Peleliu, September and October, 1944. Sledge, Snafu, Burgin, Leyden, De L'Eau, Lt. Jones, and hard-bitten WWI veteran Sgt. Haney patrol the Japanese-controlled Umurbrogol Hills. The men finally come off the line and revel in the thought of rest and hot chow. An injured Col. Puller brings his men down from the hills, and Sledge recognizes Chuckler being carried out on a stretcher. Meanwhile, Basilone continues his bond tour back home, appearing at yet another fundraiser, with ever-growing frustration and guilt over being away from his comrades in combat for so long.
Lt. Jones and Burgin lead Sledge and the rest of the platoon on a mission and quickly realize that a nearby bunker is filled with Japanese soldiers. In the ensuing fight, Leyden is peppered in the face by grenade shrapnel, while Sledge kills an enemy soldier at close range with his bayonet. Eventually, Sledge's company is ordered back up into the Umurbrogol Hills, where they come under increasing fire from the Japanese, who are hidden in caves and pillboxes. Sledge and Snafu are pressed into stretcher duty and ordered to retrieve a wounded Lt. Jones. As they bring him down the hill, Lt. Jones is shot again, this time fatally. Then, the unthinkable. "Sniper got the Skipper, Ack Ack's dead," Burgin announces to the stunned company. The men weep openly at the loss of their beloved captain.
Later, Snafu admonishes a close-to-the-breaking-point Sledge not to remove gold teeth from a Japanese corpse, as he was obviously intending. "You don't wanna do that," he cautions, and Sledge reconsiders, settling for the Japanese insignia instead. After a month on Peleliu, Sledge and his men are finally relieved and return to Pavuvu, where they are greeted by replacement Lt. Mac and the incongruous sight of smiling Red Cross girls offering juice. As evening falls, Sledge strips naked and joins the others in a welcome and cleansing swim in the ocean.