Sadie Sink might have a larger role in the MCU than fans previously thought, as it has been confirmed that she will make an appearance in Avengers: Secret Wars. 

Deadline’s Baz Bamigboye confirmed that Sink will “join the cast of the next Avengers picture that shoots [in London] later in 2026.” The Stranger Things alum was first confirmed to join the Marvel universe back in March of this year, when it was announced she would star alongside Tom Holland and Zendaya in Spider-Man: Brand New Day. Though the character Sink will be playing is still unknown, prominent theories include Gwen Stacy, Felicia Hardy (aka Black Cat), or even the X-Men’s Jean Grey. Bamigboye’s news can lead fans to infer that Holland will also reprise his role as Peter Parker in Secret Wars, though it has not been confirmed whether Holland or Sink will appear in Avengers: Doomsday.

Sink has had a busy 2025, beginning the year off with the news of joining the MCU and starring in the Hulu musical drama O’Dessa. Sink also had success off-screen, starring in Broadway’s John Proctor Is the Villain, which received critical acclaim and several Tony nominations. Though Sink’s year doesn’t stop there, the final season of her show, Stranger Things, where she plays Max Mayfield, premieres next week on November 26th with its first four episodes. Sink will also make her West End debut in March 2026 as Juliet in Romeo & Juliet alongside Noah Jupe and directed by Robert Icke.