In Arizona, not far from Fort Apache, a U.S. Army supply column is attacked by Mexican bandits. The bandits kill all the soldiers, kidnap Miss Adams. the doctor's daughter, and loot the ammo wagons. They make out with lots of rifles, ammunition and two machine guns. Tired of frequent Mexican bandit raids into U.S. territory, President Grant sends Captain Chadwell, Lieutenant Junger and Sergeant Smith to Fort Apache to help the fort commandant put an end to the raids. The three envoys are aided by the fort's scout, and bounty-hunter, Korano. The Mexican outlaws are led by Angelo Sanchez who, in return, obeys the orders of a mad Mexican general, General Mueller a.k.a. El Supremo. The bounty hunter Korano, who often rides under a pink umbrella and recites passages from the Koran, wants to capture Sanchez alive in order to claim the one thousand dollar bounty on him. Captain Chadwell wants to destroy the Mexican outlaw gang and recover the stolen army rifles and ammunition. On a sunny day, the three cavalry men and the bounty hunter ride out of Fort Apache to accomplish their task.