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The Upside Down is Will's Mind Part Two
I highly recommend reading the first part of this theory (here) before continuing! This post is way longer than the original because I wanted to get all of my thoughts about this out in one place so here it is:



Dustin explains that El opened the Mothergate in 1983 by making a psychic connection to the demogorgan and assumes that Vecna is doing the same with his victims. Why would psychic connection open a gate to the Upside Down if the UD is not related to the mind? If gates to the UD are being opened through psychic connection, how did the original gate in 1979 open? El was not psychically contacting anyone when she originally banished Vecna, or was she?


Right before El banishes Vecna, she sees a cloudy red tunnel and a memory of her birth. This initially seems like El about to meet death, but what if it was actually a lifeline? The red cloudy tunnel looks similar to Vecna’s cloudy mindscape when he’s searching for victims. What if El was unknowingly searching for someone’s mind, found Will’s, and banished Vecna there? This would explain how she recognized him in s1 as well, she might have seen him in the red void or could sense him because she has connected with his mind before.
Now I want to answer the question of why El banished Vecna to Will’s mind specifically. This needs a bit of explaining before I get to the point so stay with me:
We know that Vecna likes to target people with trauma because their minds are more vulnerable when they’re experiencing trauma. We can assume that El’s powers work the same. Maybe Will had experienced a recent trauma that made his mind more vulnerable that day and gave El an easy (unintentional) target. But what trauma could that be?
In s1, Hopper says that he had been chief in Hawkins for four years, meaning that Hopper became chief in 1979. When Jonathan speaks to Lonnie, Lonnie asks if Hopper is still chief. This means that Lonnie was still in Hawkins in 1979. So when did Lonnie leave? We can deduce it was sometime between 1979 and 1982. Joyce brings Will tickets to Poltergeist while he is sitting in Castle Byers. Poltergeist came out in June of 1982 so this must have happened around that time. Jonathan and Will built Castle Byers the night their dad left so if Castle Byers already exists, we know this happened before 1982. So Lonnie left before 1982, but after 1979.
Onto my point, I believe that Lonnie left the same day that Vecna was banished to the Upside Down aka September 8th, 1979. This would be a fresh trauma that made Will’s mind more vulnerable to El’s powers. Jonathan and Will built Castle Byers the night their dad left and Jonathan said they were sick for a week after they built it. What if Will’s sickness wasn’t because of rain, but because his mind was being haunted by Vecna? Headaches, nosebleeds, and trouble sleeping sound like they could be symptoms of a typical cold, right? They describe Will’s connection to the Mind Flayer as a “virus” in s2 as well.


In the shed scene, Joyce’s memory is about Will’s 8th birthday. Will turned 8 in 1979. Hopper said he became chief in 1979 in the scene where Joyce is reporting Will missing and he uses that as a reason why Will is likely with Lonnie. Lonnie is linked to 1979 and Will’s disappearance now. That year is significant to Will. These two scenes indicate that Vecna being banished to the UD is connected to Will’s disappearance and is the reason why he was targeted. Why is there emphasis surrounding Will in 1979? Did something happen to him that year that was significant, maybe his mind being invaded by someone?
The destruction of Castle Byers has similarities to the night they built it. It was raining both nights and Will had trouble destroying Castle Byers the same way he struggled to hammer it together. How does the Castle Byers scene end? Will feels the Mind Flayer. So what if the parallels don’t end with the rain, what if Will felt Vecna wandering his mind the night they built it too?
Another thing that felt important: the van scene where Will talks about being different comes just before the scene of Brenner looking at the cracks in the wall left from El banishing Vecna. The song “Being Different” slightly fades us into that scene. Are they connecting Will’s differences to the day Vecna was banished?
Okay so why doesn’t Will feel Vecna for the next four years then? Will said that he doesn’t always feel the Mind Flayer, he only felt it when it wanted to use him. Vecna was dormant until the gate opened again and only made his presence known when he wanted to.
After season four, we are meant to assume that Will’s visions in season two were just Vecna visions, not him actually being transported into the Upside Down. They describe these visions as “true sight” and I think they were right! Will really was seeing into the Upside Down. That’s not the full story, though. Will’s visions were just Vecna visions, but he was also being transported into the Upside Down because that is his mind.
Will heard a baby demogorgan during one of his visions on Halloween. Why would Vecna make him hear a baby demogorgan rummaging through trash if the main point of the vision was to scare him with the Mind Flayer? Why not use the classic clock sound insead? Will was hearing actual creatures from the Upside Down during his visions because they reside in his mind.


The analogy they use in season two to describe Will’s condition is the story of Phineas Gage. It’s interesting how they compared Will’s mental hauntings to a physical injury. Phineas Gage had a rod go through his head that caused personality changes but Will’s personality changes were mostly due to PTSD and the Mind Flayer taking over his mind.
When the doctors scan Will’s brain, there are abnormalities that they can see and they specifically point out abnormalities in the hippocampus caused by PTSD. PTSD can cause physical changes to the brain like making the hippocampus smaller. Will’s brain has physical changes due to PTSD, but maybe he has physical damage to his brain in a different way. Maybe his mind is a physical location that is actively being harmed by Vecna. Maybe these comparisons to Phineas Gage are being made because they both had physical injuries to the brain, but Will’s brain is really the Upside Down. Max says that closing the gate is like cutting off the brain from the body. The UD is a brain!
On the topic of Will’s PTSD, let’s talk about the anniversary effect. Owens says that Will’s visions are worse because he is approaching the anniversary of his disappearance. At the same time as the approaching anniversary, the lab is losing control of the spread of the UD into the real world. Plants are suddenly rotting and tunnels are spreading despite them keeping it contained for nearly a year. Why is the UD’s spread speeding up as they near the anniversary? Maybe Owens was right, but not in the way he thought. Will’s PTSD response is becoming worse because of the anniversary and this is causing the UD aka his mind to spread into Hawkins faster. His mind is more vulnerable and Vecna can take over easier and enact his plans.

Will says that the more the vines spread, the more connected he feels to the Mind Flayer. Why does the UD spreading into the real world make Will feel him more? This isn’t just Vecna taking over Will’s mind, Will puts an emphasis on the UD’s spread into Hawkins. It could be that Will’s mind is seeping into Hawkins so he feels more connected to the UD and Vecna because of that. His mind doesn’t feel as distant as before.
They also describe Will as the “host” for the virus aka Vecna. The lab people talk about the tunnels/gates as if they are diseases as well. What if Will is a host in a bigger way? What if he isn’t just the host for Vecna, but the entire UD? He’s a host for both.
Why didn’t Will die in s2 when they closed the gate? Obviously they got the particles out of him, but we later learn that he can still feel Vecna so his connection was not entirely broken even though it should have been. The creatures from the UD die when the gate closes because they are cutting the brain from the body, the brain being the Vecna. So if Will is still connected to Vecna, why didn’t he die and why does he still feel Vecna? His connection to Vecna was not fully severed because the UD aka Will’s mind is still a host for him.
Another thing: Will didn’t feel pain from the UD being burned. If it’s his mind, that would hurt right? I don’t think so. Vecna took control of everything in the UD so they belong to his mind rather than Will’s, taking the pain away from Will and attaching it to Vecna.
It’s interesting how we don’t get a memory sequence during the shed scene. Both Billy and Max had memory flashbacks when they were breaking free from Vecna taking over their minds, so why not Will? They could have shown a swingset, a picture of Will’s spaceship drawing, or a clip of Castle Byers, but they didn’t. We didn’t get to see inside of Will’s mind at all. Do they not want us to see his mind? Perhaps it would be something familiar, something they want to wait to reveal until a later season.
Speaking of memories, we know that memories can help someone escape their own mind. We didn’t get a visual of Will’s memories in s2, but we did in s1. We get three flashbacks. Will and Joyce in Castle Byers, Jonathan and Will listening to The Clash, and one of Will drawing. These memories have key details that relate to the memories used in s2! Castle Byers, drawing, and Should I Stay or Should I Go. These all save Will in s2 and they may have helped him in s1 as well! Maybe Will used the same memories to make connections from his mind to the real world.


Why does the Upside Down look so different now than it did when Vecna first entered it? I originally theorized that this is because Will’s brain was less developed so his mind looked different at the time, but now I have a new theory. What if Will’s mind is stuck in a Vecna vision? If so, what is Vecna taunting Will with in this vision?
The description of the Upside Down is a place of death and decay. Will’s most prevalent trauma before he was taken by Vecna was the abuse and the bullying he faced for being a visibly gay kid. A lot of the bullying was likely about how Will would one day contract HIV/AIDs. We know Troy had implied this once in s1 and that probably wasn’t the only time. Does Will’s mind look like a place of death and illness because Vecna was taunting his fear of AIDs? Hawkins rotting with vines that carry disease with deadly spores in the air is very on the nose. Vecna was taunting Will with the idea that he will spread disease to the entire town of Hawkins just because he’s gay.
When Max made her mind look like the Snow Ball, there were no people there. The Upside Down is the same way, they even emphasize this fact multiple times throughout the show. It’s just like Hawkins but with no people. Maybe Will tried to hide in a happy memory the same way Max did, transforming the Upside Down to look like Hawkins, and Vecna immediately countered this just like he did to Max. As I said in part one, Will’s fight or flight response is often freeze so he might have frozen his own mind as a stress response, capturing the Vecna vision in time. Max tried to escape her tainted Snow Ball memory but couldn’t because Vecna interfered. Either Will froze his mind himself or Vecna prevented him from switching to a happier memory.


When Vecna realized he could reach into other’s minds, he said he became an explorer. He used this power to go inside of his parent’s minds and see them for who they are. He used the same wording of becoming an explorer when he entered the UD. The reuse of this phrase is connecting minds with the UD! He is an explorer for the same reason!
Something about the UD that I thought competed with my evidence is that voices from the real world can be heard there. I originally couldn’t explain this until I realized that Max heard voices inside her mind and so did El! The second Max’s music gate opened, she could hear the boys calling for her. El can hear people talking to her when she is in the void as well. The voices are faint and distant in both El and Max’s mind, just like they are in the UD!
Will’s disappearance has a ridiculous amount of parallels with Vecna’s victims (that will be an entirely different post in the future). Why have Will’s disappearance parallel instances of the mind being targeted where gates open to the UD because of a psychic connection? Will’s mind wasn’t involved or targeted in s1… unless?
This next bit is a bit of a reach and honestly feels unrelated but I’m leaving it anyways:
It’s interesting how the UD messes with electricity when that is a feature of someone using powers as well. The UD functions very similarly to mind powers. For example, in s2, Terry flickered the lights to lead El to her and signal that she wanted to talk. Will did the same things with the lights from the UD. Was Will controlling the lights with his mind by touching them within his mind?
When El connected Will’s mind to the radio, it blew up. The same thing happened when Will used the phone from the UD. If El using her mind made the radio blew up, then maybe Will using his mind made the phone blow up. Will is “using his mind” by simply using the things in the UD because they are inside of his mind.
Both Vecna and El are shown to cool themselves down when they are about to use their powers. El opens freezers to focus on finding Dustin in s3 and Vecna “likes it cold” because it’s easier to use powers that way. Maybe they need to be cold to use their powers because the mind is cold? A staple of the UD is that it’s cold!


Joyce gets a vision of Will and says that she can feel him. Is this in the same way that Billy, Will, and Mike could sense El when she contacted them through the void? Was Will contacting Joyce through his mind? Once Will stops trying to get to Joyce after breaking a hole in the wall, Joyce says she can’t feel him anymore. Was Will’s mind being cut off from Joyce’s because he couldn’t open a gate again from lack of energy? Henry and El both went into comas after they used too much of their powers. Will was slipping in and out of consciousness in Castle Byers shortly after this. Maybe he used too much energy trying to open the gate.
More of the UD functioning the same way that powers do:

At this point, I feel like I’m proving that Will has powers rather than the UD being his mind. Basically, Will was using his mind to communicate with Joyce, but not by holding out his hand and getting nose bleeds, he was touching things within his mindscape! He was using his mind, but in a different way because it’s a physical location now.
And now I’m going to end this post here. A lot of the evidence I brought up feels like a reach (and trust me, there were many more reaches I did not include) but here’s a repeat of the strongest evidence: music opened two gates to the UD, Will was actually being transported into the UD during his Vecna visions, psychic connection opens gates to the UD, and Vecna’s mind storm is inside the UD. It all comes back to Will and this would be a perfect way to wrap up the many questions about Will’s significance to Vecna.
As for how this could impact the ending of the show, I am a firm believer that the UD needs to be freed, not defeated. If it truly is Will’s mind, that’s a great way to show Will breaking free from that trauma by literally taking away Vecna’s control. Maybe Will can even take back some of the creatures and get them on his side like Dustin did with Dart, allowing them to take part in the defeat of their own abuser. Will is going to free his mind from Vecna’s abuse.