Before his flair for filmmaking staked a spot in history, Martin Scorsese nearly became a priest. That tidbit of trivia -- a seemingly random nugget kept in circulation by way of abundant auteur mythologizing -- offers a reasonable entry point for understanding the dominant themes in many of the director's finer works. Figures of corruption surge through his foreboding cityscapes, but cruel intentions are disarmed by the presence of a wholesome individual -- a savior leading a righteous path. Jesus may be the literal star in The Last Temptation of Christ, but the Christ-like qualities of a gun-wielding, pimp-killing Travis Bickle in Taxi Driver are hardly subtle.

No such spiritual heart beats in The Departed, which sports Scorsese's flair for technical tomfoolery while betraying his previously stalwart sense of justice. Substance loses footing to style in a big way, creating a gleefully morbid crime story that navigates nearly every turn in the Sopranos playbook. Scorsese predates that recent glorified genre looping, although it isn't apparent from the plotting. Nobody in this crowd-pleasing romp is resolutely good, but pretty much all principals involved earn their pathos through run-of-the-mill backstories borrowed from its more secular precedents in gangster fiction.

Scorsese says he hasn't seen Infernal Affairs, the 2002 Hong Kong crime thriller that serves as the launch pad for The Departed -- an admission that has rankled some remake purists. But the basic premise is just fancy cookie cutter stuff, a collage of cliches twice told and, in this case, told well: Reigning South Boston mobster Frank Costello (Jack Nicholson) taps into the police force via his blossoming disciple, the shamelessly (if confidentially) crooked officer Colin Sullivan (Matt Damon). At the other end of the spectrum is Billy Costigan (Leonardo DiCaprio) a scowling descendent of street thugs assigned by Boston's Special Investigations Unit to infiltrate Costello's gang and bring him down. Most of the tension arises from Damon and DiCaprio's calculated attempts to strike at the opposing sides of a covert battlefield without revealing themselves as canaries. Their superiors manifest as a series of terrifically exaggerated tough guy riffs played by Alec Baldwin, Martin Sheen and Mark Wahlberg, but their duties as actors -- along with Nicholson's -- are placed as secondary to the central conflict between the two younger figures.

The contrast between these principle personalities isn't particularly nuanced, but it allows similar concerns about group allegiance to permeate the cops and robbers. That both men manage to seduce the local police shrink (Vera Farmiga) is an incredulous twist no matter how you spin it, but it does allow for palpable moments of jittery anticipation when everything comes together in the end. Damon's role doesn't call for much emoting, but he does fine as a second-rate bad guy; DiCaprio, meanwhile, has finally found a role that suits his continuing youthful appearance (I personally never bought that bearded Howard Hughes rap).

At any rate, the actors are really just pawns in Scorsese's larger cinematic equation, which is anything but coy. He opens with nostalgia-hewed narration, punctuates nearly every scene with an obsequious rock rhythm, crafts a wordless, nail-biting pursuit sequence worthy of Jean-Pierre Melville, makes a rimshot reference to The Third Man in the last act and concludes with an oddball shot at religious symbolism -- but the metaphor is overt to the point of hilarity. Nicholson is the only face that exists beyond Scorsese's realm of influence, which may explain why they've never collaborated before. The actor hams it up with his own easy rider flair, resulting in an insular performance that dares anyone to call him cheesy. When Costello says he "smells a rat," then proceeds to roll his eyes, crumple his nose and sniff, Batman might as well crash through the celluloid to yank this Joker back to Earth.