What Is The Upside Down? The Wormhole In ‘Stranger Things’ Season 5 Explained

Warning: Spoilers ahead for Stranger Things Season 5, Volume 2.

Stranger Things Season 5, Volume 2 finally offered fans an explanation for the mysterious Upside Down, which had long been believed to be an eerie parallel universe of Hawkins filled with monsters, deadly vines and evil entities like the Mind Flayer and Vecna. But it turns out the Upside Down is something else entirely — and far worse.

In Vol. 2, Nancy, Jonathan, Dustin and Steve embark on a side quest into the Upside Down while searching for Nancy’s younger sister, Holly, one of the children taken by Vecna in Volume 1. While they’re there, they encounter a massive flesh wall surrounding Hawkins and initially believe Holly is trapped on the other side.

ForbesEverything To Know About ‘Stranger Things’ Season 5, Volume 2By Monica Mercuri

What Is Dustin’s Theory About The Flesh Wall In The Upside Down?

Dustin theorizes that they can’t penetrate the flesh wall because Vecna created a magical shield using dark magic (similar to Death Star II’s shield in 1983’s Star Wars: Return of the Jedi). Believing the source of that shield is somewhere inside Hawkins Lab, the group goes there to find it and barely makes it out alive after Dustin’s theory turns out to be very wrong.

Dustin comes across Dr. Brenner’s old journals and discovers that Vecna did not create the sphere; science did. The barrier is formed by exotic matter that’s keeping the Upside Down together, meaning Vecna, Holly, or anyone can’t be behind it.

Nancy and Jonathan reach the roof of Hawkins Lab just as Dustin makes his discovery. Still believing it’s a barrier, Nancy shoots the matter, triggering a sonic blast that sucks everything in the wall’s path into a void, including Steve’s beloved Beamer. She seriously disturbs the sphere but, thankfully, doesn’t destroy it to the point where the entire world is pulled in.

What Is The Upside Down In Stranger Things?

After dissecting Dr. Brenner’s journals, Dustin informs the entire crew back in Hawkins that the Upside Down is not its own world or dimension. Instead, it’s a wormhole, serving as a bridge to another world that Dustin calls the Abyss.

Ross Duffer told Deadline that they’ve known the Upside Down was a wormhole from the very beginning, adding that “it’s one thing to say it, and it’s another to try to figure out how to visualize such an abstract concept.”

The wormhole has a distinct hourglass shape, which viewers finally see on screen. Dustin later draws a diagram of the wormhole, the same illustration the Duffer Brothers used to pitch the concept to producer Shawn Levy ahead of Season 5.

“They drew this same diagram because they knew intuitively before they’d even written a word of a script that we as an audience would need help,” Levy revealed to Netflix’s Tudum.

What Is The Abyss?

The Abyss is an alternate dimension named after the realm of pure chaos and evil in Dungeons & Dragons. It’s located on the other side of the Upside Down wormhole.

Netflix describes the Abyss as a Mars-like landscape with “steep canyons and sharp rocks.” Fans get a glimpse of it after Holly briefly escapes Vecna’s lair and runs into the deserted world. Red rifts connect the landscape to the Upside Down, and she slides into one before Vecna captures her again.

The Abyss is where the show’s terrifying predatory creatures, including Demodogs, Demogorgons, Demobats, as well as the Mind Flayer and Vecna, actually live, helping explain why the group has always had so much trouble finding them in the Upside Down. It’s also where Vecna is keeping Holly and the other missing children, who are trapped within the spires of the ominous Pain Tree.

How Did Vecna End Up In The Abyss?

While it was first assumed that Eleven banished Henry Creel to the Upside Down, as seen in the Season 4 flashback, she actually sent him to the Abyss. Dustin explains that Henry would have “remained lost” if Dr. Brenner had not forced Eleven to find him. When Eleven made remote contact with the Abyss, the Upside Down was created, which Henry and his monsters have since been using to enter Hawkins.

The Abyss could be the same thing or very closely related to Dimension X, which was introduced in the Stranger Things play The First Shadow. The play reveals that, on his eighth birthday, Henry wandered into a cave in Nevada, a memory that is briefly shown when Holly and Max attempt to escape Vecna’s mind in Volume 2.

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Inside the cave was stolen government technology that had been used to replicate a World War II experiment that sent a battleship to another dimension. Henry was pulled into that realm, where he encountered the Mind Flayer for the first time. The experience altered both his personality and his blood type, leaving Henry permanently connected to Dimension X.

What Is The Plan To Defeat Vecna And Close The Wormhole?

At the end of Stranger Things Season 5, Volume 2, the team reunites to come up with a plan to stop Vecna once and for all. But doing so proves trickier than expected, largely because they need to reach 2,000 feet in the air, free Holly and the other captured children, and defeat Vecna before the worlds merge for good.

Steve comes up with the winning idea, dubbed “Operation Beanstalk,” which becomes the group’s most promising option for saving the world. Because the Abyss exists in the sky, the only way to access it is by reaching it through the Upside Down. Steve suggests allowing Vecna to continue drawing the worlds together, but only until the Squawk radio tower pierces one of the rifts.

That’s when Eleven would make her move, entering Vecna’s mind to ambush him. Steve explains that doing so would halt the worlds’ movement and create a “beanstalk” the group could climb to reach the Abyss and rescue Holly and the other children. Nancy adds that Eleven could use the bath at Hawkins Lab in the Upside Down, located directly beneath Vecna’s lair, to establish a stronger connection to him.

Max also volunteers to guide Eleven through Henry’s mind, having been trapped there for two years and knowing it better than anyone. Kali says she wants to follow Eleven into his mind as well to help defeat their brother. Before escaping the Upside Down, the group plans to plant a bomb near the exotic matter, set a timer and get out. The explosion is meant to collapse the bridge entirely, taking the Abyss, Vecna, the Mind Flayer and all of the creatures with it.

Kali later tells Eleven that the only way to end the military’s cycle of hunting her down and stealing her blood may be for both of them to remain on the bridge when it explodes, meaning they would be gone forever, too. It’s still unclear whether Kali’s motives are genuine; after all, she has the power of illusion, and Hopper has a bad feeling about her.

Stranger Things Season 5, Volumes 1 and 2 are now streaming on Netflix. The supersized series finale will premiere on the platform on Wednesday, Dec. 31 (New Year’s Eve), at 8 p.m. ET / 5 p.m. PT.