The best time-travel story since H.G. Wells's The Time Machine, by the Grand Master of science fiction, the story of Andrew Harlan, Technician and Eternal. Andrew Harlan's job is to range through past and present centuries monitoring and even altering Time's myriad cause-and-effect relationships. As a Technician with the Allwhen Council, he initiates Reality Changes that may affect the lives of as many as fifty billion people -- and a million or more of them may be so drastically affected as to be considered new individulas. Above all, therefore, a Technician must be dispassionate. An emotional make-up is a distinct handicap. Then Harlan meets Noys and falls victim to a phenomenon older than Time itself -- love. Years of self-discipline are cast aside as Harlan uses the awesome techniques of the Eternals to twist Time so that he and Noys might survive! together.

艾萨克•阿西莫夫 Isaac Asimov （1920 ~1992）

俄裔美籍作家，全知全能，被全世界读者誉为“神一样的人”。美国政府授予他“国家的资源和大自然的奇迹”这个独一无二的称号，以表彰他在“拓展人类想象力”上做出的杰出贡献。

阿西莫夫创作力丰沛，一生之中著作近500 本，涉及杜威图书分类法的每一个范畴，涵盖人类生活的每一个层面，上天下海、古往今来、从恐龙到亚原子到全宇宙无所不包，从通俗小说到罗马帝国史，从科普读物到远东千年历史，从圣经指南，到科学指南，到两性生活指南，每一部著作都朴实、严谨而又充满幽默风趣的格调。

作为人类世界里最伟大的科幻小说家之一，阿西莫夫曾获得代表着科幻界最高荣誉的雨果奖和星云终身成就“大师奖”。他于1955年完成了一部极富远见的、关于时间旅行的长篇小说《永恒的终结》，厘清了关于时间旅行的终极奥秘和恢宏构想。问世60年来，这部作品被全球科幻迷们一致奉为阿西莫夫的最高杰作。