With the reveal of who is behind the great darkness that is tearing the galaxy apart, the Justice League and the Legion of Super-Heroes are at odds over how to handle the incomprehensible evil that has brought them together. This time-spanning epic stars all your favorite superheroes from two different time periods! Batman! Saturn Girl! Superman! Brainiac 5! Naomi!...and dozens more race into battle to save the galaxy from being pulled apart! But at what cost? Will everyone survive this?