"Countdown to Final Crisis" was originally intended to run from issues #51-0, with issue #0 serving as the prologue to the "Final Crisis" limited series. Instead, it was decided that "Countdown" would conclude with issue #1 and the #0 issue was retitled to "DC Universe" #0. "DC Universe" #0 was co-written by Grant Morrison and Geoff Johns and served as a summary of recent events within the DC Universe in order to attract new readers before the company launched the "Final Crisis" limited series.