On an island on the edge of an immense sea there is a city, a forest, and a boy. The city is called Asteri, a perfect city saved by the magic woven into its walls when a devastating plague swept through the world years before. The forest is called the Barrow, a vast wood of ancient trees that encircles the city and feeds the Earth with magic. And the boy is called Oscar, a shop boy for the most powerful magician in the Barrow, who spends his days in the dark cellar of his master's shop grinding herbs and dreaming of the wizards who once lived on the island. Oscar's world is small, but he likes it that way. The real world is vast, strange, and unpredictable. And Oscar does not quite fit in it.

But it's been a long time since anyone who could call himself a wizard walked the world, and now that world is changing. Children in the city are falling ill; something sinister lurks in the forest. Oscar has long been content to stay in his small room, comforted in the knowledge that the magic that flows from the trees will keep his island safe. Now, even magic may not be enough to save it.

Anne Ursu has written an unforgettable story of transformation and belonging - a spellbinding tale of the way in which the power we all wield, great and small, lies in the choices we make.