(Introduction part 2)
With most of humanity left behind, all remaining resources after the refugee project were poured into building vaults. Time was short. Instead of starting from scratch, in most cases, deep military complexes and other wartime shelters were expanded to take in many times more people than they were originally bulit for, able to sustain themselves without having to be in contact with the surface.
Most of humanity was secured this way, however not everyone could be saved. Some volunteered to give up their place, others were simply denied entrance.
Once the absolute limit was reached, the vaults have closed their doors, one after the other, each killing the hope of many still in line to enter.
The asteroid has landed in the Ural Mountains. With it, it brought immense energy, heat and power which quickly vaporized some of the earth's water, dropping worldwide water level by many meters, and resulting in a thick cloud layer covering the skies across the globe. The result