Speed 0896785 ( 0138 )

LAPD SWAT bomb disposal officers Jack Traven and Harry Temple are tasked with preventing a bombing on a city elevator containing 13 people, masterminded by a vengeful extortionist, Howard Payne. After narrowly rescuing the passengers, Jack and Harry hunt down Payne, resulting in Harry getting wounded. Payne seemingly blows himself up while Jack and Harry are conferred medals in a ceremony. However, it is revealed that Payne has faked his death, and has become personally bitter towards being defeated by Jack and his subsequent recognition. After blowing up a bus to divert Jack's attention, Payne contacts him with a new deadly scheme: a bomb planted on a city bus that will activate upon reaching 50 miles per hour (80 km/h) and detonate if the bus slows below 50 but is also set to go off sometime before noon.

Jack receives the ultimatum from Payne—$3.7 million in ransom or the bomb will go off. Racing through traffic, Jack gets a ride from a Jaguar owner named Maurice to warn the bus driver of the bomb. Realizing he has surpassed 50 and the bomb is already active, Jack boards the bus, but a felon's panic leads to the driver being shot; a passenger, Annie Porter, takes over the driving. With the bomb armed and passengers aware of the threat, Jack contacts Harry for help while trying to keep the bus moving. Payne agrees to allow the wounded driver to be handed to the paramedics as a sign of good faith. Annie's seatmate, Helen, panics and attempts to get off the bus, but Payne sets off a smaller bomb underneath the steps, sending Helen underneath the tires and killing her.

Despite Payne's constant surveillance, Jack maneuvers the bus through several dangerous obstacles, including a gap in the freeway, and directs it to Los Angeles International Airport to prevent traffic issues, and being unable to defuse the bomb due to Payne's methodical planning. Meanwhile, Harry discovers Payne's identity as a former Atlanta Police Department bomb squad officer, who was place on administrative leave after losing his thumb, and developing long-lasting bitterness with being undercompensated with nothing but a "cheap gold watch". Harry leads a SWAT team to arrest him: however, most of the team, including Harry, is killed when Payne's house, having been rigged with bombs, explodes.

Seemingly out of options, Jack is left hopeless until he notices Payne is monitoring the bus through a hidden camera, allowing him to be one step ahead at every moment, seeing that Annie was sporting a University of Arizona shirt and remembering that Payne constantly called her a 'wildcat'. A clever ruse involving looping the surveillance footage allows the passengers to escape, and the empty bus explodes while crashing into an empty cargo plane. While noticing the LAPD has made the delivery and are waiting to apprehend him, Payne notices the looped feed on the news and realized that he has been bested by Jack once again, as he intended to let the bus explode after the random delivery to prove his self-satisfication.

After noticing that Payne hasn't collected the ransom, Jack discovers the drop-off in a trash can is connected to the subway system as a ruse so that Payne could collect the money safely. Jack chases Payne into the subway system, where he discovers that Payne has posed as an officer to kidnap Annie, simply to spite Jack out of his continued bitterness, despite having the ransom. Payne straps an explosive vest to Annie, but his plans unravel when he discovers an exploding dye pack in the duffel bag of money. Furious, Payne fights Jack on the train roof, eventually resulting in Payne's decapitation from an overhead sign. Jack deactivates the vest, but the subway train cannot be stopped. Jack instead accelerates the train, causing it to derail and crash onto Hollywood Boulevard. Jack and Annie emerge unscathed and share a kiss as onlookers watch in amazement.