The nature of the Upside Down has been one of the biggest mysteries of Stranger Things. Even as the characters have become pros at navigating the parallel universe, they still don’t know much about it. That changes in season 5’s Christmas Eve batch of episodes, when a trip to the Upside Down version of Hawkins Lab gives Dustin (Gaten Matarazzo) a lot more information. Like so many of the characters in the show, he explains what he learned to his friends by putting it in terms borrowed from Dungeons & Dragons.
[Ed. note: This article contains major spoilers for Stranger Things season 5, volume 2]
The first hint about the true nature of the Upside Down comes in season 5, episode 3, “The Turnbow Trap,” when the Party enlists Erica Sinclair (Priah Ferguson) for help in their ridiculous kidnapping scheme. Erica is annoyed because she’s enjoying her science class, where Mr. Clarke (Randy Havens) is explaining the nature of wormholes, which allow matter to cross galaxies or dimensions without crossing the space between. As is the case pretty much anytime a teacher gives a lesson in a TV show or movie, this is very plot relevant.
When Dustin discovers that the Upside Down is surrounded by a wall that forms a circle centered on Hawkins Lab, he initially posits that the group will find a sort of shield generator there that they can destroy to remove the wall and find Vecna (Jamie Campbell Bower). But instead he finds a book full of scientific notes from the lab’s leader Dr. Brenner (Matthew Modine). Brenner’s notes explain that the Upside Down is a wormhole connecting Hawkins, Indiana to another dimension. Dustin dubs that world “the Abyss” because in D&D, it is “a realm of pure chaos and evil.”
Hopper (David Harbor) is less than enthusiastic about yet another D&D reference, and if you share his exasperation, we’re here to help. Dungeons & Dragons is part of a multiverse that includes multiple campaign settings like Ravenloft and the Forgotten Realms but also many worlds that are inhospitable to human life like the Plane of Fire and the Nine Hells. The Abyss is a particularly fitting name for the world Hawkins is connected to because it’s the home of demons, including the demon lord Demogorgon.
Like so many of the reveals in this season, the true nature of the Upside Down was also hinted at in the stage show Stranger Things: The First Shadow, which opens with a US Navy ship briefly traveling to another world dubbed Dimension X. Ross Duffer told Polygon earlier this month that the nature of the Upside Down as a bridge to another dimension dates back to a season 1 mythology document.
“It wasn’t called the Abyss back then,” Duffer said. “I think the placeholder name was Dimension X, which is a Teenage Mutant Ninja Turtles reference. [The brainlike alien Krang comes from Dimension X.] We were originally planning to reveal this in season 2, but then season 2 just became too many ideas. So we just kept sort of kicking the can down the road, but it feels kind of appropriate that we finally revealed this in the final season.”
Henry gained his powers and connection with the Abyss after being exposed to materials stolen from Brenner’s lab in Nevada. Brenner then used Henry’s blood to create numerous other psychic kids, including Eleven (Millie Bobbie Brown). After Henry massacred most of them, Eleven banished him to the Abyss, where the twisted realm transformed him into his current appearance. When Brenner later forced Eleven to make psychic contact with Vecna, the connection created the Upside Down and allowed Vecna to begin exerting influence over Hawkins, starting with abducting Will Byers.
Vecna’s plan is to fuse the Abyss and Hawkins, and he’s been working on it for years by building connections between the two dimensions, opening rifts through psychically killing people and abducting more psychically sensitive children to help with his final push. This is an extremely D&D plot. Out of the Abyss, one of the first campaigns released for D&D 5th edition, features Demogorgon and other demon lords invading the underground realm of the Underdark. The 2024 Dungeon Master’s Guide explains that the corrupting power of the Abyss is so great that if a portal is opened to the plane, it can taint the area around it and draw it into the plane.
Journeying to the Abyss is extremely dangerous as it’s infested by demons and the realm itself is harmful to mortal beings. It’s the sort of adventure only recommended for high level heroes, who could finish a long-running campaign by making a last stand against an implacable evil to save the world. It’s a fitting place for Stranger Things to end, with the characters using all of their experience to go into battle one last time.
The first seven episodes of Stranger Things season 5 are available to stream on Netflix now, with the finale airing on New Year’s Eve.
