At his coming of age, Thorvald learns a shocking secret about his parentage, and sets out on a perilous voyage in search of a father he has never known. His loyal friend, Creidhe, daughter of a Wolfskin and a wise woman, was never meant to be part of this desperate journey. But love works in strange ways.

In the Lost Isles they find a population gripped by terror. The Unspoken sing away the souls of the newborn and the chieftain of the isles answers to nobody, least of all to the Christian hermits who seek to bring a measure of calm to the trouble folk.

Creidhe and Thorvald become enmeshed in a battle for survival, in which they find themselves on opposing sides. For the future of the islands depends on a visionary child: the powerful seer Foxmask. Snatched away in infancy by a young kinsman, the boy is held in a place protected by ancient forces of nature. And to retrieve him and bring peace, the islanders must endure the annual ritual of the hunt on the Isle of Clouds.

Before the summer is over, Thorvald and Creidhe will learn truths about themselves and about the world that will change them both forever.