Sadie Sink is looking forward to the day when she can "put to rest" the theories about her Marvel character.

The Stranger Things actress is currently in the U.K. filming Spider-Man: Brand New Day alongside Tom Holland, Zendaya and Jon Bernthal.

It has not been revealed who Sink is playing, and Marvel bosses are going to great lengths to keep her character's identity under wraps, with the actress wearing a head-to-toe puffer coat to protect her top-secret look around the set.

"Tom can wave at the fans because people know who he is, but then you get a glimpse of me and I'm like a penguin. That'll be the situation for a bit, it seems," the 23-year-old joked in an interview with Entertainment Weekly.

Of the theories, she added, "People will just have to wait and see. I'm excited for all of it to maybe be put to rest."

Sink started having conversations with Marvel executives while filming the final season of Stranger Things, and she noticed that fans were speculating about her playing Jean Grey, the telekinetic and telepathic X-Men character, before she knew what was happening.

"That was happening before I even knew that I would be working on this project," Sink clarified of that specific speculation. "I was like, 'Wait! What are people talking about?'"

Many fan theories involve comic book characters with red hair, including The Punisher's sidekick Rachel Cole. However, Sink noted, "A lot of people forget that hair colour can change, but, yeah, I understand all of the theories."

Sink has stopped paying attention to the online discourse around the role, however, she has had to confront the theories often during the press tour for the fifth and final season of Stranger Things, which debuts on Netflix on Wednesday in the U.S. and Thursday in the U.K.

Spider-Man: Brand New Day, the sequel to 2021's Spider-Man: No Way Home, will be released in July 2026.