Seventeen-year-old Evan feels like an outsider, amidst his adventurous, loving parents and sage younger brother as they trek the globe. But when he discovers a mysterious ancient key on the beach, Evan is driven to pursue a perilous adventure of his own, inspiring him to explore beyond the well-meaning constraints of his family and leading him to an alluring girl who is desperate to retrieve the key and return to her undersea realm. This modern mythological tale set in the magical Florida Keys introduces Evan and Maera, two capable, fiery teens whose worlds collide, challenging their beliefs about each other as well as themselves.