At the end of the century, due to the invasion of alien creatures, mankind is on the verge of extinction.
Abandoned City - the last capital city at the end of the century. Under the protection of the city's Lord Cross, a small number of nobles were able to thrive in the city.
Chen, as a genetic race with high IQ, rejected Cross's invitation and resolutely lived as a poor man at the lowest level of the abandoned city.
"Chen, don't forget the deal you made with me. If one day I find out you betrayed me..."