After taking Grandmama's sleeping potion to combat his insomnia, Gomez begins unknowingly sleepwalking at night. Morticia sees him walk out in the middle of the night and suspects he's a cat burglar. She follows him, and Uncle Fester sees her walk out in the middle of the night and suspects she's a cat burglar. They set traps for each other, and when the real cat burglar breaks in, he sets them off.