In the final scene of Martin Scorsese’s The Departed, we see the golden dome of the State House of Massachusetts from the living room of a swank penthouse apartment formerly occupied by one of the characters in the film. In the background, we hear strains of the Patsy Cline tune “Sweet Dreams.”

This particular song is an important musical theme in the film. It often plays, sung by Cline or by others, and in one instance only the melody plays — though the lyrics of the song, with their depressive, melancholy words of forlorn hope, desire, and despair are important. In The Departed, all dreams come to naught. As we gaze out the window toward the golden dome of law and order, we see a large rat creeping across the porch rail outside the apartment. On this juxtaposition of the rat against the golden dome of law, order, morality (and dreams), the film ends. The screen fades to black and credits roll.

Rats are important in The Departed. The presence of rats — human rats, informers, undercover men — in the Boston Police Department and in the gang of mobster Frank Costello, is crucial to the film’s plot. They are ratting out the plots and plans of the people they pretend to work with. Human rats, in a larger sense — rats who cheat on one another, who plot and connive and deceive, who steal and kill, who feel jealousy and ambition, who are easily corrupted by the lure of money and power and ambition in any combination — are everywhere apparent in this film, which has been hailed as a return to classic form for director Scorsese.

The Departed doesn’t really expand or reinvent the Scorsese formula so much as it provides a kind of update. The venue is Irish Catholic Boston rather than Italian New York. We see clergymen, policemen, and mobsters, most of them of Irish ancestry. The film gives a sense of the cultural context of Irish Boston, but its real focus is the story of intrigue, deception, and labyrinthine plot twists. 

The plot concerns the efforts of the Boston Police to build a case against the mobster Frank Costello (other than his name, he has no connection to the real Costello). It also follows the ascending careers of two young Irish Catholic detectives, played by Leonardo DiCaprio and Matt Damon, both connected in different ways to Costello, who sees himself as a kind of father figure to these and other protégés. In ways, this film is predictable, but it is so well acted and written that following these characters and the twisting and turning plot to their ultimate conclusions is wholly satisfying. 

DiCaprio portrayed a lead character Gangs of New York and starred as Howard Hughes in The Aviator. He also plays a lead role as undercover detective Billy Costigan in The Departed. This may be DiCaprio’s best performance in any film. It’s nuanced, powerful, understated, and convincing. But there are plenty of other good performances, from Matt Damon, Martin Sheen, and Alec Baldwin as Boston detectives to Ray Winstone and, of course, Jack Nicholson as gang members. Nicholson plays Costello. He’s great in the role, though it’s one he has played on and off throughout his career. Nicholson has some of the best lines in the film, which is full of good lines, many of them clearly written with Nicholson in mind, though Mark Wahlberg, as director of the undercover division, has his share of good lines as well. My favorite Nicholson line: “I don't wanna be a product of my environment. I want my environment to be a product of me.”