A mind-opening collection of short science fiction from one of the genre's most revered Grand Masters.
In the title story, a man's newfound ability to walk in the past allows him to dwell among dinosaurs, saber-toothed tigers... and something even more timeless. In "Construction Shack," the first manned expedition to Pluto reveals that no matter how advanced aliens may be, even they don't always get everything right. And in "Univac 2200," the thin line between humans creating technology and humans becoming technology is about to be crossed-and there may be no going back.
