Barbie stars as Merliah, a surfer who learns a shocking secret: she's a mermaid! She and her dolphin friend set out for an undersea adventure to rescue her mother, the queen of Oceana.

Merliah Summers, a mermaid from Oceana, travels to Australia for a surfing competition. But when she learns that the evil Eris is planning to take over her kingdom, she must stop her at any cost.