2013 (the “Second Amendment”); and

WHEREAS, pursuant to the Second Amendment, Maker made a partial principal payment of $25,000 and thereby reduced the principal amount due Payee to $375,000; and

WHEREAS, the parties amended the Note according to a Third Amendment to Promissory Note (Six-Month) dated the 1^st day of July 2013 (the “Third Amendment”) (for purposes of the remainder of this Fourth Amendment, the term "Note" shall mean the Note as heretofore amended by said First Amendment, Second Amendment and Third Amendment); and

WHEREAS pursuant to the Third Amendment, all remaining principal amount is otherwise to become due and payable on the 26^th day of July 2013; and

WHEREAS, Maker wishes to receive an extension of the Note, and the Payee is willing to so extend the Note; and

WHEREAS, the parties hereto desire to further amend the Note upon the terms, provisions and conditions set forth herein;

AGREEMENT:

NOW, THEREFORE, in consideration of the mutual promises herein, the parties hereto hereby agree as follows (all undefined, capitalized terms used herein shall have the meanings assigned to such term in the Note):

1. Amendment to the Note. In consideration of the mutual promises herein, the Note shall be amended so that all outstanding principal of this Note ($375,000) and interest that has heretofore accrued or hereafter accrues, on such Note shall become due and payable in a single balloon payment on the earlier of:

a. One business day following the completion ofMaker’s private placement financing to be initiated on or before July 31, 2013; or

b. The 26^th day of August 2013, notwithstanding anything else provided for in the Note.

2. Miscellaneous. Except as otherwise expressly provided herein, the Note is not amended, modified or affected by this Fourth Amendment. Except as expressly set forth herein, all of the terms, conditions, covenants, representations, warranties and all other provisions of the Note are herein ratified and confirmed and shall remain in full force and effect. On and after the date on which this Fourth Amendment becomes effective, the terms, “Note,” “herein,” “hereunder” and terms of like import, when used herein or in the Note shall, except where the context otherwise requires, refer to the Note, as amended by the First Amendment and this Third Amendment. This Fourth Amendment may be executed in counterparts, and it shall not be necessary that the signatures of all parties hereto be contained on any one counterpart hereof, each counterpart shall be deemed an original but all of which together shall constitute one and the same instrument. This Fourth Amendment shall be deemed fully executed and delivered when duly signed by the signatories and delivered via “PDF” or facsimile transmission.

IN WHITNESS WHEREOF, the undersigned have set their hands hereunto as the first date written above.

DISCOVERY ENERGY CORP.,		LIBERTY PETROLEUM CORPORATION,
a Nevada corporation		an Arizona corporations
By:	/s/ Keith J. McKenzie	By:	/s/ Lane Franks
	Keith J. McKenzie,		Lane Franks,
	Chief Executive Officer		President