The film begins when a stranger arrives in town. He takes quickly to his former mistress, Denise, who is happily married to John, and has an affair with his identiske twin brother Peter. They plan together to drive John crazy. After unsuccessful attempts to blackmail the couple receive the stranger, Gert, to help them with their evil plan.

The film begins when a stranger arrives in town. He takes quickly to his former mistress, Denise, who is happily married to John, and has an affair with his identiske twin brother Peter. They plan together to drive John crazy. After unsuccessful attempts to blackmail the couple receive the stranger, Gert, to help them with their evil plan.