A loose amalgamation of 20 short stories written between 1960 and 1966. Characters reappear through the stories, but each is an independent narrative. The majority center around two pioneering voyagers who return to Earth to find themselves in the 22nd century; four school chums whose eventual careers intersect those of the returnees; and a veteran ""Assaultman"" who does the initial groundwork in the taming of new planets. Some of the stories are mood-pieces, like ""The Moving Roads,"" in which one of the Rip van Winkle spacemen wanders the world of his ""great-great-grandchildren""; or ""Languor of the Spirit,"" which finds one of the ""Conspirators"" at low ebb between careers. Some depict historical moments--an experiment in encoding the brain of a dying scientist, an encounter with an alien intelligence. A few are humorous (like ""Cornucopia,"" in which one of the returned pioneers tangles with the cooking of the future). All are low-keyed and given to mild, oblique philosophizing about the destiny of the human animal. A pleasant, gently sophisticated collection, but far from the toughness and energy of the first Strugatsky books in this series.