After years of learning the rules of all the alternate dimensions and multiple Earths of the multiverse, the massive Arrowverse crossover, Crisis on Infinite Earths, did away with the multiverse as a whole! When all was said and done, all the separate Earths in the Arrwoverse merged into a single Earth Prime.
"We knew from last year, quite frankly, that we were going to merge and create Earth CW basically — but Earth Prime sounds better," Arrow executive producer Marc Guggenheim told reporters at a press screening of Crisis on Infinite Earths. "Even though in the comics Earth Prime is our Earth, I just personally liked the sound of Earth Prime. So all the CW shows will be on the same Earth — the CW superheroes."
Obviously, it's logistically more convenient for all the CW superhero series to exist on the same Earth since hopping on a plane to visit Kara (Melissa Benoist) in National City is just so much easier than tracking down an interdimensional extrapolator. But that begs the question, do other DC Comics shows exist on Earth Prime now? In the opening scenes of Crisis on Infinite Earths, we saw shows like Titans from DC Universe make appearances on other Earths, and even Netflix's Lucifer (Tom Ellis) existed on Earth 666. We saw them again in the final moments of the crossover, so it could be that these shows now canonically exist on Earth Prime and we'll just never see or hear about them, or it could be that those cameos should be treated as fun Easter eggs, but should not be taken seriously when considering the mythology of the multiverse.
The exact details of the Arrowverse's version of the merge are still a mystery for a now (are there suddenly dozens of other versions of each person running around Earth Prime, or did they all just become one version of that person?) but at least we know of one character from another Earth that definitively still exists independent from other incarnations of him, and that's Tom Welling's Clark Kent from Smallville.
"I didn't like the idea of thinking that there could only be one Superman and we would lose Clark — our Tom Welling Clark as Superman when the universes morphed into one," Batwoman showrunner Caroline Dries said. "And so the idea, at least, that allowed me to sleep at night was thinking if he had retired the Superman of it all, that there was a chance that he would still exist in our [Earth Prime]."
We'll miss the multiverse and all its confusing twists and turns, but Earth Prime (or Earth CW) sure sounds like a fun place to live now that it's got all our faves in one place!
Supergirl and Batwoman return Sunday, Jan. 19 at 8/7c and 9/8c on The CW. Arrow and DC's Legends of Tomorrow return Tuesday, Jan. 21 at 8/7c on 9/8c on The CW. The Flash will return Tuesday, Feb. 4 at 8/7c on The CW.