The finale of Stranger Things is upon us. That's a decade of television that has been building to this moment, as one of the most larger-than-life shows of all time - one of the last truly 'event TV shows' - prepares to come to an end. To say it's a bittersweet moment in TV history would be an understatement. But, as we've come to expect from this show, Netflix is making sure that it does so in as large a scale way as it possibly can, with a final episode that will run for two hours (and also release in select US movie theaters).
Needless to say, there will be all kinds of thoughts and feelings about the upcoming episode. Titled "The Rightside Up", it will see Eleven, Will, Mike, Hopper, Nancy, Dustin, Steve, Joyce, Robin, Jonathan, Lucas, Erica, and the rest of the gang venture into the Upside Down to take on Vecna one more time. The villain plans to launch an all-out assault on the real world one more time, bringing his dimension - otherwise known as The Abyss - crashing into it.
However, as curiosity around the super-sized final episode continues to result in an abundance of fan theories, audiences are now convinced that they know a number of major elements from the finale before the episode has even released.
The Mind Flayer will resurface as the show's true Big Bad
While our gang is bravely going to confront Vecna to stop him from destroying the world, it's clear that they are convinced that he is the actual main threat that they need to worry about. But the truth is that there is another bigger - and potentially badder - threat out there that they seem to have forgotten about: The Mind Flayer.
Stranger Things 5 Volume 2 may have hinted at the creature's dark fate, as Vecna's new "castle" is shaped like a dead spider on its back - something that fans thought might signify that the Mind Flayer died in The Abyss, potentially explaining why Vecna has taken over as the big bad of the show from season 4 onwards. But it might actually be the opposite.
Vecna's new lair may look like an apocalyptic cave, but the teeth within its walls might actually be a sign of life. Something else that might be a sign of life? The beating heart above the villain, which is seeemingly connected to the children that the evil creature took from Hawkins - the same children who our heroes couldn't figure out exactly why they were chosen. Nobody knows what Vecna's true plan is, but this theory might have just figured it out.
See, what if the children are required to create a surge of power in the Hive Mind, ultimately powering up this cave so that it can be used as a body - beating heart and all - for the Mind Flayer. The creature still exists in its shadowy particles form, but it might need a solid body in order to escape The Abyss and make its way into the real world. Could Vecna be using the children to heighten the power of the Hive Mind - in the same way that taking Will all those years ago created a strong connection to it?
Vecna may have been presented as the ultimate evil in recent seasons, but we now know that he was infected by shadow particles in the 1950s - long before the Hawkins Lab Massacre in 1979/ That would suggest that the Mind Flayer is far older than he is, and therefore the ultimate threat of the Abyss and the Upside Down. Perhaps he just needed a more human general to enact the psychic element of his plans.
Will used the word "vessel" when describing Vecna's need for the children to his friends, so it's quite possible that these kids - including Holly Wheeler and Derek Turbow - are simply vessels to power up the Hive Mind and give the Mind Flayer its ultimate body. If that's the case, our heroes are walking into a much more complicated plot than they know - and they could end up facing the darkest, creepiest, and most terrifying threat of all in The Abyss / The Upside Down - one that just so happens to be an old enemy, too.
Eleven will stay behind in The Abyss / The Upside Down
Another element of this theory is that Eleven will ultimately stay behind when the battle is done, allowing the gates to The Abyss and The Upside Down to close forever, along with her chances of a normal life. It would be a tragic spin on the story as it was Eleven who opened some of the first gates to the Upside Down / The Abyss, allowing for that first Demogorgon to break through back in the first season of Stranger Things.
On one hand, this wouldn't be that surprising as Kali, a.k.a. Eight, has been attempting to convince her to do that. However, fans are also convinced that "The Lost Sister" is actually attempting to manipulate Eleven into facing death, potentially even suggesting that she is also working for the Mind Flayer. Yes, fans believe that Kali is evil - maybe not in real life, but this version of her at least. And therefore, Eleven may end up defeating her but still ultimately agreeing to stay behind in the world that will inevitably collapse.
That being said, this would be a divisive ending as, after all Eleven and Mike have been through, they deserve to get their happy ending in a place with waterfalls - just as they spoke about in the season 5 premiere. Furthermore, the show already played similar story beats after the season 1 finale, which saw Eleven seemingly transported to the Upside Down after defeating the Demorgorgon, leaving Mike, Dustin, Will, and Lucas to think that she actually died in the battle. Repeating that in the series finale - especially when a happy ending was in touching distance for them - would be a disappointment.
Everyone else will survive (except the villains)
Stranger Things has such a large cast that, anytime they face danger head-on, there is always the fear that one of the beloved characters won't make it out alive. It is a lingering thought ahead of the series finale, but there is also a lot of evidence to suggest that this won't happen.
In the past, major deaths on Stranger Things tended to be specific to characters who were involved in those particular seasons. Bob Newby, a major addition of season 2, died in the season's penultimate episode when he was attacked by a group of Demodogs after successfully ensuring everyone else escaped. Billy Hargrove, who took center stage in season 3 after a recurring role in season 2, died when he stood up to the Mind Flayer. And Eddie Munson, who took on an army of Demobats in his debut season (playing his guitar, no less!), ultimately succumbed to his injuries in the season 4 finale.
The Duffer Brothers have suggested that there is less of a need for a major death in the finale as the characters have already been through so much. While that doesn't inherently rule out a major death, it does make it significantly less likely - because it would be hard to wrap up the aftermath of that (even if the epilogue is 40 minutes long!). So, with Eleven potentially sacrificing her freedom in The Abyss, it's likely that there won't be a need for another kind of sacrifice.
That won't be enough to ensure the villains survive, however. It's probably a foregone conclusion at this point that Vecna, The Mind Flayer, Dr. Kay, and the rest of the corrupt military soldiers will meet their end before the credits roll on the finale. Don't be surprised if some Demogorgons, Demodogs, Demobats, or even Vecna himself have their way with the military!
Honestly, this is a pretty convincing theory so it's hard to argue with fans' determination to prove this one correct. We won't have to wait too much longer to find out if that's it's correct!
The Stranger Things 5 finale will air on Netflix (and in select US theaters) on December 31, 2025 (and in many international regions on January 1, 2026).