In 1971, San Francisco is under the terrorizing eye of a psychopathic sniper called the "Scorpio Killer" (Andrew Robinson), and claims in one of his written letters to the San Francisco Police Department that he will keep killing until his demands are made. Inspector "Dirty" Harry Callahan (Clint Eastwood) is a San Francisco police officer, with a dirty attitude, and uses little methods to what the law prescribes. It becomes a menacing task for Callahan, as he's been assigned to apprehend the menacing killer at all costs, which later unravels into a cat-and-mouse game between the two men. One killer with a sinister, distasteful laughter. The other, a killer with just a plain dirty attitude who holds the badge.