Siren Phillips has lived her life thinking she's an ordinary girl, in an ordinary town. On the eve of her twelfth birthday, however, she learns that she is far from ordinary. Destined to turn into a Mermaid at the age of twelve, Siren must struggle with her new reality, saying good bye to her mother and friends, while she transitions into the water. To make matters worse, a group of Hunters are after her, trying to catch her.