‘Crisis on Earth-X’ characters
Brandon Routh said that filming the most star-studded scene in this year’s crossover event between “Arrow,” “The Flash,” “Supergirl,” and “Legends of Tomorrow” was “pretty insane.” The CW

Arrowverse star Brandon Routh shared that this year’s four-way crossover event between CW’s “Arrow,” “The Flash,” “Supergirl,” and “Legends of Tomorrow,” will feature a Waverider scene with more than 20 heroes in it. While that scene will surely give fans all the feels, Routh said that filming the moment was a bit complicated.

“We used to get upset about have 9 people, or 9 characters on the bridge and figuring out how to shoot that, but having 21 or whatever it was pretty insane,” Routh told Comic Book Resources and other news outlets during a recent press visit to the “Legends of Tomorrow” set.

“But Greg Smith, who was our director for our episode, knew what he wanted pretty quick,” Routh, who plays Ray/The Atom, continued. “You have to have your ducks in a row when doing a crossover because people are coming from four different shows, like ‘We have Melissa [Benoist] for 2 hours and we have Grant [Gustin] for an hour, and we have Stephen [Amell] for 30 seconds, so gotta get the shot!’”

“Legends of Tomorrow” executive producer Phil Klemmer told The Hollywood Reporter that they used a wider lens to shoot the star-studded scene, which he conceived.

“You will be surprised to see that we cram more superheroes onto the bridge of the Waverider than is physically possible,” Klemmer said of the massive conclusion to the four-way crossover. “I was responsible for writing a scene that had, like, 22 people in it, and I had to keep a list just to remind myself who was in the scene. I think we need a wider lens to make sure we can keep everyone in the same frame. It’s preposterous. And then you have doppelgangers, just trying to keep track of who was in the scene and what costume they’re supposed to be wearing was a real math and science.”

In an interview with Collider, Gustin confirmed that this year’s crossover is the biggest Arrowverse crossover to date. “It was bigger than ever,” he said. “There’s more people than ever included, some of the biggest sequences you’ll see with the most superheroes we’ve ever seen together at any given time.”

The crossover, titled “Crisis on Earth-X,” will air across two nights. It begins with “Supergirl” and “Arrow” on Monday, Nov. 27 at 8 p.m. EST, and ends with “The Flash” and “Legends of Tomorrow” on Tuesday, Nov. 28 at 8 p.m. on The CW.