Barbie™ stars as Merliah™, a surfing champion from Malibu. One minute she's a normal teenager and the next she learns a shocking family secret: she's a mermaid! Merliah™ and her dolphin friend Zuma set off on an undersea adventure to rescue her mother, the queen of Oceana. With help from her new mermaid friends, Merliah™ saves the ocean kingdom. In the end, she discovers what makes you different can also be your greatest strength.