Gloomy prophecies have come true! The Earth, the cradle of humanity, suffers from overpopulation, and its inhabitants are forced to spend their entire lives in the steel caves of giant cities, not seeing sunlight and eating yeast cultures, while the spacers, descendants of earthlings who settled other planets, enjoy all the joys of existence. Of course, this does not suit everyone...Isaac Asimov's famous series of novels about the adventures of the earthling detective Elijah Bailey and his partner, the robotic cosmonite Daniel Olivo, are for the first time under one cover!