Country singers are headed to Nashville. Their car breaks down and they stop overnight at an abandoned house, which turns out to be haunted. A ring of international spies (Lon Chaney, Jr., Basil Rathbone and John Carradine) who live in the house are seeking a top-secret formula for rocket fuel. While it is never revealed for whom they are spying, they carry out their activities under the cover of a supposed haunted house, which comes complete with a gorilla in the basement.