The Citadel: Dragonlance Classics, Book 3

Weapon of the Dark Queen Against a darkened cloud it comes, framed by thunder and lightning, soaring over the ravaged land: the flying citadel, mightiest power in the arsenal of the dragon highlords. In an age of war, an evil wizard learned the secret of creating these castles in the air and sought to use them to gain power over all Krynn. Against him were ranged a red-robed magic-user, a cleric, an ancient warrior, and -- naturally -- a kender. Their battle shook the skies of Krynn.