When a boy named Ico grows long curved horns overnight, his fate has been sealed—he is to be sacrificed in the Castle in the Mist. But in the castle, Ico meets a young girl named Yorda imprisoned in its halls. Alone they will die, but together Ico and Yorda might just be able to defy their destinies and escape the magic of the castle.

High fantasy and true love come to life in this novel based on the hit video game. A boy with horns, marked for death. A girl who sleeps in a cage of iron. The Castle of the Mist calls for its sacrifice: a horned child, born once a generation. When, on a single night in his thirteenth year, Ico's horns grow long and curved, he knows his time has come.

But why does the Castle of the Mist demand this offering, and can the castle keep Ico's destiny from intertwining with that of the girl imprisoned within its walls? Delve into the mysteries of Miyuki Miyabe's work of fantasy: a grand achievement of imagination, inspired by the award-winning game for the PlayStation 2.