On the list of characters I'd genuinely like to see come back from the dead on Stranger Things, Matthew Modine's Dr. Martin Brenner is far from number one. (That would be Barb, thank you.) But there's no denying that Dr. Brenner returning in Stranger Things Season 4 would make for some excellent TV, even if it wouldn't be so excellent for Eleven. And given that co-creator Matt Duffer pretty much confirmed to IGN months before Season 2 premiered that we'd be seeing the scientist again, Brenner is poised for a comeback.

Modine only added fuel to the Brenner fire when he tweeted out the Stranger Things Season 4 announcement with the words "Ding dong." So if it's true that this witch isn't dead, here are some very from Russia with love-themed theories about how the show could bring him back.

1. He Fled To Russia

After somehow escaping the Demogorgon, Dr. Brenner couldn't go back to his old experiments... at least not in the good 'ole U.S. of A. User CSEnzley on Reddit proposed that Brenner went to the USSR to continue his work with the Upside Down. Brenner's involvement could even explain how the Russians learned about the alternate dimension in the first place, how they were able to progress with their Keys so quickly, and how they knew about Hawkins.

Gizwizard on Reddit also has a similar theory that Brenner is now the mastermind behind the Russians' experiments and he's the reason why "the American" (in this theory, Hopper) isn't fed to the Demogorgon.

2. He Is "The American"

Immediately after Season 3 dropped, HouseHeisenb3rg on Reddit came up with the very popular theory that Brenner was indeed "The American" referenced in the third season mid-credits scene at the Kamchatka prison since Hopper seemed a bit too obvious.

Though their theory that Hopper is stuck in the Upside Down is most likely debunked after the Season 4 teaser showed Hopper is indeed imprisoned in Russia, it doesn't mean Brenner couldn't be another American being held in that very same Kamchatka prison.

3. He's Helping The Russians Destroy Eleven

The Russians are pretty pissed that their plan to open the Gate at the Starcourt Mall was thwarted by Eleven and her supernatural abilities. User ekdig17 on Reddit wondered if Season 4 will show the Russians intent on destroying Eleven. And what better person to help them take on Eleven's abilities (shh, the Russians don't know she doesn't have them currently) than Dr. Brenner?

His early experiments helped young Jane channel her psychokinetic abilities and make her so powerful, so the Russians could be holding him hostage to learn more about El. Or, depending just how evil Brenner continues to be, maybe he's doing so willingly.

4. He's Creating Another Eleven For The Russians Near Chernobyl

While the leading theory is that Brenner is in Kamchatka near Hopper, Redditor yourmumsnightmare has another idea. They theorize that Brenner is experimenting near the Chernobyl power plant in Ukraine. With Stranger Things headed to the Soviet Union right around the time of the nuclear disaster in 1986, fans have been wondering if Chernobyl may play a part in Season 4. (Though, it should be noted that Chernobyl and Kamchatka are thousands of miles apart from one another.)

Yourmumsnightmare's theory is that Brenner is creating another person (or people) with telekinetic powers for the Russians at Chernobyl. Eleven goes to Russia to save Hopper and when she gets wind of what Brenner is doing, she heads to Chernobyl to meet a possible Experiment Twelve. Unfortunately, their meet-up leads to a battle with their psychokinetic powers that causes the nuclear explosion.

5. He Created The Mind Flayer

What if Dr. Brenner had already been familiar with Russia because he is Russian? PegasusCoconut wonders if Brenner was born in Russia and, as a child in the post-WWII Cold War, had been a test subject with superpowers much like Eleven. According to their theory, the Russian scientists were unable to contain Baby Brenner's powers so they found a way to separate the supernatural abilities from the boy, but the powers manifested into what would become the Mind Flayer and the Upside Down.

In this way, the Mind Flayer is part Brenner, and all of Brenner's efforts with the Upside Down have been the test experiment-turned-scientist trying to get his own powers back.

6. The Doc Is A Demogorgon

Matthew Modine's Dr. Brenner was very much a human in Season 1, but SnooDoodles8000 on Reddit wonders if instead of the Demogorgon killing Brenner, it somehow experimented on him and turned him into a Demogorgon. (It makes sense that the Demogorgon would want to get some revenge on the good doctor, since he was always meddling with its home in the Upside Down.)

And perhaps, through these experiments, Dr. Brenner became an official resident of the Upside Down. If that happened, this villain might really be unstoppable with SnooDoodles8000 going on to wonder if the Russians had opened the Gate to get Demogorgon Dr. Brenner out so that they could learn how to turn people into Demogorgons.

7. He'd Be The Mind Flayer's Ultimate Host

Rather than Brenner somehow being a human-Demogorgon hybrid, he could end up the host of the Mind Flayer, like Billy in Season 3. Achakabalakoy on Reddit notes if this happened, Brenner "could be one of the most powerful host[s]" due to his connection with El. Since the Mind Flayer seems consumed with killing Eleven and Dr. Brenner was her "Papa" that helped create her, this combo of Dr. Brenner as the Mind Flayer's host could threaten to destroy her.

8. Hopper Will Kill Brenner

While it might be very cathartic to see Eleven kill Brenner, I don't really want her to do something as traumatizing as killing her "Papa." Instead, Reddit user DangerVipe wonders if Hopper will kill Brenner in Russia. They think Brenner will be exposed at the Russian mastermind toward the end of the season and Hopper takes him down as only El's true father can. Don't mess with Jim, indeed.

Brenner's Russian comeback seems inevitable (though there's always a chance he could still be hanging 'round Hawkins or living wherever the Byers family has just moved to). And with Brenner's return, not only will El (hopefully) get closure, but we might just get more insight into the rest of his test subjects.

Images: Netflix