The trend of mad-capped cameos and character reveals in The Big Bang Theory spin-off Stuart Fails to Save the Universe continued this week when the gang found themselves in the DC Universe and were saved from Mr. Freeze by Jay Garrick, aka The Flash. It’s a wonderfully world-breaking moment, but one that could’ve been considerably different with an added Green Lantern glow, if only they’d got the go-ahead.

Speaking to Deadline about their latest episode aptly titled ‘We Couldn’t Get The Green Lantern,’ the show’s co-creator, Zak Penn, recalled that when it came to making the request for a member of the Green Lantern Corps to drop in and save the day, he, along with creative colleagues Chuck Lorre and Bill Prady, got the answer they feared.

“They told us we couldn’t have him because of Lanterns, which I understood,” he explained. From there, they had to pick another hero from the DC Universe, and the idea came in a flash.

”Chuck was a little grumbly about it, but Bill and I pointed out to him that Flash was actually perfect. If we needed something that’s going from dimension to dimension, Flash worked even better than Green Lantern.” Nailing this inclusion down, along with Mr. Freeze, was handled so well after the folks at DC Comics, including artist, writer, and CCO Jim Lee, gave notes on how to handle Garrick and this mismatched foe of Batman (which the episode jokes about).

“They were great,” Penn assured. “They basically said, ‘How can we help? Other than we won’t give you Green Lantern.'” After hitting the mark so well with a pair of brilliant DC heroes and villains this time around, there’s no telling who might appear in the second season, which has now been (ahem) greenlit. There are plenty of other Lanterns to use, after all.

If you’re in the dark about what new DC movies and shows are on the way, check out our guide.