Article from WSJ, looks like a rave review:
Martin Scorsese's "The Departed," a crime drama of thrilling breadth and intensity, takes place within Boston's city limits, seems to have been made in a state of exultation, and holds you captive in a state of delight. Yes, the director has been working and reworking variations on the genre, sometimes to the point of obsessiveness, ever since his "Mean Streets" electrified the film world more than three decades ago. Here, though, his mastery is complete. This is the movie that Scorsese fans have been yearning to see for a very long time, and it's a crowd-pleaser in the bargain.
The plot involves a deadly dangerous doubles game of cat and mouse, or cat and mole. The cops -- intelligence operatives of the Massachusetts State Police -- want to take down Frank Costello (Jack Nicholson), a veritable rock star of organized crime who runs the city's most powerful mob out of South Boston. To that end, they send Billy Costigan (Leonardo DiCaprio), a rookie who grew up in Southie, undercover to infiltrate Costello's organization. But Costello has a mole in the state police; he's another young trooper from Southie, Colin Sullivan (Matt Damon), a rising star in the elite Special Investigations Unit. While both cops know one another, neither knows the identity of the counterpart who may expose him.
Plots are supposed to be dramatic engines, though sometimes they're so inscrutable that they function as brakes. Not this one, which, for all its complexities, is readily accessible, if plainly implausible from time to time, and which drives the movie so relentlessly that most of its 149 minutes whiz by. (The pace slows slightly, and paradoxically, during the ramp-up to a climactic bloodbath.) The basic idea was inspired by "Infernal Affairs," a 2002 action thriller from Hong Kong, and already a classic of sorts. But "The Departed" is an instant classic of a different sort.
The screenplay, by William Monahan, is simply sensational. Scenes play brilliantly. Feelings flow like molten lava. The dialogue overflows with edgy wit and acidulous arias of imprecation. When the smart, ambitious Colin considers renting a Beacon Hill apartment within sight of the State House's golden dome, the real estate agent says: "You move in and you're upper class by Tuesday." It's a casual joke, but a meaningful one, because "The Departed" is very much about class. It is also about loyalty, friendship, family, good and evil (there's a surprise for a Scorsese film), savage violence (another surprise), cellphones (the plot wouldn't work without them), the passage of time and a fragrant sense of place. After shifting the setting from Asia, Mr. Monahan wrote a script that could only come fully to life in Boston. (The superb Michael Ballhaus did the cinematography, the production was designed by Kristi Zea, and the film was edited by Thelma Schoonmaker.)
Matt Damon (left) and Leonardo DiCaprio as police officers on opposite sides of the law in 'The Departed'
The performances are phenomenal. At the height of his powers, Jack Nicholson plays Frank Costello shrewd and lethally funny but essentially straight, without self-parody; somehow this singular star has found his way back to the commanding simplicity of his work in "Chinatown." Matt Damon and Leonardo DiCaprio have never had richer roles, or been more strongly anchored in them (though, oddly, they're less effective in the few scenes that find them confronting one another). The flawless supporting cast includes Mark Wahlberg, Martin Sheen, Ray Winstone, Vera Farmiga, Alec Baldwin and Anthony Anderson. And through it all, Martin Scorsese maintains a control that's all the more amazing for its lightness, playfulness and invisible precision. The film hardly feels directed at all.