Jan Kulozik, based on the results of "The World of the Motherland", is referred to the agricultural planet Halvmerk, where peasant tribal families live and work for four years in the twilight zone before the sun, entering its peak of activity, scorches the planet. They must then pack everything up and move to a new twilight zone on the opposite end of the planet's axis to begin the four summer cycles all over again. The grain grown on the planet is collected by spaceships and used to feed the starving world of the galaxy. The people of Halvmerk depend on these ships because... they bring them other goods. The Earth's government has made it so that not a single planet is independent, as a result of which no one dares to rebel. But this year the ships do not arrive, meaning they are cut off from the outer galaxy, which is undergoing change. Yang decides that they must carry the grain with them to the new twilight zone. This is a valuable commodity that, if ships arrive, will provide them with the goods they need. He must force conservative farmers to accept his survival plan. The novel tells the story of the dangerous journey of the people of Halvmerk during their migration from one end of the planet to the other.