Shattered by betrayal, Aria's Companions have separated. Aven and Del have retreated to the safety of the Water tribe, leaving Owyn and Treesi behind on land to stand with Aria and help their wounded Heir heal. Despite their best efforts, Aria retreats, rejecting them both.
Owyn knows that he and Treesi can't do this alone. He starts riding out to the coastal villages surrounding Terraces, sending messages out to the deep, begging Aven to come back, telling him that the Heart can reach the Heir. Then he returns from one such trip to find Aria and Treesi have left Terraces, leaving him behind.
Abandoned, Owyn leaves Terraces. Instead of following Aria, he goes north, trying to find a way to contact the Water tribes. Trying to find a way to save everything before it's too late.
To do that, he must face his deepest fear, risk losing his heart, and accept help from the most unlikely of allies.