Age of Aquariums

The ancient city of Atlantis was sunk to the bottom of the sea under mysterious circumstances. Well, while cleaning out the school's 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 doesn't want it to be found?