He is successful in saving the girl and also manages to protect his secret. Later, Zac risks exposure when a little girl out in the ocean starts to drown and Zac dives in to rescue her. He must find a way to keep his secret while still doing his job. But he has another problem – his part-time job as a lifesaver on the local beach.

Meanwhile, Zac manages to hide his merman secret from his father. The girls walk onto land to look for Zac, but find that they have difficulty walking on two legs. With the use of Sirena's Moon Ring, they are able to gain legs of their own. The mermaids realise that they must venture onto land to find Zac and remove his powers. Heartbroken, the girls are determined to remove Zac's powers if they are ever to return to their pod again. However, the three girls are cast out of the pod as punishment for neglecting their duties and allowing Zac to become a merman. As a result of a boy becoming a merman, one of the most feared creatures in the ocean, the mermaid pod is forced to flee Mako Island. When one of the boys, Zac, discovers a hidden cave, he accidentally falls into the Moon Pool where he is transformed into a merman with magic powers. However, the girls neglect their duties and allow two boys to camp out on the island. On the night of a full moon, they are put on patrol and tasked with keeping humans away from Mako Island.

Sirena, Lyla, and Nixie are three young mermaids from the Mako Island Pod.

Mako island of secrets battlelines