Queen Ozma discovers that Oz has truly been changed forever when her former subjects, the Quadlings, refuse her request to join an army against the Nome King. They no longer see her as fit to lead them. Peter and Dorothy encounter a band of sword-wielding goblins in the tunnels below the Emerald Castle. And the Freedom Fighters make a daring aerial assault of the Emerald Castle and come face to face with a desperate and deadly Witch Mombi! Based on the Wonderful Wizard of Oz books.