Where Is The Mind Flayer During Stranger Things 4 Volume 1?

Contains major spoilers for "Stranger Things" Season 4

The first part of "Stranger Things" Season 4 revolves around the biggest and most bombastic mystery the show has introduced so far. What, exactly, is Vecna, and why is the humanoid horror monster killing people in the real world in gruesome ways?

As Part 1 of the season comes to an end, we finally find out the real identity of the creepy villain, who turns out to be the first test subject of the program Eleven (Millie Bobby Brown) was part of, One (Jamie Campbell Bower). He's the son of Victor Creel (Robert Englund and Kevin L. Johnson), and just like Eleven, he's endowed with super-strong mental powers. Unfortunately, One is so detached from humanity that he uses his power in horrifying and murderous ways, and after an epic confrontation, Eleven is able to mind-blast One into the Upside Down. 

It's a pretty cool villain origin story that further establishes the importance of Eleven in the show's lore, but as Dustin (Gaten Matarazzo) points out in Episode 7, it doesn't account for one particular Upside Down-themed mystery in Season 4: there's still no word on how the Mind Flayer ties into everything. The hulking beast that controls the Upside Down hivemind has been the show's overarching Big Bad since its introduction in Season 2, so it's a bit surprising that it hasn't had any presence in this season. Or ... has it? Could it be that we've already seen the Mind Flayer in "Stranger Things 4?"

One of the most chilling powers Vecna displays is his ability to reach out to our dimension after attaching himself to a set of creepy tendrils in the Upside Down. As the show makes clear, though, these aren't a part of his actual body. You see him walking around in possessed people's minds without any extra appendages, and the tentacle-things clearly attach to him from an unseen source in the Upside Down. What's more, the revelation of Vecna's true identity confirms that his base appearance is very much that of a human, and exposure to the elements of the Upside Down have molded him into what he is today. Still, those fleshy tendrils remain unexplained ... that is, unless he's managed to tap into the powers of some hitherto unseen Upside Down force.

Which brings the discussion to the Mind Flayer. The creature is all about mind control and creepy tendrils, and it's been heavily implied to preside over the Upside Down with its powers. Could the tentacles Vecna is using to boost his powers belong to the Mind Flayer? Has the Mind Flayer voluntarily joined forces with Vecna to rain terrible vengeance upon the people of Hawkins, who have foiled its plans so many times? Or has Vecna challenged the Mind Flayer over the control of the dark alternate dimension, and gained control of its powers? 

One pretty major reason to believe that the tentacles Vecna is using are related to the Mind Flayer is the way the physical manifestation of the giant creature uses its powers in "Stranger Things 3." When Billy Hargrove (Dacre Montgomery) challenges the Mind Flayer in the Season 3 finale, the beast uses its tentacles on him in the same visual manner as the tendrils attach to Vecna in Season 4. 

Of course, it's worth noting that before Part 2 of "Stranger Things 4" arrives on July 1, all of this is little more than speculation. Still, when you combine the conspicuous absence of the Mind Flayer in Part 1 with the visual hints we've seen so far — and the fact that Dustin specifically name-drops the Mind Flayer in Episode 7 — it seems more than likely that viewers will find out the truth about the creature and its possible relation to Vecna before the show's swan song.