During the war, Atlas dropped a DNA Bomb. Anyone not entered into its genetic code was killed. However, the dead came back as zombies as a side effect, and Atlas took some to a Bio Lab. However, some of the zombies broke out, and they infected the entire compound. Kahn, Lillith, Oz, and Decker are the only four survivors. After being over run, however, Atlas saves them. They are then sent to a Burgertown Atlas Facility, which is then overrun with infected. After rescuing survivors, a Sentinel Warbird comes in and 'saves' them. Lennox (Bruce Campbell), the Sentinel Commander, then comes out and shoots Oz, claiming that Oz was the source of the infection. He then proceeds to load the group up on a warbird. They then go to an Atlas ship. However, Oz is revived as a zombie. The Atlas ship is then infected. As the group of survivors (Lennox now joining the remaining 3) is about to escape, zombie Oz appears and comes at them.