During World War II, a Marine battalion prepares to land on a large Japanese-held island in the Pacific. Lieutenant Colonel Gilfillan warns the men that it will be a tough mission, and that they have been ordered to take Prisoner of war in order to gain information about the Japanese fortifications. Below deck, veteran Lieutenant Carl A. Anderson, a chemistry teacher in civilian life, questions his former student, Corporal Stuart Conroy, who complains that he is ill and cannot fight. Carl assures him that he has shown courage before and can do so again. In the landing boat heading to shore, Navy Hospital corpsman C. E. "Doc" Jones is worried because Carl has been suffering from "migraine" for months. Carl and his platoon have been fighting since Guadalcanal Campaign, and now only seven men remain of the original platoon. Although Doc urged Carl to seek treatment in the United States, Anderson refuses to leave his men and has been relying on Doc to supply him with painkillers.