The Hong Kong action movie Infernal Affairs has the sort of hook that would fill an arena in the rock world: Two police-academy graduates work as moles on opposite sides of the law—one as an undercover cop in the mob, the other as a gangster infiltrating the police department. Shot through by his most propulsive storytelling since Goodfellas, Martin Scorsese's remake, The Departed, orchestrates such a perfect balance between these mirroring characters that the film achieves a kind of musical symmetry. And in a Boston neighborhood where all the little Irish boys grow up to be cops or criminals, the parallels between them are unmistakable; as Jack Nicholson's hard-nosed kingpin puts it, "When you're facing a loaded gun, what's the difference?" In Scorsese's world, such dreadful ambiguities coarsen the soul.
The stakes are high for everyone in the movie, but as the cop who goes deep undercover to take down Nicholson and his crew, Leonardo DiCaprio has a look of bleary-eyed panic that reflects the hemorrhaging ulcer in his stomach. As his scheming doppelgänger in the state detective office, Matt Damon is a much cooler customer, capable of fitting in with the guys while quietly inching his way up the ladder. The higher-ups in both organizations have sharp enough instincts to suspect a mole, but with Damon denied access to undercover identities, and DiCaprio barely hanging onto his life alongside the volatile Nicholson, it takes time to winnow down the suspects. The unwitting lynchpin in this situation is Vera Farmiga, a police psychologist who has a complicated relationship with both men.
As the moles come closer and closer to getting unmasked, Scorsese's masterful cross-cutting between the two leads serves to tighten the noose around both their necks. Freed from the historical constraints of Gangs Of New York and The Aviator, which were tied by nature to a rocky chronology, Scorsese returns to the crime genre with supreme confidence and breathtaking ferocity. Right from the pungent opening line, The Departed has that Goodfellas pop, from the first-rate cast (Mark Wahlberg and Alec Baldwin are wonderfully salty in support) to the sharp black comedy to the startling incidents of violence. Scorsese is revisiting familiar territory, but the details are still fresh, thanks not only to his usual acuity in capturing time and place, but to a dense William Monahan script that nails the local vernacular. When a director of Scorsese's caliber is working at the top of his game, it's a reminder of why we go to the movies in the first place.