The final science-fiction novel by the legendary Asimov--a prequel to his widely acclaimed Foundation Trilogy, written in the 1940's. The story begins on Trantor, capital planet of a Galactic Empire that has stood for millennia; only a few citizens suspect that the Empire is about to collapse. Among them is Hari Seldon, mathematics professor and inventor of psychohistory: a science that allows him to predict and control the future. Psychohistory proves that the fall of the Empire is inevitable; but it also suggests ways to ameliorate the coming Dark Ages, and to lay the foundation for a Second--more stable--Empire. Luckily, Seldon has made important allies: the Emperor himself, who heard an early lecture by Seldon and has maintained an interest in him ever since; and Eto Dermerzel, long the power behind the throne. Essentially, the story is of Seldon's carrying out the mission implicit in the opening chapters. As with many of Asimov's last few novels, it includes a number of references to other books in his fictional universe, as well as an appearance by the long- lived R. Daneel Olivaw (the Robot series). As a result, many of the best things here will appeal primarily to those who know Asimov's fictional future in its entirety, or nearly so. That, let it be noted, is no small audience. Overall, not on a level with Asimov's best, but it may well be his most interesting fictional portrait of a scientist's life and work. A moving valedictory performance.