Boston 1975. Under a harvest moon, 'Whitey' Bulger, godfather of the Irish Mob, waits for an old school buddy. It has been a long time, and a lot has changed. Little John Connolly is now a high-ranking FBI agent. He is an agent in need of an informant - someone with a good view of Boston's dark side. He is an agent willing to be corrupted. An agent about to get played.
A gripping and chilling true story of violence, double-cross and corruption, Black Mass takes us deep undercover, exposing one of the worst scandals in FBI history.