PLAYING a paedophile who is sent to prison for molesting young girls (“But I never hurt them”) is not the kind of career move that endears stars to their agents. Kevin Bacon’s decision to play the lead role in Nicole Kassell’s debut film, The Woodsman, is the toughest professional call he has ever had to make.

Bacon is a prolific actor who is difficult to dislike even at his most calculated and creepy, usually because his choices are driven by smart pictures rather than the promise of smart money. Critical respect is always useful armour. But a film about paedophilia, directed by a complete unknown, is the twilight zone of credibility and taste. The gamble pays off; the film is hypnotic; and Bacon’s reputation remains intact. But The Woodsman is not the masterpiece I was expecting. There’s not much “revulsion” to enjoy when the film sits so squarely behind the anti-hero.

Bacon is sharp casting as a child molester thrown back on the streets after 12 years’ hard labour. Walter is a handsome shadow of his former self: dead-eyed and dismal. He shuffles to work at a lumber yard and catches the bus home to grubby digs opposite a school. He is mysterious enough to attract female attention during lunch breaks, and suspicious enough to merit investigation when he leaves the table after one forkful of food.

Walter’s rap sheet is duly handed round and a taunting cop (played with cruel conviction by Mos Def) pitches up at his flat to inspect the bed-linen and spit in the kitchen sink. Walter seems destined for an old-fashioned lynching or a lifetime of prejudice, police tea parties and despair. “When will I be normal?” he asks his therapist, a careless meddler.

The deeper question is will he ever be forgiven? The evidence is hardly promising. Kyra Sedgwick, Bacon’s real-life wife, plays a brassy fork-lift driver who claims she isn’t fazed by much, but promptly chokes on the truth after she bullies Walter into bed. “The first was a 9-year-old who told me she was 11. The second was a 14-year-old who told me she was 12,” says Bacon, cynically staring into the school playground. “Now please leave.”

You feel for Bacon as his one genuine emotional contact picks up her clothes and closes the front door. You appreciate the acid honesty, and the film’s rare empathy with its heroic “victim”. And you wonder whether Walter can chop his way out of the woods. What is going on behind those flinty eyes which seem to spark into life only at the sight of very young girls at bus stops or park benches?

The morbid tease is whether Walter is cured or not. He keeps a journal to log his thoughts, and a weather eye on Mr Candy, a stalker who seems to be grooming little boys outside the school gates. Does Walter have the desire or duty to shop him? The dilemma is scary. Paedophilia is a disease with deep roots and long fingers. But the lack of hard detail, and the grainy documentary stock, makes the film seem hours longer than its 87 minutes.

Kassell stirs the ambiguity with several expressionistic touches. Walter’s encounter with the saucy (adult) Sedgwick is a blizzard of jump cuts that make you wonder whose body he is actually grappling with. The film delights in underage innuendo. The implicit challenge is: “Who dare cast the first stone?”

Yet the medical distance the director maintains between the camera and the mucky answers is worthy of Pontius Pilate. Pass the soap.

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