Little girl Billy and the corporal of a space marine detachment Wilks are the only survivors of a colony of Earthmen. For twelve years the Government, while keeping all data about the Xenos secret, kept them locked away. But then the home planet of the monsters is discovered. To capture one of the Xenos, a military expedition is sent in—only the Corporation tries to stop it. It already has a Queen of the Xenos. And she is kept on Earth!