Abner Harris was sent to Earth on a mission of extreme urgency. The universe was in danger of enslavement by the Medlins, and the fight against them called for Harris to assume the disguise of a flesh-and-blood Earthman. But he discovered that the real villains of space were not the Medlins or the people of Earth: they were his own kind. Suddenly he was alone, alienated from his own race, hated...