Where the Cape of the Winds juts into the endless sea, there is Castle Ocean, and therein dwells the royal family that has ruled it from time immemorial. But there is an Empire growing in the east, and its forces have reached the castle. King Reymarro is dead in battle, and by the new treaty, Queen Marioza must marry one of the Emperor's brothers. She loathes the idea, and has already killed the first brother, but a second arrives, escorted by more soldiers. While Marioza delays, her youngest son, Jeon, goes on a journey in search of his mute twin, Tirza, who needs to be present for the wedding.