The Return  : third in the series Awake

It is five hundred years since a catastrophe and its aftermath nearly ended human life on this planet. In the two previous novels in this series, a single character tells of his late childhood and adolescence lived in this world, long after the devastation. Scarcely remembered is the fact that colonists from earth had gone to our neighbor planet Mars two hundred years before the catastrophe. Those pioneers on Mars were aware of the destruction on their home planet, but they were helpless to act then. Finally, contact with earth was lost entirely, and the Mars colonists could not know that there were the few survivors there. It is now possible for them to return, though it is not certain that it is safe to go back. But if there are human survivors, and if the species is not to disappear after so short an existence (only a quarter of a million years), then the Mars colonists should try to rejoin their fellow-humans on earth. This novel tells of the coming together of characters from the first two stories and of returning pioneers from the Mars colony. They are, all of them, human, and in the human species there persist even then aggressive impulses. Human intelligence can serve those impulses, or not.