Mayday Parker theory: how Tobey Maguire and Sadie Sink connect

In November 2025, two reports landed close together. One was a rumor that Tobey Maguire would return as Peter Parker in Avengers: Doomsday. The other said Sadie Sink, cast as a mystery character in Spider-Man: Brand New Day, would also appear in Avengers: Secret Wars. My theory at the time was that Sink playing Mayday Parker, the daughter of Maguire's Peter, was at least one way both reports could connect.

I argued that these reports helped explain the plan for how Brand New Day would set up Doomsday, and how both films would set up Secret Wars. I also thought the answer could come back to a famous Tobey Maguire outburst, the one where Peter tells his landlord, Mr. Ditkovich, that he'll get his rent when he fixes the door. Brand New Day went on to release on July 31, 2026, but what follows is how I saw the pieces fitting together before then.

The Tobey Maguire Avengers: Doomsday rumor from DanielRPK

On November 15, scooper DanielRPK claimed that Tobey Maguire would reportedly return as Spider-Man in Avengers: Doomsday. At that point, Tom Holland's Peter Parker hadn't been confirmed for anything past Spider-Man: Brand New Day. That was despite his ongoing appearances in movies co-produced by Sony and Marvel Studios being part of an IP sharing deal between the studios, one that involves the character showing up in a solely Marvel produced Avengers team-up movie afterwards.

Marvel also wasn't saying that Benedict Cumberbatch's Doctor Strange or Brie Larson's Carol Danvers would be in Doomsday, even though it was hard to see how the film could work without them. So there was clearly a lot happening in this film that the filmmakers were staying quiet about. And as with all scoopers, we didn't know what DanielRPK's source was, or if he even had one.

Leaked makeup photos reportedly showed wounded heroes, including Tobey Maguire

The rumor came about two months after other reported leaks surfaced on September 21 and 23. Those leaks reportedly showed actors for Doomsday in makeup chairs, with significant stages of wounds being applied to their heads. Included were characters we knew would be in the movie: Robert Downey Jr.'s Doctor Doom with some facial scarring, James Marsden's Scott Summers, Cyclops, with a bloody lip and cheek, Letitia Wright's Shuri with cuts down her eye, and Ian McKellen's Magneto with no scarring at all.

Another grid reportedly showed Channing Tatum as Gambit with blood trailing down his forehead and Mabel Cadena as Namora in blue makeup. We knew Namor's female lieutenant from Black Panther: Wakanda Forever was joining the cast because she appeared in photos of the cast at a hotel resort in Bahrain, where some of the film's production took place. In that collage were also images of Tobey Maguire in the Spider-Man suit with wounds of his own.

We didn't fully show these, and we held off on reporting them openly, because we didn't know their validity or how they got out. I also had to acknowledge it was possible DanielRPK saw these photos, judged them genuine, and published his own report as a scoop with no source, confident it would be proven true. But the Namora inclusion was random enough, and having looked at the photos, I thought hers looked the clearest. For many people, that gave some certainty to the bruised Tobey Maguire images.

Tobey Maguire in London and the idea that Doomsday kills off past heroes

There was another clue. In the week of September 10, Tobey Maguire showed up in photos with fans in the London area. That was when production on Spider-Man: Brand New Day relocated to the city, in a week we noticed was mysteriously left unmarked on the Brand New Day production calendar. But it was also around the time principal production on Avengers: Doomsday was wrapping up, also in the London area.

Based on the physical condition of these past era Marvel heroes in the reportedly leaked images, and what we'd heard about Doomsday's plot, I thought we might see a Doomsday that permanently kills off the big name heroes from past eras. That would leave Secret Wars as the movie that introduces the new era of Marvel heroes, including exciting fancast roles like a new Black Panther and a lineup of X-Men who could be part of a restored MCU after Secret Wars, characters to get to know in the Mutant Saga.

Deadline's report put Sadie Sink in Avengers: Secret Wars

That's what made the Sadie Sink report so interesting. On November 18, Deadline, which we consider a reputable news source, posted a newsletter from columnist Baz Bamigboye about Sink's next career moves. It noted that Spider-Man: Brand New Day was scheduled to open on July 31, and added: "There has been much speculation about the role Sink has in the Spidey film, and frankly, I do not know the answer, but I do know that she'll join the cast of the next Avengers picture that shoots here in London later in 2026."

The next Avengers film shooting in London later in 2026 had to be Secret Wars, because Doomsday had already wrapped. Beyond Robert Downey Jr. and the casts of Fantastic Four and Thunderbolts, which we only knew were coming because Kevin Feige said at San Diego Comic-Con in 2024 that those teams would return in the next two Avengers movies, Sink was the only new cast member with any reporting tying her to Secret Wars. To me, that meant her Brand New Day role would matter not only to that street level movie, but to the climax of the Multiverse Saga and what the MCU would look like afterwards.

Who Sadie Sink could play: Carlie Cooper, Lily Hollister, Firestar or Jean Grey

That sent me back to our list of possible characters. Carlie Cooper was the safe option I kept coming back to. She's a roller derby competitor and CSI investigator, the kind of role you would cast someone like Sadie Sink to play, and she was introduced in the Brand New Day era of the comics. Lily Hollister was also introduced then, but she's Harry Osborn's girlfriend at first, which would mean the movie needed a Harry Osborn. We hadn't heard of any young actor playing him, and I felt Sink was too high profile to be paired with a character nobody had been named for.

Next were Angelica Jones, Firestar, and Jean Grey, but really only if Marvel Studios wanted to use the fourth Spider-Man movie to plant seeds for characters with bigger roles in the Mutant Saga. I thought Jean Grey was probably too big an X-Men name and would overshadow Spider-Man in a movie that already had at least Hulk and Punisher. That said, with original Jean Grey actress Famke Janssen not showing up in Doomsday, it seemed Marvel Studios had some plans for the character. Firestar was a smaller name who had already been paired with Spider-Man and Iceman in the animated Spider-Man and His Amazing Friends.

Julia Carpenter and Abyss as Secret Wars options

Option four was Julia Carpenter, one I hadn't thrown out before because we had seen a version of the character played by Sydney Sweeney in Madame Web. But Julia Carpenter's Spider-Woman, with her black and white suit, was first introduced in the Secret Wars limited series in 1984. I imagined someone at Marvel saying that whatever version of Secret Wars they did, Julia Carpenter had to be in the lineup. I had one of her action figures as a kid and had a lot of fun with it.

Another name being thrown around was Abyss, a possible candidate if Sink was playing a multiversal figure. Abyss is a being from Jonathan Hickman's Time Runs Out storyline, which leads up to the 2015 Secret Wars event. She's associated with the Beyonders and ends up on a team investigating why the multiverse was collapsing from the incursions. Our colleague Josh from Den of Nerds had been putting out the rumor that as Abyss, Sink could even be the human form of the multiverse across these films. With respect, I didn't know. That's a lot of cosmic lore for a character who has to make sense in a street level Spider-Man story.

Why Mayday Parker became my theory for Sadie Sink

So I looked at a slightly more plausible multiversal option I had dismissed before: Mayday Parker, the daughter of Tobey Maguire's Peter Parker from his universe. Some called it an option many fans were trying to will into existence, and it is pretty awesome. But it only made sense if Maguire was in Brand New Day as well as Doomsday. That would make a street level story that already had the Hulk and the Punisher far more of a multiverse story than I thought director Destin Daniel Cretton wanted.

If Maguire was in London for Doomsday, I thought that made it less likely he was there for Brand New Day too. The exception was if we were in another situation where Marvel's post-credits scenes leading up to Doomsday were shot by the Russo brothers as scenes technically part of Doomsday, which was the case for Thunderbolts and Fantastic Four: First Steps.

So there was a version where Sink plays a character who is Mayday but goes by another name throughout Brand New Day. The plot wouldn't be concerned with her multiversal origin, only with how she relates to Peter as a friend. They could withhold the name Mayday until the end, as a play on the Brand New Day title, and set up a fifth movie as potentially Spider-Man: Mayday.

How Mayday could connect Brand New Day, Doomsday and Secret Wars

From there, I pictured a post-credits scene looking ahead to Doomsday that could reveal who she is and who she's related to: Sadie Sink and Tobey Maguire, daughter and father, maybe with the mother, Kirsten Dunst's MJ, there too. They're still living in that flat as Peter finally fixes Mr. Ditkovich's door, then looks out the window to see another door has opened, an incursion in the sky. MJ would tell him to go get him, tiger, and it cuts to black with the words "The Spider Family will return in Avengers Doomsday."

Then in Doomsday, Maguire's Peter would fight to save his wife and daughter, fail, and die. In Secret Wars, Sink could play Mayday in a Spider-Verse version of Manhattan, fighting to redeem her father. I thought that was at least one way the reports about Tobey Maguire and Sadie Sink could connect the dots from Spider-Man: Brand New Day to Avengers: Doomsday to Avengers: Secret Wars.