Cleo and Rikki are at the moon pool discussing about the full moon. Rikki explains Emma's family leaves for a weekend. Later on at the JuiceNet Café, Ash decides to take Emma out for a date tonight, but he doesn't know there is a full moon. Emma tells Ash she can't go for a date because she has to guard her house in her parents' absence. Emma leaves to change, but Cleo and Rikki catch up with her. They ask Emma to go for a date with Ash in another night. Emma tells Cleo and Rikki that being a mermaid kills her social life. Rikki tells Emma that Zane knows about all and it's safe. Emma refuses to tell Ash about her mermaid secret and asks them to let her change. Cleo and Rikki find Ash and to be firmer in his attempts to woo her.
Later on at Gilbert's House, the girls finish covering the house. Lewis arrives, but he's too late. The girls push him out because he has a date with Charlotte. Later that night, Cleo goes outside to check the windows, but she knows what the time is. Rikki hear a knock and let someone enter. The visitor is Ash with a dinner and comes back outside for more things for the dinner just as Cleo comes back home. Cleo finds a bag with a dinner. Ash finds Cleo and asks her to hold the food plate, but she catches the glimpse of the moon because he didn't close the door. Cleo then leaves to Emma's room to Emma and Rikki. As Emma goes downstairs, Rikki sees Cleo laughing and asking to go swimming at Mako Island. Rikki realizes Cleo was affected by the moon, so she goes downstairs to find Emma.
Meanwhile, Emma finds Ash. At first, she wants to kick him out, but refuses because of the moon. Emma and Ash begin talk romantically, they almost kiss just as Rikki appears. Rikki asks Emma to go upstairs to find out what happened. Back at Emma's room, Emma discovers Cleo has been affected by the moon and realizes this was Ash's fault. Rikki tells Emma that she and Cleo didn't know Ash was coming at the time of the moon. Rikki asks Emma to go downstairs to Ash as she's guarding Cleo. Cleo uncovers the window and makes Rikki "moonstruck" as well.
At the bathroom, Cleo and Rikki decide to take Emma to the bath and show Ash she's a mermaid. Meanwhile, Emma and Ash begin talk about the secrets. They almost kiss again when Cleo and Rikki show up Emma finds out Rikki has been affected too. Cleo and Rikki use their powers to reveal Emma as a mermaid, but she stops it with her powers. Emma chases Cleo and Rikki upstairs and orders Ash to stay downstairs.
Emma calls Lewis and asks him to come. Emma overhears Cleo and Rikki's laughs from the bathroom. As she enters, Emma begins discussing, but Cleo and Rikki push her into the bath with the water and Emma turns into a mermaid. Rikki comes back downstairs and tells Ash that Emma wants to show him something. Emma begs Cleo to not reveal to Ash she's a mermaid, but she ignores her and uncovers the window causing Emma to be affected too. Cleo leaves the bathroom and finds Rikki taking Ash to the bathroom. Emma tells Ash through the door she wants to show him something. Ash almost enters as Lewis appears and kicks him out.
The next day, the girls are unable to remember anything. Emma sees the dinner still on the table and says she can't remember what happened then. Later at the cafe, Lewis and Ash talk before the girls enter. Emma and Ash start talking. Emma asks Ash if he remembers the talk about the secrets and explains she wanted to reveal a secret to him. Emma tells Ash she really likes him and they kiss as Cleo, Rikki and Lewis clap.
- Charlotte is absent in this episode.
- This episode marks to the start of the Emma-Ash Relationship.
- The moon is side affects of being a mermaid that never goes away.
- Cleo: (ditsy) I touched the moon.... (giggles)
- Cleo: The moon is silver...I like silver...(giggles hysterically)
- Emma: (realizes that Rikki got moonstruck) Oh no, Rikki...
- Rikki: We want you...
- Cleo: ... to come with us...
- Rikki: ... to Mako!
- Rikki Chadwick - Cariba Heine
- Emma Gilbert - Claire Holt
- Cleo Sertori - Phoebe Tonkin
- Lewis McCartney - Angus McLaren
- Ash - Craig Horner
- Amber - Rebekah Madden-Fisher (uncredited)