Wedge Donovan (John Wayne) is a tough construction boss, building airstrips in the Pacific for the U.S. Navy during World War II. He clashes with his liaison officer, Lieutenant Commander Robert Yarrow (Dennis O'Keefe), over the fact that his men are not allowed to arm themselves against the Empire of Japan. When the enemy lands in force on the island, he finally takes matters into his own hands, leading his men into the fray. This prevents Yarrow from springing a carefully devised trap that would have wiped out the invaders in a murderous machinegun crossfire, with minimal American losses. Instead, many of Donovan's men are killed unnecessarily.