Mako: Island of Secrets

It's a full moon and the three mermaids Nixie, Lyla and Sirena are tasked to guard Mako and the moon pool. While Zac and Cam go camping on Mako island. When Zac falls into the moon pool they don't know what to do and leave him on the beach. The next day Zac finds out what he is and what he can do so he tells Cam. Because the girls let the "land boy" as they call him in the moon pool they are being cast out by their pod. So they decide to fix the problem.

Sirena, Lyla and Nixie must turn Zac back into a land boy. Using Sirena's Moon Ring, they give themselves legs and walk on land to begin their task.

In trying to get the Moon Ring back, the mermaids uncover Rita's secret.

Nixie and Sirena won't help Lyla try to "zap" Zac's powers, so Lyla decides to do it alone. This misfires when a waitress spills a drink on Lyla and Lyla rushes to hide in the refrigeration room before she transforms into a mermaid! When she can't dry her tail, Nixie and Sirena must save her before she is discovered!

Lyla and Sirena attempt to use the Moon Ring to stop the rain, but instead make it snow indoors.

Joe, David's brother has bought a new boat and decides to take it out for a spin. His fish finder locates a dolphin, but that dolphin is actually Nixie.

Zac's struggle with his merman secret intensifies when his girlfriend, Evie decides to throw him a pool party.

It's a full moon and the mermaids think that if they keep Zac out of the moonlight, he will lose his powers and return to his land-dwelling self. They stay with him in his garage on the full moon and attempt to keep him indoors.

While listening to Sirena sing, Lyla has an idea. If Sirena sings The Enchantment Song to Zac, he will fall under her spell. Everything goes south when David hears the song and falls in love with Nixie.

Against Nixie and Sirena's advice, Lyla goes with Zac to Mako Island. She steals Rita's Moon Ring to open the land entrance on Mako. But when the entrance suddenly closes, Zac and Lyla are trapped inside.