Speed is a 1994 action movie starring Keanu Reeves as Jack Traven, a member of the Los Angeles Police Department's bomb disposal squad. After he and his partner Harry ( Jeff Daniels) thwart a bomb threat/ransom plot set up by explosives expert Howard Payne ( Dennis Hopper in full theatrical villain mode), Payne targets Traven with a new hostage situation that doubles as a revenge scheme.
The day after receiving a commendation for his and Harry's hostage rescue, Jack is about to enjoy a relaxing day when he witnesses a bus explode. He then answers a ringing pay phone and is informed that another bus has been rigged with explosives which will arm the moment the bus exceeds fifty miles per hour, and that the bomb will detonate if the speed falls below that point.
Jack races to warn the bus driver, but is too late. By the time he's able to inform the driver of the bomb's existence, it's already been armed. He boards the bus while it's in transit on the freeway, but after identifying himself as a cop, one of the passengers, a criminal suspecting that Jack is after him, pulls his gun and a struggle ensues that results in the driver being shot. Passenger Annie Porter, played by Sandra Bullock, steps in to keep the bus from running out of control; it is only then that Jack is able to explain the existence of the bomb that will detonate if the bus slows down.
The second act of the movie plays out with Jack remaining on board, looking for a way to disarm the bomb and keeping the passengers calm while Annie navigates the bus through the crowded L.A. roads. Jack successfully manages to negotiate with Howard, who allows the critically injured driver to be transferred off the bus, but when one of the frantic passengers tries to force her way off, Howard detonates a bomb under the door, killing her.
Eventually, Jack and Annie manage to get the bus to LAX, where they're free to allow the bus to circle an unused runway. At the same time, Jack's partner Harry figures out Howard's identity; an ex-bomb squad cop living in Los Angeles. He accompanies a squad to Howard's address, but upon breaking into the house, he falls into a trap and is killed in an explosion.
Jack receives a taunting call from Howard informing him of his partner's death, enraging him. However, one of Howard's quips, in which he referred to Annie as "the wildcat," a reference to the University of Arizona logo visible on her clothing, tips him off to the fact that Howard is able to see the interior of the bus. With the help of a television news crew, Jack and the passengers create a looping video to play over the camera feed, hiding their actions as they finally evacuate the bus and allow it to explode.
In the final act of the film, the police set up a trap to catch Howard by luring him out to collect the ransom he demanded. The ploy fails when Howard notices the snipers staged on the nearby rooftops and finally spots a glitch in the looped recording, informing him that the hostages all escaped. In retaliation, he kidnaps Annie before escaping with the ransom money. Jack chases him into the subway system. The climax of the film takes place on board a moving subway as Jack and Howard fight on the roof while Annie is handcuffed to a pole in one of the cars and strapped in an explosive vest.
In the end, Jack gets the upper hand on Howard and manages to kill him by forcing his head high enough to be decapitated by one of the subway tunnel lights. Unable to stop the subway, and without keys to free Annie from her handcuffs, he speeds the train up so that it derails, saving them both.