During the summer of her thirteenth birthday, Arie McGinnis discovers three things that change her world and the way she sees herself; her long-missing mom isn't human; Dad has a girlfriend and wants to move to Indiana, taking Arie away from the ocean, her friends, and everything she loves; and childhood friend, Billy Hernandez, wants to be more than friends. 

Angry at her parents' deception and confused by her changing emotions for Billy, Arie must make a difficult choice: embrace her non-human side and live with her mom in the fantastical world she has only begun to explore, or stay with her human dad and move away from the only home she has ever known. 

With a quirky adventure, complex characters, complicated family dynamics, and a touch of magic, The Secret of the Sea, set in the small town of Laguna Beach, California, explores what it means to grow up and understand that some things are not always what they seem.