The series follows the success of "52", which, in contrast, did not cross over with DC's other regular titles. "52" concluded with the revelation that the Multiverse (a storytelling device which posits the existence of alternative realities) exists, and which now serves as a backdrop to several stories in "Countdown". Beginning with issue #26, the series trade dress was reworked to identify the series as "Countdown to Final Crisis". The stories taking place in "Countdown" set the stage for the approaching "Final Crisis" limited series.