Dolphin's War

Five years ago, on Princess Dolphin's trip from Zi'Govon, she ran across a starship known as the Corkscrew. Now, the same ship is bent on destroying her home. A fight between Queen Marina and the merpeople and Captain Vite Ball of the Corkscrew is looking like it will destroy the water world. Dolphin and her friends, Nixie and Coralee, are forced to return to Earth and learn that an alien ship known as the Corkscrew kidnapped two hundred people from around the world two and a half years earlier. Did the Corkscrew kidnap the people from Earth and are they aboard the alien vessel?