Nuketown Zombies is set after the events of Moon, and at the ending of the multiplayer level from the original Black Ops. A group of radiation scientists are investigating the Nuketown and they discover a soldiers that have been revived by Element 115 from a Nevada base. The zombie soldiers attack the scientists and turns them, and after receiving a distress signal, the Nevada base sends in CDC and CIA agents out to investigate. At arrival in Nuketown, the agents lost communication with Hangar 18 and become stranded…

This was the stage setting for the Nuketown Zombies.