Screenwriter William Monahan takes equal care maximizing the tension of the setup. Without resorting to unbelievable plot contortions, he has Colin and Billy intersecting and reintersecting with hair’s-breadth closeness until the final discovery. Suspense has rarely been so expertly choreographed as it is in one scene where each informer sits silently on a cell phone with the other, determined not to be the first to reveal his identity.
But it isn’t its smartly-drawn action, its ability to mine unlikely comedy, or even its amazing performances all around that elevate The Departed above many of the best of its genre—it is its subtle sense of morality that does that. Unlike in previous Scorsese films, the rats in these outfits weigh the wages of their treachery. On the surface Colin’s ice-man arrogance suggests he feels no guilt for his life of crime. However, his neediness toward his girlfriend and his obsession with appearing white collar, along with occasional bouts of impotence, suggest differently. The duplicity weighs even heavier on Billy who feels as though his soul is being scratched away by the daily evil he must perpetrate in order to achieve a more important good.
All three leading men (DiCaprio, Damon, and Nicholson) ostensibly reflect increasing internal conflict throughout the film—Damon and DiCaprio the inner pull between good and evil, Nicholson the pull between sanity and insanity—but DiCaprio’s is the conflict we walk away remembering. He makes the most of the best Scorsese vehicle since Goodfellas and the most morally cognizant Scorsese vehicle to date. It shouldn’t surprise anyone if both men are rewarded for their maturing come Oscar season.