Baron Heinrich von Helsingard is poised to conquer the Old West with his invincible army of automatic soldiers and the war zeppelin Basilisk. Atomic Robo, Doc Holliday, and U.S. Marshal Bass Reeves are all that stand between him and total conquest. But they're outmanned, they're outgunned, they have no good plans, and there's no way out alive. Oh, and Robo's nearly out of nuclear fuel because it's 1884.