It's like an amazing love song 
James McAvoy first came to prominence on Channel 4's Shameless, and has established himself as a rising star in films including , and . Having taken his first period role in earlier this year, he tackles further literary fare in Joe Wright's .
Ian McEwan's novel is a recent literary classic - had you read the book before you were cast?
I read the script first, and thought to myself, if I don't get the part I'm not reading the book because it'll be devastating. It's an amazing role and I really wanted it.
So I got the part and I did read the book, and the story devastated me all over again. It's utterly harrowing. I love Ian McEwan's writing. A lot of people said it was unadaptable for film, but I think we prove that wrong.
Could you tell us a bit more about your character, Robbie Turner?
He's the son of a gardener who works in the grounds of a large country estate. The father disappears when he's very young and he's taken under the wing of the father of the house and his education is paid for.
He's a very working class person, but has access to society that other people of his class wouldn't have had. He's been best friends with Cecilia Tallis [Keira Knightley's character, the middle daughter of the household] for his entire life but they've become divided, because he's very much in love with her.
Everything's very repressed, but these feelings of anger and sexual expression come out in one very explosive moment. This moment ultimately signals their doom.
Atonement contains some incredible war scenes, including a five-minute long shot of Dunkirk, filmed at Redcar in North-East England. What was it like working on that scale?
It was massive - we covered about a mile with that scene. There were a thousand extras and a really big ferris wheel. It was incredible to be part of that kind of choreography, it's just not something that you see done a lot.
It really is the kind of thing you see in movies directed by people who are referred to as "masters", y'know. To be involved in the work of a potential master was quite exciting.
Do you think cinemagoers expecting a conventional period drama will be surprised, especially when the rudest word in the English language plays a key role?
No one actually says it in the film, ever. We only see it typed. I know that Joe Wright was asked to take the word out of the film and he rather brilliantly said, "The _____ stays in the picture," which is good.
And, lastly, why should people go to see Atonement?
It's an incredible work of entertainment and art. It's got a lot of integrity and, like an amazing love song, it makes something depressing somehow uplifting. It makes you understand what it is to be a human being.
Atonement opens in UK cinemas on Friday 7th September 2007.
