A man of the creeps

David Cronenberg is what you might call a textbook auteur. Throughout his 40-year career, from his early experiments in gross-out horror (“Shivers,” “Rabid”) to his inspired takes on outre literature (“Naked Lunch,” “Crash”) to his current phase as a sly genre deconstructionist, the Canadian director has assembled a fiercely coherent body of work. Obsessed with the mutability of flesh and the mysteries of the mind-body connection, his films are tightrope acts, poised between the cerebral and the visceral.

On the surface, “Eastern Promises,” out on DVD Tuesday, is one of Cronenberg’s most straightforward films: a gangster thriller about blood ties and Oedipal tensions, set in a damp, noirish London. But in almost every aspect, from the sumptuous atmosphere to the nuanced characterization, the film is richer and stranger than its contours suggest. It’s a fascinating companion piece to Cronenberg’s previous film, “A History of Violence,” which also starred Viggo Mortensen and smuggled cross-currents of ambiguity into a familiar genre context.

As Christmas approaches, Anna (Naomi Watts), a midwife at a London hospital, delivers the daughter of a 14-year-old Russian girl who dies in childbirth. The dead mother’s diary, which reveals that she was a victim of the sex trade, awakens Anna’s maternal instincts (she’s still grieving a miscarriage) and a latent curiosity about her Russian ancestry.

Steve Knight’s original screenplay echoes themes of his script for Stephen Frears’ “Dirty Pretty Things,” which was also set in the seamier sectors of London’s immigrant underworld. Anna’s quest brings her into contact with a tribe of expatriate Russian gangsters: a sinister paterfamilias (Armin Mueller-Stahl), his volatile son (Vincent Cassell) and the movie’s most magnetic presence, the family’s tight-lipped chauffeur and clean-up guy, Nikolai (a transformed Mortensen).

Mortensen here plays a character as complex and inscrutable as his family-man-with-a-secret in “A History of Violence.” In both films, his finely shaded performances recall another great actorly feat in an earlier Cronenberg film: Jeremy Irons embodying twin gynecologists in “Dead Ringers” (1988). Indeed, Nikolai is the latest in a long line of the director’s conflicted heroes, from James Woods’ man-machine mutant in “Videodrome” to Jeff Goldblum’s human-insect hybrid in “The Fly” to Ralph Fiennes’ paranoid schizophrenic in “Spider.” The question of identity -- how it’s constructed, how it breaks down -- is a central theme of Cronenberg’s, one that is often connected to the human capacity for transfiguration.

Blood flows freely in his films, but it would be hard to term the violence gratuitous. His early low-budget efforts, which subjected the human anatomy to outlandish physical transformations, pioneered the subgenre of body horror. Cronenberg’s mature works take seriously the moral connotations of that phase. “A History of Violence” and “Eastern Promises” are intimately concerned with the violence done to the human body.

The centerpiece of “Eastern Promises” is an extended knife fight in a bath house that Mortensen performs in the nude, his character’s prison tattoos -- his history of violence -- inscribed on his flesh. In Cronenberg’s universe, violence and sex go hand in hand, and Mortensen’s palpably sexual self-confidence dovetails with the homoerotic subtext. The most intriguing relationship here, it turns out, is not between Nikolai and Anna but between Nikolai and Cassell’s Kirill, a tormented closet case.

Cronenberg is a master of contradiction. Like so many of his films, “Eastern Promises” both fulfills and upends expectations and derives its power from ambiguity. The plot slowly gives up its secrets, but even after the arrival of a supposedly clarifying twist, the mystery man at its center remains an enigma.