In a Russian barbershop, an assassin slices open the throat of a patron in mid-haircut. In a drugstore, a pregnant Russian girl collapses in a pool of her own blood. Elsewhere, vodka is sloshed and a balalaika plays -- Nostrovia!

This is the London of David Cronenberg's dark new movie, "Eastern Promises," where an outpost of the international Russian mob, the Vory, operates within a cultural enclave governed by harshly enforced criminal strictures. The picture moves along in a procession of vivid set-piece scenes. There's a dissection episode of disconcertingly offhand ickiness, a bordello interlude with an oddly ambiguous sexual undertone and a squirming newborn infant that could only be Cronenberg's. Most famously -- already -- there's a bathhouse knife attack in which the picture's naked star, Viggo Mortensen, is slashed and battered and hurled around the hard-tiled steam room with fearsome violence. (Cronenberg told MTV News, in an interview to be featured next week, that the movie's makeup team expended more effort on obscuring Mortensen's real bruises than in applying fake blood and prosthetic wounds.)

Mortensen plays Nikolai, a chauffeur in the service of the London-based Russian mob boss Semyon (Armin Mueller-Stahl). Vincent Cassel is Semyon's wildly unstable son, Kirill, and Naomi Watts plays Anna, a half-Russian midwife, raised in London, whose inquiry into a dead girl's diary draws the other three characters into an intricate mystery involving sex slaves, deception and murder.

The picture is distinguished by two exceptional performances. Mortensen, with his grim black suits and carefully upswept pompadour, exudes a brooding Slavic inwardness that will be familiar to anyone who's spent time in Russia itself (the actor did considerable on-the-scene research). And Cassel, that magnetic French actor (best-known here as the charming thief François in "Ocean's Twelve" and "Ocean's Thirteen"), veers frighteningly between boozy bonhomie and unpredictable viciousness. Both characters have secrets -- Nikolai's a very dangerous one -- and Anna's main function in the plot is to unearth them. Watts nevertheless brings a feisty kick to her scenes with Mortensen, and she has some of the movie's funnier lines, too. (Nagged by her mother about driving away yet another boyfriend, Anna responds, "You make me sound like a burning building.")

The script, by the English writer Steven Knight ("Dirty Pretty Things"), was originally intended for British television. Working with Cronenberg, he has plushed it out into a noirish portrayal of a criminal subculture nestled in the heart of one of the world's most civilized (but rapidly changing) cities. The expatriate orbit of the Russian mob here is awash in both bleary sentimentality (Semyon's gaudily decorated restaurant, a front for his more lucrative smuggling business, is a monument to the mobsters' old-world patrimony) and a businesslike brutality that unavoidably recalls the treacherous milieu of the "Godfather" pictures. Cronenberg's film is on a smaller, less sprawling scale, and it doesn't attempt the epic sweep of those movies. But it has a distinctive somber sheen and startling jolts of perversity, and it could only be the work of one man, a director who demonstrates here, yet again, why he's one of the best.

Check out everything we've got on "Eastern Promises."

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