The story revolves around the life of Briony Tallis (Saoirse Ronan), a young girl who, through her misinterpretation of a traumatic event, sets off a chain of consequences that haunt the lives of those around her, particularly her sister Cecilia (Keira Knightley) and Cecilia's lover Robbie (James McAvoy). The film explores themes of guilt, atonement, love, class, and the destructive nature of unchecked desires.
: Rated R for disturbing war images, language, and sexual content .