Starring Viggo Mortensen as Tom Stall, the owner of a diner in a small town, David Cronenberg's latest film, A History of Violence, closes in on an ordinary family whose idyllic life is disturbed by unexpected violence.

This being a Cronenberg film, things are sure to get twisted.

Gore and strange physical or mental transmutations are a well-known part of Cronenberg's work. For more than three decades, the Canadian filmmaker has explored sci-fi, horror, the macabre and the bizarre in films such as Scanners (1981), The Fly (1986) and the gander into a mental patient's mind in Spider (2002).

But whatever the genre, at the heart of his films lies an insightful look into the psychology of his characters.

"(His movies) always involve interesting human behaviour. He is a good student of human beings and the way they behave and the way they interact," Mortensen said at a recent interview in Tokyo.

The actor said working with Cronenberg was one of the main reasons he took the role.

"He is a good storyteller," Mortensen said. "He doesn't try to make the audience think something, you know, a specific idea. He just tells the story and you maybe ask yourself questions."

Based on the graphic novel by John Wagner and Vince Locke, the film focuses on Stall, a gentle family man living happily in Millbrook, Indiana, with his lawyer wife, Edie (Maria Bello) and two children, Jack (Ashton Holmes) and Sarah (Heidi Hayes).

That peaceful world is shattered one evening when two wanted men come into his diner with a stickup on their minds and threaten to harm his waitress, cook and customers. Tom hurls a coffeepot, jumps the counter, grabs a gun and kills the two men. Calling him a hero, the media make him a reluctant celebrity on a nationwide scale.

The coverage leads to the arrival of a horribly scarred stranger (Ed Harris) in a black limo with two toughs from Philadelphia. The man, Carl Fogarty, seems to have known Tom a long time. But he calls him "Joey" and bears him a grudge.

The film has the makings of an orthodox thriller about a man with a hidden past. There is plenty of graphic violence, sex and nudity.

The strength of this drama lies not, however, in the solution of the mystery surrounding Tom's past, but in the psychological complexity of the protagonists. Layers of personality are laid bare as the story unfolds.

Mortensen's subtle and gripping performance delivers the dark and soft sides of his character convincingly.

"Life is not so clear; people's behaviour changes all the time," Mortensen said.

Asked how he connected to this character, he said: "I just try to be honest in terms of the requirements of the story as I read it and as I understood it and talking with David.

"Because he is good at communicating with actors, not just with me, with Maria and everybody else, when we started shooting, we had a very good idea about what we were supposed to do."

The plot intensifies when Fogarty starts to tag after Tom's family and tells Edie he knows more about Tom's past than she does. Gradually, Edie's anxiety turns to suspicion, and Tom becomes desperate to protect his family.

So, how does our "history" influence our identity? Are we able to escape the past and become someone else by creating a new identity? The film invites the viewers to meditate on the question of identity as well as the nature of violence.

"For me, it (the film) made me think about the fact that it's never too late to change your attitude in life. No matter what your history is as a person, you can always change your direction," Mortensen said.

"And I suppose that would be true about a government or a group of people or a nation. Even if they are behaving in a certain way, they can stop and look at themselves honestly and change direction. It takes some effort, but you can try to change."

Despite the serious subject matter of the film, Mortensen said filming had its share of laughs.

"He (Cronenberg) has a good sense of humour and he doesn't take himself too seriously," Mortensen said. "He was always finding something to make a joke about on the set."