Nathaniel Adam cropped up a few times in the Countdown series. He first surfaced in Countdown #45 as Monarch, but not as Captain Atom until Countdown #43 (the series, like Zero Hour, was numbered in reverse) in the backup story “History of the Multiverse Chapter 7,” written and drawn by Dan Jurgens with finished art by Norm Rapmund. Countdown was a weekly series that ran from May 2007 to April 2008. Issues #26-1 bore the title Countdown to Final Crisis. The final issue, #1, was followed by DC Universe #0, which was then followed by Final Crisis.
Captain Atom next appeared in Countdown to Final Crisis #17, in the back-up story entitled “The Origin of Monarch.” As the title suggests, it tells the story of how Nathaniel Adam became Monarch. It leaves out the events of Extreme Justice, and actually contradicts them. Instead of Monarch being a part of Nate that was left in the quantum field, his rise to power is much more direct. This story was written by Scott Beatty with pencils and inks by Scott Kolins.
Captain Atom gets a brief mention and cameo in Countdown to Final Crisis #8 as well. Darkseid reveals that he is aware of the Monitor’s attempt to push Nathaniel into becoming Monarch in Blüdhaven. This issue was written by Paul Dini, Justin Grey, and Jimmy Palmiotti with Keith Giffen credited as “story consultant.” The pencils were the work of Carlos Magno with inks by Rodney Ramos.