Hammer's trademark gothic style permeates this suspenseful thriller, considered one of the acclaimed British studio's superior efforts, thanks largely to the directorial skills of Peter Sasdy. This marked his last feature-length collaboration with the studio until 1980, when he returned to direct installments of the Hammer House of Horror television series. In the film's prologue, young Anna, the infant daughter of the notorious Jack the Ripper, witnesses her mother's brutal murder at her father's hands. Years later, the lovely teenage Anna (Angharad Rees) is plagued by traumatic memories of the incident and repressed impulses in which love and death are inextricably linked. These impulses finally turn homicidal when her emotions are stirred, spelling doom for anyone who arouses her. Anna's case is handled by the repressed psychoanalyst, Dr. Pritchard (Eric Porter), whose growing physical attraction to the girl could result in far worse than a mere breach of professional ethics. Sasdy weaves the psychological elements through the story with finesse, paralleling the sexual tension between the doctor and his patient with the mounting horror of the inevitable outcome.
by Cavett Binion synopsis