In Niven's fiction, advances in technology usually have benefits for humanity, making it notable that in Svetz's society such technology as internal combustion engines has poisoned the earth and destroyed all life except for microbes, human beings, and dogs. Indeed, the planet has been devoid of life so long that people are afraid of living things. Svetz describes himself as xenophobic, meaning that he cannot tolerate living with anything other than his own kind, and xenophobia seems to be a common trait among his fellow humans. Even "the dogs were behind glass because people were afraid of them. Too many species had died.

The people of 1100 Post Atomic were not used to animals."

The society Svetz encounters when he prematurely stops his time machine contrasts markedly with his own. The wolves have formed an America that coincides with our own twentieth-century America, but they live without...