One summer morning, Princess Ariel discovers a beautiful jewel on the beach near the palace where she lives with Prince Eric. Ariel thinks it came from the sea, so she has Sebastian summon her father, King Triton, to find out. But the king shares some troubling news with Ariel: a tidal wave swept through Atlantica, washing away the city's precious treasures in the process! Can Ariel help King Triton recover the lost treasure, or will the jewels of Atlantica be lost forever?