The road to what we now know as Avengers: Endgame began in the writers room, and now that the film is out, screenwriter Christopher Markus and Stephen McFeely are breaking down just how long that road was. At its start — when Endgame and its companion film, Infinity War, were being outlined simultaneously — page after page of ideas were on the table, but the writers struggled with one key obstacle in particular: How do you defeat Thanos after you set him up as the victor?
*Spoiler Warning: There are spoilers for Avengers: Endgame below.**
The decision to end Avengers: Infinity War on the note of Thanos actually achieving everything he set out to do was one of the most powerful narrative hooks in the history of the Marvel Cinematic Universe. For the first time, a film in this saga ended with the villain getting everything he wanted, creating an instantly compelling lead-in for what would become Endgame. How do you undo what was just done by a being who has now become the ultimate power in the universe?
Speaking to The Hollywood Reporter about their time working on the Endgame script, Markus and McFeely said they "hit [their] heads for quite a while" as they tried to come up with a way for The Avengers to battle back. Finally, executive producer Trinh Tran floated an idea that would become Endgame's paradigm-shifting catalyst.
"Remember, [Thanos] is omnipotent. He is omniscient. It is ridiculous how much power he has at the opening of the movie, so for a good solid three weeks, we are trying to figure out, what is movie two with a character with that much power? At one point, I think Trinh Tran, our executive producer, in frustration said, 'God, I really wish we could just kill him.' We all went, 'slow down. What does that mean? That's interesting,'" McFeely said. "It's absolutely within his character. When we asked, 'Why would he let you?' Because he did what he wanted to do. It's strong for him to do that. We've been at it a long time and that's the kind of thing I beat myself up for not thinking of earlier. If I'm being consistent to his character, this is on the table."
So we got the now-famous shocking scene in which the surviving Avengers confront Thanos and Thanos reveals he's destroyed the Infinity Stones right before Thor impulsively beheads him. With the Stones gone and the villain dead, there was nowhere to go but backwards. Marvel Studios mastermind Kevin Feige was the voice in the room pushing for time travel as an option in Endgame, and Markus and McFeely started to see how that could work, particularly with the addition of Ant-Man to the film.
"Time travel pops up in your head early in almost any difficult situation. Well, if I travel back in time, this date would have gone much better. Generally in a movie, 'eh, that's way too easy.' We couldn't have Tony just invents a time machine," Markus said. "But delving into Ant-Man, who we hadn't used because he had a movie coming and we didn't want to taint Ant-Man and the Wasp any more than we did at the very end. ... We were planning on Ant-Man because we had access to him in the second movie, and the fact that he was bringing a whole subset of technology that did have something to do with a different concept of time was like a birthday present."
So the time travel plan started to fall into place, and we got the film we've all now seen. According to Markus and McFeely, though, we could have gotten many, many other different versions of the conclusion to the Infinity Saga. As they set out to craft the back-to-back Avengers films in the wake of Captain America: Civil War, the writers put together a 60-page document that brought every idea they had for the films to the table, "big and small." Among those ideas was the notion of adapting some version of the 2005 Marvel event House of M (which features Scarlet Witch altering reality drastically) and incorporating Marvel's cosmic hero Nova. That second idea feels more plausible, particularly when you hear how the duo planned to introduce him.
"I remember going through several scenarios of Nova," Markus said. "Thanos could come and kill all the Nova Corps, except one guy. Richard Rider, who then becomes … I think in that scenario he became the herald, kind of like the Hulk was [in Infinity War when he crashed into the Sanctum Sanctorum]. Someone who could come out and tell people. We had everything."
According to Markus and McFeely, that 60-page document is probably still somewhere in Feige's possession. Perhaps some day even more of those ideas will come to the screen.