The mother of a teenage sociopath who went on a high-school killing spree recalls her son’s deranged behavior during childhood, as she deals with her grief.

Will Montgomery (Ben Foster), a U.S. Army Staff Sergeant who has returned home from Iraq, is assigned to the Army’s Casualty Notification service. Montgomery is partnered with Captain Tony Stone (Woody Harrelson), to give notice to the families of fallen soldiers. The Sergeant is drawn to Olivia Pitterson (Samantha Morton), to whom he has delivered news of her husband’s death.