Just as Misty and her friends start to make their way back to Coral Kingdom with the magic crystals for Queen Neptuna, a storm whipped up by the evil Mantora throws them right off course!

Misty and her fellow Sisters of the Sea are lost, but they must find their way home as quickly as possible in order to complete their important mission.

Misty comes up with a brilliant plan to help her mermaid friends, as well as saving a forest deep in the ocean from a terrible end.