Zac Struggles to come to terms with the news that he's a real merman, adopted and has a new sister.

Sirena and Mimmi are training Evie outside when Cam approaches and ends up being splashed with Moon Pool water, which absorbs into his skin. He quickly finds out that he has powers and is ecstatic. When the swim team coach approaches Zac about getting back on the team, Cam states that he would like to try out. The gang tries to stop him out of fear of what might happen. Cam ignores them and swims in a trial try out, with a time 2 seconds under the world record. The captain of the girls' swim team suddenly takes a shine to Cam and the gang fears that all the extra attention might lead to their secret being revealed. The girls decide that they must somehow remove the Moon Pool water from Cam's body. When a scout from the National Sports Academy comes to see Cam swim in the next trail, the gang really panics. The girls discover that the Moon Pool water becomes unstable when it's outside of the Moon Pool long enough. At the swim trial, Cam finally sees why the gang is worried and tries to... Written by grrlpunk

Mimmi shows the girls that she can do a duplication spell with her Moon Ring. Erik finds a pearl while swimming that he gives to Ondina (he knew she liked them). Ondina shows Erik the sea entrance to Rita's house and the duplication spell. While making more pearls, she accidentally turns him into a duplication of Poseidon, Rita's cat. When Mimmi shows up, Ondina tries to change them back and winds up duplicating the two cats into four. Carly spends the day at the beach while Cam is on lifeguard duty. Since Erik has not shown up for work, Sirena and Evie help David with deliveries. Sirena and David arrive at Rita's house and accidentally let Poseidon (or Erik or a duplicate) out of the house. They leave the door open while trying to find the cat, so two more escape. Back at the beach, one of the cats approaches Carly and she becomes attached to it. Evie and Zac see another cat while delivering to her father's boat. Rita arrives home unexpectedly and the girls begin to panic when Mimmi ... Written by grrlpunk

Cam discovers a series of five outcrops on Mako reef that look a lot like the placement of the symbols on the pedestal in the Merman Chamber. He and Erik investigate one of them, finding a symbol on an underwater rock. When Erik touches it, he is transported into en endless chamber of water with no hope of escape. Ondina becomes very upset when she finds out. The whole gang (minus Evie) set out to rescue Erik. Written by grrlpunk

Sirena stops Carly from showing David a video of a Canadian kayaker being lured by a mermaid's song. Sirena watches it (with earphones) after they leave to go study. Sirena shows up at the window of their physics exam with a picnic basket. Later, she finds him at the Café and tries to lure him away but Carly reminds him that he must take a delivery. Zac sees Sirena use her powers in broad daylight to control David's boat. After helping control David's boat, he tells the rest of the gang what he saw. They figure out that Sirena is under the siren song's enchantment and rush to help free her before she puts David under the spell. Written by grrlpunk

It's Evie's birthday! Zac is throwing her a surprise party at her house with her father. In order for it to be a surprise, Zac thinks that he should act as though it's any other day. Mimmi and Sirena explain to Ondina how birthdays and parties are for land people. Mimmi makes Evie a waterlily perfume and Sirena made her a shell bracelet. Carly and Cam wish her a happy birthday at work. When Evie begins to feel like she's not special to Zac, since he seems to have forgotten her birthday, she decides to leave work early and go home. Carly has Mimmi keep her busy so that she doesn't go find out about the party. She takes her to Rita's house to give her the perfume and try to cheer her up. She lets her try on her moon ring and is called out of the room. Evie ends up shrinking herself and falling into the fish bowl Zac is giving to her for her birthday. When the girls come back into the room, they think Evie has left and head to the party with the fish bowl. Will someone discover Evie ... Written by grrlpunk

Rita and Mimmi visits Dr. Ross at the Marine Park. While they go off to do some paperwork, Mimmi takes a look around and meets a dolphin. A Marine Park worker named Chris finds her there and ushers her out of the restricted area. The girls try on dresses at the shop Evie works at and Mimmi decides that she wants to get a job to be able to pay for things. She gets a job selling souvenirs at the Marine Park. When she doesn't listen to Chris' advice about parking her cart on a slope, it gets away from her and tips over close to a dolphin area. The dolphin swims up and asks her is she has any fish or if she wants to see how high it can jump. She snaps at the dolphin and it splashes her causing her to have to dive into the water. While hiding under a small bridge in mermaid form, she overhears Chris plead with Dr. Ross for a spot in the dolphin training program. Unfortunately, it is full and he will have to wait until next year to apply again. Since everyone else has a job, Ondina gets one... Written by grrlpunk

The girls discuss the upcoming full moon. Sirena wonders if she'll ever see her sister Aquata again if the pod moves north. Ondina stresses that they should prevent Zac from activating the Merman Chamber by stopping him from going to Mako Island during the full moon. Mimmi suggests that she go with Zac and Sirena proposes that they all go. This is not to Ondina's liking and she storms off to the Moon Pool where she finds Veridia. Ondina is given a plan to assure the Merman Chamber's complete destruction. Rita tells Zac a bit about the history of the Merman Chamber. It was built by a merman during the war but he fell in love with a mermaid and decided not to activate it. The two of them formed a powerful royal alliance and ruled the seas to insure peace. These were Zac's ancestors on his (and Mimmi's) mother's side. Erik tells Zac that they should find out more about the chamber instead of dismissing it. Zac is not interested in activating the chamber anymore. Cam overhears Carly ... Written by grrlpunk

Ondina and Erik discuss the pod coming back. She is optimistic that they will come to understand that mermen are not the enemy but Erik is not convinced. They discuss it with Sirena and Mimmi who think that they will be able to live in both places, the reef and on land at Rita's house. Erik thinks that Veridia will not accept him nor let the girls live in two worlds. Cam talks to Evie about Carly who in turn tells Zac that Cam is interested in Carly. Erik rents out the Café from David to throw a party for Ondina to make her feel special. When Mimmi discovers that one of Rita's pendants is missing, she confronts Erik about where he got the money to pay for the party. Evie questions Carly about how she feels about Cam. After speaking with Rita, Ondina's worst fears are confirmed: she will have to choose between the pod and Erik, like Rita had to do with Harry. Mimmi follows Erik and learns where his funds are coming from. At the party, Cam asks Carly to dance but she tells him that ... Written by grrlpunk

Mimmi is upset that Ondina has decided to stay on land. Cam takes Carly fishing near Mako Island for their first date. The boat's anchor gets stuck so they swim to Mako to wait for a boat to come by. Trouble is, Cam loses grip of the picnic basket containing his cell phone and it floats off out to sea. Mimmi overhears Evie and Ondina discuss her staying on land and becomes even more upset. At the Marine Park, a young girl named Patty steals from Mimmi's souvenir cart after acting like a spoiled brat. Zac learns from David that Carly has not shown up for her shift and that she and Cam went fishing earlier. Zac finds them and is able to talk to Cam without her knowing. Cam feels humiliated because Carly can built a shelter, start a fire, and catch food better than him. Zac decides to help him. Meanwhile at the Marine Park, Sirena watches the cart while Mimmi goes after the thief. She finds her by the dolphins where she continues to be a brat by throwing the stolen plush dolphin into the... Written by grrlpunk

Cam tells Erik that the trident's stone glowed when mermaids were near. Erik then approaches Zac about finding the broken pieces of the trident. Zac goes to Sirena, Mimmi, and Ondina about this matter. Sirena and Rita reveal where they had hidden the stone. Rita thinks that the Merman Chamber, when activated, will drain the magic from the Moon Pool thus all mermaids' powers. Zac takes the stone to hide but finds that it is calling him. Erik approaches Cam with more information about the trident and makes him an offer. Zac goes over to Evie's house and tells her that he feels like he cannot resist the pull of the trident stone and that part of him wants to start the chamber, even though he knows that it will hurt mermaids. Erik overhears this and tries to take the stone when Evie's father interrupts. Zac gives the stone to Cam for safekeeping. Cam contemplates Erik's proposal and asks Carly her opinion. Ondina and Erik discuss the possibilities of what the chamber really does and the... Written by grrlpunk