Kingsley Ward transmigrates into an apocalyptic world, where radiation has caused Abyssal Beasts to run rampant across the globe, and all humans live on various floating Mobile Cities. Congratulations to the transmigrator for awakening the Lord System, you are rewarded with a Mobile City! You only need to complete Daily Check-ins at cities and famous attractions to select upgrade rewards, and thus, the most luxurious and safest Mobile City in the apocalypse is born.