The world has been in chaos for several years now. There's devastation and terror everywhere. There are infected and mutants everywhere. The survivors are becoming fewer and fewer. You were one of them. You were a professional soldier before the apocalypse. Afterward, your main task is to survive. Many of the survivors wondered how you managed to survive all these years. Maybe luck and survival skills. But no one, not even you knew that your immune system is completely invulnerable to various diseases, viruses and parasites.

Among the survivors there were legends about a clever infected (Leon) who is very sneaky and cunning. Everyone who encountered him was infected.