Two years after he helped save Middle Earth from unspeakable evil in the award-winning "Lord of the Rings" trilogy and a year after he raced his horse across the Arabian Desert in the 19th century-set adventure flick, "Hidalgo," actor Viggo Mortensen has opted to star in - gasp!- the contemporary big-screen thriller, "A History of Violence."

Helmed by "The Fly" director, David Cronenberg and based on John Wagner and Vince Locke's graphic novel, the film is about Tom Stall, an Indiana family man (Mortensen) who earns unwanted attention after he kills two men - seemingly in self-defence - in his diner. "Secret Window" beauty Maria Bello plays his wife, Edie, while "Pollock" actor Ed Harris plays Carl Fogarty, the mysterious threatening outsider who is certain Tom is not who he says he is.

"Any questions I had, (Cronenberg) answered them and then some," Mortensen recently told reporters in Manhattan, describing the movie as a "twisted and very dark story."

"I wouldn't have wanted to be in this movie directed by someone else because there would've been a good chance that it would've just been some kind of revenge story, or vigilante-type story," explained the handsome, 46-year-old New York native.

"And that would've been kind of dull, and not very grounded and thought-provoking," he continued. "This is thought-provoking on so many levels because he's just a lot more intelligent and has a much clearer vision than most directors, along with his obviously high degree of technical competence. He knows everything there is to know about his equipment, and his lenses. He knows the history of movies and so he had the guts to, on this movie, just tell it in a very straightforward manner; very plain...He didn't show off and that makes the story much more effective and, I think, more uncomfortable to watch."

Speaking of scenes sure to make moviegoers squirm in their seats, the film features a particularly steamy love scene between Tom and Edie on a staircase. Even though he and Bello watched out for each other while they were shooting the often awkward scene, Mortensen said there was little need to do so since Cronenberg tried to make them both as comfortable as possible.

"We had David protecting us both," the actor recalled. "If he wasn't protecting us, you still felt that you were in good hands, and that there was a good reason to go for it. And when we were doing that scene in particular, he didn't call 'Cut!' He rolled for a long time, which is how it evolved, in the few takes that we really did on that. Once it got going, on the stairs, it was uncomfortable, but I think both Maria and I recognise that that was right; that it was that way, and that the longer it went on , the more changing back and forth there was in terms of who was running the show, which was interesting. It was kind of a microcosm of their relationship in a way, on some level, you know? That power struggle."

Mortensen speculated that most relationships, even the healthiest ones, go through power struggles since bother people are usually at some point grappling to discover their own identity and trying to determine how they fit in - whether it's in a relationship or a community. Since the study of human behaviour fascinates Cronenberg so much, this theme is one that often appears in his work, Mortensen pointed out.

"And this movie's no different in that regard than other explorations that he's made," observed the thoughtful, soft-spoken actor. "And the idea that we all have secrets, some secrets bigger than others, but nonetheless, it's a normal human thing. It's a self-preservation thing to not tell even your closest friend everything, absolutely everything, that you're thinking or that's inside you. The people who say anything that comes into their mind, whether they're sober or not, at any time, no matter who's there, are considered to be unusual and are people that most people find dangerous or threatening...(Cronenberg) obviously, in most of his movies, likes to watch what happens when secrets can't be kept - from oneself and from others."

While the movie certainly lives up to its name, Mortensen is quick to note that the violence is shocking, but not overdone.

"David made it so that people can see what that is like - not pleasant," he remarked. "But it's shown very briefly. There's not much of it, but it's memorable because it's very matter-of-fact and he gives it strength."

For the Danish-American actor, who is also an accomplished poet, photographer, painter and jazz musician with a love for telling stories, headlining "A History of Violence" wouldn't have been possible had he not played the hero Aragorn in the the three "Lord of the Rings" fantasy epics.

"I wouldn't have gotten this role if it weren't for having been in that popular project," he admitted, insisting life hasn't changed much for him other than the increased quality of the parts he gets to play.

"So, that's just a practical thing and it was nice to work on this movie, and the one I did after David's movie, called "Alatriste," in Spain. Augustin Diaz Yanes was a similar kind of director in the sense that he was very well-prepared, very organised, and he didn't waste a lot of time and energy. He didn't have to, on the set, try to figure out what the hell was going on. So, it was nice to get the opportunity - which I would not have had - to play a principal role in that one, or in this movie, if it wasn't for "Lord of the Rings." So beyond that, I don't get (much extra attention). I don't give a lot of thought, to be honest with you."