This episode begins with mermaids Nixie and Sirena having a swimming race to see who can go faster. When two members of the Mermaids pod tell them to go on their duties, Nixie asks why can't she celebrate with the mermaid pod. The members reply that once they pass their test they will join the mermaid pod and celebrate. They go to Lyla and she says she will take the forshore and they take the rest. Nixie and Sirena help young boys Zac and Cam catch a fish. They then decide to camp out on Mako Island. That night Zac puts his hand in the trident shape and it opens a portal to the Moon Pool. This causes him to recieve a blue tail and powers. The 3 Mermaids tell the mermaid pod and they are blamed even though it was not their fault. Sirena, Lyla, and Nixie decide to follow him to see what he does and to see if he has powers. He nearly shows his best friend Cam his powers but the mermaids take control of the water so it doesn't work. Zac then falls in the ocean and discovers he has a tail. After the Mermaids return to the Island, Sirena's sister from the pod tells them they are being cast out and gives Sirena her Moon Ring. Zac then shows Cam his tail and newfound powers as the show ends.