When old Uncle Kahana and his dog find a newborn with a curious birthmark abandoned on a reef in Hawaii, he soon discovers just how special the child is: the boy is completely allergic to water. His allergies make it impossible for him to eat raw seafood or rare meat—a travesty for an islander. Kahana is able to convince his niece and her family to adopt the boy, whom they name Alexander, or Zader for short. Zader seems like a typical 11-year-old boy facing the usual challenges: fitting in with his peers, getting into a good prep school, and getting along with his surfing-crazed brother. In reality, however, he is the descendant of an age-old predator from the sea. As he matures and learns how to work around his mysterious allergies, Zader's life begins to turn upside down, and he will not only have to come to terms with who he is, but what he is.