Awakening in a lighthouse tower on a small island, everything is a mystery to a teenager who has no memory of his past. Venturing out toward a distant light flickering in the window of a cottage, the boy discovers a childlike creature held captive in a gilded cage. He makes an impulsive decision to rescue the prisoner, Wilo. She turns out to be surprisingly resourceful and knows more than she is willing to share about his past. She protects him when soldiers show up looking for a fugitive and delivers him to a hardworking farm family. Given a name, Brennan is accepted by the family as one of their own, and befriended by the son and daughter, Mathuin and Cailean.
Recruited to attend a school where they are taught the faerie arts of illusion and elusion, they also learn the history of the conflict which has made orphans of most their their schoolmates; a history which is inextricablly entwined with Brennan's past. He finds himself at the center of events which have culminated in a war that has pitted the two kingdoms of Faerie and Humankind against each other, with individuals of mixed blood, like Brennan and Wilo, caught in the middle. An encounter with a magical yew tree brings him face to face with a villain named Feardorcha whose dark powers and devious manipulations have ensnared anyone with a weakness to be exploited. When one of their friends is captured and in deadly peril, Brennan and his band of orphans, gypsies and animals must take on challenges beyond their capabilities to rescue a friend in need.