Sir John Rowan (Peter Cushing), a prominent surgeon, meets and falls in love with twenty-something fashion model Lynn Nolan (Sue Lloyd). Despite the difference in their lives and ages -- he a respected medical professional in his fifties, she the toast of Carnaby Street, running in a circle of poseurs, pretenders, and people famous for being famous -- he is madly in love with her, "madly" being the operant word here. His jealousy leads to a fight at a photo shoot, which results in Lynn's disfigurement. Driven by combination of guilt and love, Rowan violates medical protocols with a procedure, involving the transplant of tissue and pituitary secretions from a female cadaver -- that restores Lynn's beauty, and rescues their romance. But it turns out that his success is only temporary, and soon her face is deteriorating, requiring another operation -- only this time, without a cadaver available, Rowan must secure a "donor" himself. He chooses a prostitute, whom he kills and decapitates, rationalizing her death to himself rather unconvincingly. Oblivious to the terrible cost of her surgery, Lynn is relieved to see her beauty restored. But Rowan is unhinged by the murder he has committed, and fearful that the police will eventually trace it back to him. And his colleague Dr. Steve Harris (Noel Traverthen), who is engaged to Lynn's sister (Kate O'Mara), is becoming suspicious over Rowan's furtiveness about his achievement -- if his success with Lynn is half what it seems to be, why does he seem to be in no hurry to publish an account of his procedure and its results? The couple finally decide to go off on holiday to a seaside cottage and forget their worries -- until her face starts to show signs of deterioration. Now they need a new "donor," and first attempt to entice a young girl (Wendy Varnals) they meet at the beach back to their home. But complications ensue, first because Rowan doesn't want to commit another murder, and then because this girl isn't what she seems, and disappears -- soon the doctor has to look for yet another victim, whom he find on a train. And then their home is invaded by the gang of hippie/thieves led there by the girl. And little does anyone, including Rowan, realize that Lynn has gradually gone even crazier than her doctor/fiance.