Stranger Things Finally Reveals What The Upside Down Really Is

Spoiler alert: This post discusses plot details from Stranger Things Season 5, Episode 7.

It may have taken nearly a decade, but Stranger Things has finally given fans the answer to its most central mystery. In the penultimate episode of the series, the Hawkins team is able to figure out what the Upside Down really is — and it’s not another dimension like everyone has always guessed. No, the truth is a lot more complicated than that.

Of course, it’s the science fiction-obsessed Dustin who has the epiphany. After discovering Dr. Brenner’s journals in the Upside Down version of Hawkins Lab, Dustin is able to deduce that this mysterious, red, lightning-filled realm is actually wormhole. So, it’s technically not another world itself, but rather a bridge that connects Hawkins to another world, which Dustin dubs the Abyss. Vecna lives in the Abyss, and uses the Upside Down as his portal from his dimension into Hawkins.

Dustin also uncovers how the Upside Down was created. He theorizes that when Eleven created the wormhole back when she was a child, during the moment that she banished Henry from her world to the Abyss. The Duffer Brothers confirmed Eleven did create the Upside Down in a Dec. 26 Variety interview: “Yes. The answer is yes,” Matt Duffer said. “Not her fault, I would say! She was forced to do that.”

This Upside Down explanation was teased earlier in Season 5, when Mr. Clarke was teaching Erica’s class about the properties of wormholes.

Elsewhere in the Duffer Brothers’ Variety interview, the show creators confirmed that the Upside Down being a wormhole to the Abyss was part of the series’ canon from the very start.

“That was all the way back in Season 1,” Matt said. “Netflix just wanted us to explain the mythology to them, because we were very adamant early on, ‘We don’t want to explain it in the show. We like that there’s mystery, and that there’s a lot that you don’t understand by the end of the season.’ They said, ‘That’s fine, but we would like to know.’ I think it was actually a really good exercise — we spent quite a bit of time with our writers figuring out exactly what the Upside Down was. We wrote a 20-page mythology document. It wasn’t called the Abyss at that point; it was called Dimension X, which is a Ninja Turtle reference.”

“But yeah, that’s been in there, baked in there, for a while,” Matt continued. “We’ve been holding those cards back for so long; it was a real relief to actually be able to show our hands here.”