Book two of six. When Will's best friend, Bella, moves to the Gold Coast, Lauren gets a bit uneasy. Will her and Will's relationship start to get rocky? On top of that, another girl, Charlotte, comes into town. Will she stir things up? Rejoin Will and the gang for another adventure of epic proportions! Sequel to H2O: Just Add A Merman.

Will Johnson has a big secret. He is a merman. When he moves to the Gold Coast of Australia, he meets three girls named Cleo, Rikki, and Emma. They become fast friends. The funny thing is, the girls were just recently turned into mermaids. Does Will find out? What happens if he does?