When Emily Windsnap's boyfriend Aaron is captured by pirates, there's only one option - join a rival pirate crew and persuade them to help rescue him. The Pirate Prince agrees, as long as Emily assists in finding the Trident's Treasure first. But as if boarding a pirate ship weren't dangerous enough, Emily soon discovers that pirates hate mermaids. If her true identity is revealed, her life - and Aaron's - will be at risk. How will Emily keep her secret when the only way to win the treasure is by turning into a mermaid?