Although the great destruction caused a sharp decline in the world's population and most cities disappeared, the scientific level of human beings was not affected at all. So within a few years, the surviving people had established villages and settlements, and their lives also returned to peace. This instead eliminated many problems caused by excessive population, such as food and pollution, etc., coupled with the change of mentality, the problem of overpopulation will not appear again in the future. In addition to the emergence of the monster that hindered traffic and wired communication, life can be said to be better than before the destruction. At least the scene of green grass can be reproduced on this planet.