With the second part of The Multiversity due out this week, I gave the opening issue of Grant Morrison’s latest cosmic epic a second read over the weekend. Though there’s a lot that could be discussed, including the continual use of songs to power things, a reference to a “drug-induced hallucination” that I assume was Morrison poking fun at himself, and the outright awesomeness of Captain Carrot, the part I enjoyed the best was that the characters appear in comic books on Earths other than their own.

It’s not a new concept, and Morrison is obviously tying it into a larger point he’s trying to make with the framing scenes that speak to the reader, but it’s a great throwback to the story that pretty much kicked off the whole idea of a Multiverse in comics. That would be “Flash of Two Worlds!” from The Flash #123, an issue that turns 53 years old this month. In that book, writer Gardner Fox and iconic Flash artist Carmine Infantino have Barry Allen discover that by vibrating at a certain frequency, he will end up on a parallel world we eventually come to know as Earth-Two, where the heroes of the Justice Society live — most notably Jay Garrick, the original Flash, whose comic book adventures on Allen’s Earth inspired him to take the same name.

That was the first time DC tried to address the different versions of its characters who had appeared in comics during the 1940s, and it’s fair to say it was a watershed moment for fictional characters appearing in and crossing over between different universes. It’s great to see the heroes of The Multiversity relate to each other in the same way, and it’s even more appropriate that a Flash is his Earth’s representative on the multi-dimensional team since he’s an expert on comics. It just goes to show you that no matter what strange directions Morrison ventures off into, he knows how to work with cool stuff from the past at the same time.