Having recently learned the location of his parent's graves, Monte Segundo heads for an abandoned ranch near the U.S.-Mexican border. Hoping to recover some of his lost memories, he returns to the site where his father and mother were murdered thirty years before.

Hiding under the stones of one of the graves, 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, Ahayaca, to remain hidden and sends the rurales back toward Mexico.

They travel together for safety because the rurales believe Ahayaca knows the location of the lost Tayopa mine and won't give up until they find him. Reaching Tucson, Ahayaca delivers a stunning message to the Yaqui Indians and then, with Monte's help, heads south to Sasabe, Arizona, the home of his secretive tribe. There the rurales, as well as Monte, come fact to face with a culture that has remained hidden for centuries.