An American crime thriller film about an undercover state cop who has infiltrated an Irish gang and a mole in the police force working for the same mob race to track down and identify each other before being exposed to the enemy, after both sides realize their outfit has a rat.
At the end of The Departed, Dignam kills Sullivan after finding out that he was the rat all along and responsible for Billy Costigan's death. Did Dignam do this on his own accord? Or was he part of ...
When does he find out in the movie? Is it when he says on the phone: "So it is you. Thank God you're all right. We were very worried." And how exactly does he know it's Costigan? Sorry, I've watched ...