Nightmare Castle

Stephen Arrowsmith (Paul Muller), a scientist, has his home laboratory in the castle owned by his wife Muriel (Barbara Steele). Arrowsmith finds her having sex with a gardener, David. He attacks and disfigures David with a hot poker and burns Muriel\\\'s face with acid. Before electrocuting both of them, Arrowsmith is told that he is not Muriel\\\'s heir, but that the estate has been willed to her stepsister, Jenny (also Steele), who is mentally unstable. Arrowsmith removes David\\\'s and Muriel\\\'s hearts and hides them in an urn. He uses their blood to rejuvenate his aged servant, Solange (Helga Liné).

Sometime later, Arrowsmith marries Jenny, planning to have the rejuvenated Solange drive her insane. Jenny begins having nightmares, which include the sound of beating hearts and Muriel\\\'s voice urging her to murder Stephen. Arrowsmith brings Dr. Derek Joyce (Marino Masé) to the castle to treat Jenny, who becomes convinced that supernatural forces are at work. Joyce discovers the hidden hearts of Muriel and David. The murdered dead return as ghosts. Muriel burns Stephen alive while David reduces Solange to a skeleton by draining her blood. Dr. Joyce then burns the disembodied hearts and leaves the castle with Jenny. 

A sadistic count tortures and murders his unfaithful wife and her lover, then removes their hearts from their bodies. Years later, the count remarries and the new wife experiences nightmares and hauntings. The ghosts of the slain return to exact their bloody revenge, until their hearts are destroyed.