A collection of twelve stories, three of which focus on Debbie Dayla and her interactions with a cetacean kingdom named Lagenora in the South Atlantic, where Debbie meets Prince Sparfiacus, a dusky dolphin who is thorium powered and can change from dolphin to humanoid and back. Conflict arises when Debbie's father, Roger Dayla (of Dayla Industries) decides to drill into one of the dolphin-inhabited seamounts for oil. Two other stories, "The Duchess of Darby" and "The Blinners of Gathona" feature shape-changing dolphins and porpoises amongst humans. All other stories except two are stand-alone with incidental tie-ins to Debbie or the cetaceans of Lagenora. A glossary is provided for fictional and real-life words.