World War II soldier-turned-U.S. Marshal Teddy Daniels investigates the disappearance of a patient from a hospital for the criminally insane, but his efforts are compromised by troubling visions and a mysterious doctor.

As a seasoned homicide detective, Thomas Craven has seen the bleakest side of humanity. But nothing prepares him for the toughest investigation of his life: the search for his only daughter Emma's killer. Now, he is on a personal mission to uncover the disturbing secrets surrounding her murder, including corporate corruption, government collusion and Emma's own mysterious life.

Authorities, journalists along with the cast & crew from _Departed, The (2006)_ talk about the film's influences. Among them being a real-life Boston gangster named Whitey Bulger, who is the mold for Jack Nicholson's character.

To take down South Boston's Irish Mafia, the police send in one of their own to infiltrate the underworld, not realizing the syndicate has done likewise. While an undercover cop curries favor with the mob kingpin, a career criminal rises through the police ranks. But both sides soon discover there's a mole among them.