Joseph Fiennes claims he doesn't remember the look on Harvey Weinstein's face when he turned down a five-picture deal with Miramax in the late 90s in order to do more theatre. He does, however, remember his reasoning. "I could see it in the piles of scripts: I'm not going to get the roles I want, but how do I challenge that? I wanted freedom."
Shakespeare in Love, the film that gave Fiennes instant promotion to Hollywood's premier league, is now almost 10 years old, and he still has his freedom; this week he returns to the stage in a new play, 2,000 Feet Away. Hunched over a coffee table in a rehearsal room in south London, he stares at a script covered in turquoise highlights, running rapidly through his lines in a heavy midwest accent. Fiennes, who has just turned 38 - receding slightly but with heartthrob credentials otherwise intact - apologises for being preoccupied, and then ploughs on.
Fiennes is three weeks into rehearsals. The play is a cracking debut by Australian writer Anthony Weigh. Ambiguous yet incendiary, it takes its title from the distance, under Iowa law, that sex offenders are required to maintain from places where children congregate. "It's a play about fear, and how you want to sort something out, and you try to drive it away," says Fiennes. "But it comes back to bite you twice as hard."
Fiennes plays a town sherriff in Eldon, Iowa. Forced to move a neighbour away from a nearby school, he escorts him to a motel outside town, which is a holding pen for local sex offenders. But the poison spills through the community. "People who wouldn't ordinarily think about [paedophilia] do," says Fiennes. "The prime example of someone whose mind is twisted is the 12-year-old girl [who in the play lives opposite the motel], who has 27 pictures of sex offenders on her wall instead of Bambi. She becomes a Lolita. The soul you want to protect becomes tainted by this feeding of information."
2,000 Feet Away is being staged in the tiny Bush Theatre in west London - at 80 seats, it is the smallest venue Fiennes has performed in - but the subject matter means it has the potential to be explosive. And this may be just what Fiennes needs. While he may have voluntarily stepped away from Hollywood, he has since lowered his stock with duds such as Rancid Aluminium and the execrable Killing Me Softly. His recent screen roles have been more challenging - he played a paedophile in 2006's Running With Scissors; Mandela's prison guard in Goodbye Bafana; Martin Luther in 2003's Luther. His next screen role is as the glowering muscle in The Escapist, a grimy, evocative prison-break thriller from first-time director Robert Hyatt.
"There's definitely a nice range opening up," Fiennes says. "In your early 20s, you get the Romeo scripts, and you do a film that pops in a wonderful way, and that changes everything. But you get more scripts based on that, because film is about money. Why be a forward, if you're a goalie? For me, going from Shakespeare to Running With Scissors is my fight to say: I can play [other] positions."
Fiennes may have eluded typecasting, but he has struggled to find another role that has captured the imagination in the way Shakespeare did. He talks about theatre as his lifeblood: he worked as a dresser at the National Theatre for four years in his late teens, and did an apprenticeship at the Young Vic. In recent years, he has played the tubercular artist in John Osborne and Anthony Creighton's Epitaph for George Dillon, Berowne in the National's Love's Labour's Lost, and the lead in Marlowe's Edward II at the Sheffield Crucible in 2001.
Fiennes is typically exact on the differences between stage and screen acting. For instance, the extra possibilities offered by the close-up: "Cinema's interesting when it's here [he mimes a camera near his face] and you say something, but you mean something else. The syntax of films is what's not said, but on stage a character's language informs you about their DNA." He could be describing his own strengths and weaknesses. He doesn't have the febrile screen charisma of his brother Ralph; he is a more immediate, strident performer, more coloured by the theatre.
Fiennes' mother was Jennifer Lash, a writer who overcame her own abusive childhood to create a loving, peripatetic, artistic home for her six children; their father was the photographer Mark Fiennes. Ralph is the eldest, and Joseph, with his twin Jacob, the youngest. The family lived between homes in London, Wiltshire and Ireland, but Fiennes says the constant moving didn't bother him. "You make it work. It's a survival technique in the schoolyard - making new friends." "Energy" is a word that crops up a lot in Fiennes's conversation, and in his case it doesn't just sound like actor-speak. For him, acting really does mean being physically out there: in the otherwise muted Goodbye Bafana, the film comes alive when he stick-fights a feisty Mandela. He took up rock-climbing after playing a mountaineer in Killing Me Softly, and half-killed himself trying to surf 15ft waves in Australia while filming The Great Raid in 2002. He ripped his lip off in a brutal wipe-out, requiring a graft from his earlobe to reconstruct it - the reason he's now rarely clean-shaven in photographs.
So you can't say Fiennes isn't up for new experiences. Last December he filmed his directorial debut in Russia, The Spirit, a nine-minute short by a new writer. He says he has long been fascinated with feral kids, from Romulus and Remus to Mowgli, and was looking for someone to flesh out a script on the subject. "So I said, 'Hey, you wanna cut your teeth?' And he came back and wrote something completely different," he laughs. "But it kinda worked, and it was The Spirit."
Fiennes only had a week to cast, scout locations and find an interpreter. "It was: OK, Joe, go - it was a baptism of fire. It was exhausting and fun." He found himself on set in the forest four hours' drive from Moscow every day, trying to cram in scenes before sunset at 3pm, "and when the sun goes down in Russia, it really goes down".
If The Spirit doesn't quite reach the Tarkovsky benchmark Fiennes aspired to, the film has plenty of atmosphere. He has since shot two shorts for the US Campaign for Burma, and smiles when I ask him if he's preparing more: "I think I am, yeah. Watch this space."
Talking about directing is the only time Fiennes lets his guard down, and puts his Rada-esque mannerisms aside. Art, in its many guises, has pride of place on the family crest, after all, even if Fiennes finds it hard to say why. "I'm still finding out - and it's a lifelong experience. Just after I pop my clogs, come back to me on that one. Right now, I'm at the centre of it, and it's not a bad place to be."
2,000 Feet Away is at the Bush, London W12 (020- 7610 4224), until July 12. Watch Joseph Fiennes' films at youtube.com/user/uscampaignforburma