While visiting his mother's grave, Barry Allen, known as the Flash, is alerted to a break-in by his enemies Captain Cold, Captain Boomerang, Heat Wave, Mirror Master, and Top at the Flash Museum. Defeating the Rogues, he discovers that they have been hired by his archenemy, Professor Eobard "Zoom" Thawne, as part of a plan to destroy Central City. With the help of the Justice League, Barry foils Thawne's plot, but Thawne's taunts over the death of his mother still haunt Barry as he departs.

The next day, Barry wakes to discover that the world has radically changed: his powers are gone, his mother is alive, his wife Iris is married to a colleague, and the Justice League does not exist. Aquaman and his Atlantean forces have sunk most of Europe, while Wonder Woman has led the Amazons in conquering the United Kingdom, and both forces are now at war after an attempted alliance between them resulted in Wonder Woman murdering Aquaman's wife Queen Mera, due to Mera discovering that Aquaman and Wonder Woman had a secret affair together and Mera confronting Wonder Woman herself. Cyborg has assembled a team to eliminate both parties and approaches Batman to join them, but his refusal leads the government to scrap the plan, and instead...