The Departed is set in South Boston where the state police force is waging war on organised crime. Young undercover cop Billy Costigan (Leonardo DiCaprio) is assigned to infiltrate the mob syndicate run by gangland chief Costello (Jack Nicholson). While Billy is quickly gaining Costello's confidence, Colin Sullivan (Matt Damon), a hardened young criminal who has infiltrated the police department as an informer for the syndicate, is rising to a position of power in the Special Investigation Unit.

Each man becomes deeply consumed by his double life, gathering information about the plans and counter-plans of the operations he has penetrated. But when it becomes clear to both the gangsters and the police that there's a mole in their midst, Billy and Colin are suddenly in danger of being caught and exposed to the enemy - and each must race to uncover the identity of the other man in time to save himself.

Synopsis

Leonardo DiCaprio, Matt Damon, Jack Nicholson and Mark Wahlberg star in Martin Scorsese's new crime drama "The Departed." "The Departed" is set in South Boston where the state police force is waging an all-out war to take down the city's top organized crime ring. The key is to end the reign of powerful mob boss Frank Costello (Jack Nicholson) from the inside. A young rookie, Billy Costigan (Leonardo DiCaprio) is assigned to infiltrate Costello's mob. While Billy is working to gain Costello's trust, another young cop, Colin Sullivan (Matt Damon) is among a handful of elite officers whose mission is to bring Costello down. But what his superiors don't know is that Colin is working for Costello, keeping the crime boss one step ahead of the police. Each man becomes deeply consumed by his double life, gathering information about the plans and counter-plans of the operation he has penetrated. But when it becomes clear to both the gangsters and the police that they have a mole in their midst, Billy and Colin find themselves in constant danger of being caught-and each must race to uncover the identity of the other man in time to save himself.