The Upside Down is one of the biggest mysteries in Stranger Things, as not even the characters in the series know much about it, but a fan theory explores an idea of how the other dimension works, which explains how Billy’s car appeared there at the same time he did, and how everything else is the same as in the real world. As viewers wait for season 4 of Stranger Things, it’s a good moment to look back at some of the biggest mysteries the series has left so far, among those everything related to the Upside Down.
Stranger Things season 1 introduced viewers to the fictional town of Hawkins, Indiana, and some of the weird events that happen there. Will Byers’ disappearance unveiled all the dangerous experiments that were taking place at Hawkins Lab, of which one opened a gate to another dimension. Named “the Upside Down” by the kids in the series, this dimension looks like the real world but in a state of decay, and it has all the buildings, cars, and other objects as the human dimension.
Season 2 saw the Upside Down beginning to take over the real world, and season 3 didn’t do much to explore it more. Naturally, this has left a lot of questions about how it was created, how it works, and more, and a fan theory might have the answer to one of those questions.
Stranger Things Theory: How Objects Appear In The Upside Down
The Upside Down is a dark copy of the human world: it’s cold, with an omnipresent fog with ash-like spores floating in the air, and the atmosphere is toxic to humans after prolonged exposure. It has the same locations and infrastructure as well, but they’re all covered with root-like tendrils and membranes. The only forms of life known to exist in that world are the Demogorgon and the Mind Flayer, so how the buildings and cars appear there is a mystery, just like Billy’s car in season 3. When he was attacked by the Mind Flayer, he was taken to the Upside Down all of a sudden (like Will in season 2), and his car appeared there too.
This made some fans question how is it possible that the car appeared there along with Billy, as there surely aren’t people or other creatures in that dimension driving cars and building houses. A Reddit user suggests the Upside Down, more than a mirror, is a snapshot, and when a person enters that dimension, it looks exactly as it did when they left the real world. Billy’s car, then, was right there because that’s where it was in the human world when he was transported to the Upside Down, and it’s also why Castle Byers existed there (among many other things). Details on Stranger Things season 4 haven’t been revealed, but hopefully, it will take some time to properly explain the Upside Down and finally solve the many questions there are about it.