Nuketown Zombies is set during the events of Moon, and after the end of the multiplayer level from the original Black Ops game. A group of radiation scientists are investigating the Nuketown remains and discover soldiers that have been revived by Element 115 from a nearby Nevada base. The zombie soldiers attack the radiation scientists and turn them, and after receiving a distress signal, the base in Nevada sends in CIA and CDC agents to investigate. Upon arrival in Nuketown the agents lose communication with Hangar 18 and become stranded...setting the stage for Nuketown Zombies.