Not a batty move for Lynch

It took director Pat Murphy nine years to make Nora, her dark, erotic movie based on the life of Nora Barnacle, lover and muse to James Joyce. Funding fell through repeatedly. It often seemed as though the film wouldn't get made at all. Susan Lynch, the young Irish actress Murphy had cast as Nora, sat by the phone for more than two years. When the calls came, the news was usually bad and Lynch would think: "Not this year. Maybe next."

Meanwhile Ewan McGregor, who'd been cast as Joyce and whose production company Natural Nylon eventually picked Nora up, turned into a light-sabre-wielding mega-star. Lynch appeared in a movie called Waking Ned, adored by the Americans for its kooky, Ealing comedy-esque Irishness. But still everyone involved in Nora kept faith with Pat Murphy. "There was this collective passion about the film," says Lynch. "We weren't ever going to give up on it. From the moment I read the script, I thought, 'If this is the last role I ever play, I don't mind'."

The finished film certainly looks and feels like a labour of love. Lynch and McGregor positively rage with emotion and lust. There is more sex in this movie - wild, anarchic sex - than in a dozen Hollywood bonkbusters. The attention to period detail also seems the result of passionate research and heroic effort.

Before she read the script, Lynch had never heard of Nora Barnacle - the country girl who worked as a waitress in dark, oppressive Dublin; who met Joyce in 1904 and fled the city with him barely four months later. They remained together, unmarried, for 25 years, until his death. "Joyce without Nora is inconceivable," she says. "She's fascinating to me in so many ways. Some people say that he treated her badly, that he manipulated her, but actually she'd never have fallen in love with anybody else. And she'd be the first one to call him an arsehole." I ask whether she thinks Nora is a feminist film, since to an extent it reclaims the memory of a woman whose personality informs every female character in Joyce's work.

"I wouldn't use that word to describe it, but I see what you mean," she says. "To have a central character who's female and Irish is rare enough in itself. And yes, Joyce is the one who talks about the repression of Catholic Ireland, but Nora is the one who really feels it. Nora was amazingly progressive, but I think in a way she represents a lot of women in relationships. She illustrates an emotional strength that a lot of women have, and we're not used to seeing that."

Appropriately then, Lynch steals the movie from McGregor. It's Nora's volatility that gives the movie its emotional charge, and her brazen beauty which holds the camera. You wouldn't describe Lynch as pretty - her face is too bold and expressive for that, the legacy of Italian and Irish genes (her mum's the one with relatives in Rome), but handsome and strong. In person, having got up at five to catch a plane to London, she wears no make-up, smokes Silk Cut like a trooper and still has perfect, porcelain skin. She's also tiny, dressed in baggy trousers and a jean jacket, clothes which make her look much younger than 28.

She grew up in a tiny village near Newry in Northern Ireland, the youngest of five children. Her dad drives tip lorries for the council. Her brother John is also an actor - George Best in the current biopic - and it was his example, combined with advice from the former leader of Newry's Newpoint Theatre drama group, which persuaded Susan to become an actress. She started out at 17, in Gaelic. Then went to drama school in London, worked at the National Theatre (Pericles, El Cid), the Old Vic (Miss Julie) and the Royal Court (with Danny Boyle) before TV parts came along, and then offers for films. Unlike the majority of young actors, she doesn't crave fame, Hollywood or big pay cheques. She recently left London to be nearer her family and her new boyfriend.

"At this point in my life, where I'm at with my relationship, where I'm at with my garden, it's right for me to be in Ireland. It felt as though my life was passing me by in London. I'm just happy to get work that I can feel passionate about, but like the rest of the human race, I love not working, too. Having a month or two off. I never feel edgy or nervous about it."

This is unusual in a profession known for its collective paranoia. She says all she really wants is to play strong women who interest her, and then describes her next film, an American movie about Jack the Ripper starring Johnny Depp and (somewhat bizarrely) Heather Graham. "I play Liz Stride, a lesbian prostitute and alcoholic. She doesn't sound particularly strong but she is. She gets murdered while she's p*****, so she doesn't feel much."

Unlike Nora, then, who couldn't hide her feelings if she tried. "God, yeah," says Lynch. "In some ways, there's something amazingly radical about Nora that you envy. But how would you live on a day-to-day basis being her? I know for a fact that I wouldn't have the courage."