Simon Cruller a.k.a. Citizen Z is a survivor of the initial zombie apocalypse, and a main character in Z Nation. He is the sole remaining human presence at the NSA's Northern Light listening post in the Arctic Circle. He is slowly going insane from loneliness, his only company is a sled-dog named Pup. He assist survivours in the post apocalyptic US. First and foremost Delta X-ray Delta and their mission to get Murphy to California.