Isabella Riosse is the daughter of a cartographer who lives on the island of Joya; an isle both steeped in mythology and shrouded in mystery. For the last thirty years, a strict Governor has forbidden the island inhabitants from venturing beyond their small township.

Isabella is fascinated with the ancient myths of Joya, which is said to have once floated freely over the seas. Preoccupied with ideas of exploration and inspired by the far-flung places her father once documented, she yearns for adventure.

When her best friend Lupe runs away, disappearing into the forbidden forest, Isabella volunteers to bring her back. With only her knowledge of ancient myths and one of her father’s maps to guide her, Isabella ventures into the perilous world beyond, where monsters lurk and magical rivers run.