Though Lum’s idea for his sale of damaged can goods was a success, grandpap was the only person who could guess the contents, and win his merchandise for free. After a rift between himself and Lum and Abner, grandpap began coaching others on how to tell what was inside the unlabeled cans. The novelty is wearing off, and Lum discusses the matter with Abner. Even with the sale coming to an end, curiosity burns as Lum and Abner remain mystified at how grandpap could tell what was inside the cans.
Abner manages to stumble on the secret, but can it be such a simple answer? Cedric is on hand to help verify that it could be possible.
Will Lum and Abner be able to spring a trap for grandpap, and get him to make a wrong guess? Will their careful plan manage to backfire on them, and be left with more damaged cans than they can hope to get rid of?