6 Big Theories on How 'Stranger Things 2' Sets Up Season 3

stranger things 2 ending
This post contains major spoilers for Stranger Things Season 2, including the season finale.

Stranger Things 2 is officially out in the wild and surely, leading many to wonder just where The Duffer Brothers '80s throwback series is going. The creators have said they need four seasons to tell the whole story, which means we’re at a halfway point for a greater plot. The seventh episode in the series clearly points in the direction that the third season of Stranger Things could go, but would the show really abandon creepy supernatural monsters or the Upside Down?

Considering all of that, here are the best theories as to where we’re going for Stranger Things 3.

stranger things mind flayer

What is the Mind Flayer?

The last shot of the season is clear: the threat of the Mind Flayer is still there in the alternate dimension, but we're left with plenty of questions.

First, recall in Season 1 that we learned that the Upside Down is a mirror of Hawkins in the real world, just without people. This is why Castle Byers was able to exist in both locations. The main characters of the show find Will in an Upside Down version of his home, where there’s a tentacle rammed down his throat. Hopper pulls the tentacle out of Will and throws it on the ground and shoots it. The tentacle writhes and screeches, the only time in Season 1 when we see that kind of behavior from an Upside Down entity.

Season 2 reveals that the tentacles have a mind of their own -- potentially controlled by the Mind Flayer -- and in the “graveyard” section of the tunnels, they almost get both Hopper and Mike at various points in the season. In the climax of Season 2, when the kids light the graveyard on fire, helps distract the shadow monster from the gate and Will long enough for Eleven to make her assault. No one this season gets a slug implanted in their stomachs (something we assumed the tentacle had planted in Will), but there are a lot more sentient tentacles making up the tunnel/vines.

In Eleven’s Season 1 vision, she sees a slug/pollywog crawl out of dead Barb’s mouth, but we never saw her alive and hooked up to the tentacles. This lead a lot of us to believe that the tentacle creature planted the slug in Barb, though we still haven’t seen anyone but Will get tentacle-mouthed. Knowing what we know about Will’s connection to the Upside Down from last season carrying over into this season: Are the tentacles that over-run the Upside Down part of the Mind Flayer or are they part of the Upside Down itself?

stranger things dart pollywog

The vines that grow under Hawkins this season -- that Hopper first penetrates in "Chapter 5: Dig Dug" -- have large organs inside them that secrete the Upside Down atmosphere, and in those tentacles, the DemoDogs can run around freely. Hopper finds a large centralized area filled with bones where the DemoDogs must feed and hatch themselves, implying the creatures are procreating, but when the tentacles grab Hopper, they don’t try to force themselves into Hopper’s mouth. It seems like the tentacles are making the atmosphere safe for something to cross over, and the conclusion suggests that it could have been the Mind Flayer in pure form that needed the atmosphere of the Upside Down to survive.

The atmosphere change wasn’t for the Demogorgons, as they can exist outside the Upside Down. There’s lots to discuss about the life-cycle of a Demogorgon, but the most interesting dangling thread about the Mind Flayer is just how long it has targeted Will. There’s something that connects Will to the “storm” that’s coming for Hawkins -- could it be that the tentacle wasn’t implanting slugs in his stomach like we thought, but preparing him to be infected by the Mind Flayer in Season 2? If so, did the beast allow Will to return to the real world to make this second season breach possible?

The first contact the Upside Down had with the real world was when Eleven opened the gate by touching the Demogorgon in the Astral Plane. Once the gate opened, the Upside Down seemed capable of crossing over almost... at will (pun very much intended). Portals have sprung up in the forest and in the school, and the season one Demogorgon even had the power to move between the dimensions, seeking blood. The Mind Flayer might be the only full sentient force in the Upside Down, and we know it wants out. It needed the main gate to transform the tunnels into an atmosphere it could survive in without a host, but it appears it doesn’t need the main gate to be open to threaten Hawkins, now that it understands the relationship between the two.

stranger things upside down gate

The Upside Down could actually be the "Underdark"

Season 2 was just as Dungeons & Dragons  inaccurate at the first (listen, guys, there is no system where there is an offensive roll for Fireball -- it’s a mistake and it will never not bug me!), but with the addition of Mad Max’s non-existent Zoomer class, we did get some valid game reference in Dustin use of "Mind Flayer" to describe the shadow monster that they’re facing. The Mind Flayers, or illithids, feed on the brains of sentient creatures and attempt to mentally dominate everyone they meet. The illithids live in the Underdark -- ring a bell? Like the Upside Down opposite Hawkins, the Underdark of Farun (the fictional land D&D takes place in) has no natural light sources, have a poison atmosphere, and are home to creatures the above-worlders consider monstrous and gross.

The Demogorgon from Season 1 is not an Underdark creature, exactly (in D&D it comes from The Abyss, but that’s neither here nor there), but the lack of connection gets a pass as Underdark is a realm in the game that didn’t get fully described until 1986’s Dungeoneer's Survival Guide (and Season 2 takes place in 1984). If the game's version of the Underdark enters the show, the Upside Down could be filled with much larger threats than the Mind Flayer. When Dustin describes the Mind Flayer in the series as being a race that thinks humans shouldn’t exist because they are inferior, he’s not describing a Mind Flayer as much as he’s describing an Aboleth, the king badass of the Underdark.

If there’s a creature that’s going to be behind the Mind Flayer, like the Mind Flayer was behind the Demogorgon, look no further than the Aboleth. Unlike illithids, Aboleths could grow to be giant, like 40 feet tall, and are described as eel-like giant creatures. Aboleths can’t breathe our atmosphere, they breathe by secreting a grey mucus like substance that did their breathing for them (like how the Upside Down atmosphere is invading Hawkins) that grey substance also starts to transform any creature that comes in contact with it into the Aboeth’s thrall (mind control). It’s the Aboleths who think that all other races are inferior to the Aboleth, not the illthids. And get this: Aboleths reproduce by egg. Which brings us to...

stranger things pollywog dart

Is Dart the Pollywog a Demogorgon? (AKA the egg question)

Riffing on Gremlins with a Demogorgon leads to a few problems. Namely, if little D'Artagnan’s life cycle is indicative of his species, there’s no way that it is an evolved version of the creature Will puked up at the end of Season 1. In a matter of days, Dart goes from Pollywog style to eating Mr. Mews the cat, to his DemoDog final state we see in the finale. That life cycle is far too rapid for Dart to be the original slug. Also, more DemoDogs show up, presumably from feeding on/growing out off dead animals in the graveyard section of the tunnels, so if they can evolve as quickly as Dart, they presumably were slugs at about the same time as Dart would have been.

When the Demogorgon is introduced in the Astral Space of season one, it’s feeding on a yellow egg before Eleven makes contact with it. Later, when Hopper and Joyce Byers enter the Upside Down to get Will, Hopper stumbles across another one of these eggs. Season 2 is pretty explicit in its use of montage in telling us that the slug that went down the sink in the season one finale was the first stage of the Pollywog lifecycle, that eventually ends in a DemoDog. Dustin suggests that if the DemoDog kept shedding its skin in stages, it could become a full-sized Demogorgon.

What is interesting about Dart is that it acts more like an animal than a mindless virus extension. If Dart can be trained with nougat treats, that suggests it has a thought process independent of the Mind Flayer’s influence. This season, the DemoDogs and the tentacles were all connected to the main threat, but we don’t know if that applies to all Demogorgons or just to the ones that fell under the Mind Flayer’s thrall for his plan to cross over into Hawkins. The last Demogorgon found Hawkins through the gate Eleven opened, but didn’t exclusively need that gate like the Mind Flayer needed a portal to cross over. The Demogorgon species eats and reproduces with slug, but it also exists separately from the Mind Flayer’s virus and the eggs.

We still don’t know a lot about why the Upside Down exists and why it’s inhabited by strange creatures while looking like a run-down version of a human-inhabited city, but the Demogorgon life-cycle has the efficiency of a xenomorph from Alien, and you know what that means: someone could try to weaponize it.

Kali (Eight) and Eleven in Stranger Things 2

Season 2's seventh episode hints at an X-Men-like Season 3

There are a few dangling threads left hanging out there in the episode "Chapter 7: The Lost Sister," but most people who binged watched Season 2 can tell you that the it felt like an episode from a completely different series. Taking the action out of Hawkins, Eleven meets Eight (Kali) and her band of misfits that have been travelling around killing people involved in the MK Ultra experiments. Not only that, but the person they happen to attack thanks to Eleven’s tracking abilities suggests that Doctor Brenner (“Papa”) is still alive and survived the Demogorgon jumping on him in Season 1.

Eleven decides she needs to help her friends and ditches Kali, but the seeds for the third season are planted: there are more psychic kids out there and the person responsible for making them is still at large, motivations unknown.  Let’s make the assumption that the children were numbered by age at Hawkins Lab, which means One -- whomever it is -- could end up being Terry Ives, Eleven's biological mother, or it could be a child that has since grown into adulthood. Maybe One died. Somehow, by experimenting with pregnant women and children, Brenner unlocked several psychic powers that he intended to use. Now, those children are all rebelling, at least whichever other kids are alive.

The only bad part about there being multiple MK Ultra kids running around the world is that Stranger Things thrives in Hawkins with the main kids. Shifting Eleven to Chicago, or if they send her elsewhere in the 1980s world to find other sisters and brothers, is going to feel just as weird as "The Lost Sister" did. However, that doesn’t mean the show isn't setting up for a battle between psychic kids and Brenner. If the government scientist lived, and he continues his work, we could end up with a Kali/Eleven against other sisters showdown, who knows?

Well, Murray, the investigator hired by Barb’s parents (and who closes down Hawkins Labs) would. Netflix's official Stranger Things aftershow suggested that Murray has a backstory that we don’t get to in Season 2, and maybe Season 3 is his time to take what he knows about Hawkins experiments and find the other psy-ops kids.

terry ives eleven's mom stranger things

The missing information on Eleven's mother, Terry Ives

In the first season of Stranger Things, electricity and activity in the Upside Down were linked. Lights were how Will was able to communicate with Joyce from the Upside Down version of their house, and flickering lights were the warning that the Demogrogan was about to cross over into the real dimension… which is why the lack of lights as an indicator this season was so unexpected. We only get one light-centric trick, and it happens with Eleven visits her near-comatose mother, Terry Ives. The lights in the Ives house start blinking, leading Eleven back to the room where Terry watches TV (Family Feud, har har), then the TV goes to static and we see Terry’s nose bleeding. Eleven says that she “wants to talk” and meets her in the Astral Plane to downloaded the origin story directly into her brain.

That has nothing to do with the lights. We don’t know what (if any) powers Terry manifested during the MK Ultra program, but the connection between Eleven’s powers and light have always included the Upside Down. Eleven can make bright lights everywhere shine as she focuses on closing the gate, but lights don’t go crazy all over town when she uses her power to murder a squirrel or move a train car. As far as the in-context clues the show gives us about how lights react to the supernatural, it’s always had to do with the Upside Down, not psychic activity.

If Terry Ives can lead Eleven through the Ives house using lights that can change power...that would suggest that Terry, or part of Terry is in the Upside Down, which would suggest that the Upside Down has at least existed since Eleven was born. Terry’s physical body is in the real world, and she’s able to communicate on the Astral Plane thanks to her MK Ultra powers, but that light stuff… it's very curious.

brenner stranger things 2

A Season 3 with Russian involvement

Stranger Things can’t be done with the Upside Down. Even if we take a season off to deal with X-Kids, the very concept of the series is intertwined with the dimension designed to bring Dungeon & Dragons monsters to life. The red-herring (like Clue suggests in all of its endings) is Communism -- the Red Threat that drives scientists to do evil things. Trying to spy on the Russians is the reason Eleven exists. Keeping the gate a secret from the Russians is what Paul Reiser’s scientist uses as a pretext for threatening Nancy and Jonathan.

Although the original Red Dawn came out in 1984 and would be a reference point for this series chronologically, Russia would be a very convenient way to bring the Upside Down conversation back to a Hawkins that now has no more nefarious lab. With the current political landscape littered with questions about modern Russia, revisiting Cold War hysteria won’t feel as dry and anachronistic as it might have a few years ago. Russia could be the big red storm that was hinted at early on in Season 2, and just imagine what would those crazy Ruskies do with a Mind Flayer.

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Dave Gonzales is a pop-culture writer and podcaster who is fully invested in the prairie dog statue theory. Follow him @da7e.