The movie Barbie and the Diamond Castleas released on DVD September 9, 2008.
The story opens with Barbie and Teresa playing music on their guitars whenBarbie’s little sister Stacy comes storming in upset about a fight she and Courtney just had. Barbie decides to tell Stacy the story of two friends, Liana and Alexa. These two friends come across a magical mirror and a new friend trapped inside. Liana and Alexa go on an amazing adventure escaping dangerous tricks and even a disagreement amongst themselves to save the Diamond Castle and the world of music from the hand of the evil muse Lydia.