We're in a chic private members' club in London, and the lighting is tastefully low, but Kelly Reilly's green eyes sparkle brilliantly. It's a Friday evening, and after four weeks of gruelling rehearsals, the actress is clearly tired. But she's also bubbling over with excitement. She is playing the title role in Michael Grandage's production of After Miss Julie, Patrick Marber's sharp update of Strindberg's tragic masterpiece, at the Donmar Warehouse, in Covent Garden. Her co-stars are Richard Coyle, whose last leading lady at that theatre was Gwyneth Paltrow, and Helen Baxendale. And, although she is already well respected within the industry, the part is likely to launch Reilly into another league. "It's amazing," she says. "There are so few roles like this for women my age. It's a fantastic playground to be in. I'm aware every day of what an amazing opportunity this is for me."
Over a glass of red wine and a packet of Marlboro Gold, Reilly tells me about the play's challenges. Her smooth, oval face, with its luminous, moonstone skin, is animated, and she looks younger than her 26 years - an impression that is heightened by her almost childlike, unrestrained enthusiasm. Words, punctuated by bright laughter (usually at herself), tumble out of her mouth, and she gesticulates wildly, occasionally flinging herself back in her chair before leaning forward to attend to my questions with an intelligent intensity.
August Strindberg's 1888 play Miss Julie is a landmark of Naturalistic theatre and deals with dark sexual subject matter in a way that is remarkable for its time and still retains the power to shock. The action takes place in the kitchen of a mansion in Strindberg's native Sweden. There, on midsummer night, the young, aristocratic Miss Julie baits and flirts with Jean, a servant, under the nose of his wife-to-be, Kristin the cook. It's a dangerous game of seduction that can end only in bloody disaster. Marber, author of the acclaimed Nineties dramas Closer and Dealer's Choice, has reset the piece in a house outside London in 1945, on the night of Labour's historic general-election victory. With its resonance of the disappointments and compromises of New Labour, the play's treatment of the class divide and of the love-hate relationship between the arrogant haves and the aspirational have-nots has a renewed potency in 2003.
"It has a real freshness to it," Reilly says, exhaling smoke and then fastidiously wafting her pale, slender fingers in the air to disperse it. "It's set at a time when people are putting the war behind them and looking forward to a brave new world. But Miss Julie can't move into that world - she comes from an aristocracy that's crumbling, and hasn't had the emotional contact to deal with the situation she finds herself in." The character has been brought up by a muddle-headed, bluestocking mother, nurturing half-baked feminist notions, and a cold, distant father, both of whose influences have left their daughter with a warped attitude toward men. I put it to Reilly that the passion between John (Marber's equivalent of Strindberg's Jean) and Miss Julie has a sado-masochistic element.
"Definitely." She nods, vigorously. "It's incredibly destructive. There's violence, there's degradation and there's huge neediness from her. She understands about power - she knows what sexual power can do to men. But she understands it naively: she has no experience; she hasn't lived. She has this boldness and ferociousness, which is what ultimately finishes her - but it's also probably how she has survived this far."
Exploring such powerful emotional territory is exhausting, and Reilly says switching off after work can be a struggle. But she is no stranger to brutal material. Her first role, at the age of 16, was as a teenage tearaway framed for murder by her own mother in Prime Suspect IV. And in 2001, she was in the Royal Court's revival of that most notoriously horrific of plays, Sarah Kane's Blasted. When she read Kane's script, which was inspired by the atrocities of the Balkan conflict and featured harrowing depictions of rape, mutilation and cannibalism, her reaction was extreme. "I hated it. It repelled me. The writing was so vivid and raw. But it was absolutely real and, for me, fascinating. I often seem to do roles that involve a lot of delving into myself, but I'd like to think I'm not a masochistic actor. It's more that I'm interested in these characters' humanity. I want to show people about the world we live in. That's my driving force."
Reilly was born in Epsom and grew up in Chessington, with her dad, a policeman, her housewife mum and her brother, who is now a professional golfer. She went to school at the local comprehensive, where, she says, her academic career was scarcely stellar. "I never liked school. I never shone, I hated exams and I failed everything. I didn't have any confidence in my ability and I was very, very shy." But she did get her first taste of drama there, and says: "A whole new world opened up for me." She took a summer course at a London drama school, but hated it. So, instead, she found a regular performers' showcase and bagged herself a slot. She was spotted by an agent, and two weeks later was on the Prime Suspect set alongside Helen Mirren.
More small parts in television followed, and in between Reilly nipped back to school to finish off her A-levels. Then the playwright Terry Johnson, who had admired her in Prime Suspect, supplied her first two theatre roles, the second of which was in his production of The London Cuckolds, starring Caroline Quentin, at the National Theatre. It was Johnson, too, who later cast Kelly in his West End stage version of The Graduate, in which she played Elaine to Kathleen Turner's Mrs Robinson.
For a young actress, she has had a remarkably star-studded career. She has worked with Mirren again, on screen in the film Last Orders. And last year she effortlessly outshone Minnie Driver, Hank Azaria and Matthew Perry in Lindsay Posner's West End production of David Mamet's Sexual Perversity in Chicago. Reviews of the production were mixed but they all agreed on one thing: Kelly was a hit.
She wears her success lightly, insisting that it's "about the play", not the performers, and rebuffing my observation that the big-name actress Helen Baxendale has settled, in After Miss Julie, for by far the smallest of its three roles, insisting: "It's an ensemble piece." But she admits that, when she is working with famous faces, she still has to pinch herself occasionally. "I've always been starstruck. I got the role in Sexual Perversity, and then I found out who else was in it, and I thought: 'Why the hell have they cast me?' And I remember Friends being on TV before I started rehearsals, and I had to turn it off. The first day he walked in, I thought: 'It's Chandler - this is really surreal.' But within two days he was Matthew. And you quickly remember that everyone has their own internal chaos going on. You're in a room, thinking: 'Oh my God, what did I just say to Matthew Perry?' or 'What does Minnie think of me?', when actually they're doing the same thing. I mean, it was a big deal for them, coming into the West End - if there's anywhere you're going to feel really exposed, it's there - and they didn't have to do it. It took courage."
She'll need all her own courage on the opening night of After Miss Julie. "When I heard I'd got the job, I cried, then I laughed, and then the fear kicked in immediately. So I'll be very scared!" She grins, obviously relishing the prospect, despite the nerves. "It's only in the past two years that I've stopped feeling that every job's my first. I've started to go: OK, I'm all right. I've earned my place here. I don't have to feel inadequate because I don't have the training or the technique or the tools. I've got those now."
So, what next? "I'd love to work with a female director - I've only ever worked with men. And I really want to do some Shakespeare. But I don't have a plan of what I'd like to do or where I want to be - I'll just have to see what develops. Because, quite honestly, where I am at the moment is a place beyond my wildest dreams."
'After Miss Julie' previews from tonight and opens on 25 November at the Donmar Warehouse, London WC2 (0870 060 6624)Reuse content