It's a full moon and the mermaids think that if they keep Zac out of the moonlight, he'll lose his powers and return to his land-dwelling self. Then they can return to their pod.
Zac's struggle with his merman secret intensifies when his girlfriend, Evie, throws him a pool party. At the party, Cam pushes Zac into the pool and the mermaids see his transformed state.
It's Lewis's birthday. Cleo and the others have some ideas how to celebrate but Charlotte quickly takes over and organises a surprise party for Lewis. Charlotte's plans don't seem to be about Lewis and Rikki eventually has enough and leaves. The party is at Charlotte's house with all of Charlotte's friends.
Nate bullies Lewis, pretty much because he can, and when Nate's jet-ski is damaged he blames Lewis, demanding payment. Meanwhile Emma, Rikki and Cleo continue to have problems accommodating Charlotte as a mermaid, she won't listen to any advice. Charlotte takes their attempt to help as an attempt to boss her around.
There's a fourth mermaid in town - Charlotte! Emma, Rikki and Cleo reluctantly have to deal with the newcomer. Charlotte is overjoyed, thinking this is the best thing that's ever happened to her. No matter how much they all try to explain how tricky it is being a mermaid, Charlotte won't listen.
The girls want Lewis to destroy Max's research folder Charlotte is getting too close. Reluctant to give it up, Lewis decides to take it back where it belongs - to Max. Suspicious, Charlotte follows Lewis to Max Hamilton. Max tells all to Charlotte when he discovers she's the granddaughter of his one true love - Gracie.
Saskia's bullying of Tara results in a painful injury. Kat convinces Miss Raine to grant her an audition to return to the Academy but has to let Abigail train her.
Grace encourages Tara to take action against Saskia's cruel treatment of her Kat commences training for the Moulin Rouge and Sammy is assigned a Third Year, Ollie, as a tutor to get him through his exams.
Jana, on her way to school, is surprised by Alric. Far from being terrified she flings herself into his arms. Jana hadn't been banished from the pack at all. Alric had sent her in to lure Rhydian into coming back with her. She has taken too long. He wants all three of them to return by the end of the day. In school, Tom is humiliated by Jimi showing off his judo in the gym.
It's a lunar eclipse, and Jana is bursting with excitement! This is the ultimate night for Wolfbloods, one where their wolf and their human are finally at one. They become a wolf on the inside, whist remaining - for an hour - human on the outside, apart from veining and yellow eyes. It's a buzz! Jana invites Rhydian to spend the eclipse with her on the moors, but Rhydian isn't sure.
Sammy returns home for his Grandpa Morrie's funeral and to ask his father to support his Academy tuition. While an act of sabotage severs frenemies Tara and Abigail and Kat auditions for the Moulin Rouge.
Exams are over and, with one night of freedom, both the boys and the girls go on a mission to prove they'll have more fun without each other.
Liam's dad, a farmer, has ploughed up an old skeleton of a wolfblood in mid-transformation – and Liam is boasting about his ancestor being a werewolf hunter. Our Wolfbloods go to investigate. Jana is livid, telling tells the others they have a duty to give it the traditional wolfblood burial.
Maddy finds a strange girl stealing her school clothes from the washing line. The thief turns on Maddy. It's a wolfblood! Maddy gives chase but Rhydian stops her, recognising the girl as Jana, daughter of Alric. Maddy is shocked to see Jana arrive at school the next day with her uniform on, greeting Rhydian like a long lost “friend”.
Kuru reports to Omar and the council of elders about Vashan's hostile intrusion in the other world, but they can't counter a royal. Meanwhile Vashan has used the magical gem again, and using a box and carpet can prevent being sent back.
The gang decide not to let BRANDON know about the toy lighthouse until they know more about it.
The quest to save Lars from Ragnar gets even more complicated as Alisa discovers that Dracula has Nicu. Now she has to save both boys. In the prison of eternal light Ivy is told that Alisa needs to take a different path…
Joe, who delivers seafood to the Ocean Café, has a new boat and takes his brother DAVID out for a spin. His fish-finder locates a dolphin, but it's not like any dolphin he's seen before.
Relentless rain keeps the mermaids indoors and unable to look for Zac. Lyla and Sirena try to use the Moon Ring to stop the rain.
While Nixie and Sirena discover shopping, Lyla looks for Zac at The Ocean Café. When a waitress accidentally spills a drink on Lyla, she rushes to the cool room.