The ancient city of Atlantis was sunk to the bottom of the sea under mysterious circumstances. Well while cleaning out the schools new aquarium Sabrina notices some rather unusual underwater inhabitants. Transforming herself into a tiny mermaid she discovers the lost city of Atlantis. Sabrina wants to restore it to its rightful glory but can she do it without exposing her powers to Mr Kraft and her mortal classmates? And what if someone doesnt want it to be found?