Brian O'Conner (PAUL WALKER) was once an L.A. cop sent undercover to investigate a string of tractor-trailer hijackings. That led to Dominic Toretto (VIN DIESEL), the leader of a criminal gang that included the likes of tough girl Letty (MICHELLE RODRIGUEZ). While infiltrating Dom's team and street racing activity, he also ended up romantically involved with the leader's sister, Mia (JORDANA BREWSTER).
After getting too deep in that new lifestyle, Brian ended up letting Dom go, resulting in the cop losing his job. However, he was then recruited by the Feds to capture other criminal types and has been working for them ever since. Now, his boss, Richard Penning (JACK CONLEY), is putting pressure on Brian and his team to nab notorious but anonymous drug kingpin Antonio Braga who's been importing heroin into the U.S.
After forcing a suspect to give up the name of a man who works for Braga, Brian goes undercover, posing as a competitor in a street race overseen by the kingpin's second-in-command, Ramon Campos (JOHN ORTIZ). Under the watchful eye of his henchman, Fenix Risse (LAZ ALONSO), and the alluring Gisele Harabo (GAL GADOT), Brian realizes if he wins, he'll get closer to figuring out who Braga is and then nabbing him.
He's not alone in that quest, however, as Dom has also arrived on the scene to participate in the race. But his motive is driven by his desire to avenge the murder of his lover. The agent and the fugitive ex-con aren't happy to see each other, and don't let on about their previous association. From that point on, the two end up being forced to work together in their effort to bring down the kingpin.