The Abyss: Stranger Things Season 5's Upside Down Reveal Explained

This article contains spoilers for "Stranger Things" season 5, episode 7 — "Chapter Seven: The Bridge."

It took the better part of five seasons, but "Stranger Things" has finally revealed the truth about its most mysterious element. Beginning with "Chapter Six: Escape from Camazotz," season 5 dives into the truth behind the Upside Down, as well as all those previously hinted at alternate dimensions that came before this dark iteration of Hawkins. Specifically, as Dustin Henderson (Gaten Matarazzo) comes to realize over the course of the episode, the Upside Down is actually a wormhole that serves as a sort of connecting bridge between time and space. 

Indeed, it appears that this is the payoff to all those hidden clues hinting at time travel from the first half of season 5. "Chapter Seven: The Bridge" only further elaborates on the subject by having Dustin deliver a big speech in which he introduces the idea of the Abyss. The term, as Dustin explains, refers to the separate dimension that's home to the show's many strange and dangerous creatures. This is also where Jamie Campbell Bower's Vecna (love him or hate him) was banished by Eleven (Millie Bobby Brown) prior to the start of the series.

To put it another way, the Abyss is where the weirdest entities on "Stranger Things" hang their hats, while the Upside Down is merely an unstable wormhole bridge that connects the two dimensions. The problem? That same wormhole could also end up tearing everything apart, should the mysterious, so-called "Exotic Matter" that's keeping it all together fail to hold.

"Stranger Things" is fond of naming major threats after Dungeons & Dragons concepts, and the Abyss is no exception. This chaotic evil demon plane is composed of increasingly hard-to-reach dimensions that contain many and varied horrors ... as well as particularly strong entities that control said horrors. Sound familiar?

As "Stranger Things" season 5 races toward its big finale, it has a particularly good excuse to recycle D&D elements, too. After the dramatic death of his mentor, Eddie Munson (Joseph Quinn), in "Stranger Things" season 4, Dustin's affinity for D&D is greater than ever, and he sees himself as the upholder of Eddie's Hellfire Club legacy. Because of this, it's hardly surprising that he would choose to name the Abyss (itself the most horrible place in the show's universe) after one of the most hellish planes of existence that the game has to offer. And hey, there's no denying that it's a cool name, right?

"Stranger Things" season 5 is streaming on Netflix. The series finale drops December 31, 2025.