The following contains spoilers from Stranger Things Season 4, Volume 2, streaming now on Netflix.
Stranger Things Season 4 was, by far, the most dramatic season yet, and the primary reason that it did so well was that it did everything that it was supposed to do. As advertised, the super-sized season raised the horror-factor, while introducing a terrifyingly real villain. It also showed fans a lot more of the Upside Down and raised the stakes for Season 5 by leaving Hawkins in shambles, after an Empire Strikes Back-inspired ending.
While that might make Stranger Things sound predictable, it's important to note that Season 4 had its fair share of plot twists. Before the season debuted, Netflix released the first few minutes of "The Hellfire Club," which made Eleven look like a murderer. Later in the season, that was proven wrong, but fans believed it was true for quite a while. Vecna's identity as Henry Creel was also a huge surprise, along with the possibility that Eleven is his physical child. All of those twists kept fans on their toes, but Season 5 may be headed for an even bigger twist that involves Mrs. Karen Wheeler.
As part of the marketing for Season 4, Netflix released a whole set of Stranger Things posters. With muted colors, an Upside-Down-looking background and location silhouettes, the posters were really, really cool. However, retrospectively, there's an odd detail that everyone just ignored when the posters came out -- Mrs. Wheeler got her own poster, which makes no sense. She had minimal screen time (even in a super-sized season), and she was the only side character who got a poster.
Some fans on TikTok noticed how weird it was too and tried to come up with a solution by breaking down the poster. The breakdown, which has received millions of views took special note that the location silhouette in Mrs. Wheeler's poster -- the Creel House. That led them to the conclusion that Mrs. Wheeler could be Henry Creel's supposedly dead sister, Alice Creel.
At first glance, it's a ridiculous theory because Henry murdered his sister and his mother. Hypothetically, though, it's possible. Fans thought that Henry was dead until the end of the season, so there's no reason why Stranger Things couldn't set up a reveal that Alice survived too. If this ends up being true, it would mean that Mike was essentially Eleven's cousin because Vecna is essentially her father. Because of Mike and Eleven's relationship, that would be an incredibly weird twist of events, but it would also open Mike up for a relationship with Will in Season 5.
Honestly, the odds that Mrs. Wheeler is Vecna's sister are pretty slim. While it's possible on a theoretical level, it would just be a really weird plot twist, even for Stranger Things. However, it's still odd that Mrs. Wheeler was the only side character with a poster. So, there may be more to her than meets the eye. Maybe fans will get some answers in Season 5, but hopefully, she's not related to the ultimate villain from the Upside Down.
Stranger Things Seasons 1-4 are streaming now on Netflix.