Maya Lin's life on the Gold Coast was beautifully uncomplicated. As the grounded mediator between her cousin Emma and her best friend Cleo, her biggest daily challenge was stopping her younger brother from ruining her dad's marina workshop, and avoiding the devastatingly handsome new apprentice, Flynn Miller, who seemed to make it his personal mission to tease her. But one accidental trip to Mako Island changes everything. Stranded in a mysterious volcanic cavern under a full moon, Maya and her friends transform into something impossible. Now, Maya can turn water to mist and vapor in a heartbeat, a handy trick when you only have ten seconds to hide a giant fish tail. As the secrets grow and the full moon looms, keeping the truth hidden from her sharp-eyed family becomes a full-time job. And it doesn't help that Flynn is always hanging around the water, getting closer than ever to discovering her biggest secret... and catching her heart.