According to Rachael Stirling, there are certain books that, as a young woman, "capture a little part of you and you'll remember them forever". For Rachael, Sarah Waters's Tipping The Velvet falls squarely into that category. Fitting, then, that she should be starring as its heroine, Nan Astley, in Andrew Davies's daring adaptation for BBC Two.
Rachael, who went to Wycombe Abbey School, says: "I first read the book last year and I felt passionately about it." The young actor explains earnestly: "The one thing I minded more than anything was that the film should be funny to watch. I didn't want it to be a breast-beatingly serious drama about lesbians, which it's not. It's a simple tale about this girl and the fixes she finds herself in. It has a vibrancy and an energy that just blow you away."
Set in the 1890s, Tipping The Velvet is a sensuous and entertaining love story, and Nan, the heroine, is at its heart, is a heroine as appealing and charismatic as Elizabeth Bennet in Pride and Prejudice. As she grows into womanhood, Nan realises that she is attracted to women, not men, and the story follows her awakening, as she embarks upon a series of romantic adventures in the sexual underworld of Victorian London.
True to the original novel, Davies's scripts do not fight shy of portraying the whole of Nan's extraordinary story. And though Stirling knew the book "back to front" and has worked with Davies before. He penned ITV's modern reworking of Othello, in which she played the scandalous Lulu. When she received the scripts she admits that she was still taken aback at their candour.
"Andrew, naughty man, has got a lot to answer for!" she laughs. There are, she continues, "ways and ways of writing stage directions" even, she is convinced, when a dildo is involved.
Rachael turns serious for a moment. "But, listen, you don't see exactly what's written in the scripts. I'm not saying that you don't see anything you do and, needless to say, it's all justified and done very carefully but, as (director) Geoff Sax invariably said in every single scene, 'It's more the art of what isn't seen'. After all, you don't want to watch your leading girl through clasped fingers, embarrassed at what she's doing."
Resolutely determined not to trade on her starry family connections her mother is Dame Diana Rigg Stirling, 25, has spent the last four years carefully carving out a name for herself on her own merit.
Early on, she went "undercover" shunning interviews and concealing her background from agents and other actors to win a place at the National Youth Theatre and find an agent. By the time people realised who her mum was, Rachael was an established presence in her own right, with roles in popular films Still Crazy, Maybe Baby and Iain Banks's Complicity already under her belt.
"Looking back, I probably dealt with it in the wrong way," she says now. "I thought that admitting that she was my ma would somehow take away from my own achievement, which is dumb, and I now celebrate it and am hugely proud of it. She reads the odd script but she doesn't get involved with my work the joy is that we have that in common. She's my ma, not Diana Rigg."
Rachael, who has inherited her mother's striking dark looks, says that the experience of striding out on her own put her in a good position for tackling the role of Nan in Tipping The Velvet.
"I found it quite hard, during filming, to separate myself from Nan, simply because she's like most other young women who are trying to find their own identities," she says. "She's got a wonderful spirit of trial and error about her she tries anything and goes anywhere and meets anyone, just to try and discover who she is. She throws herself into things 400 per cent. She's strong, brave and funny, she's modest and charming. More than anything, she's determined to find someone to whom she belongs and somewhere to be at home, and the three episodes take viewers on a journey of her life."
And it is, Stirling agrees, quite a journey. "It's the 1890s and Nan doesn't feel she fits in particularly in Whitstable with her family. She doesn't belong in the oyster parlour, she's tempted by the theatre and finds herself drawn to Kitty. She goes from innocent girl to music hall star to rent boy to live-in lover with a manipulative, rich lesbian! Every single day of filming was a complete joy because I discovered something different about her."
As research, Rachael, who has a degree in art history from Edinburgh University, immersed herself in the period in which Tipping The Velvet is set.
"Through paintings, I'd gathered a certain amount of information about that period and I knew that the pornography that came out of Victorian England was shocking at that time. I also did a fair amount of research into male impersonators like Vesta Tilley; Kitty's the first one Nan's seen but it was a pretty common act."
Unlike her co-star, Keeley Hawes, Rachael couldn't wait to hit the stage for the drama's rollicking music hall scenes.
"I'd done a certain amount of singing and I knew I had a voice in me," she laughs, "and it turned out to be a belting voice rather than starling-like. But I loved the singing and it's not like becoming a great opera singer it's rather more nudge, nudge, wink, wink!
"Performing in front of the audience was great fun but there was something slightly different about when they were doing close-ups of us and there were only six people in the audience. You take a great big bow and there are six people going, 'Yeah, it was alright. Cut!'"
The actor says that she's thrilled to be part of a drama that was dubbed controversial months before the first scene was even filmed.
"Apart from Oranges Are Not The Only Fruit and the odd snog on Brookside, there's very little else that's ever delved into lesbian relationships. Tipping The Velvet is about love, and it shouldn't matter whether it's two women or a man and a woman. Nan's so funny that you shouldn't mind whether she falls in love with a man or a woman, you want her to be happy at the end of it.
"If the lesbian theme makes people tune in, then all the better. I hope by the end of it, they're carried away by Nan and her story, so it overrides any titillation that they first expected. But there's definitely titillation there they won't be disappointed on that one!" she grins.
These days, Rachael "practically" lives with her boyfriend, John Lycett-Green, a DJ, in North London. The pair recently spent months apart while Rachael was filming The Triumph Of Love in which, incidentally, she plays "a cross-dressing comedy maid opposite Mira Sorvino" with director Clare Peploe and legendary film-maker Bernado Bertolucci in Tuscany. But now they're making up for lost time.
"On my down time I'm a DJ bitch," Rachael laughs. "I sit behind the decks and I thwhack any girl over the head who comes up slobbering over my boyfriend and anybody who comes up and asks for S Club 7!"
