Lum and Abner after having discovered the secret of how Grandpappy Spiers could tell the contents of their unlabelled cans ruined the whole thing by switching the cans around to fool Grandpap. It fooled him alright but not half as much as it fooled Lum and Abner and on top of that a truck from the wholesale arrived and dropped off a load of damaged cans that Lum had ordered when their grab bag sale was doing good...