Due to genetic mutations caused by nuclear leakage, mankind finally built a city in the sky after hundreds of years of hard work... In the new century, human youth You Wen woke up one day and found that the entire human base on the ground had become an empty city. Where will he go? What kind of story will happen with Tiancheng again...
Concept: In a collapsing world, the enemy of mankind is not the strange species, but the unknown human nature.