A ship heading from Earth to Athena, a planet 500 light years away, is suddenly attacked by the Gerns, an alien empire in its expansion phase.

The Acceptables would become slave labor for the Gerns on Athena, and the Rejects are forced ashore on the nearest 'Earth-like' planet, called Ragnarok.

Ragnarok has a gravity 1.5 times that of Earth, and is populated by deadly, aggressive creatures and it contains little in the way of usable metal ores.

The novels follows the stranded humans through several generations as they try to survive there, and their unswerving goal to repay the Gerns for their cruelty.

Floyd C. Gale wrote that he "read this yarn with the same glow of pride in the indestructibility of the human race that I once received from van Vogt's early The Alien".