After a series of wars, due to the lack of natural resources. The government attempted its last-ditch attempt. A virus leaked into the water supply, the original plan was to affect the young, elderly, and weak in an attempt to control the population. This turned into a widespread pandemic leading to a mass zombie infestation. The issue was after the person who had been infected died, they would become undead creatures known as "Necrotics" whose goal was the spread the virus. Those who survived the initial virus would eventually become a Necrotic due to the viruses living in their systems or being attacked by those already undead.