In this lyrical tale, Ultima, an old curandera or healer, comes to live with the family of a young New Mexican boy who learns from her about the healing powers of the natural environment and the human spirit. Antonio's family respects her wisdom and legendary power, though some in the community believe she is a witch. Antonio finds himself drawn to her and under her tutelage develops an awareness of the primal energies of earth and sky that affect human lives and fate.

He goes with her to gather herbs and to visit the sick and comes to understand a connection between healing powers and knowledge of nature. Though he never receives a rational explanation of how Ultima foresees events, cures illnesses, blesses or curses, or why and when she chooses not to intervene, he learns that the knowledge healing requires is threefold: knowledge of the patient, the healing substance, and one's own limitations. He learns that healing requires making oneself vulnerable to sickness and to the spiritual as well as physical needs of the sick.