Eminent British surgeon Sir John Rowan falls asleep in his apartment before he is to attend a party with Lynn Nolan, his fashion model fiancée. At the party, Lynn introduces him to photographer Mike Orme, who persuades Lynn to pose for him. There is a jealous fight between the two men, and a floodlight topples on Lynn and disfigures her face. To overcome Lynn's despair, Sir John attempts to restore her beauty by injecting into her face a pituitary extract and operating with a laser beam. Using a gland stolen from a hospital corpse, Sir John surgically recaptures Lynn's loveliness and takes her on a holiday; but the remedy proves to be short-lived, and Lynn's face again becomes a hideous mask. In the desperate hope that live tissues will be more permanent, Sir John decapitates a Soho prostitute and operates again. This remedy also proves to be temporary, and Sir John realizes that he will have to continue killing in order to preserve Lynn's appearance. Sir John's associate, Dr. Stephen Harris, perceives what Sir John has been doing to restore Lynn's beauty. Unaware that Lynn has encouraged Sir John to commit the murders, Stephen and Lynn's sister, Val, rush to warn her. Meanwhile, Sir John and Lynn are being harassed in their country home by hoodlum friends of their lastest victim, a young woman named Terry. After killing Terry's husband, the now-deranged Lynn activates the laser beam and demands that Sir John operate once more. The laser goes out of control, however, and kills the hoodlums as well as Sir John, Lynn, and the newly-arrived Stephen and Val. The house, littered with corpses, burns to the ground. Sir John arrives at the party where Lynn introduces him to her photographer friend.