WWW- In The Departed, director Martin Scorsese returns with breathtaking assurance to the arena in which he is at his best: the gritty and complex crime drama.

Loosely based on the 2002 Hong Kong thriller Infernal Affairs, Scorsese’s latest is his best since 1990’s Goodfellas. Two and a half hours race by as this twisting, turning tale blazes its exciting, funny, brutal path.

The film’s score and editing brilliantly heighten the film’s energy, keeping the audience somewhat off-kilter and unsure where things are headed.

Set in the mean streets of South Boston, the film hinges on the duplicitous actions of two young cops, played winningly by Matt Damon and Leonardo DiCaprio. DiCaprio – in his best performance in a Scorsese movie – plays rookie Billy Costigan, who has a foot in tough South Boston, where he lived with his father, and another in the wealthier existence of his mother and stepfather. Smart and educated, he disappoints the moneyed relatives by becoming a cop.

Once on the force, he is goaded into going undercover by a good cop/bad cop pair played by Martin Sheen and Mark Wahlberg (in a wildly compelling performance).

The police department is hellbent on taking down crime boss Frank Costello, played with just the right blend of menace, sleaze and dissipation by Jack Nicholson. Costigan’s infiltration of Costello’s ring grows more terrifying the deeper it gets.

Meanwhile, rising police department star Colin Sullivan, superbly played by Damon, leads an increasingly fraught double life. Named as head of a team that investigates Costello, he also secretly works for the crime lord, helping him elude the police. When the department realizes it has a mole in its ranks and Costello begins to grow suspicious of his men, Damon and DiCaprio’s characters face a host of dangers. It’s a riveting dance in which they must keep a step ahead of their cohorts and each other, to avoid exposure.

To further complicate matters, both men fall for the same woman, a department psychologist played by an oddly lackluster Vera Farmiga.

Unlike many by-the-book crime dramas, the characters are nuanced, dialogue is crackling and the action crescendoes to a startling ending. This group from Boston is far more fascinating than Scorsese’s Gangs of New York or reclusive Aviator Howard Hughes. Kudos to him for coming back from those flawed, but ambitious, efforts with one of the best films of his career.