Five years after attacking the human-colonized worlds of the Spiral Arm, the enigmatic hydrogues maintain absolute control over the galaxy's gas-giant planets. Still reeling from renewed attacks by the hydrogues, the Terran rulers don't realize the other dangers they face. The Ildirans, believed to be allies, are abducting humans for breeding experiments. Far-flung colonies plan a rebellion—and military robots, used to build cybernetic legions to fight the war, have secretly exterminated their own makers—and may soon turn on mankind. Five years ago, humans thought they ruled the cosmos. Today they are the galaxy's most endangered species.