With stylish oddities like The Fly, Dead Ringers and A History of Violence, among others, behind him, David Cronenberg re-teams here with History co-star Viggo Mortensen and collars Dirty Pretty Things screenwriter Steve Knight for a highly entertaining but sometimes revolting look at a particularly venal branch of the Russian mob.

Mortensen, as the Russian rising star in a gang specializing in human trafficking, drugs, and killing on a dime (or ruble), and Naomi Watts, as a gentle nurse of Russian heritage who stumbles into gangland muck, are intriguing moral counterpoints. They are also the key ingredients that make Eastern Promises a highly delectable and cinematically rich borsht that upscale film fans will devour. Knight, whose Dirty Pretty Things focused on the illicit sale of human organs in London, establishes himself as England’s screenwriting specialist in urban amorality.

Eastern Promises begins with anything but. A pregnant and profusely bleeding homeless 14-year-old Russian girl named Tatiana ends up in a London hospital, where she dies. Anna (Naomi Watts), of Russian heritage, is the nurse in charge who cares for the surviving baby, whom she names Christine. Anna also confiscates Tatiana’s diary and, although not speaking Russian, notices prominent mention of a Russian restaurant in London.

Anna visits the owner, Semyon (Armin Mueller-Stahl), hoping he will translate the diary so she can unlock Tatiana’s identity and find baby Christine’s remaining family. But unbeknownst to Anna, Semyon is also leader of the evil and powerful Vory gang of Russian mobsters, known for their tattoos, secrecy and engagement in unusually vile crimes.

Once Semyon reads the damaging content, he takes action because Tatiana has exposed the cruel tactics of the Vory gang. Semyon attempts to coax the diary out of Anna’s hands, but she has only given him a copy.

We hear details of the diary in voice-overs as Tatiana describes her horrendous kidnapping from Russia and her forced journey into drugs and the sex trade. The diary also reveals that it was Semyon who raped Tatiana and is the father of her baby. Semyon assigns his top henchman/heir apparent/chauffeur Nikolai (Mortensen) to get the incriminating journal, which Anna, growing suspicious, has handed over to her Russian-speaking Uncle Stepan (Jerzy Skolimowski), a frequent visitor to Anna and mother Helen’s (Sinéad Cusack) home.

Nikolai, who has bonded with Semyon’s sadistic, loser son Kirill (Vincent Cassel), is soon saddled with the task of killing Stepan. The reward is entrée as a “Vor” (a made-man, Russian-style) into the Vory gang. Hereafter, writer Knight delivers some nifty twists that happily outshine some gooey melodrama, but not before Cronenberg gives us scenes of barely watchable savagery.

Eastern Promises is essentially a character-driven crime thriller but is also a bloody tour de force laced with considerable nudity and sexually bold content that will rattle the squeamish. Mortensen’s startling performance as a coolly amoral thug provides ample compensation, as does the terrific support of all the film’s co-stars. Mueller-Stahl, Cusack and Skolimowski don’t have as much to chew on, but Watts is touching in her quiet torment and bravery and Cassel is particularly delicious as the thoroughly reprehensible, screwed-up mob boss’ son.

Beyond the lurid, the film also manages scenes of considerable tenderness and adorableness (courtesy of baby Christine) and is also blessed by Howard Shore’s restrained score, which lets the film’s other estimable elements breathe through.

Cronenberg does it again—a fact that will please most savvy filmgoers with strong stomachs.