Nia, a young mermyd of the Bluefin clan, has had one wish all her life—to be an Avatar in her beloved home of Atlantis. The ten Avatars rule the beautiful and peaceful undersea city alongside the ancient Farworlders, whose magic keeps their world alive. To be an Avatar is an honor and a great responsibility, and Nia dreams of taking her place among the noble ten. Now, at sixteen, Nia has a chance to see her dream come true. Atlantis is choosing its next Avatar, and Nia knows she is supremely qualified. But there is something Nia doesn't know—if she gets her heart's desire, it could mean the end of her treasured world of Atlantis forever.

The sea is the birthplace of legends. Corwin has spent all of his sixteen years scavenging the land for his next meal. But when he discovers a unique shell of exquisite beauty, he is convinced it will bring him the riches he's longed for. His hopes are dashed when the shell is stolen from him by evil King Vortigern's men. But the shell has left its mark. Corwin's head is filled with visions of a beautiful and mysterious girl. Soon, he comes face-to-face with the girl of his visions—Nia, a mermyd from the ocean's depths, the lost city of Atlantis! Together, Nia and Corwin must search for the stolen shell, for it holds the key to the future of Atlantis and also to Nia's and Corwin's very survival.

Nia and Corwin have braved the dangers of the land and rescued their companion, but now they face the real challenge by returning to Atlantis to rally the mermyd people to rise up against the reign of the evil Ma'el. Original.