1847. Assuming the identity of a dead Jesuit priest, a survivor of the famine in Ireland travels to South America where he is tasked with rebuilding the missions among the natives. Inducted into local life, Father James Carmichael finds love with a native woman and becomes acquainted with the ways of the Guaraní, discovering ayahuasca and ritualism. In a battle with his own gods and demons, the priest fights for the life he envisions, his own self the ultimate stake of the struggle. Worlds are shattered, realities crumbled, lives destroyed. His soul victim to the crucible of the New World, what is tempered in the chaos will be outside his control.