Rio dreams of leaving the underwater city of Atlantia and living in the world Above. But all Rio's hopes for the future are shattered when her twin sister, Bay, makes an unexpected choice, leaving Rio stranded Below.
Set within a civilization that lives deep beneath the sea, twin sisters, Rio and Bay, are about to make the most important decision of their lives. Will they choose to stay Below, sacrificing their soul but living in happiness, or to go Above, keeping their soul but living in weakness and misery. No one could have predicted their choice.