The surprising lack of a pay-off to Eastern Promises marks a rare misstep for Cronenberg, who either overlooks or ignores the contrivances that mar Knight's disappointing follow-up to the similar (and superior) Dirty Pretty Things. Set primarily in London's Russian community, Eastern Promises stars Naomi Watts as Anna Khritrova, a midwife born to a Russian father and English mother (Sinead Cusack). Saddened by the death of a Russian teenager in childbirth, Anna resolves to find the baby's relatives. However, the only substantive information Anna can find about the dead girl is in her personal diary, written in Russian (a language Anna's never learned).

Ignoring the advice of her ill-tempered Russian uncle Stepan (Jerzy Skolimowski) to turn the diary over to the police, Anna finds a translator in Seymon (Armin Mueller-Stahl), the cultured, Old World owner of the Trans-Siberian restaurant. What Anna doesn't know is that Seymon is actually a ruthless member of the feared Vory V Zakone criminal brotherhood—and that he and his volatile son Kirill (Vincent Cassell) have a sordid history with the dead girl that must remain secret. To that end, they rely on trusted driver Nikolai Luzhin (Mortensen), whose cryptic, soft-spoken demeanor betrays nothing, making him all the more formidable of enforcers. Yet for reasons that are a bit too hastily introduced later, Nikolai seems to want to help Anna—even as he rises in the Vory V Zakone.

Evocatively shot by Cronenberg's longtime cinematographer Peter Suschitzky, Eastern Promises provides a viscerally disturbing glimpse of the Eastern European "people traffic" conducted by the Vory Z Zakone (a real-life criminal syndicate) and others. There are scenes here as nerve-fraying as anything as Cronenberg's ever done; a fight scene in a public bath is almost unbearably intense. But as more and more of the narrative puzzle pieces fall into disappointingly routine place, the insidious dread of the film's first half gradually dissipates, as the narrative contrivances begin to accumulate. It also becomes increasingly difficult to suspend disbelief vis-à-vis the actions of Watt's heroine, who knowingly puts herself, and her family, in harm's way, yet never goes to the authorities. The police, in fact, are shown briefly, investigating the related-murder of a Chechen gangster, but then conveniently disappear until Cronenberg and Knight bring them back for a late-breaking plot twist that's clumsily revealed and insufficiently developed.

Although Eastern Promises fails to live up to the expectations raised by A History of Violence, it's not a complete letdown. And Mortensen has never been better. Playing the enigmatic Nikolai, his sinewy physique covered in tattoos, he's a mesmerizing presence, both lethal and morally conflicted. He fulfills the promise of A History of Violence; regrettably, the same cannot be said of Cronenberg.