Barbie & the Diamond Castle is a 2008 computer-animated musical film directed by Gino Nichele and produced by Mattel Entertainment with Rainmaker Entertainment. It first premiered on Nickelodeon on September 7, 2008, and it was later released to DVD on September 9, 2008. The thirteenth entry in the Barbie film series, the film features the voice of Kelly Sheridan as Barbie and the cover of the song "Connected" recorded by Katharine McPhee. It follows the story of Liana and Alexa (the in-universe roles of the dolls, Barbie and Teresa) on their journey to find the mysterious diamond castle.