"The Departed" is a remake of the 2002 Hong Kong film "Infernal Affairs." The movie follows two undercover agents - one a cop (Leonardo DiCaprio) who infiltrates a Boston crime syndicate, and the other a mobster (Matt Damon) who joins the police department. As the story unfolds, both agents find themselves caught in a web of deception, loyalty, and betrayal. The film features an all-star cast, including Jack Nicholson, Mark Wahlberg, and Martin Sheen.