During the twelfth century invasion of Ireland, Emily, one of the last of the druids, must master her power to keep her kind from being annihilated.
Her parents lied to her. They told her a druid's power was only to heal people and that hers was defective. They also said her family was the last of their kind. An accident introduces Emily to Bren and an entire clan of other druids. From Bren she learns there are two kinds of druids, those that heal, and those that can use their power to fight. Turns out her power isn't so useless after all. But Emily doesn't have much time to master it before the invaders from across the ocean arrive. A betrayal brings them to her front door in search of a healer for their wounded. Emily's mother is given a week to heal the son of the warlord or they'll return to slaughter her entire clan. The lines of enemies and friends blurs and in the end she will have to choose between her country and keeping those she loves alive.