A potential crossover between 'The Flash,' 'Arrow,' 'Legends of Tomorrow,' and 'Supergirl' is in the works

Arrow type TV Show network The CW genre Superhero

If you thought this season’s four-way crossover between Arrow, The Flash, DC’s Legends of Tomorrow, and Supergirl was epic, just wait until you see what the producers have planned for next year.

During the Invasion crossover, the heroes of Supergirl, The Flash, Arrow, and Legends teamed up to battle the Dominators. However, some fans griped that it wasn’t quite a four-way crossover because the storytelling didn’t actually take place across all four shows. Save for a brief epilogue scene during Supergirl‘s winter finale, the action was mainly featured on The Flash, Arrow, and Legends, making it a four-way crossover on three shows.

However, the producers are already hard at work figuring out the logistics of rectifying that for next season. “Next year, we’re hoping to do a true four-way crossover,” executive producer Andrew Kreisberg says. “The great thing about our dear friends at the CW and Mark Pedowitz picking the shows up as early as they did has allowed us to start building the schedules for next season.”

Explaining that the shows continue filming other episodes while shooting the crossovers, Kreisberg says, “One of the big things we learned from two years ago, which made the crossovers this year slightly easier, was building in shut-down days, where shows just went dark. The single hardest factor in doing the crossovers is actors’ availability because the shows keep going on. You’re basically juggling four shows worth of schedules.”

“The thing that we didn’t really plan on — because we weren’t aware that we were going to switch Supergirl from CBS to CW and it was really going to be part of it — that was the one show that didn’t have built-in shut-down days, so all the other ones did,” Kreisberg continues. “Melissa [Benoist] ended up being heavily in Flash and then in Arrow, so Supergirl was the one we needed to shut down the most and it was the one that we didn’t have any opportunity to. Now that we’ve gotten the early pickup and we’ve started designing the seasons, we’re building in those dark days, and actually more dark days on Supergirl than the other shows, to make it a little easier.”

Thus, there’s a strong chance of seeing a real four-way crossover next season — though it’s not yet officially confirmed.

As for the upcoming Flash-Supergirl musical crossover, that will mainly take place on The Flash, with Kara, Winn (Jeremy Jordan), J’onn (David Harewood), and Mon-El (Chris Wood) appearing. “We would’ve had everybody, because I know this one can sing,” Kreisberg says, referencing Chyler Leigh, “but somebody actually had to be part of an episode of Supergirl, because we actually keep filming these things.”

Hence, while the others are away, Alex and Maggie (Floriana Lima) “have a bigger storyline in that episode to free other people up,” Kreisberg says, also teasing there will be a big hour for Winn, James (Mehcad Brooks), and Lyra (Tamzin Merchant) in episode 16, as well as episode 18. “Winn, James, and Lyra have a really funny story in 18 too, where the three of them try crime fighting as a trio, which doesn’t necessarily go well. She kind of becomes the Yoko of the team.”

Supergirl airs Mondays at 8 p.m. ET, The Flash airs Tuesdays at 8 p.m. ET, DC’s Legends of Tomorrow airs Tuesdays at 9 p.m. ET, and Arrow airs Wednesdays at 8 p.m. ET on The CW.