Think you already know everything there is to know about Avengers: Endgame? Think again!

In a new interview, writers Christopher Markus and Stephen McFeely reveal some Endgame alternate story ideas that didn’t make it into the final cut – including an interdimensional battle in which our heroes face off against versions of themselves.

If it feels like Markus and McFeely have spent years offering commentary about the back-to-back juggernauts of Avengers: Infinity War and Avengers: Endgame, it’s because they have. But there were still a few stones left unturned. In a new discussion with Vanity Fair, the screenwriters spilled even more details about making these two Marvel Studios mega-hits.

You may have heard about how, during the process of trying to break the stories for these films, the writers hung up baseball-style cards that depicted all of the Marvel characters they had access to. Here’s a brief back-and-forth with them explaining how that worked:

McFeely: On one wall is Movie One, and one wall is Movie Two, and the third wall has baseball cards of all the Marvel characters, and we could move them around … VF: Are they actual collectible cards? McFeely: They’re all in my dresser. I think I’ll hold onto them for a while. VF: I mean, are they specially made for this? One of a kinds? Or the kind anyone could buy commercially? McFeely: Marvel makes them. Yeah. Some intern in-house makes them. They have a magnet on the back. They get dog-eared and bent and stuff. [Each one] says if we have them or not for this movie. And there was a little rating. We didn’t know how much [money] each actor made, but it had either one dollar sign or up to five dollar signs. VF: So you would keep in mind how much they cost to be in the movie? McFeely: It was sort of just a guideline. Markus: They would allow us to do anything in anybody’s contract. We’d get to renegotiate it as needed, but it was a fascinating glimpse into the other side. VF: Was Marvel ever like, “There are too many dollar signs in this scene?” Markus: No, it was, “You better damn well have a good story for us!” McFeely: You actually try not to leave the five-dollar-signs on the sidelines.

But even more interesting are the ideas that didn’t make it into the final cut, including an interdimensional confrontation and some major shuffling of Smart Hulk’s storyline:

Markus: There was a sequence in [Infinity War] where they went into the places in the Doctor Strange universe called the Mindscape and everyone faces themselves. It was great but had absolutely nothing to do with anything. VF: Faced themselves, as in battled themselves? McFeely: Banner meets the Hulk, I think in the arena from Ragnarok. Only one of them was getting out of there, and then that one showed up in Wakanda [in Infinity War] and he had merged. That merging that currently happens in [Endgame] in a diner, and he’s eating a huge stack of pancakes? That initially happened at the end of Infinity War. VF: How did that alternate version play out? McFeely: The Hulk refuses to come out, if you remember, and [in the discarded storyline] they eventually came to a realization or a compromise and he busted out of the Iron Man suit and beats the heck out of this [monster]. That whole Third Act is a march toward losing, and this Hulk scene is a big win, right? It’s a guy solving his problem and being a funny character because now, he’s eloquent. We had to, at the last second, scrap all that, put aside all these scenes that used to have Smart Hulk and then re-shoot the First Act of Endgame, going to Thanos’ country lodge, that used to have the Smart Hulk. … Markus: We wanted everybody to have this enormous journey in the five year jump [after the Thanos snap], and to really see, in sometimes shocking ways, how the loss had affected them. We hadn’t given Banner [a change] because we had transformed him earlier, and he had nowhere to go. And suddenly by needing to take it out of the first movie, it was the perfect thing.

That’s the first I’m hearing about the Mindscape, and if it was on the board at one point, I have to wonder if it struck Marvel’s Kevin Feige as an idea that may be worth saving for a different project a little later down the line. Based on the title alone, it seems very like we’ll see a face-off like that in Doctor Strange in the Multiverse of Madness, especially since we know that the reality-altering Scarlet Witch is going to be involved in that film.

For more on Avengers: Endgame, be sure to read /Film’s oral history of the film’s jaw-dropping climactic final battle scene.