Barbie and the Diamond Castle is a tale of enduring friendship. Best friends Liana and Alexa live in a humble cottage in the woods, bound by their love of music. When they are given an enchanted mirror, Liana and Alexa find themselves embroiled in an adventure to release a young apprentice trapped in the mirror by the cruel Muse, Lydia.Liana and Alexa's friendship is put to the test when they set out to defeat Lydia and find the Diamond Castle, and many obstacles are set in their way...