Rumors rising out of the Yucatan jungle report healings and miracles attributed to a holy relic. Father Pablo Diego Corellas discovers that even his own parishioners are making secret pilgrimages to the decrepit plantation where it is held. There, Doña Josefa, a mysterious woman who is either mystic or mad, possesses an artifact that she claims is a fragment of the robe worn by Christ at his trial. Guarded by armed Mayan farmers, she holds sway over an ever-growing number of pilgrims desperate for the healing power of the Purple Robe.
Much against his own wishes, young Father Pablo is dispatched to the interior to investigate, while a police captain and a vacationing American couple make plans of their own for the robe. But when the relic is stolen, they soon discover that miracles have unforeseen consequences, and that no one is beyond their reach.