Freely adapted from the Pulitzer Prize-winning book by Seymour Hersh, this film recounts the My Lai massacre in Vietnam and the story of a platoon of American soldiers led by Second Lieutenant Wm. Calley. Falling into an ambush, they come under enemy fire and in the disastrous fight that ensues, two young soldiers lose their lives; a third is so badly injured that Sgt. Cowen is forced to put him out of his hopeless agony.