When a madman dubbed the "Scorpio Killer" terrorizes San Francisco, hard-boiled cop Harry Callahan (Clint Eastwood) -- 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.