Conor, in the middle of convincing a tribe to join his own, encounters a mysterious woman who many suspect is a Banshee, the legendary herald of death. Problems arise when the woman foretells the death of a child in the tribe, causing chaos.

Conor and Fergus encounter a man named Doyle, who has garnered a following among the young and homeless, and Fergus is shocked to discover his abandoned daughter, Molly, is one of Doyle's loyal followers. While Conor fights for his land and to free the children from Doyle's grasp, Fergus tries to reclaim his lost daughter.

In search of their missing friends, Conor, Fergus and Catlin journey to an island and are forced to participate in a deadly game of cat and mouse.