Since Superman & Lois launched on The CW last season, fans have frequently questioned why characters from the other Arrowverse shows -- especially Supergirl, which centers on Superman's cousin -- have not made appearances on the series. Tonight, fans got the answer: Superman & Lois takes place on a world that is not the Arrowverse's Earth-Prime. Furthermore, in the world of Superman & Lois, Superman is the only superhero, meaning that most of the characters of the Arrowverse are not part of the series' world, and the Man of Steel at the center of the show does not share memories with the Superman who first appeared in Supergirl.
Supergirl, in fact, is the touchstone that series showrunner Todd Helbing used. When we asked him whether it was similar to the first couple of seasons of that series, the producer virtually finished our sentence.
"Yeah. I think that's a good analogy. When Supergirl was on CBS, they were on their own world, right?" Helbing explained. "If you think about it, John Henry started on a separate planet, they had their own version of Kal-El, it's very much that. So the Arrowverse is on Earth-Prime, we're on a different Earth. I'm not sure what number that is yet . So Diggle's history...he's John Diggle but his history is not exactly the John Diggle's history that was in Arrow, and that holds true for every character."
John Diggle, played by David Ramsey, is one of the most beloved characters from the Arrowverse. He first appeared in the Arrow pilot, and was a series regular on all seven seasons of that show before popping up on The Flash and Superman & Lois after Arrow was over. The character was confirmed to make an appearance in the season finale of Superman & Lois this year, but that version will apparently be an alternate universe version of the Diggle fans know and love.
The revelation came about midway through tonight's season 2 finale, when Same Lane told Jonathan and Jordan Kent, "I've been working for the DOD for a long time. I've seen things you would not believe: glimpses of other worlds, and the Leagues of superheroes they have on them. And even though we only have your father on this planet, thank God that we do, because he's the finest of any Earth."
With the end of Batwoman and DC's Legends of Tomorrow this season, The Flash now stands as the only CW series set on Earth-Prime. While Superman & Lois and Stargirl exist within the Arrowverse multiverse -- and in fact are currently taking part in a comic book crossover with the other shows -- the world that launched with Arrow in 2012 is pretty underrepresented on the network right now. This also might explain the decision to feature everyone except Superman & Lois in the "Armageddon" crossover on The Flash earlier this year.
Superman & Lois ends its second season tonight and will return to The CW in early 2023.