When a madman dubbed 'Scorpio' terrorizes San Francisco, hard-nosed cop, Harry Callahan – famous for his take-no-prisoners approach to law enforcement – is tasked with hunting down the psychopath. Harry eventually collars Scorpio in the process of rescuing a kidnap victim, only to see him walk on technicalities. Now, the maverick detective is determined to nail the maniac himself. When a man calling himself the Scorpio Killer menaces San Francisco, tough-as-nails Police Inspector Dirty Harry Callahan is assigned to track down the crazed psychopath.