In 1970s South Boston, FBI Agent John Connolly (Joel Edgerton) persuades Irish mobster James "Whitey" Bulger (Johnny Depp) to collaborate with the FBI and eliminate a common enemy: the Italian mob. The drama tells the story of this unholy alliance, which spiraled out of control, allowing Whitey to evade law enforcement, consolidate power, and become one of the most ruthless and powerful gangsters in Boston history. -- (C) Warner Bros

John Connolly and James "Whitey" Bulger grew up together on the streets of South Boston. Decades later, in the late 1970s, they would meet again. By then, Connolly was a major figure in the FBI's Boston office and Whitey had become godfather of the Irish Mob. What happened between them - a dirty deal to trade secrets and take down Boston's Italian Mafia in the process - would spiral out of control, leading to murders, drug dealing, racketeering indictments, and, ultimately, to Bulger making the FBI's Ten Most Wanted List.