User blog comment:Damac1214/Black Ops II - DLC 5 Rumors surface/@comment-10261308-20130620023410/@comment-3228520-20130621152633

Mob of the Dead never happened. Regardless if Arlington breaks the cycle he is still stuck in the Purgatory, which is an alternate universe within the "real" universe. They are all dead in the real universe and Zombies didn't happen until 1943, if I'm not mistaken.