This is an elegant little novel that adopts an idea that Poul Anderson also developed in "Flight to Forever". Matt Fuller, a research assistant in 21st century MIT, finds a machine that can jump ahead to the future. Using it begins an adventure in which he witnesses the continual development of humanity while questing for a process that would allow him to travel back to the past. It's an adventure that left me eagerly pushing forward to the end of the book, then starting it over again. Fans of science fiction will find much to like, as will anyone who enjoys an entertaining read.