“Now I must play the final scene. The death of Dr. Death.”

Paul Toombes (Vincent Price) is a successful horror movie actor. His Dr. Death character is his trademark. Dr. Death is a skull-faced sadist. While hosting a party to celebrate both his fifth Dr. Death film and his engagement to Ellen Mason (Julie Crosthwait), adult film producer Oliver Quayle (Robert Quarry) tells Toombes that Ellen once worked for him in X rated movies. Toombes gets angry at Ellen. Humiliated Ellen runs from the party. In her room someone dressed as Dr. Death kills her. When Toombes later enters the room he finds her dead, her severed head falls to the floor. Toombes’ is acquitted of the crime, however, his career is over and the trauma sends him to a mental institution for years wondering if perhaps he was responsible for her death.

After his release from the mental institution Toombes visits his old friend Herbert Flay (Peter Cushing). Flay was the screenwriter who created the Dr. Death character. Flay says that he and Quayle have partnered to produce a Dr. Death television series and they want Toombes to recreate his character. While staying at Flay’s home Toombes finds Faye Carstairs (Adrienne Corri) his one time co-star and Flay’s wife. She lives in the basement having been driven mad by a disfiguring car accident. She plays with spiders.

A young woman, Elizabeth Peters (Linda Hayden), from the cruise ship Toombes took to England has followed him to Flay's house. While on the ship she had stolen his watch. She approaches someone she believes is Toombes dressed as Dr. Death. She is killed with a pitchfork. Scotland Yard suspects Toombes of the murder.

When Toombes’ new co-star is found hanged by her own hair Scotland Yard once again suspects Toombes. The foster parents of Elizabeth try to extort money from Toombes. They also end up dead. On the set, the director is crushed by a prop bed. A trap that appears to have been intended for Toombes.

While on his way to an interview Toombes is chased through the studio by the masked man. Julia Wilson (Natasha Pyne), Quayle's public relations chief, believes she has discovered why people are being killed and Toombes is being stalked. She is killed. Toombes discovers her body and suffers a nervous breakdown. He takes her body to the set. He locks himself inside and sets it on fire.

“Madhouse” was released in 1974 and was directed by Jim Clark. This is the final movie that sees the collaboration between Vincent Price and AIP. It also represents the end of the horror genre in its classic form. In 1974 we see the rise of a new horror movie form, the slasher movie. The film didn’t do as well at the box office as expected. There also were mixed reviews on it. It’s too bad. I would have preferred to see classic horror movies go out with a bang instead of a whimper.

The film clips shown at various times in the movie are clips from movies that Price had done in the past. Some showed performances by Basil Rathbone, and Boris Karloff. “The Pit and the Pendulum” and “The Fall of the House of Usher” are also prominent.