The film tells the story of Pistone, played by Johnny Depp, who is an undercover FBI agent tasked with infiltrating the Bonanno crime family in New York City in the late 1970s. To do so, he assumes the identity of "Donnie Brasco," a jewel thief from Miami who is introduced to the mafia by his friend Lefty Ruggiero, played by Al Pacino. As Donnie becomes more involved with the mafia, he gains the trust of Lefty and the Bonanno family. He participates in criminal activities such as stealing cars, gambling, and eventually, murder. Donnie struggles with his growing loyalty to Lefty and the other mafia members and his duty to the FBI. As the FBI closes in on the Bonanno family, Donnie is forced to make a choice between his loyalty to the mafia and his duty as an FBI agent. The film reaches a dramatic climax as Donnie's true identity is revealed, and he becomes a target for the mafia.