Emma and Rikki love exploring their new mermaid powers. Cleo however, is not so sure. In fact, she'd do anything to give up her tail and become a normal girl again. But, aftr hearing rumours that sea turtles are becoming caught in fishermen's nets, Cleo begins to change her mind...Will Cleo learn to embrace her mermaid powers and use them to solve the mystery and help save the turtles?