American pathologist Nora Gavin fled to Ireland three years ago, hoping that distance from home would bring her peace. Though she threw herself into the study of bog bodies and the mysteries of their circumstances, she was ultimately led back to the one mystery she was unable to solve, the murder of her sister, TrÔiona ... Determined to put her sister's case to rest and anxious about her eleven-year-old niece, Elizabeth, Nora returns to Saint Paul, Minnesota, to find that her brother-in-law, Peter Hallett, is about to remarry and has plans to leave the country with his new bride ... Time is short, and as Nora begins reinvestigating her sister's death ... What is the significance of the "false mermaid" seeds found on TrÔiona's body? Why was her behavior so erratic in the days before her murder? Is there a link between TrÔiona's death and that of another young woman? Nora's search for answers takes her from the banks of the Mississippi to the cliffs of Ireland, where the eerie story of a fisherman's wife who vanished more than a century ago offers up uncanny parallels.