The Departed is a 2006 American crime thriller film directed by Martin Scorsese and written by William Monahan. It is a remake of the 2002 Hong Kong film Infernal Affairs and is also loosely based on the real-life Boston Winter Hill Gang; the character Colin Sullivan is based on the corrupt FBI agent John Connolly, while the character Frank Costello is based on Irish-American gangster Whitey Bulger.
The Departed stars Leonardo DiCaprio, Matt Damon, Jack Nicholson, and Mark Wahlberg, with Martin Sheen, Ray Winstone, Vera Farmiga, and Alec Baldwin in supporting roles.
The film takes place in Boston. Irish Mob boss Francis "Frank" Costello (Nicholson) plants Colin Sullivan (Damon) as a mole within the Massachusetts State Police; simultaneously, the police assign undercover state trooper William "Billy" Costigan (DiCaprio) to infiltrate Costello's crew. When both sides realize the situation, Sullivan and Costigan each attempt to discover the other's identity before they are found out.
South Boston cop Billy Costigan (Leonardo DiCaprio) goes under cover to infiltrate the organization of gangland chief Frank Costello (Jack Nicholson). As Billy gains the mobster's trust, a career criminal named Colin Sullivan (Matt Damon) infiltrates the police department and reports on its activities to his syndicate bosses. When both organizations learn they have a mole in their midst, Billy and Colin must figure out each other's identities to save their own lives.
