Beyond the civilized lands of Erondar, the Stone Towers are crumbling. The great monoliths are falling one after another under the wild thrusts of an evil force. The Ancient Prohibition that binds the Abominables inside their dark world is soon to be broken. Alben the Wizard knows what must be done. He will send for Myrva, a young follower of the powerful Technocrats; he will choose Ecuba, the fighting nun, to protect him; and he will call back Ian Aranill, a former Empire officer - followed by Gmor the Orc, his loyal friend - to use his scouting experience.