The fourth season of "Stranger Things" seemingly introduces the most powerful villain we've met so far: Vecna, a deadly monster from the Upside Down. But Vecna isn't just any interdimensional baddie - he used to be One, another test subject like Eleven in the lab run by Dr. Brenner. While the show has made it clear that Vecna is "Stranger Things"'s new main baddie, we can't help but keep an eye on Dr. Brenner, who's back after inexplicably surviving a brush with the Demogorgon. In some ways, Dr. Brenner actually might be the baddest of them all, so let's take a closer look at the evidence (and theories) so far.
Does Dr. Brenner Have Powers in "Stranger Things"?
Even as we learn more and more about the backstory of the lab where Eleven and her "siblings" originated, we still know remarkably little about the mad scientist she called "Papa." A lot of questions remain about who he is, how he got involved with the project, and how he's managed to survive all the dangers and near-death experiences working with these superpowered kids has brought upon him. Is it possible that he has powers of his own, and that's how he has stayed alive through all of it?
We can't help wondering about the details of Dr. Brenner's "work" with the kids in the lab. Did he "give" them powers simply through sheer mad-science experimentation, or was he able to give them superpowers because he already had a head start from having powers of his own? Dr. Brenner having powers would also explain a lot of things about his unlikely survival; we've seen him survive a Demogorgon attack and One's attack on the lab, and who knows what other "accidents" happened during his time at the lab.
One Reddit theory takes this possibility even further, positing that Dr. Brenner might be "000," or the original superpowered being. The Reddit user Jamcam007 points out that we never see the spot on Dr. Brenner's wrist where numbers would be; it's always covered by a watch. It's also worth considering in the context of the "patient zero" colloquialism traditionally used to denote the original source of something unusual. If there's a patient zero among the superpowered humans, then Dr. Brenner would definitely be an interesting possibility, although this theory doesn't seem likely at this point.
By the end of the fourth season, it appears that Dr. Brenner has no supernatural powers of his own - just the good old powers of manipulation. He's excellent at psychologically manipulating Eleven for his own ends. That manipulative behavior seems to indicate that, lacking powers of his own, he needs her power to keep pursuing his goals with the Upside Down and One.
What Is Dr. Brenner's Link to the Upside Down?
The connection between the Upside Down and the experiments - both at the lab in Hawkins and at the Russian facility - has already been made clear. Human experiments have cracked open a door to that demonic dimension, allowing monsters through. But we still don't know for sure how the Upside Down came to exist in the first place.
One possibility: Dr. Brenner is, somehow, personally responsible for the creation of the Upside Down, not just for breaking through to it. This could go one of two ways: either as part of the "Dr. Brenner has powers" theory, or simply through supernatural science experiments gone horribly wrong (or horribly right, depending on what his original intentions were). His reactions to displays of power - Eleven discovering the monsters, for instance, or even her more violent accidental uses of power - seem more awestruck than horrified, further indicating that he's getting what he wants out of his experiments. The only time he truly seems horrified is after One's killing spree - that is, after his life's work is all but destroyed.
Dr. Brenner's interest in the Upside Down could also closely connect to his interest in Eleven. It seems too unlikely that he has helped El get her powers back just because he believes it's the right thing to do. He knows how powerful she is, and he knows how powerful their enemies in the Upside Down are. Could he be trying to use El not to defeat the monsters for the good of everyone, but to take control of the Upside Down for himself?
These theories turn out to be partially right by the time the fourth season ends. It is true that Dr. Brenner has been lying to Eleven about the exact reasons for his experiments and interest in the Upside Down. The "Soviet spying" was always just a ruse - really, he's been obsessed with tracking down One in the Upside Down, heedless of the collateral damage.
He's not the one directly responsible for the creation of the Upside Down, though he is indirectly responsible because of the tormenting of his test subjects. That (dis)honor belongs to One, who finally reveals to El what really happened after she banished him to an alternate dimension. When he arrived, he found a dimension rich with untapped, supernatural potential, and he molded it to suit his purposes. The spider-like creatures from the Upside Down derive from his obsessions; the power-stealing Mind Flayer was created by One to steal El's powers so that he could build more "gates" and consume the entire dimension of the real world. Dr. Brenner didn't create the Upside Down, he just created the monster who did.
What Does Dr. Brenner's Crossword Puzzle Mean?
We all know that the "Stranger Things" writers like to hide their clues in plain sight. A pair of Reddit users zoomed in and took a closer look at Dr. Brenner's crossword puzzle from the opening minutes of season four, and it looks like there could be some relevant hints buried there.
Among the words in the puzzle are some ominous references, such as "Robespierre," famed for the Reign of Terror in revolutionary France, along with several references to Russia and the Soviets, like "Tsar" and "Eurasian." The name "Kali" also appears, aka the name of Eight, one of the surviving test subjects from the lab.
Were these meant to be hints or - as one clue in the puzzle says - just a bunch of "shams" meant to misdirect us? For the time being, it looks like many of those are clues that either are irrelevant or won't be revealed until the final season; none of the major "clues" in the crossword appear to have any relevance to the way the season wraps up. Dr. Brenner seems like he's finally out of the picture for good by the end of season four, but the devastating effects of his mad-science experiments will continue to live on as "Stranger Things" barrels towards its final act