Cam is on lifeguard duty when Erik quizzes him about Zac's connection to Mako. Erik is splashed and rushes into the ocean, disappearing. Cam paddles out in search of Erik, only to discover that Erik is a merman. Meanwhile, Sirena and Ondina engage in a contest of mermaid powers, whipping up a dangerous storm over the ocean. Cam gets in trouble for losing Erik, but Erik stages a fake rescue, making Cam a hero. Erik now has an ally in Cam – and Zac doesn’t like it.