Co-director of Avengers: Doomsday, Joe Russo, has addressed going into production on the Marvel Phase 6 film without a finished script.

The movie was originally set to be Avengers: The Kang Dynasty; however Marvel pivoted away after Jonathan Majors was convicted of assault. The Russos took over, and shooting began without a finished script.

However, according to Joe Russo, that’s not necessarily a drawback. “We always view the script as a living organism,” Joe told AP News. “We’re improvisation-based, rehearsal-based directors. We like to see what the actors bring to the characters, and sometimes you don’t get the actors until a few days or few weeks before you shoot them. And a lot of the time, that’s when the magic happens.”

The supersized Doomsday cast list includes Chris Hemsworth as Thor, Anthony Mackie as Captain America, Chris Evans as Steve Rogers, the Thunderbolts, the Fantastic Four, Letitia Wright’s Shuri, Tom Hiddleston’s Loki, and, of course, Robert Downey Jr.’s Doctor Doom.

“Honestly, I have absolutely no idea because we didn’t even have a script,” Bucky Barnes actor Sebastian Stan revealed, when asked by Le Journal du Dimanche what to expect from Doomsday. “We were just shooting scattered scenes. It’s a different way of working, continuous, constantly evolving. The producers didn’t want us to read it in its entirety, to avoid journalists asking us questions.”

But, Nightcrawler actor Alan Cumming did lay eyes on a script. “We eventually saw a script. It took a while, but we had a script,” he told ET.

“Yeah, I did read a full script, but those scripts change quite a bit. You know what? Probably not, it probably didn’t have a full, like, third act. I don’t think it had an ending. I don’t think anyone gets to see that stuff,” The Thing star Ebon Moss-Bachrach told the Happy Sad Confused podcast.

Avengers: Doomsday arrives this December 18. While you wait, check out our guide to all the upcoming Marvel movies and shows for everything else the MCU has in store.