“Supergirl and The Flash finally crossed paths in last night’s highly anticipated crossover event, “Worlds Finest.” The long-awaited episode was just as charming and heartfelt as you imagined, seamlessly bringing together two of the most earnestly likable heroes on TV. But though Barry Allen (Grant Gustin) finds a way to speed back to his Earth by the end of the episode, this may not be the last time that he teams up with Kara Danvers (Melissa Benoist). The series producers recently discussed the possibility of future crossovers, as well as what’s next for both heroes.
In “Worlds Finest,” Barry accidentally speeds through the barriers of his world to the alternate Earth occupied by Kara and co. He arrives just in time to save her after she falls from the Catco building while unconscious. After a couple minutes of confusion and a brief introduction, the two become fast friends, teaming up to take down Livewire and Silver Banshee and to find a way to get Barry back home
So why was it Barry to make a trip to Supergirl’s National City instead of the other way around? Producer Greg Berlanti said it was a purposeful choice, having Barry share his experience with Supergirl the way that Oliver’s Arrow once did for him. “It’s maybe a little more fun at first to bring the veteran from that show to the chemistry of a new show,” he explained, per IGN. “You know, the first year of a new show is, for us, a steep, steep learning curve, and every episode you’re learning from. Sometimes you learn the hard way, and sometimes stuff works out. So I think [the crossover] was an opportunity to learn about the newer show.”
That being said, the trip won’t go entirely unacknowledged on The Flash. Audiences will learn more about how exactly Barry ended up in Supergirl’s universe in the March 29 episode of The Flash…”