DiCaprio plays Billy Costigan in this crime thriller directed by Martin Scorsese. Billy is an undercover state cop who has infiltrated an Irish gang and Colin Sullivan is a mole in the police force working for the same mob. They both race to track down and identify each other before being exposed to the enemy, after both sides realize their outfit has a rat. Co-starring Matt Damon and Jack Nicholson.
They’re two sides of the same coin, it’s true. They’re products of their environment. They make certain choices early on in their own lives that affect everything that goes on in the film.