Cass lives in a camper van with her eccentric mother on the beach, afraid to be different, though she knows already that she is. This is a story about a mother and daughter, the risks that must be taken to protect ancient secrets, and an evolution of familial love. It is also about mythical creatures that live among us - not mermaids, since Cass's mother is quick to state that she is "No one's maid," but about Girls of the Ocean. The super hero women and girls tasked with protecting the water and the people in them.