Join Barbie "Brooklyn" Roberts and her sisters Skipper, Stacie, and Chelsea on an undersea journey as they turn into mermaids to help save the world of Pacifica! Barbie and Barbie are summoned by Isla (from Dolphin Magic) to compete to be the undersea Power Keeper in a series of trials meant to discover their inherent powers in Barbie Mermaid PowerTM. They discover whether they are Earth, Air, Water, or Fire mermaids during these competitions, all while making new animal and mermaid pals. Barbie, Barbie, and family experience firsthand what it's like to balance the worlds above and below the water in this fish-tale of friendship, adventure, and bravery, and learn a lesson in uncovering their inner strengths along the way.