Plot

After a chance encounter, headstrong Kathy is drawn to Benny, member of Midwestern motorcycle club the Vandals. As the club transforms into a dangerous underworld of violence, Benny must choose between Kathy and his loyalty to the club.

After a chance encounter at a local bar, strong-willed Kathy (Jodie Comer) is inextricably drawn to Benny (Austin Butler), the newest member of Midwestern motorcycle club, the Vandals led by the enigmatic Johnny (Tom Hardy). Much like the country around it, the club begins to evolve, transforming from a gathering place for local outsiders into a dangerous underworld of violence, forcing Benny to choose between Kathy and his loyalty to the club.—Focus Features

In 1965 Chicago, Benny, an impulsive young biker, will stop at nothing to prove his mettle to Johnny, the formidable leader of the local Vandals Motorcycle Club. But as Johnny realises his days at the helm are numbered, he begins the search for his successor. To everyone's surprise, including Benny, he is the perfect candidate. However, as the Vandals gain power and notoriety, Benny must confront the harsh truth: brutal violence is creeping up on his once-beloved club. With law enforcement and rival gangs closing in, both Johnny and Benny face an impossible dilemma: put family first or succumb to the unforgiving law of the streets.—Nick Riganas

In 1969, Benny is attacked by two men in a bar for wearing his colors. His foot is nearly severed by a shovel during the altercation. Johnny forces the owner to provide the names of the men and orders his men to burn down the bar. While Benny is recovering from surgery, Johnny pressures him to come to a motorcycle rally before he is fully healed, to Kathy's objection. Johnny offers Benny leadership of the club when he eventually steps down, but Benny rejects it.

A 20-year-old delinquent known as "the Kid" asks Johnny to allow him and his motorcycle club to join the Vandals. Johnny initially dismisses them but decides to test the Kid by allowing only him to join. When he expresses his willingness to abandon his friends, Johnny rejects him. The Kid attacks Johnny with a knife, but Johnny beats him and warns him not to come back.

In 1973, Lyon interviews Kathy about the fate of the Vandals. She explains that Johnny became despondent after the death of his lieutenant Brucie in a vehicular accident, and the club grew increasingly violent after drug-addicted Vietnam War veterans joined the ranks. At a party, longtime member Cockroach is beaten by new members when he drunkenly expresses a desire to leave the club to become a motorcycle cop. Kathy is nearly gang-raped while Benny is busy; she is narrowly rescued by Johnny. Furious, Kathy demands Benny quit the Vandals. Instead, he leaves her for several days.

Cockroach, scared for his life, asks Johnny to help him. To allow Cockroach to safely leave the club, Johnny and Benny stage a break-in, where they shoot him non-fatally in the leg. Afterwards Johnny confides in Benny the club has become wild and violent and he can't control it anymore. Disturbed by the increasing violence of the club and again rejecting Johnny's offer of leadership, Benny quits and leaves Chicago for parts unknown.

The Kid, now a member of the Vandals Milwaukee chapter, challenges Johnny to a knife fight for leadership of the Vandals. In a parking lot, Johnny confronts the Kid who pulls a handgun and kills him. Kathy relays to Lyon that after the Kid took over the Vandals, they became a large criminal gang involved in drug trafficking and murder. The original members either fell in line, left to obtain legitimate jobs, or died.

Benny returns home after learning of Johnny's death and Kathy comforts him. He and Kathy relocate to Florida, where Benny works as a mechanic and has stopped riding motorcycles. Kathy tells Lyon that they are happy, and Benny doesn't miss the biker lifestyle. She looks out the window at Benny, who smiles as the sounds of motorcycles are heard. (thanks to Wikipedia)