Earth is dying. Its human population has declined catastrophically; people have become so isolated that few children are being born. The usual cause of death is self-termination.
The Futurists, aided by the worldwide computer network known as Central, take a desperate gamble. They reach into the past to extract candidates who might possess the qualities that the people of 25th Century Earth have lost: courage, determination, curiosity, and stubbornness.
But how to know if they’ve found the right ones?
The candidates are transplanted to a parallel-dimension version of Earth during the late ice age. Darwin’s World is a world of cold and hunger, of savage beasts and predatory humans. Equipped with only a knife and hatchet, the transplants must survive or perish on their own. Their children will, in turn, be transplanted to Future Earth.