A beautiful hitchhiker, Miki, entices two Western Gas & Electric servicemen to a remote cabin in Mill Valley, California, where they are both killed by a radical militant named Bobby Maxwell. In San Francisco, California, Inspector Harry Callahan and his partner, Frank DiGeorgio, respond to a hostage standoff at a liquor store. Held at gunpoint, Harry agrees to the thieves’ demand for a police car, then speeds his vehicle through the store window and shoots the assailants. Back at the police station, Capt. McKay reprimands Harry for “excessive use of force” and transfers the inspector to the personnel department. Harry grudgingly saunters into an examination board for hopeful inspectors, where a representative from the mayor’s office, Mrs. Grey, announces that she is monitoring the board to ensure affirmative action. When Harry grills applicant Kate Moore about her inexperience, Mrs. Grey accuses him of intimidation. That night, Bobby Maxwell and his militant organization, which includes Miki the hitchhiker, drive the stolen Western Gas & Electric truck to the Hamilton Firearms Co., planning to rob the arsenal to for the sake of “the people.” After killing a security guard, the group loads weapons and U.S. military Light Anti-Tank Weapon (LAW) rockets into the truck, but DiGeorgio and his new police partner arrive to investigate. As Maxwell stabs DiGeorgio in the back, the officer misfires and hits Miki. Although Maxwell’s minion, Lalo, tries to save Miki, Maxwell shoots her dead. The group steals off with the contraband, running over DiGeorgio’s partner in the process. Harry and his colleague Lt. Bressler rush to the hospital, where DiGeorgio reports with his dying words that the attacker was a pimp that he and Harry questioned in an unsolved murder years earlier. Back at the police station, Capt. McKay receives a cassette tape from Maxwell’s group, which identifies itself as the People’s Revolutionary Strike Force and threatens to blow up buildings around the city unless they are paid $1 million. McKay, who believes the Strike Force is composed of black militants, reinstates Harry to the homicide division to work the case. Harry notes that Miki, who was found dead at the crime scene, was a known prostitute, and argues that the killer is a pimp, as DiGeorgio reported. Harry is chagrined to discover that his new partner is Kate Moore, the young woman he interrogated at the inspector interview. When the partners attend a LAW rocket demonstration, Harry pulls Kate away from the launcher’s backfire, saving her life. The inspectors then visit the coroner’s office to learn that DiGeorgio’s murderer used killing techniques indicative of Special Forces servicemen in the Vietnam War. As Kate grows squeamish and runs outside, a bomb detonates in the building’s bathroom, prompting Harry and Kate to chase a Strike Force operative named Henry Lee Caldwell, whom Harry vaguely recognized on his way inside. During the pursuit, Caldwell drops his briefcase in a dumpster, but Kate retrieves it as Harry follows the militant across apartment rooftops. Caldwell falls through a skylight, lands on the set of a pornographic film and gets away until Harry detains him at a church. Sometime later, Harry delivers the dynamite that was stashed in Caldwell’s briefcase to Lt. Bressler, who reports that the “suspect” is a member of the black militant group Uhuru, lead by Big Ed Mustapha. Harry and Kate visit Mustapha’s headquarters, where Kate fends off aggressive men while Harry learns that Caldwell left Uhuru to “go white,” joining the criminal organization of a fellow Vietnam veteran. Noticing that Mustapha’s office is filled with stolen artifacts, Harry threatens to bust the radical leader for robbery unless he provides information about Caldwell’s organization. Mustapha negotiates for the prison release of an Uhuru member, then reviews Harry’s list of names which includes all of the pimps that he and DiGeorgio once interviewed; Mustapha identifies Bobby Maxwell as Caldwell’s new leader. After Harry and Kate leave, Capt. McKay, Lt. Bressler and a SWAT team surround Mustapha’s building and load Uhuru members into a paddy wagon. Later, McKay strategizes with the mayor to credit Harry and Kate to for the Uhuru arrests, noting that the commendation of a female inspector will impress the electorate. When Harry realizes that Uhuru is being blamed for Hamilton Firearms Co. theft, as well as the ensuing threat of violence and the blackmail, which has now been increased to $2 million, he refuses to participate in the publicity stunt. As Harry states his case to the mayor, McKay suspends him and Kate runs after her partner, offering support. Harry lets down his guard, reporting that Maxwell, their primary suspect, will be impossible to find without Mustapha, and Kate suggests they post Mustapha’s bail. Sometime later, Maxwell’s Strike Force kidnaps the mayor after a San Francisco Giants baseball game by ambushing his limousine and raising the China Basin Bridge so he cannot escape. That evening, Maxwell’s girl friend and second in command, Wanda, telephones a local radio station to announce the Strike Force’s demands, leaving a cassette tape in the phone booth. After listening to the tape, which sets a $5 million ransom for the mayor, Capt. McKay and Lt. Bressler find Harry in a pool hall and demand cooperation, but Harry refuses their plan to negotiate with the terrorists. Harry later meets with Mustapha, who identifies the Strike Force and leads him to Wanda, a masseuse. At the massage parlor, which fronts as a brothel, Harry learns that Wanda has left her job to become involved with a church, lead by Father John. Kate later briefs Harry about the militant, radical priest, who gave rehabilitation seminars at San Quentin State Prison while Maxwell was an inmate. At John’s church, Harry bullies the priest for information as Wanda, dressed as a nun, aims her gun from behind; however, Kate appears in the pews and shoots Wanda dead, saving her partner’s life. Distressed by the violence, Father John tells the detectives that the mayor is being held hostage at Alcatraz. The inspectors take a boat to the abandoned prison island and a gunfight ensues. After finding the mayor and shooting his captor, Kate shields the politician from Maxwell and his henchmen. As she reunites with Harry, she warns her partner that Maxwell is aiming from behind and is caught in the crossfire, herself. As Kate dies, she urges Harry to carry on without her. Although Maxwell resumes control of the mayor and leads him up an observation tower, Harry pursues them from a distance with a LAW rocket. As Maxwell leaves the mayor on a lower floor to look for Harry from the top, Harry launches the rocket and kills Maxwell. Disinterested in the mayor’s promise of commendation, Harry stands over Kate’s body as Capt. McKay arrives by helicopter. Unaware that the standoff has ended, McKay announces to Maxwell that he is delivering the Strike Force’s $5 million ransom.