With a movie as big and complex as Avengers: Infinity War, clearly finding the final story and structure of the film was a process. But last night, at Collider’s exclusive IMAX screening of the film, co-director Joe Russo revealed just how different Infinity War might have been had they followed a very different path.

Russo and his brother and co-director Anthony Russo took part in a two-hour, wide-ranging Q&A after our screening of the film, moderated by Collider’s own Steve Weintraub, and during the discussion Joe revealed that one draft of Infinity War followed a non-linear story and was narrated by Thanos (Josh Brolin) himself:

“We did three drafts of this that were all radically different. One draft involved Thanos as the narrator of the film. It was non-linear in structure, it had backstories for the Black Order, and they were all introduced in very cool sequences. But it ended up being a 250-page script and we thought, ‘Alright, we can’t fit all of this storytelling.’”

However, when the Russos and screenwriters Christopher Markus and Stephen McFeely decided to change directions, they didn’t just completely toss out the 250-page script. Instead, that longer, very different draft informed their refined approach to telling the Infinity War story:

“A lot of times when you work on a movie of this scale and you end up with a 250-page draft, it’s the bible for the movie. You gain a lot of information. You write characters out in a way that you start to understand what it is they want. I think writing out Thanos’ narration gave us insight into who he was as a character and what we wanted him to do in this film. So then it was much easier once we started pulling all that out to make it subtext for him as a character, and to make a more linear structure.”

So how did the Russos decide that a linear approach was the right way to tell this story? Believe it or not, they say they found inspiration in films like Out of Sight:

“We did a lot of development on this, but at a certain point we thought, ‘This is really a heist movie, and Thanos is enacting a heist. It’s gotta have a certain structure to it that reflects a heist film.’ So if you look at the movie, its actually is sort of like Two Days in the Valley or Out of Sight where there’s multiple McGuffins that Thanos is chasing and that all the other characters are trying to get to first, or stop him from getting. So it’s a very simple structure. We thought, we have so many characters in the movie, we have to simplify the structure. I think that’s really what led us from that 250-page draft to what the movie is now is simplifying the plot, keeping it linear, and letting the character moments come through.”

Indeed, the Russos have said before that they approached Infinity War as a heist film, and now we know how they landed on that idea.

Watch Joe Russo talk about the early draft of Infinity War in the video player above, find out why Marvel’s Netflix heroes didn’t make it into the film here, and look for much, much more from our Q&A on Collider soon.