Chicago, 1845. I&M Canal gravedigger Enda Hughes buries a hanged man on Suicide Hill. A priest dies of a sudden heart attack. When a curse is found pinned to the church door from a stranger claiming he was denied alms, it sets off a chain of mysterious events that begin to plague the town of Keepataw. When the canal foreman alerts Enda to an order of phantom monks seen wandering the cemetery, it calls everything she and her apothecary husband, Keir, know into question. As revengeful deaths, ancient visions, sinister monks, and visitations from unsettled spirits plague their town, the Hughes and encamping Native American tribe must use their medicine and magic as a barrier to save themselves from the unholiest of brotherhoods.