After failing to save a mortal girl, Cassius, god of the seas is transformed into a mortal as a punishment. With his magic limited, the other gods attack his territories leaving his people downtrodden and helpless. A journey begins to end the war, and Cassius joins with the hope of regaining his power.

As a sailor aboard The Delphis, Cassius discovers that being mortal is far different from what he'd ever imagined. He sails the seas, learns to fight, and meets a mysterious captain. But no matter how far he sails, the ghosts of his past haunt him as he battles monsters and conquers storms. Alongside the crew of The Delphis, and with gods and mortals trying to stop him, Cassius must uncover the secrets of magic and the destiny of the world.