10 DC Comics Stories That Changed Everything

In "Flash of Two Worlds" an otherwise innocuous meeting between the new Silver-Age Flash, Barry Allen and his Golden-Age counterpart Jay Garrick, would change the structure of the DCU forever.

Since Barry's introduction, the DCU had been functionally rebooted, with no mention of the Justice Society or any of its founding members. Fans of the original Flash and his fellow WWII era heroes were left to wonder what became of them. Right until this story gave a definitive explanation to their curious absence.

The story itself is rather unremarkable. Barry Allen vibrates his body at such a frequency that he phases through realities to Keystone City, the home of Jay Garrick. Three of Garrick's enemies are committing robberies around the city and the two flashes have to team up to stop them.

The significance of this story isn't in the events themselves but the implications. We learn that the Golden-Age DCU still exists and all of their adventures did happen, just in a universe separate and parallel from the one that was currently being written. In subsequent books the two timelines would be designated Earth-1 (Silver-Age continuity) and Earth-2 (Golden-Age) but they would be far from the only ones.

The book was a hit and heroes found themselves dimension-hopping on a regular basis, meeting alternate versions of themselves and discovering new realities.

While this device gave writers more freedom to play with their characters and environments, canon became more muddled and hard to follow over the next 25 years. Right up till DC devised a brilliant plan that would "fix" it forever.