When a grant of real property purports to be an absolute conveyance but is intended to be defeasible on the performance of certain conditions, the grant is not defeated or affected as against subsequent purchasers or encumbrancers in good faith and for value, unless an instrument of defeasance duly executed and acknowledged is recorded in the office of the recorder of the county where the property is situated.
N.D.C.C. § 35-03-09