Heroes and villains are locked in battle over three of the five partially-merged Earths. Despite the villains' overwhelming numbers, their lack of experience working as a team makes it an even contest. But as the superhuman war rages, the Spectre calls out for it to end. The threat posed by the Anti-Monitor hasn't ended! He has traveled back to the dawn of time, seeking to change the past so that the multiverse is never created, and only his anti-matter universe remains!Heroes and villains put aside their differences to work together on a massive scale. To confront the threat of the Anti-Monitor, the heroes will travel to the dawn of time to do battle with him because only at the dawn of time can history be changed. The villains will travel ten billion years into the past to Oa, where they will attempt to stop Krona from glimpsing the dawn of time, the event which created the fractured multiverse.