This violent crime drama finds a San Francisco detective assigned to protect a government witness from being murdered by the mob. Bullitt (Steve McQueen) must protect Chicago hoodlum Johhny Ross to insure his testimony before a jury indicting gangland activities. Captain Bennett (Simon Oakland) is Bullitt's superior who supports his man, but the scheming politician Chalmers (Robert Vaughn) has his own agenda, assigning a federal agent (Norman Fell) to watch and report back to him directly. The witness, or so viewers are led to believe, dies in a fleabag hotel. Bullitt lets people believe the witness is still alive, prompting the mob to come after the stoic, hard-as-nails sleuth. In one of the most exciting car chases in cinematic history, the crooks and Bullitt chase each other through the streets of San Francisco. Jacqueline Bisset, Vic Tayback and Robert Duvall also appear in this feature which turned McQueen into an international star.