User blog comment:AndImBatman/A theory: New Black Ops II Zombies Storyline/@comment-200.104.118.230-20130112232920/@comment-50.8.164.22-20130118051604

Samantha' body was in suspended animation when she was in the pyramid, meaning she doesn't die. So when the Original Character travelled time she waited. That is why the world is in a zombie apocalypse when the Original Characters arrived in the Theater (Kino der Toten).