Delta X-Ray Delta was a group of survivors in the apocalypse, who were traveling from New York to California, to transport Murphy, the only living being with the vaccine for the zombie virus in his blood, to a lab to make more of the vaccine.

In the group, were 10K, Warren, Doc, Murphy, Mack, Vasquez, and Charles. The group had a connection to a man named Citizen Z who was in an NSA base in Antarctica, helping guide them on the mission.

They were riding in a truck through Philadelphia.