Sadie Sink’s Cryptic Tease Ignites Spider-Man 4 Frenzy — Did She Just Hint at a Major Marvel Role?

Sadie Sink joined Spider-Man: Brand New Day back in March and, eight months later, we still have no clue who she is playing. She knows we want to know. She also very much is not telling us.

What she will not say

At the Stranger Things Season 5 premiere in November, Entertainment Tonight tried to get one word about her Marvel character. Sink smiled and punted.

'I thought this was the Stranger Things premiere. I wasn't prepared.'

They tried again. Her follow-up was basically a brick wall: 'Mmm, no.'

This is the vibe around her MCU debut so far: purposely vague, kind of funny, and engineered to make the internet freak out. Which, mission accomplished.

What is actually confirmed

Here is the real, non-speculative stuff. Sony and Marvel announced Sink for Spider-Man: Brand New Day in March 2025, with Destin Daniel Cretton directing. She is joining Tom Holland (Peter Parker), Zendaya (MJ), and Jon Bernthal (Frank Castle). Mark Ruffalo shows up as Bruce Banner, and Michael Mando returns as Mac Gargan. Filming kicked off in London in mid-2025, and the movie is currently dated for July 31, 2026.

What the cameras caught on set

Set photos that popped up in October handed fans their first clues. Sink was seen in camo pants and military boots, and in separate footage she is on a stretcher being taken to the Department of Damage Control. That screams 'something superhuman just happened' or at least 'DODC thinks it did.' She was also spotted in a beige hoodie and a khaki coat on different days, so she has multiple looks in the film.

What people think this means

The whispers behind the scenes are contradictory: one source says she is a villainous shapeshifter, another claims she is on Peter Parker's side. When the Jean Grey rumors started flying in March, Sink told the Happy Sad Confused podcast she had nothing to say about any of it, but admitted the speculation was 'really cool.'

Fans have been busy workshopping their guesses on X: one post in March flat-out claimed 'She's playing Jean Grey.' Two November posts leaned the other way — 'Rachel Cole, apparently' and 'This already feels like a villain origin story.'

• Jean Grey: The most popular pick, especially with Marvel gearing up to fold the X-Men into the MCU and Sink's red hair making the fan art effortless. If Cretton is seeding mutants through Spider-Man, this would be a swing.
• Rachel Cole-Alves: A former Marine who partners with the Punisher in the comics. The camo pants and boots match the vibe, and Bernthal is in this movie. That said, DODC hauling her around muddies the waters.
• Firestar: Classic Spider-Man-adjacent hero with mutant ties in some runs. The DODC angle could fit if she triggers a public powers moment.
• Mayday Parker: A deep-cut Spider-legacy play. Less likely given the current MCU continuity, but the rumor mill does not care about likelihood.
• A brand-new villain or a shapeshifter: Multiple outfits, DODC custody, and those 'villain' whispers keep this in play. It would also explain the airtight secrecy.

Meanwhile, on the Stranger Things front

On November 7, 2025 at LAX, Sink told TMZ she took home two mementos: Max's skateboard (it's now hanging above a doorway in her place) and the cassette Walkman that blasted Kate Bush's 'Running Up That Hill' and kept Max alive in Season 4. The final season of Stranger Things is rolling out in three parts: November 26, 2025, December 25, 2025, and December 31, 2025.

Bottom line: Sink's Spider-Man role is still under wraps, production is ongoing, and the studio is clearly fine letting fans analyze every boot tread and hoodie seam until the marketing kicks in. Brand New Day hits theaters July 31, 2026. Who do you think she's playing?