Sophia Myles talks about her meteoric rise to fame and reveals what it was like to kiss a screen hunk.

Four years ago Sophia Myles was just a gawky schoolgirl from Middlesex studying for her exams. Not even in her wildest daydreams did she imagine she would one day end up in bed in Prague, kissing Hollywood heartthrob Johnny Depp.

“It was incredible,” says Sophia, who plays Depp’s wife in the forthcoming thriller From Hell, based on the Jack the Ripper killings. “I tried to be cool and pretend it wasn’t a big deal, but I have to admit it was brilliant. I was being paid to go to bed with Johnny Depp and, yes, he was a great kisser.

“I always thought he was great actor and a very sexy man and it’s true, he’s both. The kissing scene took seven or eight takes, but I wasn’t complaining. The strangest thing was that a few weeks ago I went to see Chocolat and there was Johnny up on the huge screen. I was thinking to myself, `I’ve done a love scene with that man’!”

Alas there was no real romance between the smitten Sophia and Depp, who is happily married to French pop singer and actress Vanessa Paradis.

“He was such a gentleman,” she says with a sigh. “He showed me photos of his wife and baby girl. He is obviously madly in love with them both.”

After filming that project, Sophia went straight into making the lavish two-part ITV adaptation of Charles Dickens’ The Life And Adventures Of Nicholas Nickleby, which starts on Sunday. It concerns what befalls Nicholas and his sister Kate, played by Sophia, when they are forced to seek refuge with an uncaring uncle after the death of their father. The stellar cast includes Charles Dance, James D’Arcy as Nicholas, Gregor Fisher, Pam Ferris and Liz Smith. It shows just how far Sophia, who has just turned 21, has come. And she owes her success to a silly schoolgirl crush.

“I only chose drama as a GCSE option because I had a massive crush on my teacher,” she laughs. “As part of the course we put on Teachers by John Godber. After the performance, this man came and asked if I could go to the BBC TV Centre tomorrow to audition for The Prince And The Pauper.

“I was gobsmacked and said something stupid like, `I can’t, I’ve got maths tomorrow’. Anyway I went, had two auditions and they cast me. At the time I thought it was just a laugh. I was still sitting my GCSEs and I believed this was just a one-off and would never happen again. Then I got a call from a woman, who later became my agent, who asked if I would consider doing more acting. I said yes, as long as it was during the school holidays.”

Alongside her studies more film and TV work followed. She appeared in Big Women, Close And True, Oliver Twist and a film of Jane Austen’s Mansfield Park. “That was funny because I was studying Mansfield Park as one of my set texts for A-level and I absolutely hated it!” she laughs.

It soon became obvious that Sophia had to make a choice between acting and university.

“I had a place at Cambridge to study philosophy and my parents were keen for me to go,” says the only daughter of a vicar. “But I’d had enough of education by then. I thought I can either sit in a classroom and study Jane Austen or I can bring Jane Austen to life on screen and get paid lots of money for it – no choice really.”

Unfortunately, that decision has meant she’s been so busy working that she has not had time for romance.

“I had a boyfriend for about a year, but that ended seven months ago,” she says. “I think my career frightened him off. There has been no one since then. My problem is that I can’t have casual flings because when I am with someone I have to be very serious about him.”

Despite her success, Sophia’s feet are firmly on the ground, something she puts down to her family. “My 17-year-old brother Oliver is not at all star-struck or interested in what I do,” she grins. “I know he won’t watch Nicholas Nickleby because he’s just not interested in that kind of thing.”

Her parents are also coming to terms with her choice of career. “Mum and dad were more frightened about it than me,” she says. “They were worried that I might struggle, but now I’m earning more than the two of them put together they are starting to relax. Like most parents they are happy if I am happy. They are as baffled by all this as I am.”

Sophia, who shares a flat in West London with a girlfriend, next plays the lead in The Snow Queen based on Hans Christian Andersen’s classic story

“It starts filming in October in Budapest, then it moves to the Dolomites, and then I have to go to the North Pole for two weeks. I’m learning to ice skate and I will have to ride an elk at some point. It’s going to be totally wild,” she says.

But being out of work for six months at one time made her realise there are hard times as well as good. “I was on my own in London and I started to wonder if I’d actually made the right decision to go into acting,” she recalls.

“That taught me a lot. Up until then it had all been plain sailing and I was starting to get a bit blase about the whole thing. I know I’ll have long periods of unemployment in the future, but now at least I’m prepared for when it happens again.”

The Life And Adventures Of Nicholas Nickleby, Sunday, ITV, 9pm