Freely adapted from the Pulitzer Prize-winning book by Seymour Hersh, this film recounts 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.

Gripped by tension and hysteria, the platoon moves on, eventually coming to a small fishing village where they give vent to their thirst for revenge.

In a journey filled with violence and terror, the soldiers go through a collective personality change; in frenzied delirium, they execute Calley's ever more crazed orders, until the final tragic day comes: 16 March 1968 .........