Dennis' school is putting on a play which Mr. Wilson ends up being in (not by choice) because him and Tommy (who is also in the play) get handcuffed together before the play starts.

Mr. Wilson buys a treasure chest at an auction thinking that it has buried treasure in it. Mr. Wilson later discovers a treasure map drawn by Dennis. Although Mr. Wilson thinks the map is authentic so he plans to take a trip to the island and dig for the treasure.