Plague Z was a plague that caused the infected to become stronger, but took control of their brains to infect more people by attacking them, turning them into "zombies". This global pandemic lasted for 7 years, staring from Patient Zero being infected on April 5, 2020 and the last zombie being shot down on July 27, 2027. During this 7-year time period, now known as The Zombie Years, the zombies attacked humans, and spread themselves to almost all countries of Earth. Almost 5 billion people died during these years, vast areas were left depopulated, and a 75-year long period of near-total anarchy followed the plague.