In 2710, a new type of virus spread globally, and its spread was incredibly fast.
In just three weeks, the virus swept across the world. The fertile soil that used to be prosperous and full of vitality is now littered with corpses and overgrown with weeds, turning it into a crumbling "steel forest."
Each refuge camp agreed upon a meeting and announced voluntary teams from each camp to recruit elites from all over to form multiple teams. They were called "Cheetah Teams".
Multiple teams divided up and headed south, heading towards the research institute located deep in the dense forest.
Purpose: Save human civilization