At some point soon, The Flash will take a trip to Earth-2 on The Flash -- and when he gets there, it's likely he will run into more than just doppelgangers for existing characters.
With the success of characters like Firestorm on The Flash and Black Canary on Arrow, one of the challenges to the series is that sometimes it's easy to imagine that showrunners don't particularly want ot introduce a potentially-beloved character just for a one-and-done episode. So with Earth-2, you've got the built-in excuse that they aren't going to be regulars because they aren't going to follow us all back at the end of the year.
Who might pop up? Well, we've got some ideas.
First of all, there's a quartet of really obvious choices for potential additions. Why? Well, because you have to think back to the season premiere and consider Al Rothstein, who was the episode's villain.
Atom-Smasher's alter ego -- Albert Rothstein -- was one of a handful of names rattled off by Harrison Wells/Eobard Thawne during the Season One episode "Power Outage," in which he revealed that he knew the names of everyone killed by the particle accelerator explosion at S.T.A.R. Labs and felt all of their losses personally.
Of course, it turns out that at least two of those characters so far -- Firestorm and Atom-Smasher -- have been less dead than previously advertised. So...who might we see coming up in the near future?
The Enlongated Man is often overlooked as a character, since he shares much of his power set with super-genius and Marvel Comics icon Reed Richards, and/or DC's own Plastic Man, who has an even broader range of uses for those powers and a long history of appearances in other media to keep him fresh in people's minds.
Dibny, though, certainly has always had his fans. The biggest difference between he and the other stretchy characters is his near-Batman-level detective skills, complete with a nose that "twitches" when he's onto something.
In addition to a long run with the Justice League International, he and his wife Sue appeared in James Robinson's critically-revered Starman series.
The character died at the end of 52, sacrificing himself to defeat Neron and Felix Faust. At the end of that series, he and Sue -- who had been murdered at the start of the best-selling and controversial Identity Crisis series -- appeared as ghost detectives.
The superhero known as Damage would be a perfect fit for TV.
With vaguely-defined powers, Grant Emerson theoretically has the ability to absorb and redirect energy...but how it's used and how it looks? That's up to the creative team.
Interestingly, Emerson played a key role in the Zero Hour crossover -- a time crisis where the heroes of the DC Universe battled both Parallax in the form of Hal Jordan...and Extant, a villain with strong ties to Atom-Smasher.
Amazing Man -- sometimes hyphenated as Amazing-Man -- is a legacy hero whose various iterations, including Will Everett and his grandson Will Everett III, have worked with a number of DC teams including the All-Star Squadron, the Justice League and (try not to laugh) Extreme Justice.
The elder Everett could duplicate the properties of inorganic items (so he couldn't steal your powers, but he could make himself hard as rock), as could his grandson. But while the elder could also manipulate the magnetic properties of the world around him, the younger couldn't do that. Instead, he had energy absorption powers.
A south American model with a family history in the espionage business, Bea DaCosta spent some time in every third organization in the DCU.
Originally created for the Super Friends comic book, she was introduced into mainstream continuity after the Crisis on Infinite Earths and, along with Ice, became key members of the Justice League. She has been a member of the Global Guardians, Justice League International, Super Buddies and Checkmate. She currently appears in Justice League 3001.
There are some more options open to the writers, as well. Just about anybody who's ever been on the Justice Society is likely fair game, but even among those names, there are some possibilities more likely than others.
It's a power set they've already used a few times, so it would be relatively cheap from a character-development point of view. And yeah, she's got a number of very vocal fans, including former JSA writer and current DC Entertainment Chief Creative Officer Geoff Johns.
Cyclone, along with the Johns-created Stargirl, are a pair of legacy heroes who have the powers of their predecessors. In Cyclone's case? That's Ma Hunkle, the Golden Age Red Tornado...whose helmet we're pretty sure we saw on the Legends of Tomorrow trailer!
Speaking of whom! If we're going to have the younger, "trainee" generation of heroes, I'd love to see how Cyclone, Stargirl and Jesse Quick interact together.
And if she were to come with her stepfather S.T.R.I.P.E., that's even better!
There are certain characters that -- even practical stuff aside -- we're not likely to see unless it's on Earth-2, where Warner Bros. can clearly distinguish between different versions of the hero.
With Alan Scott, there's nobody more closely associated with Jay Garrick in the DC superhero canon. The pair are generally thought of as the two most recognizable names of Earth-2.
Since we've already seen clues that Green Lantern could show up in the Earth-1 timeline over on Arrow, but never had anything close to the character actually getting to appear on the show yet.