In the title story of this collection, Earth has entered its final ice age—precipitated by the cooling of the sun. In this forbidding climate, a small tribe of nomadic human survivors travels toward the equator ahead of glaciers moving down from the North Pole, carrying with them a handful of relics from the 21st century—and racing against the ice to preserve them from annihilation.

This collection is a showcase of groundbreaking stories that wrestle with the moral, psychological, and ethical implications of scientific advancement—written by one of the foremost science fiction authors of our time.