A mouse ventures out of his hole at a quarter after midnight. His tail gets caught in a mousetrap, but he escapes unharmed. It looks as if the coast is clear. He waves forth the other mice. Out they come, young and old, male and female, all ready to play music and have fun. But though the house is safe inside, outside lurks a very hungry cat. He manages to break inside and eat the cuckoo bird out of a clock for an appetizer. For his main course, he wants a mouse. But he'll have to deal with the entire mouse community, and their resourceful use of musical instruments as weapons, before he'll get one.