In the late 1930s, a terrible deliberate lie — even one whose genesis we understand — wreaks havoc on the lives of three Britons: chilly socialite Cecilia (Kiera Knightley); her lover (and the housekeeper’s son), Robbie (James McAvoy); and her younger sister Briony (Saoirse Ronan), with whom the lie originated. The repercussions stretch into World War II, where death etches the lines of guilt, anger and lost opportunities even sharper. While Ian McEwan’s meta-novel, upon which this film is based, drew more complex relationships between fiction and fact, and just what power the creator of a narrative ultimately holds, Joe Wright’s film surrenders mostly to the melodrama and a softer, more audience-friendly conclusion. Atonement also bolsters its lace-hanky tears with a grand war-is-hell sequence (in a showy, if technically impressive five-minute tracking shot) and a sex scene or two. This is a well-acted literary adaptation, complete with handsome cinematography, sumptuous country-house interiors and gorgeous cast draped in period clothes.