Several teenage boys in Galesburg, Illinois are murdered, each apparently by a different killer. Local policeman John Brady (Murphy) investigates. The victims are sons of men who previously collaborated with John to investigate the unethical experiments of Galesburg University professor Dr. Le Sange (Dignam), who reportedly died years previously but still gives lectures via old films. Le Sange's research is being continued by Gwen Parkinson (Lewis). John, whose late wife had worked for Le Sange, becomes convinced that Le Sange is still alive and is waging a vendetta against those who wronged him. Unbeknownst to John, Gwen has enlisted his son Pete (Shor) as a research subject. Gwen's "experiments" involve mind control, turning the subject into a programmed killer.