In 2600 AD, due to a local gamma ray burst that swept across the earth, the earth's ozone layer was destroyed, and thousands of creatures were exposed to the sun's strong ultraviolet radiation.
In order to survive, humans have turned their attention underground. Organized by the World Government, a city - the underground city - was built three thousand meters underground.
Due to limited resources, the underground city cannot accommodate humans around the world; and in order to ensure the diversity of human society, the world government has carried out very strict and picky screening of people entering the underground city, not only ensuring the existence of every country and every nation, but also ensuring the existence of every profession: executives, white-collar workers, or sweepers...
One hundredth of each type of outstanding people can enter the dungeon.
In the underground city, everything is controlled by the world government. From the moment of birth, everyone's destiny has been drawn. Of course, this birth was not a birth in the traditional sense.
In a dungeon where your life is highly controlled, the only thing you can decide is your own death - submit a death application to the life and death testing team. After review and approval, professionals will come to inject you with HIV, extract your DNA, and bring it back to the testing team for cloning. The clones, or descendants as the dungeon dwellers call them, will repeat your life path until they file for death.
Our heroine Mi Lu, or the second generation of Mi Lu, is the deputy head of the life detection team (the first branch of the life and death detection team). This position is inherited from her DNA contributors, the Milu generation.
By the way, it is now 2689 AD, the 88th year since the underground city was built.
Concept: What kind of secrets are buried underground?