The Departed

The Departed is a 2006 crime thriller film directed by Martin Scorsese and written by William Monahan. It is both an English-language remake of the 2002 Hong Kong film Infernal Affairs and also loosely based on the real-life Boston Winter Hill Gang; the character Colin Sullivan is based on the corrupt Federal Bureau of Investigation (FBI) agent John Connolly, while the character Frank Costello is based on Irish-American gangster and crime boss Whitey Bulger. The film stars Leonardo DiCaprio, Matt Damon, Jack Nicholson, and Mark Wahlberg, with Martin Sheen, Ray Winstone, Vera Farmiga, Alec Baldwin, Anthony Anderson and James Badge Dale in supporting roles.

The film takes place in Boston and the surrounding metro area, primarily in the South Boston neighborhood. Irish Mob boss Frank Costello (Nicholson) plants Colin Sullivan (Damon) as a spy within the Massachusetts State Police; simultaneously, the police assign undercover state trooper Billy Costigan (DiCaprio) to infiltrate Costello's mob crew. When both sides realize the situation, Sullivan and Costigan each attempt to discover the other's identity before they are found out.

The Departed was a critical and commercial success, grossing $291.5 million on a budget of around $90 million and receiving acclaim for its direction, performances (particularly of DiCaprio, Nicholson, and Wahlberg), screenplay, and editing. It won several accolades, including four Oscars at the 79th Academy Awards: for Best Picture, Best Director for Scorsese (his only personal Oscar win to date), Best Adapted Screenplay for Monahan, and Best Film Editing for editor Thelma Schoonmaker. The film also received six nominations each at the 64th Golden Globe Awards (winning one) and the 60th British Academy Film Awards, and two nominations at the 13th Screen Actors Guild Awards.

In 1980s Boston, Irish mob boss Frank Costello introduces himself to a young Colin Sullivan. Many years later, Sullivan has been groomed as a spy inside the Massachusetts State Police (MSP) and joins the Special Investigation Unit (SIU). Another police academy recruit, Billy Costigan, is selected by Captain Queenan and Sergeant Dignam to go undercover as a criminal and infiltrate Costello's crew.

Costigan serves a term in prison for his cover and further commits several crimes, drawing Costello's attention. Sullivan begins dating police psychiatrist Madolyn Madden. Costigan manages to get Costello to recruit him into his organization. Over the next year, Costigan becomes increasingly involved. His mental state declines, but Queenan and Dignam convince him to continue. Costigan begins seeing Madden for his court-ordered therapy.

The MSP and Costello both realize they have moles in their respective organizations and task Costigan and Sullivan to find them. Meanwhile, Costigan learns that Costello is a protected FBI informant, sharing his discovery with Queenan. He and Madden begin an affair.

One night, Costigan follows Costello into an adult theater and witnesses him giving Sullivan an envelope containing information on his crew. Costigan is instructed to get a visual ID of Sullivan but is unsuccessful. When Sullivan realizes he is being followed, he stabs a man, mistaking him for Costigan, and flees. Costigan, fearing Costello will soon discover and kill him for being the mole, calls Queenan to end the undercover operation, but Sullivan has Queenan followed, lying to the other officers that Queenan may be the spy. Sullivan also calls Costello's gang to inform them of the meeting.

When Costello's men arrive, Queenan helps Costigan escape before being thrown from the building to his death. This causes a firefight between the police and Costello's men. In the wake of Queenan's murder, Dignam and Sullivan get into a physical altercation at the precinct, leading to Dignam's suspension. Timothy Delahunt, one of Costello's henchmen wounded in the gunfight, tells Costigan that he knows he is the mole before succumbing to his wounds.