Rod Steiger stars as Christopher Gill, a serial killer who is fixated on his late mother, an actress, and preys on middle-aged women who remind him of her. He adopts various disguises to put his victims at ease before choking them. The murderer strikes up an adversarial relationship with Morris Brummel (Segal), the detective investigating the murders, via the telephone.
The film features a B-plot concerning Brummel's own mother (Eileen Heckart), who wants her son to be more like his brother (and settle down). Brummell's love interest in the film, Kate Palmer (Lee Remick), surprisingly manages to win over his mother, but is later targeted by the strangler...
