Brian O'Conner is an undercover cop infiltrating Hollywood's street racing scene, which is suspected to be the origin of a string of high-speed truck hijackings. Going by the name Brian Earl Spilner, O'Conner races elite street racer Dominic Toretto and two other racers. Brian loses the race and his car to Toretto but gets in his good graces by saving him from arrest in a high-speed escape, after the police are called in to arrest the street racers. Before long, both men are spotted and interrogated by an asian gang lead by a man named Johnny Tran, who allows them to live but shoots at and destroys Brian's Mitsubishi Eclipse before leaving.
Brian reports his findings to his superiors, but they soon notice he's getting close with Toretto, growing wary of him. Once he is scolded for the destruction of his car, he receives the chasis of a Toyota Supra, which is restored by Toretto's team. As the car is near complete, Mia and Brian grow close and begin a relationship. Before he and Brian take the Supra out for a "test drive" (a race against a Ferrari, in which the Ferrari loses) Toretto shows Brian his 1970 Dodge Charger, explaining that he and his father built it and that he's never driven it because it "scares the shit" out of him. He also explains what led to his father's demise as well as why he was banned from the tracks for life. After another truck hijacking occurs, the police move in and arrest all the members of rival racer Johnny Tran's gang, but find that the DVD players in his warehouse were legally purchased and that they are not the ones doing the hijackings. Brian's superior tells him about the truckers arming themselves and that it has to be Toretto doing it, giving him a sudden deadline. Brian casually asks Toretto that whatever he is doing, he wants in on it as well. Toretto agrees as long as Brian wins the upcoming Race
During Race Wars, Toretto's friend Jesse races his Volkswagen Jetta against Johnny Tran's Honda S2000 for pink slips and loses. In a state of panic, Jesse drives away from the race. Shortly after beating Jesse in a race, Tran then confronts Dominic Toretto and accuses him of calling the cops on him and having him being disrespected in front of his father and family, which leads to Dominic punching him out and they having a scuffle on the ground (not realizing the person responsible for the SWAT invasion, Brian O'Conner, was right in front of him). During the night, Toretto and the rest of the clan drive out. Brian confesses to Mia that he's a cop and tells her that the truckers are now armed. He convinces her to come with him to save her brother and his friends.
They trace his cell phone and track him down. Toretto pulls out the Honda Civics to make one last truck jacking. While pulling the job, Toretto notices the truck driver is armed with a shotgun. Vince's arm is trapped in the wire as Letty and Toretto try to rescue him. Letty's Civic soon flips over and Vince soon skids off the road. Brian catches up and gets Dominic off. Brian phones in for a life flight helicopter, revealing to Toretto his serial number and that he is a cop. Vince is taken to a hospital, and Toretto and Mia drive off angrily.
Brian confronts Toretto at his house. When Jesse comes back, Johnny Tran and his cousin show up to pull off a drive-by, killing Jesse in the process. Brian and Dominic drive out to go after them. Dominic forces one cycle to flip over using his 1970 Dodge Charger. Brian successfully shoots Tran, killing him. They then find themselves at an intersection and engage in a street race to a set of train tracks exactly a quarter mile away. As a train approaches, both cars manage to speed up and pass the tracks as the train barrels down on them. Dominic is then sideswiped by an unexpected truck and his car flips over. Brian then goes to check on Dominic. Suddenly, they notice that the cops are coming. Knowing Dominic will be arrested when they arrive, Brian gives his keys to Dominic, saying, "I owe you a ten-second car." Brian then allows Dominic to escape.
