Vietnam, 1969. As they prepare to be sent into action again, a platoon of the 3rd Battalion of the 101st Airborne receives five FNGs as replacements- Beletsky, who constantly frets that he won't be able to remember everything he is taught, Languilli, who gets annoyed when people Mis-pronounce his name, Washburn, Beinstock and Galvan, the quietest but most promising of the new intake. Taken under the wing of their war-weary squad leader, Sgt Frantz, the recruits are taken through a crash-course in battlefield skills, everything from oral hygiene to a demonstration from a captured NVA soldier as to how skilfully enemy troops can penetrate perimeter defenses.The platoon has a new commander, Lieutenant Eden who is going to need the skills and experience of both Frantz and platoon-Sgt Worcester. The platoon's specialist MG-team is composed of the burly Pvt Duffy and his Mis-matched, bespectacled buddy Pvt Gaigan. The three African-American veterans of the unit- Motown, 'Doc' Johnson and Sgt McDaniel- all have first-hand knowledge of the racial discrimination still practiced in the army. The FNGs get their first sudden taste of war when a quiet spell beside a river is interrupted by an enemy artillery barrage and Galvan is killed. The platoon enters the A Shau Valley and runs into an enemy patrol, sparking a firefight in which Sgt McDaniel is killed. This loss provokes considerable bitterness and tension as McDaniel was near the end of his tour and, being black, was denied any chance to score rear-line duties at headquarters.The Battalion commences an assault on the enemy-held Hill 937 which soon grows into a major battle as unexpectedly heavy resistance is encountered and the NVA, rather than using hit-and-run tactics, are instead defending well-entrenched positions. The platoon is forced to attack the hill repeatedly against stubborn opposition and US air-strikes steadily strip away all vegetation, leaving the hill a barren, scorched wasteland. In one assault, a battle-crazed Duffy, wielding an M-60, seems on the verge of carrying the day as the enemy begins to crumble. But a Mis-directed fire support by helicopter gunships causes many friendly-fire casualties. The assault fails and Duffy are among the fatalities.In between attacks, the shrinking platoon tries to rest, talking about the social upheavals back home. Beinstock is devastated by a Dear-John letter from his girlfriend whose college friends have told her that it is immoral to remain partnered with a soldier. Beletsky gets a letter on tape from his girl back home and Frantz is surprised, and not a little moved, that she mentions his name. Frantz makes it clear that he has no time for draft-dodgers back home and says that they should at least show up, even if they don't use their weapons. He also has an angry confrontation with a TV reporter, telling him that he has more respect for the NVA on the hill because 'at least they take a side'.The increasingly exhausted platoon keeps trying to capture the hill. The tenth assault takes place in torrential rains, turning the hillside into a river of mud. Gaigan is killed and Doc Johnson is wounded. Before he is evacuated, the latter tells Frantz and Worcester to take the hill so that they at least have something to be proud of. The 11th and final assault is mounted by the survivors whose bitterness and exhaustion is overcome by anger and unit pride. The final enemy positions are overrun but the cost is heavy. Lieutenant Eden is wounded, losing his arm. Worcester, Motown, Beinstock and finally Languilli are killed before the few survivors make it to the summit. Frantz, wounded by an enemy bayonet, rests on the hill-top alongside Beletsky and Washburn as the battlefield finally goes silent.