In the fifth century, the arrival of a brutal band of pre-Viking Norse raiders entwines the Mother Goddess of Celtic Ireland in a desperate bid to rid her island of the invaders turned settlers. Danu and her fellow Tuatha Gods draw Breanna Ban Morna, a Gaelic warrior with blood from both sides, into a quest to find Lann Dàn, one of three pieces of magic needed to remove the Norse Dreadlord and his ilk from their land.
While meeting Danu in a secret grove, Croí Dàn, the Heart of Destiny, chooses Breanna as Erin's Hero. As the Mother Goddess sets the young warrior on a quest to find the Blades of Destiny, little does Breanna know the Dreadlord has invoked ancient enemies of the Tuatha. After an intervention by the Sun God Lugh, Erin's Hero pursues her goal of vanquishing the Norsemen.
Yet, when the headstrong warrior chosen by the Tuatha Gods to save the Gaels of Erin learns her Chief is in danger, she decides he must be her priority and not another quest for magic laid upon her by Lugh. Will her decision doom them all to a destiny that leads to the Norse ruling the Gaels of Erin?
