In 2784 after decades of zombie invasions the scientists finally discovered the so-called zombie-genome which is able to equip dead corpses different abilities. Generally it manifested itself as recovery of motion functions and need for food. But in some cases scientists found out that the creatures had totally independent behavior and strong desire to control and destroy all species around for their personal purposes. As soon as the military got informed of such qualities of zombie-genome, they immediately started to develop a new kind of biological weapon. After many experiments they finally made the first prototype of a biological weapon which had its own mind and shapeless jelly-like body. It had an ability to take control of any living creature. This weapon gave them an opportunity to resolve any conflict by force. But one day there was an emergency. One of the labs in Colony No4 went out of power just for a few seconds. It was enough for the young bioweapon to feel free and escape. Source: The Developer Website.