Poul Anderson 
No World of Their Own 

Space explorers returning to an unrecognizable Earth after five millennia away find themselves caught up in a deadly political power game on a planet racing toward intergalactic war Five thousand years have passed since the interstellar spacecraft Explorer left Earth, and now Edward Langley and his two crewmates are returning home. The faster-than-light mission that took only a year for Langley, Matsumoto, and Blaustein has cost them the only world they ever knew. This future Earth is unrecognizable, its global society ruled by a benevolent, all-powerful computer and divided into a strict class structure of masters and slaves. Though war has been eradicated for generations, tensions between the powers on Earth and colonists on Centaurus over mineral mining are rapidly reaching a violent breaking point. The homecoming of three astronauts from the distant past should have no bearing on the present political situation. But the crewmembers did not come back alone—and the alien visitor who accompanied them holds the key to victory or total defeat.   One of the most acclaimed of the Golden Age science fiction masters, Poul Anderson has written a provocative and enthralling tale of the future that incorporates his trademark blend of hard science, sociology, and humanism. At once thrilling and thought provoking, No World of Their Own is classic speculative fiction at its page-turning best, as only the incomparable Anderson could imagine it.