With ‘Crisis on Infinite Earths’ about to (finally!) begin on the CW this coming Sunday, December 8th, Arrowverse producers Marc Guggenheim and Greg Berlanti have recently shared their thoughts on the history of the crossovers during an interview with EW. Of course, it all started when they first brought in Barry Allen to ‘Arrow’ to create a backdoor pilot for ‘The Flash,’ a series they really wanted to do but knew it would prove challenging due to the nature of his powers.

While speaking about ‘The Flash’ and the difficulties in producing such a special FX heavy series, Berlanti stated:

“It’s famously what put the original Flash show out of business years ago; they couldn’t get the episodes done in time.”

Of course, after launching ‘The Flash,’ we still did not see a crossover immediately (minus Stephen Amell appearing in a brief cameo in the pilot for ‘The Flash’). According to Guggenheim, the original impetus for the crossovers did not even come from them, but rather the head of the network. In his words:

“[CW President] Mark Pedowitz was like, ‘I want to cross over these two shows,’ Greg and I both grew up on The Six Million Dollar Man and The Bionic Woman. In all honesty, [those two shows] were the inspiration from the crossover. The first Flarrow crossover was so hard at the time, but looking back on it, it was embarrassingly easy because it was a crossover in the sense that Oliver appeared on Barry’s show and Barry appeared on Oliver’s show, but the two storylines of each episode were relatively separate from each other. So, it wasn’t that narratively ambitious.”

Current Warner Brothers president Susan Rovner remembers meeting with Berlanti and Guggenheim when the idea of ‘Supergirl’ came around and she was impressed with their pitch right from the beginning. Current Executive Producer of the Arrowverse  and president of Berlanti Productions Sarah Schechter also recalled when ‘Supergirl’ was pitched, an idea she liked a lot and could relate to:

“I thought it was a fantastic idea. I remember [Greg] said to me, ‘I think I figured out Supergirl. It’s Ginger Rogers. Ginger Rogers had to do everything Fred Astaire did but backward and in heels.’ That really resonated [with me] as a woman working in this business.”

Even though ‘Supergirl’ was not even on the CW at the time, they still had a crossover with ‘The Flash’ during the first season, not for any particular reason, but just for a desire for the actors and the characters to interact. As producer Sarah Schechter explains:

“Grant and Melissa are just so effervescent. It wasn’t calculated. It was a very pure, creative desire [of] wishing we could see them together.”

Of course, the next series the guys put together was ‘Legends of Tomorrow,’ which had some trouble getting out of the gate and did not really seem to find its stride until the second season. When putting together the first episode of ‘Legends of Tomorrow,’ Berlanti remembers the frenzied experience of trying to combine all those characters and some of the risks they took, including a very complicated crossover done while trying to launch the new series:

 “We literally just did clips from our other shows that we hadn’t used, and we shot two days of just like, ‘Wouldn’t this be cool to see all of these characters onscreen at the same time?’”

Guggenheim also recalls that crossover as a turning point for the Arrowverse, claiming:

“That’s when things got really crazy because even though we were only crossing over two shows, we were doing a singular storyline, but we were also introducing the Legends characters and launching Legends at the same time we were prepping the Legends [premiere]. I remember Greg and I looking at each other going, ‘No one has ever done this: Crossed over two shows and setup a third all at the same time.’ It was like juggling flaming chainsaws while atop a unicycle. We were like, ‘And no one will ever know how hard this is.’”

After ‘Supergirl’ moved to the CW, the creatives decided on their biggest crossover yet with “Invasion!,” though they also continued the smaller character crossovers that year with events like the musical crossover between ‘The Flash’ and ‘Supergirl,’ which according to Guggenheim is one of his favorite crossover types:

“These crossovers exist along a spectrum and I have to say just as a fan, one of my favorite types of crossovers is when we just crossover one or two actors, or one or two characters, like when Diggle and Lyla show on Flash, for example. Doing those repeatedly over the course of various shows and various seasons, that is what makes the universe feel lived in to me and just conceptually my favorite thing to do.” 

Now with four series on the air, they made certain efforts to make sure every show had its own feel and tone with Guggenheim pointing out:

“If you look back on that particular season that year, you’ll see Legends became wackier, Supergirl went more in on aliens, Flash went more in on science, and Arrow went more in on gritty crime.”

Also having all 4 series meant the producers could attempt their most ambitious crossover yet. ‘Crisis on Earth-X,’ proved to be very trying for everyone involved due to its size and scope, though Guggenheim and Berlanti still consider that crossover one of their greatest accomplishments with the Arrowverse, even with all the extra work that it required. According to Guggenheim:

“It killed all of us. We were feeling the effects of it literally a year after. The network had to really, really convince us to do another crossover because after ‘Crisis on Earth-X,’ we were all pretty burned out. We were like, ‘Can we take a break and then come back for Crisis on Infinite Earths?’ And The CW was like, ‘No, no, don’t worry. It doesn’t have to be all four shows. It can only be three hours.’”

Ironically, that is how they came up with the idea to do the out of the box concept of the ‘Elseworlds’ crossover, which the stars of ‘Supergirl,’ ‘The Flash’ and ‘Arrow’ all claim is their favorite crossover till that point, mostly due to the comedic nature of the plot and the juxtaposition of the heroes switching lives/powers, and because the crossover also got to introduce ‘Batwoman’ to the CW. Of course, everything really has been the lead up to ‘Crisis on Infinite Earths,’ as one could make the argument that it has weighed over ‘The Flash’ since the pilot episode and has motivated a lot of what has come since.

Luckily for fans of both the ‘Arrowverse’ and the original comic of ‘Crisis on Infinite Earths,’ both Berlanti and Guggenheim seem very aware of the responsibility they have to due it justice, with Guggenheim saying:

“My main goal has always been, ‘How do we honor the original Crisis on Infinite Earths?’ I think we’ve crafted something really, really special.”

Are you caught up on all the ‘Arrowverse’ shows and ready for ‘Crisis’ to begin next week? Do you have any theories on what may happen? Feel free to share any thoughts or theories in the comments below!