A gripping true story of violence, double-cross and corruption, Black Mass takes us deep undercover, exposing one of the most outrageous scandals in FBI history. Boston, 1975. Under a harvest moon, 'Whitey' Bulger, godfather of the Irish Mob, waits for an old school buddy. Since they last met, Little John Connolly has become a high-ranking FBI agent. Connolly needs an informant - someone with a good view of Boston's dark side. Whitey needs certain priority treatment. Soon the die is cast.