Hollywood just added another twist to its ever-growing Marvel puzzle. A new report suggests that Stranger Things star Sadie Sink—who is set to appear in Spider-Man: Brand New Day—will also show up in the next Avengers film. And while Marvel remains silent, the timing and filming details strongly point toward this being Avengers: Secret Wars.
Below is everything confirmed, everything contextual, and everything fans are already speculating about.
Report Claims Sink Is Crossing From Spider-Man to Avengers
The story originates with industry reporter Baz Bamigboye, who revealed that Sink’s role in Brand New Day isn’t a one-off. According to his reporting, Sink is expected to appear in the next Avengers movie, which will film in London in 2026.
Sadie Sink sits for an interview – YouTube, COVETEUR
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Marvel hasn’t confirmed anything, and no one has revealed who she plays in Brand New Day—a secret the studio has somehow kept locked down through months of production.
But if she’s already being lined up for another film, her character is clearly more important to the studio’s long-term plans than previously assumed.
Why This Points Directly to Avengers: Secret Wars
Bamigboye’s article does not name the specific Avengers project. However, Marvel’s schedule does.
Avengers: Doomsday has already filmed and will release in December 2026. The only Avengers film scheduled to shoot in 2026 is Avengers: Secret Wars. That film then releases December 2027.
Robert Downey Jr. at the Avengers Doomsday cast reveal – YouTube, IGN
Those dates line up perfectly with the production window referenced in the report.
So while the source doesn’t state the title outright, industry context makes it extremely likely that any Sadie Sink follow-up appearance is tied to Avengers: Secret Wars.
A Mystery Role
Sink’s Marvel character remains the biggest mystery of the upcoming Spider-Man film slate. Fan speculation has ranged from completely grounded roles to full-blown multiversal identities.
Avengers: Secret Wars logo – Marvel
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Some common fan predictions include:
- The actual Mary Jane Watson
- Jean Gray of the X-Men
- Felicia Hardy/Black Car
- Gwen Stacy
None of this is confirmed. Marvel has not released a character name, description, or costume look. All we know is that she’s possibly important enough to carry forward into a major crossover event.
What This Means for the Multiverse Saga
If Sadie Sink really is jumping from Brand New Day into Avengers: Secret Wars, it signals something interesting about her character’s purpose.
Tom Holland as Spider-Man in Spider-Man: No Way Home (2021), Marvel Studios
She either plays a character who exists across multiple universes, making her a natural fit for a multiverse collision story, or her character is set up as someone meaningful to Spider-Man’s world and simply continues that arc into the bigger ensemble.
Either path is significant—Marvel does not casually cast recognizable rising stars across multiple films unless they have a reason.
A Rising Star Who Fits Marvel’s Long Game
Sink’s star power has surged thanks to Stranger Things and critically acclaimed stage work, including a recent major nomination for her latest theater role. Marvel scooping her up for more than one movie means they expect her to be part of the franchise for years.
Sadie Sink at a photo shoot – YouTube, COVETEUR
Considering Marvel’s aggressive rebuild after a rocky run of recent projects, this feels like a strategic bet on a dependable young talent.
What’s Next
Here’s how the release order plays out:
- Spider-Man: Brand New Day — July 31, 2026
- Avengers: Doomsday — December 18, 2026
- Avengers: Secret Wars — December 17, 2027
If Deadline’s reporting is accurate, we won’t have to wait long to see where Sadie Sink fits in to the Avengers universe.
Josh Brolin as Thanos in Avengers: Infinity War (2018), Marvel Studios
More to come as this story develops.
Do you think Sadie Sink will appear in Avengers: Secret Wars? Sound off in the comments and let us know!
