Two young mermaids, Ondina and Mimmi, run away from the Mako Island pod with Sirena to try to turn the merman Zac back into a land boy. But Zac's connection to Mako is growing stronger. If they fail, ...

Sirena, Nixie and Lyla are part of a mermaid pod, which lives in the waters of Mako Island. As young members of the pod, it is their job to protect the Moon Pool and guard it from trespassers. But on ...

The chamber's true purpose is revealed: to drain the magic from all mermaids. Zac risks his life to shut it down and restore the mermaids' magic.

Cam shows Nixie that he is hiding the trident in his school locker. Evie agrees to keep everyone's secret until after Zac is turned back into a normal human. Cam apologizes to Zac for betraying him.