Reynolds plays Yaqui Joe, an Indian who robs a bank in order to buy guns for his people who are being savagely repressed by the government. Set in turn of the century Mexico, it tells the story of his flight into Mexico and his pursuit by an American lawman. They eventually become allies and team up with Welch to take up the cause of the Indians.
In the early 1900's, Yaqui Joe, a half-breed Indian, robs an Arizona bank and flees across the border into the Mexican town of Nogales where the governor, General Verdugo, aided by a German military advisor, Von Klemme, is waging a war of annihilation against the Yaqui Indians. Verdugo captures Joe and orders him shot, whereupon Lyedecker, a black American deputy assigned to bring the half-breed back to the States, intervenes and is himself arrested. The two men escape to the hills where they are joined by Sarita, a beautiful Indian revolutionary. After Joe has revealed that he used the bank loot to purchase 100 rifles for the Indians, General Verdugo once more captures the two men and orders them shot. Determined to see that the rifles reach her people, Sarita leads an attack on the General's hacienda and frees the two men as well as the rifles. Enraged, Verdugo retaliates by storming a Yaqui village and taking children as hostages. Lyedecker, finally won over to both Sarita and the Indian cause, rescues the children and vows to destroy Verdugo. Taking over the leadership of the Yaquis, Lyedecker ambushes Verdugo's train while Sarita distracts the attention of the soldiers on board by taking a public shower. The railroad manager, Grimes, captured by the Indians, escapes and warns Verdugo that the Indians plan to attack the town with the train, but Lyedecker outwits the General by filling the train with dead bodies. As Verdugo's men open fire on the corpses, the Yaquis attack from behind. During the bloody battle, Verdugo is killed and his men are defeated, but Sarita also pays with her life. Returning to the United States without his prisoner, Lyedecker leaves Yaqui Joe to take over the leadership of the Indians.
