In the events of Justice League Part 2, Superman has been brainwashed by Darkseid, the Justice League could not prevail, Darkseid holds the Anti-Life Equation in his hands, and the world has been destroyed! But there is still hope, The Flash tries to run back to the past, but ends up in different parallel universes where he meets alternate versions of DC characters like Thomas Wayne, Arthur Fleck, The Batman Who Laughs, Reynolds Green Lantern, Batman Beyond, Michael Keaton's Batman, and thousands of otthers! The Flash then recruits these alternative characters and the Justice League from the past in a war to stop Superman, Darkseid, and his incredible army!
