The battle for Crystal Castle

"The Harmony Stone has been stolen from the Crystal Castle, and without it the Kingdom of Fantasy is vulnerable to an ancient enemy, The Invisible Army; Geronimo, together with Queen Blossom's daughter, Winglet, embarks on a mission to find the ancient crown which will defeat the Invisible Army and restore harmony to the empire--but they must make it back to the Crystal Castle before it is overwhelmed by the enemy"--Publisher.