As war looms in the Pacific, even cowboys are called on to fight the enemy. Horses are desperately needed by U.S forces stationed in the Philippines, and the Range Busters - Crash Corrigan, Alibi Terhune, and their newest partner, Davy Sharpe - are hired to accompany a herd to the islands. But first they must battle Axis spies right in Texas, as they foil a plot to steal the very horses destined for shipment.