Stranger Things Season 5 Volume II finally shed some light on the Upside Down in the third act of the fifth episode. We finally learn what it is in the next episode: a wormhole, not an alternate dimension. Dustin describes the Upside Down like this to Steve: "It’s a wormhole. A bridge between two points in time and space”. Dustin also reveals that Henry/Vecna is not holding the kids hostage in the Upside Down.Vecna is holding the kids hostage in the world, the Upside Down links the Earth with, dubbed "the Abyss". Not much is known about the Abyss, but we do catch its glimpse in the Stranger Things Season 5 Volume II Episode 7, "Chapter Seven: The Bridge". Also, the penultimate episode featured reunions and the heroes finally learning the true nature of the Upside Down.What is the Abyss in Stranger Things Season 5 Volume II? View this post on Instagram Instagram PostFor a decade, fans thought that the Upside Down was an alternate dimension, and even the characters in the series described it as such. However, Stranger Things Season 5 Volume II finally reveals the true nature as a wormhole. It is a bridge between the Earth and an unknown planet called "the Abyss", the realm of pure chaos and evil in Dungeons & Dragons.Matt Duffer cited Bridge on the River Kwai (1957) as the inspiration behind the revelation that the Upside Down serves as a bridge between two worlds:“We love the film Bridge on the River Kwai. The idea in that film is they need to blow up this bridge. It’s a major military goal. So we thought the idea of a supernatural version of that, where … our characters ultimately need to blow up this ‘bridge’ that connects Hawkins to an evil dimension was a really cool goal and something we hadn’t seen before. That was something we’d been working toward for a couple years.”We see a small portion of "the Abyss" in the penultimate Stranger Things Season 5 Volume II episode twice: once Holly escapes captivity, and the second time when Vecna takes her back as a hostage. The seventh episode ends with Vecna preparing to merge The Abyss with the Earth as the heroes strategize to let it happen to get close to Henry to kill him and end this battle once and for all.Jamie Campbell Bower calls the Stranger Things Season 5 finale "explosive": View this post on Instagram Instagram PostJamie Campbell Bower sat down for an interview with Deadline after Stranger Things Season 5 Volume II streamed on Netflix. He discussed various revelations in that interview. But just before concluding the interview, the interviewer asked Bower what he hoped people took from Vecna after the finale. To this, the actor replied:"So with regards to what we can expect for the finale, I am genuinely, really excited for Episode 8 to come out. I feel like Episode 7 is — because I obviously know what’s coming in 8, and we do leave on quite, in my opinion, knowing what’s coming, quite a hefty cliffhanger, and 8 comes in steaming hot, right off the back of 7. It’s go time. It’s really, really explosive. I’m really excited for people to see that, because I know how it felt to work on it, too, and that’s really cool. What do I hope people take away from this character? Wow, I’m still in process on that. Like, I’m genuinely still in process on that, because I spent so much time in it, and I don’t know if I can yet see the wood from the trees. I’m not sure. So much of this character is based on the idea of loneliness. So much of this character is based on the idea of salvation. I had to fall in love, and I did fall in love with Henry Creel. I had to want to protect him. I had to want to nurture him and love him, because that’s my duty as the person that’s playing him. I have to understand him, and I don’t know how it feels to be a viewer, yet, watching that from afar, I don’t know. I’d have to give myself another six months to truly be able to absorb that."The finale releases next week on December 31, 2025. Binge the three Stranger Things Season 5 Volume II episodes on Netflix before that.