In this world, there are 2 big companies that were working together to create a Bio weapon that can be used on humans, like Umbrella corporations (RE au) and ATLAS corporation (COD au)...3 years ago the experiment went wrong and the whole world was consumed by the first prototype of infected is Zombie, but this time they're smart and able to evolve to become more strong and dangerous....the operator who worked for them like Kaltsit, Amiya, and W has no choice but to survive...the rest are canon