Stranger Things' third season was arguably its most high-energy yet, with the Mind Flayer making his presence felt big time thanks to the giant Meat Monster comprised of Hawkins' dead and decaying citizens. However, by the time the season wrapped, with Chief Hopper (David Harbour) seemingly dead, the Russian invasion stopped, and Eleven (Millie Bobby Brown) moving away with the Byers, it appeared things were settling down.

However, amid the end credits, which showed the Russians with "an American" and a Demogorgon of their own, it's clear a fourth season will be just as action-packed. To add to the mystery looming, one Redditor has now dropped a juicy theory suggesting there's another villain waiting in the wings for the teenage gang of heroes: none other than Eleven herself.

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Eleven uses her abilities in the mall in Stranger Things

The theorist first suggests that at the 2:42 mark in the finale's closing act, as Joyce (Winona Ryder) drives the kids away from Hawkins, a shadow falls over Eleven, hinting the Mind Flayer possessed her. It does seem to be the shadows of the trees as they drive by the woods to be honest, but there is some credence to El getting taken over by the dark lord of the Upside Down.

After all, she was bitten when the first, smaller Meat Monster wrecked Hopper's cabin in the woods and this limited her powers later on. We're not sure if it infected her or mentally broke her or if she just strained her psychic abilities like you would a muscle, but to pull the piece of the monster out she needed the gang to operate on her leg and then, she finished the job using the last of her telekinesis.

The user believes this infection is still lingering inside her, which would make for a much more intriguing story if El -- who's often the deus ex machina to banishing the creatures and sealing rifts to the shadow world -- is now the one the rest have to do battle with.

Turning the gang's biggest asset into their worst enemy is indeed an enticing thought, flipping the calculus of the entire series, but the thing is, we do know she has some of her powers still -- they're just very restrained, as seen when she tried to move her teddy at the end of the season. If she was truly infected still, she'd probably have all her powers as the Mind Flayer either would be controlling her fully or not at all -- just yet.

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There's nothing to suggest she was co-opted after the operation. However, seeing as Will (Noah Schnapp) was possessed by being infected, we can't rule out that some piece of the Mind Flayer's still in her. Will was possessed in Season 2 when he tried to confront it outside his school and it went down his throat, while Billy (Dacre Montgomery) was bitten, pulled inside Brimborn Steel Works and became the monster's avatar by presumably getting filled with its essence.

Now, while this never happens to El, a partial infection could spread and eventually grow. We don't know if it's hibernating, festering and multiplying inside her like a normal virus, so this might provide an explanation as to why her powers are shorting out.

El turning to the dark side is a very interesting concept and there would be a lot more added drama and overall emotional turbulence with her boyfriend, Mike (Finn Wolfhard) and bestie, Max (Sadie Sink) having to contend with yet another loved one going evil on them.

It would fit the plot pretty conveniently but in a good way, and would also make the show as unpredictable as it is dynamic. The chemistry of the cast is so good, seeing them going against one of their own would be a major step up and continue to show the Duffer brothers are about more than just one-dimensional heroes in '80s throwbacks saving the day.

El's been the best hero the show's had and one of recent pop culture's most beloved figureheads so to have her corrupted would be a stroke of twisted genius. But that said, we need something more concrete than a little scrape on her foot to really peg her as a monster-in-the-making. If the show goes that route, though, we'll be all in, as it would bring her Jean Grey comparison full-circle with a Dark Phoenix-like swerve.

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