Stranger Things: Vecna and the Mind Flayer explained

The epic conclusion of Stranger Things 4 has arrived, and it brought with it some of the biggest reveals yet. As our teenage heroes fought off the devious Vecna, the villain’s past was revealed — and along with it, the origins of the show’s other big bad, the Mind Flayer.

But it came in the midst of a lot of crazy action, and Stranger Things has a knack for giving us huge info drops without explicitly spelling out what they mean. If you have questions about the relationship between Vecna and the Mind Flayer, you’re in the right place. We’re going to break it down using what we learned in the season 4 finale.

It should go without saying, but major SPOILERS for Stranger Things season 4 lie ahead.

Where did the Mind Flayer come from?

During the Stranger Things 4 finale, we finally discover the origins of the Mind Flayer, the giant spider-like mind-control monster from seasons 2 and 3. After Eleven and Henry Creel’s climactic battle in Hawkins Lab at the end of Volume 1, she blasts him into another dimension with her telekinetic powers. In the finale, we find out more about what happened to him there.

After being zapped by otherworldly energy that deformed his body, Henry explored this untouched plane filled with wandering Demogorgons, floating rocks, and dramatic peaks. It’s important to note that this land is not the Upside Down…or at least it’s not the Upside Down yet. Henry says it is “unspoiled by mankind,” and it has no buildings or any other signs of the mirror dimension beneath Hawkins. No doubt we’ll find out how this world and the Upside Down are connected in Stranger Things season 5, but as it stands, the world Henry explored was totally unique.

One of the things Henry encountered was a swirling black cloud of particles. It’s not clear whether the cloud was sentient before it encountered Henry, or what exactly it even was. But its very presence inspired him to create, testing his godlike powers. He used his psychic abilities to mold the particles into a shape inspired by his childhood love of black widow spiders, and the Mind Flayer was born.

Who’s actually in charge, Vecna or the Mind Flayer?

Near the end of Stranger Things Volume 1, Dustin speculated that Vecna is the Mind Flayer’s “five-star general,” but the truth is nowhere near that simple. From the information we got during the Stranger Things 4 finale, we can conclude that Henry Creel is the one calling the shots; in fact, Henry is the Mind Flayer.

The Mind Flayer, it turns out, isn’t even its own being at all. Instead, it is a living extension of Henry Creel’s will, which he can use to possess other beings. Here’s what Henry told Eleven during their final confrontation:

"At first, I believed you had sent me to my death. To purgatory. But I was wrong. I was somewhere new. I became an explorer. An explorer of a realm unspoiled by mankind. I saw so many things. And one day, I found the most extraordinary thing of all [referencing the Mind Flayer particles]. Something that would change everything. I saw a means to realize my potential. To transcend my human form. To become the predator I was always born to be."

Creating the Mind Flayer allows Henry Creel to stretch his mind in seemingly limitless directions, “transcending his human form” and possessing other beings. We’ve seen this time and again throughout Stranger Things, and Will Byers confirms it in the season 4 finale when he reflects on being possessed by the Mind Flayer in season 2. He tells Mike that he can tell Henry Creel is still alive because of their lingering connection.

"It’s strange, knowing now who it was this whole time, but…I can still remember what he thinks, and how he thinks. And he’s not going to stop. Ever. Not until he’s taken everything. And everyone."

This confirms that the voice speaking to Will when he was possessed was Henry. So all that exorcist stuff that happened to Will in season 2? Henry. The possession of Billy and the rest of the Hawkins residents who formed the fleshy Mind Flayer from season 3? Also Henry. When Billy spoke, that was Henry too.

Did the Duffers always plan for this? If not, they’ve retconned it in well enough that it holds up.

What about the Upside Down hivemind?

There’s one other element to all this, and that’s the hivemind of the Upside Down, which connects all the creatures and tentacles so that if you hurt one of them, it hurts them all. This is something we’re expecting to be explored more in Stranger Things 5, because as it stands it’s not entirely clear whether the act of Henry creating the Mind Flayer connected him to an already existing hivemind, or if Henry uses the Mind Flayer to create the hivemind. But we did get one pretty crucial clue that hints at the latter being true.

When Hopper, Joyce, and Murray return to Kamchatka prison in the season finale, a Russian guard describes the Demogorgon attack to them. He explains how the Demogorgon and “shadow” particle tanks shattered during the chaos, and the particles went into the seemingly dead Demogorgons, possessing them. The group of Demogorgons then rampaged through the prison, killing everyone in sight.

As we saw in the finale, when Murray torched all of the Demogorgons with a flame thrower, it hurt the tentacles in the Upside Down enough that they released Steve, Robin, and Nancy in the Creel House. So, after being possessed by the Mind Flayer, we can say for certain that the Demogorgons were part of the hivemind. Whether they would have been before that or not, there is certainly some kind of connection between Henry, the Mind Flayer, and the Upside Down hivemind.

Given that Stranger Things 4 gave us more information about the show’s mythology than ever before, there’s no doubt that these mysteries will be integral to its fifth and final season.

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