In Scorsese's new film, no one is a goodfella

The trailers for Martin Scorsese's "The Departed" might lead you to believe that it's yet another goomba festival from Scorsese Inc. I'm happy to say it's better than that. Comparisons to "Goodfellas" and "Casino" notwithstanding, it has a verve and texture all its own. It also has, courtesy of William Monahan, some of the best dialogue that Scorsese has ever worked with.

Unlike Scorsese's other gangster pictures, "The Departed" works both sides of the fence. It's about both crooks and cops, although some of the cops are, technically, crooks. And the setting is Boston rather than New York, which means that everybody in the cast gets to try out their accents. (A few, like Mark Wahlberg and Matt Damon, already have them.)

Damon plays Colin Sullivan, a south Boston kid who, early on, was befriended by Frank Costello (Jack Nicholson), head of the Irish mob, and now acts as his mole inside the Massachusetts State Police Department's elite special investigations unit. Leonardo DiCaprio's Billy Costigan, an unruly cadet in the police force, is picked by Captain Queenan (Martin Sheen) and his bullying aide Sergeant Dignam (Mark Wahlberg) to infiltrate Costello's mob. They even put him in jail for a time in order to bolster his bona fides with the bad guys.

But who are the bad guys exactly?

Much is made in this movie about the tissue-paper-thin morality of law enforcement and the empathy between thugs and police. Sullivan and Costigan, raised in the same tough neighborhood but unaware of each other, are practically twins. Both are impostors living double lives. Unbeknownst to each other, they even share the same woman, a psychiatrist, played by Vera Farmiga, whose curiosity overrides her clinical instincts.

"The Departed" shares its basic story line with the 2002 Hong Kong cult hit "Infernal Affairs," but Monahan's script is a thing entirely unto itself. I don't really buy into the film's grandstanding about identity and deception. Costigan's identity crisis, and his repugnance for inhabiting an underworld he furiously rejects, would have more weight if we saw more of who he was before he was drummed into service as a mole.

What really links the police and the perps is their almost Joycean love of language. They get a sensual pleasure in the way their vitriol rolls off the tongue. David Mamet or Terry Southern in his prime would have had a hard time matching these words.

Scorsese knows exactly how to use his players for maximum effect. He knows, for example, that Wahlberg is best showcased in small doses, that Alec Baldwin shines in character cameos, that Nicholson, in yet another of his bravura turns, is at his most original when he's flying high. Nicholson's Costello is both mythic and mundane – a legend in the community who is at the same time all-too-distressingly mortal.

He places himself on the front line of drug deals not because he needs to be there, but because he likes being the hood ornament. He's a grungy peacock who becomes increasingly knockabout as things unravel.

DiCaprio's performance is a revelation only for those who have underestimated him. In Scorsese's previous films, "The Gangs of New York" and "The Aviator," he seemed callow and miscast, but here he has the presence of a full-bodied adult. He's grown into his emotions.

An argument could certainly be made that "The Departed," which boasts a body count almost as high as Hamlet, is not much of a stretch for Scorsese. After all, crooks are crooks whether they be from New York or from Boston. But how can you complain when you're having so much fun? Grade: A–

• Rated R for strong brutal violence, pervasive language, some strong sexual content and drug material.