During World War II Japanese forces hold a crucial observation outpost on a New Hebrides island which they use to radio orders for attacks on Allied ships. U. S. Navy Lieut. Sam Lawson, an officer noted for his proficiency in speaking Japanese, is ordered to accompany a group of British commandos on a mission to destroy the radio installation. Lawson sets out with the commandos' ineffectual leader, Captain Hornsby, and soon three of the British soldiers are killed in a Japanese ambush. Lawson and Pvt. Tosh Hearne, a cynical Cockney, become increasingly distrustful of Hornsby's ability, and upon reaching the Japanese camp, Lawson refuses to go into the radio hut. Hornsby destroys the hut himself but is killed while trying to escape; the remaining five commandos retreat through the jungle with the Japanese in close pursuit. Major Yamaguchi, the Japanese commander, offers clemency to the commandos if they will surrender. Private Campbell and two of the other soldiers do so, but Yamaguchi kills Campbell for mutilating the body of a Japanese soldier in order to steal a ring. Hearne and Lawson then ambush and kill Yamaguchi and continue their flight until they reach a clearing near the British lines. They make a break across the clearing, but only Hearne survives to report Lawson's heroism.