The events of Nightfall take place on Kalgash, a planet that is always bathed in sunlight everywhere. The culture that has evolved is similar to the one that has developed in the United States. There are cities, freeways, automobiles, amusement parks, scientists of all kinds, religions, and all sorts of people. Their politics are complicated, marked by compromises and infighting. The dominant religion—the Apostles of Flame—seems at odds with Kalgash's modern culture; scientists tend to view it with apprehension because some of its views would limit freedom of thought. This distrust helps create the disaster that will come.

The scientists are reluctant to lend credence to the belief of the Apostles of Flame that an apocalypse is near; the Apostles of Flame oppose the secularism represented by modern science.

Even after scientists warn of the coming eclipse, politicians are reluctant to antagonize people and...