Anna (Angharad Rees) is unknowingly the daughter of Jack the Ripper, and as a child witnessed the death of her mother at her evil father's hands. Some fifteen years later the young woman has become terribly troubled by something and enters strange violent trances. Her case is assigned to psychiatrist Dr Pritchard (Eric Porter) who believes he can cure Anna, but as he uncovers her violent memories and her murderous behaviour is unleashed he starts to fear that the case is spiralling out of control.