A contract still exists for a treasure hunt, made between Napier and Robert Logan of Restalrig. Napier was to search Fast Castle for treasure allegedly hidden there, wherein it is stated that Napier should "do his utmost diligence to search and seek out, and by all craft and ingine to find out the same, or make it sure that no such thing has been there." This contract was never fulfilled by Napier, and no gold was found when the Edinburgh Archaeological Field society excavated the castle in between 1971 and 1986.