Having recently learned the location of his parents' graves, Monte Segundo heads for an abandoned ranch near the U.S.-Mexico border. Hoping to recover some of his buried childhood memories, he returns to the site where renegade Apaches murdered his father and mother thirty years before. However, with the Mexican Revolution spilling over the border, Monte's visit to the graves is cut short. Hiding under the stones of one grave, Monte is astonished to discover an emaciated fugitive desperately trying to hide from a band of approaching rurales. Resenting the intrusion and distrusting the rurales, Monte allows the fugitive to remain hidden and sends the rurales back toward Mexico. The fugitive, named Ahayaca, can barely walk but explains he must, at all costs, get to the Yaqui Indians living near Tucson. Knowing the rurales will soon return, Monte and the mysterious Indian flee across the desert toward Tucson. To purchase needed supplies, Ahayaca produces three small pieces of sculptured gold, one bearing an antiquated Spanish mining stamp. Believing Ahayaca knows the location of the lost Tayopa mine, the rurales continue their pursuit all the way to Tucson and then join forces with an arms dealer and cattle thief. In Tucson, however, Ahayaca delivers a stunning message to the Yaqui Indians but then, with Monte's help, heads south to Sasabe, Arizona, the home of his secretive tribe. There, the rurales, as well as Monte, come face to face with a culture that has remained hidden for centuries.