MacKayla Lane was just a child when she and her sister, Alina, were given up for adoption and banished from Ireland. Twenty years later, following Alina's murder, Mac returns to Ireland to seek justice. She discovers that she comes from a lineage both blessed and cursed, catching her in an ancient conflict between humans and immortals hidden among us for centuries. During her quest, Mac faces devastating events as she tries to control the Sinsar Dubh, a book of dark magic that has the power to create and destroy worlds. This leads to an epic confrontation where Mac, initially the hunter, becomes the hunted. Throughout her journey, Mac is forced to confront the truth of her origins and make a life-altering choice that could either save the world or lead to its destruction.