After the earth is conquered by aliens and programmed to be slaves, the human slave of the alien leader is kidnapped and deprogrammed by rebels. The slave assassinates his owner, with disastrous results.

Major Skokes returns (Quality of Mercy) to the war against the aliens. He's been stationed aboard a ship making a last ditch effort to destroy the alien home world as a Re-commissioned Prisoner of War. After the ship is attacked only a handful of survivors, suffering from lethal doses of radiation, attempt to complete the mission and end the war.