A dimwitted cat believes he can catch mice just like in the story of the pied piper of Hamlin. He goes to his attic where a tough Brooklyn-voiced mouse proceeds to destroy Cat's horn. So without the Piper premise, we go into a straight series of gags where the cat sets traps that are instantly overcome and a huge mallet is wielded by mouse on cat's cranium multiple times. At one point shadows of the theatre audience talk to the characters, and later they speak out to them. A running gag where the cat keeps falling through a trapway is part of the conclusion.