Ariel meets Scuttle for the first time and must use his help to rescue Sebastian from a gang of pirates.
Sebastian realizes that his parents are coming to visit and must try to create a huge scheme to make it appear that he is the king of Atlantica.
A stream of pollution threatens Atlantica.
During a trip to the North Pole, Ariel finds frozen dinosaurs and thaws them with her father's trident.
Apollo, a great Atlantican hero, comes to visit, and Ariel wants to go on an adventure with him, only to learn that he isn't all he's cracked up to be.
Flounder gets bitten by a howling hairfish and starts to turn into one!
Gabriella returns to visit Ariel as she shows her all of her new human things. However, Ursula's spell causes her treasures to go crazy and begin attacking innocent merpeople.
The Evil Manta returns and introduces his son, who he wants to be just as evil as he is.