Not only will Tyler Hoechlin’s Clark Kent/Superman return to the Arrowverse for this year’s crossover, but his iconic girlfriend Lois Lane will make her first appearance. But this exciting news could also be a hugely important indicator that Batwoman might not exist on Earth-1. It’s possible that the upcoming Batwoman show could take place entirely on Supergirl’s Earth-38.

Deadline reported Wednesday that Tyler Hoechlin, who appeared as Superman in four episodes of Supergirl’s second season, would return to the Arrowverse for this December’s annual crossover event. Clark Kent’s love interest Lois Lane hasn’t been cast yet, but Deadline also revealed that she’d also play a role.

Superman will also appear in all three episodes of the crossover which implies that Supergirl and her world will have a much larger role to play in this year’s crossover, unlike the last two when she temporarily migrated over to Earth-1 to join in the fun.

So do Barry and Oliver go to Earth-38? Or does Supergirl bring Superman over to Earth-1 for the first time ever?

Arrowverse 2018 Crossover
The Arrowverse crossover omits 'Legends of Tomorrow', but we're starting to think it might not take place on Earth-1.

We knew from previous hints in the Arrowverse shows that Gotham city exists on Earth-1 and Earth-38 and that Bruce Wayne exists in the former. (He also exists in Earth-2, but that doesn’t matter all that much here.) There isn’t actually any indication that Gotham has a vigilante on Earth-1, and there’s no mention of Bruce Wayne in Earth-38.

The only definitive evidence of a Bat-person actually operating as a vigilante anywhere in the Arrowverse has been on Supergirl. In the episode “The Darkest Place,” Kara says, “My cousin worked with a vigilante once — tons of gadgets, lots of demons. Vigilantes are nuts.” The show had further mentions of “Clark’s scary friend.” Both these details definitely sound like Batman, but they’re also decidedly gender neutral.

So what if “Clark’s friend,” the vigilante with “lots of demons” on Earth-38, is actually Kate Kane’s Batwoman? What if Batman doesn’t exist at all in the Arrowverse, and the core plot of this year’s crossover takes place in Earth-38’s Gotham City where the heroes team-up with Batwoman, the city’s only hero?

Batwoman as she appears in DC Comics.
Batwoman as she appears in DC Comics.

As crazy as this theory sounds, it wouldn’t be much different from the alternate timeline in which Robert Queen became the Green Arrow instead of Oliver Queen. Even with time travel like with Flashpoint, timelines change, evil people become good, and some heroes become villains. So what if Bruce Wayne doesn’t exist and a different hero stepped up to fill the same role?

This theory would probably cheapen the unique nature of Kate Kane as a character, transforming her more into a genderbent version of Bruce Wayne’s Batman, but there are many precedents for that happening across the Arrowverse. And there’d still be room to tell Kane’s tale in an authentic way that respects the character’s comics history.

If The CW does decide to set Batwoman on Earth-38 instead of Earth-1 — where Arrow, The Flash, and Legends of Tomorrow takes place — it would be a bold move for the Arrowverse, but it would make the most sense for this year’s crossover event and for the broader multiverse. Batwoman seems like she’ll be a veteran vigilante when she joins the Arrowverse, and the only place where that seems possible is on Earth-38. Outside of that, Supergirl could use some super-cool allies to team up with over on her Earth too.

The 2018 Arrowverse crossover will air December 9 through 10.