A teenage girl marries an older, wealthy French Marquis, whom she does not love. When he takes her to his castle she learns that he enjoys sadistic pornography and takes pleasure in her embarrassment. She is a talented pianist and a young man, a blind piano tuner, hears her music and falls in love with her. The woman's husband tells her that he must leave on a business trip and forbids her to enter one particular room while he is away. She enters the room in his absence and discovers the full extent of his perverse and murderous tendencies when she discovers the bodies of his previous wives.