At a secluded mental institution, Dr. Bain (Donald Pleasence) maintains order while electricity fuels the asylum's hi-tech security system that keeps the nearby neighborhoods safe from menaces like Frank Hawkes (Jack Palance) and "Preacher" (Martin Landau). Meanwhile a new doctor, Dan Potter (Dwight Schultz), arrives in town with his family, but the inmates don't take kindly to his presence and believe he has killed off their former therapist. Suddenly a power outage leaves the town in chaos…and now the maniacs are free to roam the streets and hunt down the man they believe has invaded their lives. With the area quickly descending into riots and chaos, the innocent few must fight for their lives when they're left terrified, cornered and alone in the dark!