The Flash gets a chance to go back in time and right a violent, decades-past crime against his mother. However, the ripples of his good intentions prove disastrous, as a fractured, alternate reality now exists in place of the familiar one. Superman is nowhere to be found, and Batman is a grittier, more violent Dark Knight. Together, with Cyborg, they race to restore the continuity of Flash's original timeline, while this new one is ravaged by war...