However, without prior knowledge at the time, the three Atlas employees also shared the a similar genetic mutation with Oz that prevented them from becoming infected. Oz arrived at the helicopter landing pad along with three other Atlas employees: Lilith Swann, Jim Decker, and Kahn. Unbeknownst to Oz and everyone at the facility, he was actually the cause of the outbreak, which was planned by Atlas. Afterwards, a zombie outbreak occurred in the facility, forcing him to evacuate. On one night, while performing his 'usual clean up duty', Oz spotted streaks of blood on the ground, along with several broken glass casings and some dead bodies. The brainwashing was not entirely successful, however, as Oz still retains some of his old memories, such as his hatred for Atlas, although he has a very hazy recollection of his life in Sentinel, only remembering that he fought in some 'wars'. After having reverted, Oz was brainwashed into believing he was an Atlas employee, who worked as a janitor at the Atlas Biogenesis Research & Development facility, run by Kahn. Oz was special, compared to the other infected patients, as he was somehow able to revert to his human form, thanks to a special genetic mutation. Atlas managed to capture him and began experimenting on him. In the midst of the battle, Oz was caught in the radius of a Manticore bomb, and was one of the first to become infected. He, along with several other Sentinel soldiers, were sent to New Baghdad to contain a prison riot, while also fighting off the Atlas Corporation. Oz was formerly a soldier working for the Sentinel Task Force, known among them as one of the best.

Call of duty advanced warfare infection