Coral Kingdom is protected by six powerful crystals which fade each year and have to be replaced. Queen Neptuna sends six young mermaids on a mission to fetch the new crystals. Can they battle the wicked-natured Mantora, help the sea life and make it back in time?
Sophie and her friends discover a dolphin in distress. When Mantora tries to interfere, Sophie leaps to the rescue to help her mermaid friends, as well as untangle a dolphin from a very knotty situation.