Zane has a surprise: his dad bought the café and made him manager. He renames it after Rikki, whom he makes a full partner. Tone-deaf Nate nearly ruins the first life music performance, but Lewis saves with Isabel Bella, whom the other mermaids accept after discovering she's one of them as they all abused their power to hassle playfully taunting surfers. Hunky local nature lover Will goes diving around Mako island. He discovers the magical cave, but it's a full moon and the serpentine water column knocks him out before escaping to attack the others. It grabs Rikki, but the other mermaids follow and liberate them. Will is totally confused, but unharmed. Written by KGF Vissers

Will and Bella discover they're the new kids in school. He's determined to return to Mako island and search for the cave entrance to find out what happened to him. Bella offers to come along to keep an eye and try on him. The others decide to follow, even Lewis who's convinced nothing remains to be discovered about the moon lake. During the journey Wil tells he was previously schooled at home. They arrive and manage to get Will out before the water tentacle reappears, albeit too weak to hurt anyone, unlike full moon. Written by KGF Vissers

Cleo applies for the vacant job of assistant dolphin trainer, despite the water splashing risks. She's hired on trial basis by chief trainer Laurie, who ignores her utter lack of talent and chases Will, who strikes an instant friendship with star dolphin Ronny. Her humiliating failures would be fatal hadn't Will, who takes pity on her apparent aqua-phobia, brilliantly done all the work hidden underwater. Nate's band is fired by Rikki on account of its lame sound. Self-centered Belle presumes that's personal against her. For lack of an short term alternative, Zane rehires them. Written by KGF Vissers

It's Valentine's Day. Bella, who can have any other boy, dreams of Will, who is concentrating on athletics and biology, oblivious to her romantic thoughts. Rikki claims she's against the commercial nonsense, yet is disappointed when Zane expects her to work extra as it's one of the café's busiest days. Cleo spoils Lewis's annual fishing trip because that is lame to a mermaid. Cleo's kid sister Kim is driving their father mad having become flirtatious and shamelessly milks knaves Kyle and Corey's rivaling generosity. Dad Don thus has to neglect the fishing permit officer, Sam, but ends up dating her. Written by KGF Vissers

Zane has bought motorbikes to earn rent from clients, but also organizes a rugged range race, offering $1,000, confident to win himself. He actively recruits competitors, greedy for their $200 entry fees, including Will, who has to borrow the cash. Learning Will has experience from his parent's Andes posting, bad loser Zane enlists Nate to cheat roughly, but fails. Will's precise recollections about the aggressive moon pool tentacle help Lewis devise a test which shows the key is mixing water from the ocean itself and the waterfall, albeit apparently very weak except at full moon. Written by KGF Vissers

Will orders a mono-flipper, which allows him to dive almost like a mermaid. He accepts to form a private study group with Bella, ignoring she imagines that virtually makes them a couple. Will shows her his impressive boathouse, full with treasures from his family travels, but cancels the first appointment. Having seen him receive a slightly older female there and dive with her, she assumes he's 'cheating' and meanly abuses him publicly and even under water, seconded each time by Rikki, only to find later it's just his sister Sophie. Will still forgives them. Lewis devises a cool trick to test the magic water combination. His science teacher Taylor sees it and suggests to use that as overdue science project, crucial to pass the course. He wouldn't as it may give away the Moon Pool secret, but Cleo sort of takes over without thinking trough. Written by KGF Vissers

Zane already hired Will's somewhat haughty sister Sophie for the job in the café Rikki wanted to give Bella, who doesn't really care after all. Dan introduces his girl-friend Samantha Roberts to his daughters. Cleo is willing but can't accept swimming. Kim refuses but accepts bribery to bless their engagement. Written by KGF Vissers

Drawing helps Will remember he lost his torch on Mako, so he decides to return there. It's a full moon, so the scared mermaids spend the night together at Cleo's. Will is angry when Bella, who invited him to ask her help any time, refuses to accompany him. Suddenly, a water tentacle sneaks up and drags Bella to the moon pool. The moonlight tries to transform her into water, but Cleo can counter the effect. Lewis, who had placed a camera in the moon pool, joins Will on the expedition, retrieves the camera but can't prevent Will from finding his torch embedded in the waterfall rock and Will takes it home. Lewis's tape is distorted hopelessly, as if by EMP. Written by KGF Vissers

Lewis wants the tentacle-potential cave water safely disposed of, but the girls can't resist experimenting further behind his back. Cleo's goldfish Hector gets caught in a floating bubble, which may drop him in the wild. Will, who has a school assignment appointment with Bella, is painstakingly kept away. Lewis grudgingly accepts to accompany Cleo's father as a golf partner. Although a novice at the game, Lewis proves a natural, yet decides to let Don win. Written by KGF Vissers

Will is delighted when Bella brings him a rare deep sea fossil. He invites her to come discuss it and her music at his boathouse, but she runs when he keeps asking about her water-phobia and other quirkiness. Rikki sneaks in and realizes his study of Mako already covers all the pieces of the mermaid story puzzle. Although nearly on kissing terms, Bella grudgingly accepts to dump him while he spills water on her and discovers she's a mermaid. She lies to be the only one, the others supposedly don't even know. After some consideration, Will promises to keep her secret. Written by KGF Vissers

Bella thinks Sophie is mean because she coaches Will ruthlessly, but that's only because she's found a corporate sponsor, Rob Kent. Will lets Bella act as 'guest coach', but to demonstrate her idea of facing water as his friend, she dives with him. When Sophie arrives with Rob, Will has to pretend he's too tired to prevent Bella being found out as mermaid. Zane and Rikki launch the café in hosting corporate functions. He leaves her in charge of the first booking, but it turns out that the 'junior talent agency' consists of children who want junk food and a clown. When Will calls Bella fascinating because she's a mermaid, she keeps him at arm's length, fearing he's not really interested in her. Written by KGF Vissers

The café staff is flat out, so Sophie commandeers Will to help out as delivery boy. He notices strange things and a fake bill as his tip. When Rikki delivers to the same men, actually counterfeiters Steve and Chris, on their boat, she sees a bag full of fake bills and is kidnapped. Will exchanges his information with Cleo and Bella for the truth about the Mako mermaids, then helps them free Rikki, so they can celebrate her birthday with Lewis and Zane in the moon cave. Written by KGF Vissers

Pa Sertori finally announces his wedding to Samantha 'Sam' Roberts. Cleo is completely out of the mood when Kim betrays that Lewis, the best man, has, unexpectedly, won an overseas three years scholarship, which he must confirm and leave for the day after the café-beach ceremony. Kim practices more sabotage. Everything works out in the end, on Mako. Written by KGF Vissers

Zane resents Will having become part of the team but fails to make the girls doubt his reliability. Hearing Will needs a sponsor for his competitive diving without oxygen, Zane asks a demonstration claiming the café is interested. In fact he hires Cameron and Nate so he can cheat be diving 40 meter himself and receiving oxygen. Will decides to go for 60, fair, but ends up unconscious. Rikki arrives just in time as mermaid, finds out the truth and gets him a generous contract. Meanwhile, the Moonpool study shift from the controlled tentacle to the rock which swallowed Will's diving lamp. It turns out to contain a blue crystal, identical to the one Bella found in the Irish sea when she became a mermaid. Written by KGF Vissers

Laurie's Dolphin Rescue needs funds, so Will and Bella think of a rock benefit. Sophie snaps up the idea for Zane's café, with her in charge. Bella seems petty complaining about 'her idea being stolen' and refuses to play songs from the official list, which gets her band banned. Sophie messes up everything. At the Sertori home, Kim turns her sabotage efforts against Sam to the bathroom and manages to shift the blame on Cleo. Written by KGF Vissers

It's the next full moon, so the gang is to hold a slumber-party in the café. Zane is jealous of Will's invitation, so he invites his own rowdy mates. Kim also turns up, and as she lacks permission, pa Don, who once again is made to believe Cleo just as mischievous. Rikki swims alone to the moon cave at tentacle time. Only Will arrives in time to witness the confrontation, but it turns only on him, yet she tells the others Will saved her and swears him to secrecy. Written by KGF Vissers

The Sertori girls wouldn't welcome Sam's dinner guest and colleague, park ranger Ryan, until they see the handsome devil. As a natural scientist, he eagerly offers to help Cleo with a 'school project', actually the gang's study of the moon cave rock, which they discovered to be strongly magnetic. Rikki is hostile to the whole idea and retreats into the cave, feeling best there. Will reluctantly breaks his word to her by telling the other mermaids about Rikki's apparent control over the tentacle, which she now refuses to presume hostile. Written by KGF Vissers

Park ranger Ryan discovers Cleo lied about the magnetic rock and sets out to explore Mako. Zane refuses to join Rikki on a secret mission, actually spying on Ryan. Will is in time to stop her after destroying his magnetometer. Seeing how the others turn away from her, Will regretfully betrays to them their tentacle experience, which only adds to her bitterness. Sam stupidly forbids Ryan to pursue his research with Park Service means. Written by KGF Vissers

It's the big day for Will, Gold Coast free diving championship. 'Coach' Sophie and sponsor Zane expect him to be dead-eager, but Bella notices he cares less for winning then for loyalty to his sister. Finally he decides to do it and wins, then refuses to pursue the competitive circuit. Meanwhile Rikki had playful trouble with a dolphin, whose balls she promises Cleo to collect, and coldly dumps Zane. Written by KGF Vissers

Now that Rikki and Zane have broken up, he rehires and appoints Sophie as the café's new manager. She immediately asserts her new authority by changing the staff and the decor. Meanwhile, something is causing Bella to sneeze and set off her mermaid powers uncontrollably. Because of this, Cleo is pushed into temporarily replacing Bella as lead singer of the band. Written by grrlpunk

Will made a jewel like Bella's from the blue crystal he found in the cave. Experiments show they attract, and when meeting cause a power-cut, to unsuspecting pa Sertori's despair during the football season finale. Ignoring Will's call for caution, the mermaids seek and find a third crystal, for Cleo. Meanwhile Zane, who came confront Will about Rikki, finds and takes the second, which he tries to get Rikki back with, but she stands by the break-up, acting jealous about Sophie, escalating to Zane threatening to divulge the mermaids' secret. Written by KGF Vissers

The next full moon is at exam time. Rikki doesn't concentrate on study, wondering only about the cave and crystals, unlike Cleo, whose concentration breaks down when she realizes the moon phase requires the mermaids to hand in their papers five minutes early. The tentacle makes its way to the mermaids earlier than expected, unstoppably, causing weird phenomena. Will has to overthrow the water cooler so the physics exam is cancelled and rescheduled for the next day. Meanwhile in the cave, the tentacle reacts to the crystals by showing a comet's impact, perhaps its own arrival on earth. Unable to stop Zane from intruding on Mako, Will has to follow him; their arrival seems to end the cave show. Written by KGF Vissers

It's the end of the school year and the student council organizes a beach party instead of the traditional formal dance. Sophie hopes Zane will finally accept that Rikki broke up with him so he'll change the café's name from Rikki's to Zane's. Will wants to go to the party with Bella but after he practices asking her with Rikki, he's mistakenly assumed to be her new boyfriend, so Bella asks Nate. Cleo gets a telescope she assumes to be from Nate, not Lewis, but it turns out to be from Ryan. Ultimately the truth comes out. Written by KGF Vissers

Zane's warning not to neglect girls' need to be the center of attention makes Will attempt to show an interest in her musical career, but that stirs trouble in Nate's band. Her lukewarm, even physically disastrous interest in his fossil collection is easier solved. Kim's nagging 'only we never go on holiday' drives dad Sertori to seek a part-time second job now trawler fishery is slow. His success as pirate captain Don however proves too tough competition for Cleo's dolphin show within the marine park. Written by KGF Vissers

National park scientist Ryan examines why the fish are moving, so as to wreck Don's catch. Ryan's question about the moon-cave crystals, which he realizes must stem from a comet, bring him in contact with Sophie, who points out the mermaids. Zane's café is about to go bust in a week. Realizing that would cost her job, Sophie comes up with a plan: harvest the precious stones for sale, and suggests they must come from Mako. They enlist Zane to finance the necessary equipment. Written by KGF Vissers

Just before the gang's graduation, comet Eva approaches, which they work out is attracted by the moon cave crystals and nearly caused a major catastrophe in Ireland where it was probably diverted by a mermaid centuries ago. They frantically try to work out how, finding not the crystals are the key but the tentacle. At graduation day, Cleo gets the ideal present: Lewis is back. Written by KGF Vissers