Everything You Need To Know About The Arrowverse's Crisis On Infinite Earths Crossover

For the past few years, the annual crossovers between the CW's roster of superhero shows have been some of TV's most entertaining events. We've seen the Flash and Supergirl sing their way through their feelings, taken a trip to Gotham City to meet Batwoman, and even watched the heroes of the Arrowverse take on their Nazi counterparts. This year, though, we're slated to get the biggest, most ambitious crossover that superhero television has ever pulled: Crisis on Infinite Earths.

With a story that runs across five hours of television in December 2019 and January 2020, Crisis is set to include not just all of the current DC shows, but also a roster of heroes drawn from a long history of television. It's exciting stuff, but it raises a question: just how did we get here? From the long tradition of crises throughout the DC Universe to the way it might just end an era, here's everything you need to know about the Arrowverse's take on Crisis on Infinite Earths. 

The CW's version of Crisis on Infinite Earths is notable for being the first event of its kind to take place on television, but the comic book history that leads up to it starts all the way back in 1961 — or maybe even before, depending on how you want to look at it.

The short version goes like this. Back in the '40s, after Superman was introduced to the public and proved to be wildly popular for the public and extremely profitable for its publishers, there was a whole wave of superhero comics hitting stands. When the company that would eventually become DC Comics acquired a few of its competitors, they decided to put a few of them in the same book, creating the Justice Society of America and the first shared universe in comics. By the late '40s and early '50s, however, the bubble burst and superheroes fell out of popularity, leading to only a few of the most consistently popular to stay in publication while the rest, like the Golden Age versions of the Flash and Green Lantern, were canceled and seemingly condemned to obscurity.

But then, in the late '50s, the creators and editors at DC decided to dust off a few of those pulpy concepts and reboot them in a slightly more sci-fi direction, kicking off the Silver Age with an all-new, mostly different version of the Flash. Right from the start, though, there was something weird: in that first story, Barry Allen was inspired to take the name "The Flash" because he'd read comics about Jay Garrick, the Golden Age Flash, when he was a kid. With that, DC began to flirt with the idea of a multiverse, where different versions of their characters existed on parallel worlds, some of which were considered to be fictional on the others. This all came together in 1961's famous "The Flash of Two Worlds," where Barry and Jay crossed the vibrational barrier between their worlds and met up for a single adventure. It turned out that this was just the beginning.

By 1964, DC had codified the idea of the multiverse into Earth-One, the somewhat arrogantly named primary DC universe that featured the ongoing adventures of the Silver Age heroes, and the home of the Golden Age versions, who politely allowed themselves to be called Earth-Two despite the fact that they came first. Marvel, incidentally, would later goof on this concept by declaring that their universe, full of more relatable, everyman heroes, was Earth-616. With all that in place, there was only one thing left to do: a crossover!

JLA #21 and 22 featured "Crisis on Earth-One" and "Crisis on Earth-Two," in which the Justice League teamed up with their Golden Age counterparts in the Justice Society to battle for the fate of two universes, which kicked off two important DC traditions. First was the idea of an annual JLA/JSA crossover, usually around Thanksgiving, which continued for the next 20 years. The second was that almost all of these crossovers, which spread out throughout the DC Multiverse, used the same naming convention as the first one, making capital-C "Crisis" the shorthand word for a threat that went beyond the scale of a single universe.

Over the years, there was "Crisis on Earth-Three" (the world where all the good guys were bad guys), "Crisis on Earth-S" (the Shazam world), "Crisis on Earth-Prime" (the "real world" where the heroes were all comic book characters, which wound up being destroyed by nuclear war) and, of course, "Crisis on Earth-X" (Nazis), among others. Eventually, though, things spiraled to the point of being as big as they possibly could.

In 1986, DC promised "worlds will live, worlds will die, and nothing will ever be the same," and for the most part, they delivered with a year-long event called... Crisis on Infinite Earths. The big idea was that DC was restructuring their entire multiverse into a single streamlined whole, but rather than just rebooting all the comics, they made it part of a story. A villain called the Anti-Monitor (who presumably did not monitor things) was wiping out universes, and the ones that remained coalesced into a single unified timeline where the Golden Age characters had been around in the '40s, and all of our favorite modern-day heroes were either their successors or just hadn't been around then. 

In the process, major characters like the Flash and Supergirl were killed off with as much permanence as there can be in superhero comics. It took Barry Allen 20 years to come back, and while there was a new version of Supergirl less than two years after her death in Crisis, Superman's cousin Kara Zor-El wouldn't reappear until 2004. That wasn't quite the end, though.

The "Crisis" brand was so strong that DC kept it around even after they bailed on the multiverse. Another event devoted to fixing up the complicated DCU timeline was called Zero Hour: Crisis in Time, there was a modern-day JLA/JSA team-up against the fifth dimension called "Crisis Times Five," and in 2006, Infinite Crisis, as its name implies, came along to reverse all the changes and reintroduce the multiverse. The branding was even co-opted by lesser stories like Identity Crisis and Heroes in Crisis, but Crisis on Infinite Earths still loomed large in the minds of fans as the biggest worlds-shattering event in DC's long history.

If you were wondering why we spent so much time talking about the comic book history of Crisis on Infinite Earths, it's because the TV version is following in the same tradition, with a very similar history. It began with Arrow, and fittingly enough, it all got started with the same character who kicked off the comic book multiverse back in the '60s: The Flash. 

After Arrow's somewhat surprising success — who would've thought that a CW show based on Green Arrow, of all characters, would wind up running for eight seasons? — the network showrunners expanded its universe with a spinoff starring the Flash, which in turn led to Legends of Tomorrow, about a time-traveling group of heroic misfits getting into the kind of fights that end with a literal demon fighting a 12-foot Care Bear (really). Those shows became the "Arrowverse." Meanwhile, CBS launched an unrelated show about another high-profile DC character, Supergirl, which would move to the CW with season 2, while NBC tried to get in on the action with a short-lived show about DC's morally gray magician, Constantine. Then there was Black Lightning, another CW offering that was separate from the big, bold world of superheroes that Arrow had stumbled into founding.

That meant that there were multiple shows about DC heroes, some of which were set in their own separate universes. With so many superheroes to work with and the idea of a shared universe becoming a well-known piece of pop culture — thanks partially to the fact that a 20+ movie franchise that you've probably heard of was hugely successful — meant only one thing. Viewers were going to get a crossover — first within the Arrowverse itself and then, once Supergirl got into the mix, spreading into these other universes, too.

Much like it had in the comics, the idea of an annual crossover quickly became a tradition for the Arrowverse. It started with Ollie Queen teaming up with the Flash for a couple of story arcs that ran through their respective shows in 2014, and then a backdoor pilot for Legends of Tomorrow the following year.

Things really started to pick up in 2016. That March saw the Supergirl episode "Worlds Finest," which saw the Flash vibrating his way to Supergirl's universe, now called Earth-38. It was notable for a few reasons, with one of the most important being that while they were both shows based on DC characters who shared producers, Flash and Supergirl were airing on different networks at the time. That then led to a full-on three-part Arrowverse/Supergirl crossover called "Invasion!" and then, just to cap things off, March 2017 saw "Duet," an episode of Flash where Supergirl showed up. That aired 51 weeks after the initial Flash/Supergirl crossover, marking the end of a year when Supergirl (and the Martian Manhunter, Superman, the Guardian and all of the other DC stalwarts who had popped up on that show) became a part of Arrow's extended multiverse. Oh, and it was also a musical.

It's worth noting that both "Worlds Finest" and "Invasion" were both named after DC crossovers — the long-running Superman/Batman team-up title and a 1988 line-wide event in which three alien races invaded Earth at the same time, respectively. That tradition was continued with "Crisis on Earth-X," which, like the comic it was named for, featured the introduction of a world ruled by Nazis, complete with an evil Supergirl. Hilariously, this came after a season of Flash introducing more and more of the multiverse, leading one of the many versions of Harrison Wells on that show to explain that while they had previously talked about there only being 52 worlds, Earth-X was a secret fifty-third Earth that nobody ever talked about because they all agreed it sucked. 

In December of 2018, the Arrowverse — now a full-on multiverse — launched "Elseworlds," a crossover that ran through Green Arrow, Flash, and Supergirl. Unlike the other crossovers, this one wasn't named after a specific story. Instead, "Elseworlds" was the name of a post-Crisis imprint at DC focused on alternate realities and possible futures. It's a fitting name, too, and to call the CW's "Elseworlds" ambitious is underselling things quite a bit. For one thing, it involved twisting the setup of the previous crossovers by also throwing in a body-swap between the Flash and Arrow, which gave us a truly delightful moment of Grant Gustin growling "You have failed this city!" 

More importantly, "Elseworlds" served as the Arrowverse's introduction to Batwoman. In the comics, the modern Batwoman, Kate Kane, had been introduced in 2006 before taking over Detective Comics for a year. As a lesbian, she was DC's most high-profile queer character, with a backstory that saw her being dismissed from the Army while at West Point under the "Don't Ask, Don't Tell" policy. She's also Bruce Wayne's cousin, and on the show, Batman's absence from Gotham City has inspired her to take on a heroic identity fo her own. Her appearance in the "Elseworlds" crossover, where she was portrayed by Ruby Rose — who is herself a gender-fluid lesbian — paved the way for Batwoman to join the CW's lineup. 

The thing is, "Elseworlds" was not the self-contained crossover that "Crisis on Earth-X" was. The specific story of Barry and Ollie temporarily switching identities and poking around Gotham City was wrapped up, but crossover also spent a lot of time with the Monitor, the Anti-Monitor, and the Psycho Pirate, all of whom were key characters in the comic book version of Crisis on Infinite Earths, setting up the next big crossover a year in advance. One of the other major characters in the original Crisis, Harbinger, was actually introduced way back in Arrow's first season. 

What really makes the upcoming Crisis crossover so interesting is that the CW shows have a huge amount of characters to play with when they're setting up a gigantic multiversal crossover. There's the Arrowverse, of course, anchored by Green Arrow and the Flash, with heroes like Vibe, Mr. Terrific, Black Canary, the Elongated Man, Killer Frost, and even more obscure characters like gun-toting weirdo Wild Dog showing up in their supporting casts. Also, there's Legends of Tomorrow, with Firestorm, the Atom, White Canary, Vixen, and more — including Zari Tomaz, who thankfully does not use the codename of the comic book character she's based on. Plus, they folded in John Constantine, bringing actor Matt Ryan back for the role after the cancellation of Constantine. And, of course, we have Batwoman.

Outside of that specific universe, though, the CW also has Supergirl and the heroes of Earth-38, including Kara Danvers, J'onn J'onnz (the Martian Manhunter), the Guardian (the masked heroic identity of Superman's Pal Jimmy Olsen), the 31st-Century Legion of Super-Heroes (Mon-El, Brainiac 5, and Dream Girl), and, you know, Superman. There's also Black Lightning, which features the title character, along with his daughters Jennifer and Anissa, the heroines known as Thunder and Lightning, and Grace Choi. 

But here's the thing: those are just the shows going on now. Before the current run of successful shows, the CW and its predecessors also ran Smallville, a show focused on a younger Clark Kent that ran for ten years and wound up including everyone from Hawkman to Zatanna, and the short-lived Birds of Prey, another take on a female-focused, Batman-free Gotham City about the Huntress, Oracle, and Black Canary. Those are all in play for TV's Crisis on Infinite Earths... and that's just the heroes. 

The stage is set for Crisis on Infinite Earths to hit the airwaves in December, and from everything we know so far, it's going to be big. We already know that characters from Smallville are going to be showing up, with Tom Welling and Erica Durance reprising their roles as that universe's Clark Kent and Lois Lane. Birds of Prey is back in the mix, too, with Ashley Scott stepping back in the role of Helena Kyle, the Huntress, 17 years after Birds of Prey was canceled. 

There's even more stunt casting, too. Kevin Conroy, who has been the voice of Batman in various video game and animated projects will be playing a live-action Bruce Wayne for the first time since he took on the career-defining role for Batman: The Animated Series in 1992. The details have yet to be released by the CW, but he definitely looks like he'll be playing the older version of Bruce that he voiced on Batman Beyond. Even more intriguing? Burt Ward, who played Robin on the 1966 Batman television show alongside the late Adam West, has also been cast in an unannounced role. It's certainly possible that he could be showing up as a 74-year-old Robin, but at this point, who knows?

Also, if Tyler Hoechlin and Tom Welling weren't enough Supermen for you, Crisis on Infinite Earths also marks Brandon Routh's return to playing the Man of Steel. Routh — who already has a role in the Arrowverse as the Atom, Ray Palmer — starred in 2006's Superman Returns, and, in all honesty, was a better Superman than his boring, lackluster movie deserved. Seeing him back in costume as an older Superman with a costume inspired by Mark Waid and Alex Ross's Kingdom Come storyline is intriguing — not just because it's Routh getting a second chance at the part, but because whatever the big problem is in Crisis, it's going to need at least three Supermen to solve it. Kind of makes you wonder what Ollie Queen's going to be doing there. If they can't fix it, is shooting it with an arrow really going to help? 

Even more than the destruction of the DC multiverse, the Crisis on Infinite Earths comic book is remembered for featuring the deaths of Supergirl and the Flash. That might seem pretty ominous, considering that the TV version is going to prominently feature both of those characters, but in reality, they're probably the two major characters who have the least to worry about.

They are, after all, the stars of their respective shows, which from all indications are both going strong into the indefinite future. That's a marked contrast from the setup in the original comic — Supergirl ddn't have her own title at the time, and Flash had lost a huge chunk of its readership thanks to its title character being put on trial for muder in a storyline that lasted for two years. They were, in other words, pretty expendable in 1986, a trait their televised counterparts do not share. 

Ollie Queen, on the other hand, might not be so safe. The CW has announced that Arrow's eighth season will be its last, so if any of our main characters are on the chopping block, it's him. Even there, though, it seems unlikely. There are still two more episodes of Arrow's final season after Crisis on Infinite Earths ends, and while one wrap-up episode about Ollie Queen's funeral would be understandable, two would be pushing it. That doesn't mean they won't pull it off, though — stranger things have happened, like, say, a show about Green Arrow running for 170 episodes and redefining what superhero television could be. All things considered, that's pretty weird.