Earth was a crowded world of vast cities, manned by robots who carried out all of the menial tasks, who saw to it that everything contained functioning normally. Interplanetary travel was now an established...

These were the last weeks and days before the end of the world, before total destruction overwhelmed Earth and every living thing on the surface of the planet. No one knew exactly how long they had before...

They came out of the great abyss which lay around the Earth, from the planet of a star so distant that it could not be seen with the naked eye. Their purpose was survival and the conquest of Earth. They...