 As a boy, Mark Lewis was subjected to bizarre experiments by his scientist-father, who wanted to study and record the effects of fear on the nervous system. Now grown up, both of his parents dead, Mark works by day as a focus-puller for a London movie studio. He moonlights by taking girlie pictures above a news agent s shop. But Mark has also taken up a horrifying hobby: He murders women while using a movie camera to film their dying expressions of terror. One evening, Mark meets and befriends Helen Stephens, a young woman who rents one of the rooms in his house. Does Helen represent some kind of possible redemption for Mark - or is she unknowingly running the risk of becoming one of his victims?