Taran, the evil mermaid Queen, is determined to get her hands on the silver pearl that will make her more powerful than ever. only Lizzy, Kes and their friends from the undersea world can stop her. But when Taran takes a very special hostage, Lizzy and Kes are faced with a terrible choice. Must they give up the pearl? Or do they have the courage to challenge Taran, and defeat her?