Tinkle, a Golden-Chime Mermaid and the protector of the underwater city of Gold Chime, is losing her power. So the city will stay safe, she must pass on her abilities to the young Golden-Chime Mermaid, Twinkle. But Twinkle has been captured by the evil warlock, Grim. The city needs a hero to rescue the young mermaid, but for twenty years no hero has appeared. As time is running out, a young silver-scaled merman named Dart arrives to undertake the task. Dart must find the mermaid and free her from the large sea serpent that is guarding her. In order to free her, he must complete several quests. With every task Dart undertakes he faces more and more unexpected dangers, and he only has ten days to complete the quest before the old Golden-Chime Mermaid loses all her power.