In AD 3963, life on the surface ushered in a mass extinction, and humans had to evacuate the earth and go to live on the planet Hain in the 38th galaxy. Only the upper class of society were evacuated, and a large number of people at the bottom of society were left on the surface simply because of insufficient resources. Just when people were at a loss what to do, Ma Gan, a civilian scientist, led a team to build an underground base long ago, and mankind also survived the disaster. But the relationship between heaven and earth has been very tense since then. The story takes place 70 years later...
Purpose: Unity and cooperation