It had to be incredibly erotic and passionate 
Keira Knightley is the biggest British film star of her generation, instantly familiar from blockbusters including , and . It was her starring role in Joe Wright's , however, that gained her an Academy Award nomination, and she has reunited with the director for an adaptation of Ian McEwan's literary classic .
How would you sum up Atonement?
Blimey! Well, it's about the tragedies that can occur when the line between fact and fiction get blurred. That shouldn't give too much away!
Tell us about your character, Cecilia Tallis?
We meet Cecilia - the second child of the household - and Robbie Turner [James McAvoy] - the son of the housekeeper - at a point where they can't communicate with each other. Cecilia's having to deal with her own snobbishness, the fact she fancies him even though they've been brought up as brother and sister. There's all sorts of conflicting emotions going on.
What did you make of the original novel? Had you read it?
I read it before we started shooting. It's wonderful when you're working from a book like Atonement because Ian McEwan draws his characters so beautifully. It meant I could use the book a little bit like a blueprint. He does these incredible internal monologues which were a bit of a gift.
Does Atonement's incredible visual style (which involved stretching Christian Dior stocking over the camera lenses, to achieve a soft focus) reflect the imagination of young Briony Tallis, your character's sister?
I think that the 1935 section of the film has a fairytale quality to it. The reds are very red, there's a magical quality to it, and a part of that is emphasising Briony's imagination. Briony is very much a character who lives in her own head. She's a writer, she's constantly inventing stories and she puts all the people around her into those stories, and that's when tragedy occurs.
For a film with only one sex scene in it, in which the characters remain fully clothed, the whole film is incredibly sexually charged. How do you go about creating that sort of atmosphere?
The 30s and 40s were the pinnacle of the stiff upper lip and that very famous British emotional repression, and it was really interesting to look at that with Cecilia.
She can't express what she's feeling, and therefore this rage is constantly bubbling underneath her which explodes, perhaps, in the library scene [she smiles]. It had to be incredibly erotic and passionate because you have to believe that these people waited three years without seeing each other based on that moment.
It was incredibly important that you get that tension between Cecilia and Robbie because it's certainly not really spoken about, it's about what's not being said. It was really thrilling to play, actually. When you tap into the mindset of that period you understand how that sort of tragedy could happen.
A lot of people have already described Atonement as an Oscar contender. Have you started thinking about the awards season yet?
No. Honestly, no. I think you have to count your triumphs as they go along, and there have already been so many as far as this film goes. I think if we got any awards then that would be wonderful but if we don't, then that shouldn't belittle the experience or the piece of work.
And, finally, why should people go to see Atonement?
Because it's beautiful. And it'll make you cry.
Atonement opens in UK cinemas on Friday 7th September 2007.
