The narrative is based on two historical figures, Jean-Baptiste Lamy and Joseph Projectus Machebeuf and rather than any one singular plot, is the stylized re-telling of their lives serving as Roman Catholic clergy in New Mexico.
Near the beginning of the novel, Latour and Vaillant are saved from being murdered by the villainous Buck Scales (at whose house they have sought shelter for the night) by Scales's abused wife Magdalena.