Vintage from the 1970s. Before his breakout novel INTENSITY, Dean Koontz wrote several science fiction novels, including this one. From the back cover: The Naoli came to Earth as conquerors, while the last men skulked through the ruins of their civilization. The two races, Human and Naoli, were the most powerful intelligences in the galaxy — and destined to be immediate and perpetual enemies! The adult Hulann met the boy Leo … and each became a traitor to his race. For it was only through treason that the future of each race could be assured! First edition, first printing, Lancer, New York, 1970.