Mako Mermaids: An H2O Adventure

When the Eastern mermaid Weilan frees one of Ondina's little mermaid students from a net, Ondina and Weilan clash. On the night of the full moon, Joe and David go fishing in open water. The mermaids are also in the water when they encounter a terrifying water dragon. Joe unwittingly distracts the dragon, allowing the mermaids to escape.

Ondina is in the Moon Pool when she has a close call with two boys from the marine park, Chris and Karl. They're investigating the sea monster Joe claims to have seen and decide to explore Mako's underwater caves. The mermaids magically create a waterspout to convince the boys that this is what Joe saw. The boys are convinced and the mermaids are safe - for now.

Zac fails a biology test and persuades Weilan to use magic on him to help him pass the next one. Zac suddenly knows all the answers - but Weilan is stumped. They're not just swapping minds, they're also gradually swapping bodies. Ondina and Mimmi stumble on a way to stop the process, by adapting a recipe for Arctic Marshmallow in the Moon Pool.

When Evie's Dad tells her to clean the house, Evie uses her moon ring to make a mop clean automatically. But the mop goes haywire and attacks Evie with water. She calls for backup and finally the mermaids are able to freeze and shatter the mop. Meanwhile, Joe tells David he's closing down the café. Cam saves the café by becoming co-owner with money borrowed from his dad.

The mermaids come up with a plan to trap the dragon inside a Chinese puzzle box that they get from Uncle Shen, a kindly antique dealer in the local markets. But the box is unstable and sucks in Poseidon and Ms Trumble. Weilan must take bold action to free them. Meanwhile Carly and Cam are beginning dance lessons. It's a disaster and the relationship is only rescued when Cam takes lessons from Zac.

Mimmi is asked to help Karl at the marine park and must hide her true identity from him. When she realises a new dolphin is about to give birth prematurely, she has to convince Karl to help. In the grotto, Evie's moon ring lesson backfires, leaving Ondina and Weilan stuck in mid-air. Ondina and Weilan have to put their differences aside to solve their problem.

Weilan reveals an Eastern mermaid power called 'Turn the Tide' and Zac thinks he can use it against the dragon. Evie discovers Zac and Weilan practising 'Turn the Tide' in secret and thinks there is something going on between them. Ondina is jealous of Weilan's power and is determined to master it, practicing in the café cool room, but she nearly exposes the mermaids' secret to Joe.

On the night of the full moon, Veridia tells Ondina to protect her class of little mermaids - and that all of them should stay away. The mermaids disobey Veridia and join the pod. But Weilan tricks the pod into waiting in the shadows of Mako while Zac lures the dragon into the Moon Pool.

Ondina blames Weilan for the dragon taking Evie's tail. Feeling responsible, Weilan considers leaving Mako, but some sage advice from Uncle Shen helps her reconsider. When a spell to give Evie a new tail backfires, Ondina can no longer get legs. Weilan and Ondina reconcile and Weilan helps Ondina get legs again. Meanwhile, Evie comes to terms with losing her tail and goes diving with her father.

When Zac discovers a magical seashell that makes wishes come true, he accidentally sends the mermaids back in time. While Zac finds that the present world has radically changed, the mermaids must deal with 10 year old Zac. The mermaids have to convince young Zac to wish things back the way they were so everything in the past and present will return to normal.

During a lesson on Mako Island, one of Ondina's little mermaid students, Amaris, goes missing. Chris and Karl come to the island to survey the turtle population and encounter Ondina, Mimmi and Weilan searching for Amaris. They join the search. The mermaids must stop the land boys from finding out who Amaris really is.

Chris and Mimmi go on a date. Ondina tails them and stops Chris from kissing Mimmi by wetting her so that she bolts and cloaks. Weilan helps Ondina realise she's afraid for Mimmi because of a past bad relationship. Meanwhile, Cam transforms the café into an upmarket restaurant. It's a flop, until Carly and Evie save the day and a big crowd shows.

Mimmi and Zac share a vision of their mother Nerissa. Although Weilan says the water dragon killed Nerissa, Mimmi thinks she may be alive. But when she tries to conjure the vision of Nerissa with her moon ring, the dragon appears and chases her. The dragon threatens to attack Mimmi, but then mysteriously disappears.

A spell goes wrong and turns Rita into an old woman. The mermaids rush to find a cure so Rita can attend a school board meeting to decide whether she or Ms Trumble is Principal. Once cured, they arrive at school just in time, but Rita surprises everyone by deciding to give up teaching and go back to life in the ocean. At Veridia's invitation, Rita takes over Ondina's class of little mermaids.

While at the 'Secrets of the Deep' book launch, the mermaids realise that a bracelet on display is the key to destroying the dragon, according to the Legend of Jiao Long as revealed by Uncle Shen. They ask the bracelet's owner, a land girl with mermaid powers named Rikki Chadwick, if they can borrow it. Rikki refuses, so the mermaids try and take it.

On the night of the full moon, the pod plans to attack the dragon by conjuring a massive lightning storm. Weilan realises the dragon is Nerissa trapped by a spell and that the bracelet will free her. Rikki gives them the bracelet. Weilan and Ondina plead with Veridia to stop the storm, while Zac helps Mimmi get close to the dragon. The power of the bracelet frees Nerissa from within.