David Cronenberg‘s Eastern Promises, which opens today, is another gangster movie, like the director’s 2005 A History of Violence. While the two films are quite different, as Cronenberg explained on promo trip to D.C. a last month, one thing that links them is star Viggo Mortensen. “I love Viggo,” Cronenberg said. “He’s just a mensch of mensches, a wonderful collaborator. The lead actor and the director, I’d say, account for 90 percent of the tone on the set. And we both like the same kind of set. Funny, but serious. Efficient, but relaxed. And very humane.”

The film is about Russian gangsters in London, but the cast is diverse. It was a great puzzle. There are not Russian actors around who speak Russian well enough and act well in English. And I didn’t want to do the traditional thing, cast English actors and they’ll do fake Russian accents. So instead I cast German and French actors who did fake Russian accents.

Polish director Jerzy Skolimowski also has a role. That was my idea. Totally out of the blue. I remembered that Jerzy had played a KGB agent in White Nights. So I said, “Where is he?” It turns out he knew my cameraman, so we got in touch with him.

There are many “family” connections here. The movie’s cast includes Sinéad Cusack, the wife of Jeremy Irons, who starred in your Dead Ringers and M. Butterfly. And Skolimowski directed Irons in Moonlighting. Yes, and that was the movie that convinced me that Jeremy was right for Dead Ringers. Because there, unlike most of things I had seen him in, he was vulnerable and funny, and I needed those characteristics.

Steve Knight, who scripted Eastern Promises, wrote Dirty Pretty Things. Did you like that movie? I liked most of it. I think the ending was a little too neat and sentimental. I think what happens with Steve is that he just falls in love with his characters, and he can’t bear to do bad things to them. [Laughs] There was some of that in the original script, and I expunged it. Mercilessly. But Steve was a very happy expunger.

The script was a lovely collaboration. For example, the whole tattooing thing, which is a central metaphor in the movie, was peripheral in the original screenplay. Viggo, doing his own research, as he does, found a book called Russian Criminal Tattoo, which is fantastic. It explains the symbology of the tattoos, why you have no identity in the prisons without them, and are not trusted if you don’t have them. I sent it to Steve, and it really snapped the whole movie into focus.

I imagine that, everywhere you go, people ask about the film’s steam-room knife fight. Yes. The knife fight is really realistic. I want my audience to really experience it. I think people go to a movie to become someone one else, to live another life for a while. I wouldn’t want to shortchange them. If you want to be Nikolai, this is Nikolai’s life.

But as you watch, you don’t just feel Nikolai’s vulnerability; you feel your own. Absolutely. I guess—-and this is the first time I’ve thought of it, I swear—-it’s like the shower scene in Psycho. It’s nakedness, steam, knife. Now that’s interesting. I really had not thought of that before. But it’s classic. You’re never more vulnerable than when you’re naked and wet.