Keira Knightley Will Appear Partially Nude

...for a racy scene in new movie 'Atonement.'The 'Pride and Prejudice' star will disrobe before plunging into a deep fountain and emerging soaking wet in a clingy slip.The film's director Joe Wright is quoted by Britain's Daily Express newspaper, "I wanted to cast Keira as a woman, a sexual character. She's only ever played girls before."There is a key scene with James McAvoy where she dives into