There’s no feeling quite like the frisson of joy that comes with a superhero crossover. Like countless other consumers of superhero fiction, I felt that familiar jolt of excitement yesterday, when Warner Bros. announced that Grant Gustin will appear as the title character of the CW’s hit The Flash on CBS’s Melissa Benoist–led Supergirl. I’m not exactly sure why crossovers have that kind of emotional effect. Perhaps it’s like a birthday party where you introduce two disparate friends and they hit it off right away. Perhaps it’s like being stoned in a freshman-year dorm room and contemplating the ways in which all the particles of the universe are connected to one another. Or perhaps it’s like witnessing the construction of a massive urban-planning project take form.

That last comparison is not an unreasonable metaphor for what Warner and its superhero sub-brand, DC Entertainment, are doing with this crossover. They appear to be building a shared superhero universe that’s more complex and insane than anything that’s existed outside of the niche world of comic books. We don’t know exactly what the plot justification of this crossover will be, but there are two logical options: It could be revealed that The Flash’s Central City has been just a few miles away from Supergirl’s National City all this time, or it could be that they’re parallel universes, accessible to one another only through some interdimensional sci-fi MacGuffin. I hope against hope that it’s the latter option. If it is, DC is making one of the most ambitious creative declarations in all of filmed superhero fiction.

Until now, DC’s eternal rival, the Disney-owned Marvel, has been regarded as the most grandiose builder of connected superhero worlds. Since the release of the interconnected Iron Man and The Incredible Hulk in 2008, Marvel has kicked off the era of the global superhero megabrand by boldly declaring that all of its filmed stories — from The Avengers to Jessica Jones and beyond — exist in the so-called Marvel Cinematic Universe, commonly referred to by the abbreviation MCU. Agent Carter’s title character had a romance with the Captain America of The Avengers, The Avengers’ climactic alien battle devastated the Manhattan of Netflix’s Daredevil, Daredevil’s nurse Claire Temple shows up in a critical episode of Jessica Jones, and so on. It’s a massive project, executed with totalitarian precision by Disney: When a butterfly flaps its wings on Agents of S.H.I.E.L.D., it could cause an earthquake in the next Spider-Man movie.

DC, on the other hand, has generally had a much more shambolic and uncoordinated approach to adaptations of its comic-book icons. The Christopher Nolan Batman movies had nothing to do with the TV show Smallville. The Oliver Queen introduced on Smallville was totally unrelated to the Oliver Queen of Arrow. And none of those characters walked the same Earth as the Superman of 2013’s The Man of Steel. This was all by design. Cynthia Littleton of Variety had a great article about Warner Bros. chairman/CEO Kevin Tsujihara’s approach to fictional universes, which appears to boil down to “the more the merrier.” Movie and TV creators were more or less free to come up with whatever they wanted and not worry about MCU-style cross-brand synergy.

As a result, there’s been an explosion of unrelated DC franchises on film and television. We’re in the early stages of a DC cinematic universe (its technical name is the DC Extended Universe, or DCEU) where the events of Batman v Superman: Dawn of Justice will impact Suicide Squad and subsequent flicks like Aquaman and Justice League. But the DCEU was developed independently of DC’s hit TV shows. The results have been liberating for the average viewer. Marvel forced you to watch Captain America: The Winter Soldier in order to understand the first-season climax of Agents of S.H.I.E.L.D., but if you’re a fan of DC’s proto-Batman series Gotham, there is absolutely no need to hit the cineplex in order to get caught up. Arrow, The Flash, and Legends of Tomorrow all exist in a shared universe, but it hasn’t been tied to the DCEU, Supergirl, or Gotham. For the most part, all the DC properties are tubs on their own bottoms.

But a compromise measure could be at hand. If the upcoming Supergirl/Flash crossover is explained through interdimensional means, Warner and DC will have executed a revolutionary have-your-cake-and-eat-it-too maneuver. Flash has heavily featured stories about traveling to parallel universes, so it stands to reason that they could be continuing that plot device here. The results would open a new door for storytelling. Maybe Supergirl and The Flash aren’t taking place on the same planet Earth — but what if, every once in a while, they could visit each other’s Earths for a wild caper?

That’s a well-worn concept in superhero comics of both the Marvel and DC variety. In those printed pages, Batman could get stranded in an alternate reality where Superman is a bad guy; Spider-Man could travel to a parallel universe where someone else got his spider-powers; even the Marvel and DC characters have crossed over with one another a few times, leading to tussles between the Avengers and the Justice League. The possibilities for high-concept stories are limitless — and best of all, when any given story is done, all the characters can retreat to their own home universes and go back to more straightforward adventuring. This conceit is often referred to as a multiverse, and it’s a versatile tool.

If DC’s filmed properties are moving toward a multiverse, more power to them. Sure, multiversal stories have sometimes led to narrative chaos in the world of comics, with alternate versions of characters popping in and out of existence and whole events being retroactively declared to have happened in another universe. But as long as interdimensional tales are kept in moderation, they can add a ton of spice to the superhero genre. The Supergirl/Flash crossover could be the dawn of a new era for DC Entertainment, one in which they rip off the brakes and speed toward the limitless possibilities that have defined mainstream superhero comics for decades. They could, in effect, be out-MCU-ing the MCU in terms of intricate mythology-building.

We’d still mostly get self-contained stories, but creators would have access to a useful backdoor: If someone has a great idea for a story about Gotham’s Jim Gordon solving a case with The Flash’s Joe West, if there’s a nutty notion about Stephen Amell’s Oliver Queen fighting Jared Leto’s Joker, if a writer wants to show a battle between the Superman of Supergirl and the Superman of The Man of Steel, then any of that is possible within the new DC rulebook. And when one of those stories is over, it’s back to your previously scheduled simplicity. It’s doubtful that stories like that are on the table right now, but a precedent has been set. DC’s film and television properties could soon become a carnival on infinite earths.