The "Scorpio Killer" (Andrew Robinson) is a sniper who taunts the police with cryptic messages and frustrates them with his ability to kill his random victims whenever and wherever he chooses. San Francisco Police Inspector Harry Callahan (Clint Eastwood), armed with a .44 Magnum and a lack of regard for civil liberties and Miranda warnings, is loosed upon the unsuspecting city to put a stop to Scorpio's killing spree. Callahan bristles at the city's bureaucracy, and at his chief's insistence that a new partner (Reni Santoni) tags along, but soon they are on the trail of the killer. Their investigation is frustrated as much by the bureacratic interference as it is by the killer himself, but "Dirty Harry" will get his man: no matter the cost.