This article contains spoilers for Stranger Things season 4.

Stranger Things season 4 revealed Vecna has been the true villain all along - and there have been clues to his existence in the first three seasons. Stranger Things has become a pop culture sensation, and it's easy to forget the show was originally proposed as a limited series. The Duffer brothers' first script suggested Eleven would die defeating the Demogorgon, and they conducted a hasty rewrite when Netflix asked if it would be possible to have a second season.

Stranger Things season 4 retconned the franchise's history, introducing viewers to Vecna - a powerful being who had apparently been responsible for everything that's been happening in Hawkins. Vecna was Dr. Brenner's "Number One," inspiration for the experiments he conducted with Eleven and other children like her. Eleven unwittingly freed him, and he massacred the other Hawkins children; he was unable to defeat Eleven herself, however, and she banished him to the Upside Down. There, he used mysterious shadow particles to create the Mind-Flayer, and thus fashioned the hive mind.

Related: Stranger Things Season 4 Volume 2 Easter Eggs & References

It's a massive retcon, of course, and the very fact the Duffer brothers originally pitched Stranger Things as a limited series means claims they had this planned all along should be dismissed as exaggerated. That doesn't mean it's particularly problematic, however; in fact, the Vecna/Mind-Flayer connection fits surprisingly well with previous seasons. Here are all the details that can now be seen as clues to the Vecna reveal.

If Jane Is Eleven, What Happened To The Other Hawkins Kids?

Stranger Things Hawkins Lab Massacre Number One Talks To Eleven

The most obvious clue lies in the fact Jane is numbered "Eleven," not "One." This immediately confirms Dr. Brenner has had previous test subjects. At first, viewers had wondered whether the other subjects had been failures, and Eleven the first success; that idea was disproved in Stranger Things season 2, which introduced Kali. Another escapee from Hawkins Lab, Kali had been Number Eight. Tie-in comics began exploring some of the other Hawkins children, but according to comic book writer Jody Houser they weren't allowed to deal with Number One. "Really the one restriction we got was we couldn’t use the number One," she told Gizmodo. "Other than that, any other number was up for grabs." Viewers now know this was because the Duffer brothers had their own plans for Number One. Ironically, the Vecna retcon effectively renders all those comics non-canon anyway, because it turns out the other Hawkins kids were all slaughtered in 1979.

The Lights Flicker Around The Mind-Flayer's Presence - Just As They Do Around Eleven's Powers

Stranger Things Mind-Flayer

The next clue is a subtle one; the fact the lights flicker around Upside Down entities in exactly the same way they do when Eleven uses her powers. This is a clear hint that there are similarities of some kind between Eleven and the interdimensional entities plaguing Hawkins - and now those similarities are explained. The flickering lights are indicators of psychic phenomenon, not necessarily of dimensional breaches.

Stranger Things' Recurrent Clock-Chime Motif

Grandfather Clock in Stranger Things Season 4

Meanwhile, attentive viewers have noticed another recurring motif; the chiming of a clock at key moments. In Stranger Things season 1, the ticking of a clock can be heard when Will first encounters the Demogorgon around Murkwood. There's an actual chime when Hopper enters the tunnels Demodogs and vines have burrowed beneath Hawkins in Stranger Things season 2. This was probably just a creepy sound effect, but the importance of Vecna's grandfather clock in Stranger Things season 4 makes it feel significant.

Related: Vecna's Powers May Explain Stranger Things' Two Kali Plot Holes

How The Demogorgon Knew Its Way Round Hawkins Lab

Stranger Things season 1 opening scene with scientist attacked

Several scenes in previous seasons of Stranger Things can now be retconned as important clues. Indeed, the opening scene in Stranger Things' pilot episode has now been rewritten. In this, one scientist runs for his life immediately after Eleven opened the new gate in Hawkins Lab, and he manages to get to the elevator. The Demogorgon has gotten there ahead of him, however, and attacks him from the ceiling. This had always seemed a little odd, given that Stranger Things' Hawkins Lab should have been a new environment to the Demogorgon and it shouldn't have been able to navigate it quite so easily. But that Demogorgon has now been retconned as Vecna's scout, and Vecna knew his way around the lab from his time working there as an orderly. It now makes perfect sense.

How The Demogorgon Got Into Will's House

Stranger Things Season 1 Will's House Bolt

The Demogorgon scout then leaves Hawkins Lab to explore the nearby woods, where it crosses paths with Will. He flees from the creature, managing to escape into his house, where he latches the door and then tries to call for help. To his horror, though, he watches as the latch slides open from the inside. This was clearly Vecna using his power of telekinesis to let the Demogorgon in without making too much of a mess, because Demogorgons have never again seemed to display such abilities.

Will's Season 2 Hallucinations Are Similar To Season 4's Visions

Will Byers in Season 2 of Stranger Things.

Moving on to Stranger Things season 2, Will - rescued from the Upside Down but clearly still under its influence - begins to experience horrific visions of this nightmare realm. With the benefit of hindsight, these visions are almost identical in approach to the ones experienced by Vecna's victims in Stranger Things season 4. The parallels are striking, and these visions should now be seen as important clues.

Will Refers To The Mind-Flayer As "He"

Mind Flayer in Stranger Things 4 Finale

Will ultimately falls prey to the Mind-Flayer, infected by its virus. He tries to resist, but is unable to prevent the Mind-Flayer using him to set a trap for the soldiers who are trying to keep the Upside Down at bay. It's interesting to note that he consistently refers to the Mind-Flayer as "he," a line that was taken to refer to the Mind-Flayer but can now be seen as a deep, subconscious awareness of Vecna himself.

Related: How Did Henry Creel Get His Powers In Stranger Things?

Billy Was Raised Up Telekinetically When Fighting Against Eleven

Stranger Things Billy's feet drag across the floor

The next major clue is in Stranger Things season 3, episode 4. There, the young heroes of Hawkins subject Billy to "the Sauna Test," using elevated temperatures to try to flush the Mind-Flayer virus out of his body. The attempt is unsuccessful, with Billy drawing upon the power of the hive to break free. It's interesting to note that Billy becomes a literal puppet, with his feet trailing in an unnatural way as he is dragged upright. This was clearly Vecna, using his telekinesis.

The Mind-Flayer Was Able To Strip Eleven Of Her Powers

The Vecna/Mind-Flayer retcon also affects the end of Stranger Things season 3, in which Eleven was stripped of her powers. Few people would know more about Eleven's powers than Vecna; he had been an orderly at Hawkins Lab, and he'd surely have taken the chance to study Dr. Brenner's notes. This can now be seen as a deliberate act on Vecna's part, inducing a stroke-like event so Eleven would need to relearn her powers. It's telling that Vecna only launched a direct invasion of Hawkins in Stranger Things season 4 when he believed Eleven was out of the way.

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