Wang Cheng is transported to a post-apocalyptic world where radiation has caused mutated beasts to run rampant across the globe. All humans now live in various floating mobile cities. Congratulations! The transmigrator has awakened the City Lord System and received a mobile city as a reward! Simply check in at cities and famous landmarks to choose upgrade rewards. And so, the most luxurious and safest mobile city in the apocalypse is born.