Very few people know the location of a mysterious school where heroes of the past train those who belong to the future. Ben Taylor only learns of the school's true purpose when he is sent to the Principal's office to talk about his fear of water. Miss Templeton gives him a simple test to see if he is a Chosen of the Guardian. That very day Ben is sent through a portal to a watery world of mermaids and monsters. “Has a mistake been made?” This is the question on everyone's mind, including Ben's. Ben's only chance of success depends on discovering the secret of his own true self in a terrifying world where nightmares come to life.