The Departed (18)

Undercover cop Billy Costigan successfully infiltrates the South Boston crime ring fronted by Frank Costello. Meanwhile, one of Frank’s underlings, Colin Sullivan, worms his way into the upper echelons of the police force, acting as an informant for his boss. The two snakes in the grass begin to lose sight of their true selves as they become wrapped up in their false identities. Fearful that they will be exposed, the two double agents try to learn one another’s identities and kill off the competition.