Madhouse (also known as The Revenge of Dr. Death) is a 1974 horror film directed by Jim Clark for Amicus Productions in association with American International Pictures. The film, which is a British-American co-production, stars Vincent Price, Natasha Pyne, Peter Cushing, Robert Quarry, Adrienne Corri, and Linda Hayden. The film was based on the 1969 novel Devilday by Angus Hall.

Plot

Paul Toombes is a successful horror actor whose trademark role is Dr. Death, a skull-faced serial killer. During a party in Hollywood marking his fifth Dr. Death film, Paul announces his engagement to Ellen Mason, who gives him an engraved watch as an engagement gift. However, adult film producer Oliver Quayle reveals to Paul that Ellen previously performed in his movies and had also slept with him. Distraught at Paul's angry reaction, Ellen returns to her room, where a masked man in a Dr. Death costume approaches her with a knife. An apologetic Paul enters the room shortly after, only for her severed head to fall from her shoulders when he touches her. Although he is acquitted, Paul isn't sure whether he was the killer. His career is destroyed as he spends several years in a mental hospital.