On a summer day in 1935, 13-year-old Briony Tallis witnesses a moment's flirtation between her older sister, Cecilia, and Robbie Turner, the son of a servant. But Briony's incomplete grasp of adult motives and her precocious imagination bring about a crime that will change all their lives, a crime whose repercussions are followed through the chaos and carnage of World War II and into the close of the twentieth century.