Across the Spider-Verse's most important plot point came from one of Spider-Man's most prolific writers

It turns out the idea to make the spider that bit Miles Morales come from another universe came from long-time Spider-Man comic writer Dan Slott.

In Into the Spider-Verse, you might have noticed that the spider that bit Miles glitched out a touch, much like how the rest of the Spider-People do. It would be fair to think that this was setup for what later came to light in Across the Spider-Verse, where it turns out this spider was from another universe. As it turns out though, that particular plot point wasn't actually thought of for the first film - and in a recent interview with Popverse, Slott shared that he was the one that came up with it.

"I gave them the beat that was the 42 spider," Slott said. "I said to them in a note that the spider that bit Miles glitched, that meant by your rules, it had to come from another dimension. They didn't have this, they just thought it looked cool to have the spider glitch in the first movie.

"I said to them, the spider glitched, that means the spider came from another dimension, that means Alchemax pulled it through the collider, that means if it had a number 42 on it, someone from Alchemax put 42 on it, which means it's the spider from Earth-42. If you follow this further down the rabbit hole, that implies that's a spider that shouldn't have bit anyone from Earth-1610, which means that the Chris Pine Spider-Man was their one and only Spider-Man. Miles was never meant to get bit. When Miles got bit, he went back for the spider. If he hadn't gone back, Chris Pine wouldn't have had to stop to save him. He would have put the goober in the machine, he would have shut it down. There never would have been an explosion."

Obviously, those of you that have seen Across the Spider-Verse know that this is pretty much exactly what Miguel O'Hara told Miles, in an attempt to discredit the young superhero's status as a Spider-Person. As it turns out, that climactic scene where Miles and Gwen Stacy are in two separate universes got a note from Slott too, with the comic book writer explaining the text splash that states Miles is in Earth-42 was his idea too.

"The second Uncle Aaron shows up, you need to flash on the screen, Earth-42 Even though you show it on that monitor, but that's only for the people who are paying attention, you need to make sure that the eight-year-olds who are watching this aren't lost," Slott explained.

The full interview with Slott is worth a read, as it goes further into some of the other ways that he contributed to the film. For those that don't know, Slott is the original writer behind the Spider-Verse series of comics, so it's not a surprise to hear that he's also contributed to the films too.

Interestingly, the film's directors also recently shared that the film's ending came about because test audiences didn't like how it originally ended.