The last thing fifteen-year-old Julia Dickinson expects while vacationing with her parents in Cancun is to find an ancient crown in an underwater cave, try it on. . .and be transformed into a mermaid. And not just any mermaid, but a direct descendant of the long-lost Princess Leilani and the heir to Leilani's throne. The idea of being a queen is exciting, and the members of the mer-clan are overjoyed to have a leader once more. . .but Julia's not at all sure she's ready to give up her life as a human. Julia's fate hinges on a missing magic ring. Before she can become queen, she must find the ring, lost for a hundred fifty years, since the crown is useless without it. And when she learns that the combined power of crown and ring can make her human again, she's even more motivated to search for it. Accompanied by one of the merclan elders, Julia embarks on a perilous quest to find the ring. Along the way she blunders into a fishing net and meets Chac, a seventeen-year-old Mayan boy enamored of merfolk who promises to help her in her search. But if and when Julia does find the ring, can she also find happiness as a mermaid queen?