Ok, so here is how I think the zombie mode on Black Ops 2 fits in with the rest of the zombies storyline. I will go back to Moon and even Kino der Toten in this post. P.S: I'm new to this website, but have always been thinking of storyline theories. Enjoy!
Ok, so this may take a while. Haha! Let's start with the most important characters first. Marlton's story will take me all the way back to Kino der Toten. Do you guys know the picture frame with the silhouette in it that people are saying is the "missing character". Well, I think this Marlton, and I have proof! In Nuketown Zombies, when you knife the fallout shelter, you can hear Marlton in it. He says things about being kicked out of the group. Is he talking about the BO1 characters? I think so. I think he was working with Richtofen in group 935 and he helped him capture Dempsey and Nikolai. Then Richtofen betrayed Marlton and did the same thing to him as he did to Maxis and teleported him to the future when the rockets were launched and he completed is "grand scheme". Marlton then escaped the fallout shelter and joined the group in the events of Tranzit and Die Rise. Now, I know Nuketown is in Nevada and Tranzit is in Washington, but perhaps, since Marlton is so smart, he made a portable teleporter or, even better, a Gersh Device. (Maybe we will see the Gersh Device later on).
Samuel, I think, is going to be a HUGE part of the story later on. Let's go to the solo Die Rise cut scene. In it, Samuel says to Richtofen "You can't tell them about the flesh, what I've done! They'd kill me if they knew." After he says this, a picture flashes up VERY quickly. The picture is of Samuel eating and arm. Now here comes the big theory. He was a zombie in Call of the Dead and was revived by the VR-11 and was taken by the aliens. The aliens brainwashed him and experimented on him. They then returned him to Earth after they were finished and he didn't remember any of the events from before. When he returned, he was poor, homeless, and confused. He landed in Washington. Most of all, HUNGRY. So after the outbreak, he found a dead zombie and had to eat it to survive. AND the reason why ONLY he can hear Richtofen is because he was exposed to 115 from eating the zombie. And why do you think he is big on conspiracies and aliens? He was apart of both things and still is.
Misty and Russman knew each other before the events of Tranzit. Perhaps Misty gave him food every day or something. We all know Russman is homeless. He wears one boot and one sneaker. I don't think they are big to the story. Now for the Die Rise theory...
Since the characters have completed the Easter egg, Richtofen transported them forward (great leap forward) not only to China, but also in time. We know the characters have time traveled previously, and maybe there was some space-time continuum involved, and that's why we have TED-D (the bus driver). I think Tranzit takes place in the 70's or 60's (some time around there). Maybe they were teleported by Richtofen to present day 2013 in China to complete his next task. And in the end of the Die Rise cutscene, Richtofen say "Accept your fate, begin anew!" And the characters die. Then, they appear on the roof again and Samuel says "Have we been here before?" I think they are in a never ending loop until they complete their task, kind of like the scientists on the radios for the Shangri-La Easter egg.
Well, that was a mouthful! I hope you all take this into consideration! It took me like a month to think of this and an hour to write it. I even added some theorizing as I was writing. This is pretty much my only way to get my COD ideas out. So please listen! Good night guys! :D