Protagonist

Character Role Analysis

Billy Costigan

Billy is our main man from start to finish. After all, he's the undercover cop working on the side of law and order. Yes, Colin Sullivan is likable in his own way. But he's also responsible for getting a police captain killed, and he has no real problem with abusing his power as a police officer to help a murdering mob boss.

In the end, we're probably pretty sad when Billy dies and probably a little relieved when Costello and Sullivan die. We're also rooting for Billy to end up with Madolyn, but things just don't work out that way, because The Departed has a dark ending overall. Many fans actually don't like the ending to this movie because they're so upset that Billy dies.