Mimmi and Sirena prepare a potion that helps the user to look younger. Rita applies some before a school excursion to the Marine Park, accompanied by Dr. Ross, the park's handsome Director.
The full moon strikes Cleo, turning her into a magical siren, attracting all the young males in the vicinity. Cleo enjoys the attention and is encouraged to sing for them, but a concert at the Juice Bar as the moon sets reveals her truly awful voice.
Emma trains Byron for the swimming competition. At first they get along well and even share a kiss, but too soon Emma becomes the training dragon. Byron fires Emma but when he wins the comp he tries to hug her and she recoils.
Zane tries to impress his dad by entering in the local film competition, filming his attempt to break his Dad's windsurfing record around Mako Island. He gets into trouble with sharks and unbeknownst to him, is saved by mermaid Rikki.
Rikki uses her abilities as a mermaid to earn some quick cash but when she accidentally becomes involved in a fish smuggling operation she sets out to get her revenge.
The National Ballet comes to town and Tara is thrilled to learn that Kat's mother is Natasha Willis, the Company's Principal dancer and her childhood idol. Sammy's girlfriend, Mia, also arrives forcing Sammy to evaluate his growing feelings.
Sammy is forced to choose between dance and his father when compulsory Saturday ballet classes clash with his Synagogue services. Christian struggles to accept the rules of the Academy.
As the net closes in on Gerwyn, help comes from unexpected sources.
Jeffries gets a lot more than more than he bargained for when he decides to follow Tom and his friends.
Alexandra orders Kuru to lie for her, which he reluctantly does after consulting Omar in Manshipoor, while Vashan would stick to the rule royalty must be truthful. She attempts first to pass off Kuru for an exchange student, while he openly treated her as princess.
To blend in, ZOEY and KIKI start attending AMBER's school – and find it nothing like school on LUMINA.
After Kuru's visit, Alexandra's family is unusually accommodating. Kuru reports in Manjipoor that the princess isn't ready for the throne, but the guru is confident she'll grow into it and gives him the magical royal runes. Finding out she's adopted as Kuru said, she goes crazy, wants to run away and tears up a family picture.
With their space ship obliterated and no other way of getting home, KIKI and ZOEY settle into the teenage world of Lightning Point at AMBER's house.
On the ship the Elisabetha the vampires set sail for Hamburg, to save the Vamalias from the Redmasks. Alisa is discovered by a Redmask but manages to escape through the roof in the attic. In the street she is stopped by Hindrik, who came back to save her. Alisa meets the other Heirs when they arrive on the ship. The Heirs hear that they're on the ship to start vampire school.
When Evie attempts to retrieve her father's watch from the marina's waters, David sees her tail. He's determined to prove mermaids exist and places cameras in the water.
Ondina reports back to the Mermaid Council but doesn't mention the existence of Erik, or that Evie now has a tail. She's followed home by a young, adoring mermaid.
Mimmi's insatiable curiosity leads her to land school, where Erik quizzes her about the symbols he saw in the merman chamber, hoping she knows their meaning.
A charismatic newcomer, Dr Denman, tempts Lewis with the promise of scientific fame and fortune. Will he abandon his friends and risk their secret, all in the name of science?
The effects of the full moon turns Emma into a carefree, wild mermaid. At her father's birthday party she's the opposite to her usual, organised self. Can the other girls stop her before all is revealed?
Rikki gains an admirer in Emma's younger brother Elliot when she saves him from drowning. She lets him down hard causing him to run away and hide in the fernery. The girls find him just as the watering system is about to start.