It's been seven peaceful years since Morgana was frozen in the South Sea. But those days are over. Old and new enemies stir. A haunted warrior comes from the east. Powerful forces watch from afar. And things long forgotten are slowly remembered. Can this new darkness be stopped? Or will evil cover all in ruin? No matter of who emerges victorious, the world will be changed.

When Ariel saves Sebastian from Marina's attack, it is not without paying a price. She wakes up with amnesia, and remembers very little. The only sea creature she remembers, however vaguely, is Sebastian. As she works her way in piecing her memories back together, it is with the support of her childhood protector and constant companion.