The Departed is an Academy-Award winning 2006 crime thriller film directed by Martin Scorsese, starring Leonardo DiCaprio, Matt Damon, Jack Nicholson and Mark Wahlberg. It is an American remake of the 2002 Hong Kong crime thriller Infernal Affairs.

This film takes place in Boston, Massachusetts, where notorious Irish Mob boss Francis "Frank" Costello (Nicholson) plants his protégé Colin Sullivan (Damon) as an informant within the Massachusetts State Police. Simultaneously, the police assign undercover cop William Costigan, Jr. (DiCaprio) to infiltrate Costello's crew. When both sides of the law realize the situation, each man attempts to discover the other's true identity before being found out.

Two just-graduated officers from Massachusetts State Police Academy follow opposite sides of the law: William Costigan is assigned to work undercover with the Irish mobster Frank Costello to get evidences to arrest him. His true identity is only known by his superiors Dignam and Oliver Queenan. The protégée of Costello, Colin Sullivan, is promoted in the Massachusetts State Police and is the informer of Costello. Each police officer gives his best effort trying to disclose the identity of the other "rat". Written by Claudio Carvalho, Rio de Janeiro, Brazil

Billy Costigan, a young man from a crook family, wants to do redeem the Costigan family by joining the cops. However, the cops see him as the perfect mole because of his crook family, so they send him undercover to the Irish Mob. Meanwhile, Frank Costello, the mob boss, sends in Colin Sullivan to become a cop for the opposite purpose. Both get caught up in their double lives and become obsessed with finding the other mole, as does Costello and Queenan, the heads of each side. Written by hnt523

Years ago, a powerful Irish mafia figure placed a small selection of his youngest, brightest men into the Massachusetts State Police Academy as cadets. Their purpose is to eventually rise within the prestigious ranks of the state police department, to serve as the eyes and ears of their boss. While somewhere else, a young cadet was assigned with an equally dangerous task: infiltrate the Irish syndicate headed by the man sending in his own to the Massachusetts State Police. Now, one cadet is an up and coming police official with a torn allegiance to his job and to the criminal mastermind that put him there. While the other cadet is the trusted number two of that man, only finding his professional duties are becoming blurred with his current state. But new clues have lead to unfortunate discoveries, when both sides realize they're being watched by the enemy. It's now all just a matter of time before the men assigned to find out whose the infiltrator, could come to a bloody end when someone's identity may be revealed. Written by mystic80

In South Boston, the state police force is waging war on Irish-American organized crime. Young undercover cop Billy Costigan is assigned to infiltrate the mob syndicate run by gangland chief Frank Costello. While Billy quickly gains Costello's confidence, Colin Sullivan, a hardened young criminal who has infiltrated the state police 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 mob 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. But is either willing to turn on the friends and comrades they've made during their long stints undercover? Written by Anonymous

Revolves around a rivalry between the Massachusetts State Police and an Irish-American gang. A gangster is chosen to infiltrate the state police while a young police officer is chosen to infiltrate the gang. When their paths cross, what will be the result? Written by Ninja01