The planet Zantia has a secret: most of its men are gone! The prime minister has passed a law legalizing the kidnapping of men for sale to women as mates! A man named Cassius Thorne and his two associates lures Buck there with a phony distress signal - the latest of his captures. It seems most of the Zantian men are prisoners of the Ruathans, with whom they fought a war. That's a problem, because Earth is presently locked in tense, failing negotiations with Ruathan ambuquad ambassador Mr. Devronin - Ruatha is Earth's chief source of the rare mineral barbasite. So when Buck becomes involved in a Zantian plot to kidnap Devronin, Wilma must stop him...