By EW Staff
Updated December 03, 2007 at 05:00 AM EST
Alex Bailey

You take a beloved Ian McEwan book, have an Oscar winner (Dangerous Liaisons‘ Christopher Hampton) adapt it for the screen, and cast an Oscar nominee (Keira Knightley) and winner (Vanessa Redgrave). Factor in the British accents, and you get Academy gold, right? ” It is the best script I’ve ever read,” says James McAvoy (The Last King of Scotland). Though, wary of overselling, he adds, ” It’s a little hard to fulfill all that promise.”

True enough: Even with that pedigree, putting the novel on screen was complicated. The saga starts in 1935 with servant’s son Robbie (McAvoy) falling in love with Knightley’s upper-class Cecilia Tallis — just as her sister, Briony, falsely accuses him of sexually assaulting their cousin. Dark, yes, but also romantic, McAvoy says. ”It was a time of social repression, very different from nowadays. Now it’s ‘I love you, let’s go and have sex.’ People didn’t find it easy to examine their emotions, and I find that hugely enchanting to play.”

The drama spans six decades, including Robbie’s service in World War II and a present-day Briony (Redgrave) — now an author — coming to terms with her transgression by rewriting her own story. It’s Joe Wright’s favorite part. ”Pride & Prejudice was the first film I ever made with a happy ending, and I was nervous about the commercial cop-out of that,” says the director, who pledges to stay as true to the novel as possible within the confines of reasonable running time. ” And here was a story about happy endings.” Sounds abstruse, but McAvoy begs to differ: ” You could have a much simpler story that’s written badly, so it’s much more complicated. This was easy peasy.”