| Director | Ted Post |
|---|---|
| Box office | $44.6 million |
After being acquitted of mass murder on a legal technicality, Carmine Ricca, the boss of the Italian-American San Francisco Mafia, leaves the courthouse in his limousine. While traveling on a city road, the driver is pulled over by a San Francisco Police Department motorcycle cop, who then guns down all of the occupants of the car. Inspector Harry Callahan visits the crime scene with his new partner, Earlington "Early" Smith, despite the fact that the two are supposed to be on stakeout duty. Annoyed by this, their superior, Lieutenant Neil Briggs, berates Harry, and seems eager to keep Callahan out of the murder investigation.
While at the airport, Callahan overpowers two men trying to hijack an airplane. He later meets rookie officers Phil Sweet, John Davis, Alan "Red" Astrachan, and Mike Grimes while visiting the police firing range. Sweet is an ex-Army Ranger and Vietnam veteran and impresses Harry with his great marksmanship skills, admitting his friends are equal or even better. Meanwhile, a motorcycle cop shoots up a pool party, leaving no usable evidence of his crime.
As Callahan and Early take down criminals at a local drugstore, a pimp murders a prostitute for withholding money from him. The next day, the pimp is killed by a patrolman. While investigating the scene, Callahan realizes that the culprit is a traffic cop. He assumes the culprit to be his old friend Charlie McCoy, who has become despondent and suicidal after leaving his wife Carol. Later, a motorcycle cop murders drug kingpin Lou Guzman. The killer, revealed to be Davis, encounters McCoy in the parking garage and guns him down.
At an annual shooting competition after meeting his close friend Frank DiGorgio, Callahan learns that Davis was the first officer to arrive after the murders of Guzman and McCoy. He retrieves a slug from Davis' weapon and has ballistics match it to the bullets from the Guzman murder. Callahan begins to suspect that a secret death squad within the SFPD is responsible for the killings. Briggs insists that Ricca's former Mafia associate, Frank Palancio, is the real culprit. Callahan persuades Briggs to assign Davis and Sweet as backup for a raid on Palancio's offices. However, Palancio and his gang of mafiosi are tipped off via a phone call, Sweet falls victim to a deadly shotgun blast, and all of Palancio's men are killed in the ensuing shootout. Palancio attempts to escape, but Callahan jumps on the hood of his car, causing him to lose control and crash into the arm of a crane, killing him instantly.
Briggs angrily suspends Callahan for the death of Sweet. After returning home, Callahan finds Davis, Astrachan, and Grimes waiting for him, presenting him with an ultimatum to side with them; Callahan refuses. While checking his mailbox, Callahan discovers a bomb and manages to defuse it. A second bomb, however, kills Early before Callahan can warn him.
Callahan informs Briggs about the bomb and discovers Briggs is the secret leader of the death squad. Briggs defends his actions, claiming that he is only doing what the broken legal system cannot; Callahan responds that he knows the system is flawed, but he has chosen to stand by it until someone comes up with some other task which is better. At gunpoint, Briggs orders Callahan to drive to an undisclosed location while being followed by Grimes. Callahan manages to disarm Briggs and knock him unconscious before running Grimes over.
Davis and Astrachan appear on their motorcycles, causing Callahan to flee onto a derelict aircraft carrier in a shipbreaker's yard. Callahan kills Astrachan and takes his motorcycle, leading Davis in a series of jumps between ships. The chase ends after a large jump with Davis unable to stop as he careers off the ship into San Francisco Bay, drowning on impact. Callahan is then confronted at gunpoint by Briggs. The lieutenant mocks Callahan and states his intention to have him prosecuted for the murder of the vigilante officers. As Callahan backs away from the car, he surreptitiously reactivates the timer on his mailbox bomb and tosses it in the back seat, which destroys the car and kills Briggs moments later. Callahan then repeats a comment similar to what he said to Briggs earlier: "A man's got to know his limitations." Then he leaves the area.