Four years later, the virus has spread and it's infected had overrun all the major cities in the world, with only a few survivor outposts remaining.

Despite warnings from the arrested lab technicians, they proceeded to release the 109 caged people which proved to be a fatal mistake, not aware that they were carrying the highly infectious N4 Virus. In the year 2016, a private biological research facility was raided by French police forces after several allegations of illegal experimentation involving human subjects.

Zombies are reanimated corpses infected with the N4 Virus often found roaming through the major cities of the world.