Enjoy high-sea thrills as Barbie, Chelsea and the rest of the Roberts family set sail on an adventure cruise. “Barbie & Chelsea The Lost Birthday” tells the story of Chelsea, Barbie’s precocious youngest sister, and the rest of the Roberts family as they set sail on an adventure cruise for her seventh birthday. When they cross the International Date Line, Chelsea discovers her actual birthday has been lost and she embarks on a fantastical journey through an enchanted jungle island in order to save it.