Now exposed as the greatest danger to all life, the Anti-Monitor launches a relentless assault on the remaining Earths, which are desperately trying to endure within a pocket universe. These worlds, along with their populations, are being obliterated one after another! On the few planets that persist, even the fabric of time is fractured, prompting heroes from bygone eras to unite with the Justice League and their motley crew of allies to confront this embodiment of malevolence. As they prepare for their final battle, the question remains: will the superheroes’ ultimate sacrifice be sufficient to rescue everyone?