In this review I share my thoughts on the ending. I don’t name any specifics but if you fear spoilers, read no further. Just know that this is one of my favorite films and I recommend it to everybody who isn’t offended by violence or foul language.
The Departed has so many great tricks up its sleeve: it has an interesting theme, it is crafted to perfection editorially and visually, and it is written for people who know how to watch movies without having to be beaten over the head with exposition.
Billy Costigan has two identities long before joining the special undercover unit of the Boston State Police. The son of divorced parents, he split his time between different parts of the city, with different behaviors and even different accents. In a way he has no real identity except for the one he wishes to project; as a respectable member of his family, and not a crook. What better way to be respected than to join the state police? Unfortunately, his motives are easily spotted by his superiors, and they use his less-than-savory family background to put Billy up as a mole with the Irish Mob, headed by the eccentric and unstable Frank Costello.
Colin Sullivan was drafted at a young age to work for Frank Costello. Sullivan has graduated the police academy at the start of our story, so he is now Costello’s mole inside the Boston State Police. Colin has his identity as a police officer, but he also has his identity as an associate in the Irish Mob.
The Departed is an amazing study in the nature of identity and how one's real self, projected self, and perceived self all become hard to disentangle. At all points in the movie, motives are up in the air, and we are left to wonder whose identity is at the forefront of every character decision. Is Billy a cop here, is he his father’s son, is he Costello’s new soldier? Is Colin in it for Costello or is he in it for the state police and personal glory?
On top of that, it is thankfully a suspenseful crime saga, well shot and well-acted. Having a great theme is one thing, but packing it on top of a movie that is so well crafted makes it a movie worth remembering. Thelma Schoonmaker won a well-deserved Academy Award for this picture, and the writing and directing won as well (a first for Martin Scorsese).
So we have a movie with a great theme, and crafted to perfection, so what else is there to say? I can say that The Departed is a rare movie that doesn’t treat the audience like simpletons. You’re either paying attention or you aren’t, and it’s your fault if you can’t keep up. Some people would say the film is too complicated; I say some people are too used to being fed exposition. I love not having to be told what I already know.
So what we have is a movie with three strengths, and these strengths make The Departed one of the best films of the Aughties. And when that final bit of symbolism scurries through the shot, I don’t feel like I’m being beaten over the head with obvious symbolism. Instead, I feel reminded of what all the departed main characters of the movie had in common. I’ve always thought that was brilliant.