Revenge is not as sweet as an apprenticeship

Forgive a killer? A new film explores the dilemma. By Robin Buss

"There is a language of the body, too," says Olivier Gourmet, talking about his preparation for the part that won him Best Actor award at the Cannes Film Festival last year for the Belgian film The Son (Le Fils). His character, also called Olivier, is an instructor in carpentry at a workshop for apprentices, who becomes obsessed with Francis (Morgan Marinne), one of his pupils. For the first 20 minutes of the film, the audience is left speculating about the reason for Olivier's evident unease when the boy is around. Why does he follow him back to his digs? If the man is a paedophile, his body language doesn't suggest it. And why this student in particular? Dour, taciturn, Olivier is an enigma.

We learn that he has lost a son, murdered by another child, Francis, now released from a detention centre, and starting an apprenticeship under a new name. Chance has brought him into Olivier's class; Olivier has recognised him despite his new identity - and for us the quiet man's obsession takes on a new, and perhaps even more sinister implication. The carpenter is a deeply wounded man, whose marriage has failed and his life been devastated by his loss – all of which Gourmet conveys in a compelling performance, with the minimum of dialogue. Words, he says, are "crude and empty, and not charged with the 'innerness' of the character."

We met in Paris, where Gourmet was launching the film, together with its directors, Jean-Pierre Dardenne and his brother Luc. Although far from taciturn, he showed some of the intensity he brings to the character of the carpenter as he talked about his preparation for the part, his interpretation of it and working with "les frères". Had they been inspired by any real events, for example by the murder of James Bulger in Liverpool?

"Yes, in part," Luc said. "By the story of the boys' parents: we had the idea of a film about the father of a murderer. Then the father, instead of being the father of the killer became the father of the [dead] child. And then what interested us was revenge. How would Olivier react? And, despite all the 'good reasons' that he might have for killing him, how to resist the desire for revenge."

The brothers have strong feelings about the cult of retribution, both in the cinema and in the tabloid press; so to that extent the film has a message. "It's dangerous to make a film to teach a lesson," Luc says. "But we do hope that the audience follows Olivier at some point and puts aside the desire to kill. Olivier escapes from it. It's a liberation, after all, and one that the audience feels."

On the other handyou never have the feeling that Olivier's eventual rejection of violence is inevitable or easy – thanks largely to Gourmet's ability to convey the character's inner pain and conflicts. "Olivier doesn't forgive," Luc insists. "it's just that life is stronger. Life is stronger than death. He doesn't kill, and no doubt he'll teach the lad a trade, that's all. He doesn't say: 'I forgive you.' He's not going to take the lad home and adopt him." "Their whole relationship is based on physical things," says Jean-Pierre. "Learning movements, learning a trade."

Gourmet met carpenters and people who had lost children in similar circumstances to those of Olivier in the film, appropriating their body language. "There's a whole lot of physical work that I do before filming. I'm someone who likes to watch people, their physical attitudes, in cafés, in the park, the station, on the train ... If I play a journalist, there may be a little of you in it." At the same time, The Son, he says, is "truly universal – death, passion, hatred, revenge, the desire to kill, forgiveness, tolerance ... Anyone can identify with this character."

A hand-held camera allowed the cameraman to follow the actor around more easily, but the film in the end breathes tradition, rather than innovation. The Dardenne brothers admiration for Mizoguchi and Bresson is clear, and their spare, reflective film treats a potentially sensational subject with restraint and humanity.

'Le Fils' (12A) is out on 14 March