During the first decades of the 21st century,what was called global warming caused the appearance of a new pandemic disease:Lilith.
Lilith infested the entire human race in less than five weeks.
Even if scientists soon found a vaccine, they rapidly realized the human body addiction to the vaccine. One threat warded off, a new one soon appeared, coming from the sky.
During the years following Downfall day, survivors started to search for vaccine at all costs and started an era of chaos. What we now call the old society was replaced by small groups of people without any notions of country.
The biggest of those groups, named Consortium, took control of the remaining vaccine stocks and started to rule the world imposing vaccine rationing.
Now, the only legal way for other clans to access vaccine is the Race Of Chaos where every remaining group racers compete until death of victory.