Dr Phibes (Vincent Price), horribly disfigured from the car crash which killed his wife, decides to take revenge on the surgeons who failed to save her. He and his mute assistant (Virginia North) set about killing each surgeon using one of the biblical Seven Curses of the Pharoah.

The newly regenerated Doctor (Tom Baker), assisted by Sarah, Harry and the Brigadier, has to track down the theft of the components for a powerful new laser gun, and the death of a prominent politician. Sarah investigates the mysterious Think Tank, where it becomes clear that robot K-1 is being misused by its political extremist masters and the Doctor has to prevent the robot from being used to start an atomic war. Tom Baker's first story as the Doctor.