[This article contains spoilers for Stranger Things Season 2]

Stranger Things creators Ross and Matt Duffer say that they themselves have actually mapped out the workings of the Upside Down, the terrifying alternate dimension that keeps causing so many problems for the series' characters, but there's a chance they may never fully reveal its nature to viewers. A Lovecraftian other world that exists alongside our own and can occasionally be entered through portals, the Upside Down looks like our reality but is in some advanced state of decay, the air swirling with ash and everything encrusted with strange rotten-looking vegetation and other forms of slime.

The Upside Down was where Will Byers ended up in Stranger Things season 1 after his disappearance and was where poor Barb was taken to meet her demise at the hands of the show's main monster, the Demogorgon. Stranger Things season 2 (now on Netflix) returns to the Upside Down in a big way, plunging Will straight back into the nightmare world and bringing him face-to-face with the show's most horrific creation yet, a hulking multi-limbed shadow creature that takes possession of his body. Stranger Things 2 also introduces us to the Demo-dog, another denizen of the Upside Down who escapes into our world and begins doing nasty things.

Though season 2 goes a lot further in developing the workings of the Upside Down and some of the creatures who dwell there, there are still many mysteries to be discovered. However, in an interview with THR, the Duffer Brothers indicated that they may ultimately keep a lot of those mysteries to themselves. Ross Duffer explained:

"It's a balancing act. If you tell too much, it loses a little bit of that mystery. We obviously will shed more light on it moving forward, but we want to do it a little bit at a time. Even at the end, I don't think we're going to answer all of those questions, and I don't think we even necessarily need to. We're telling this story from the point of view of very human characters. There's no way they can ever truly fully understand this place. We have our Upside Down document which describes its rules and its mythology in quite a bit of detail, but I think we're just going to slowly parse that out, and maybe not even fully use all of it. Our favorite thing to do on this show is that these characters, especially the kids, are able to make these leaps about the Mind Flayer and how it operates and what it wants, but they're just basing this off of games that they've played. They don't really know for sure. There's really no way for them to fully understand it. In real life, you wouldn't be able to fully understand this entity from another place. You could never fully understand its motivations. That, to us, is scarier than knowing exactly what it wants."

Season 2 ends with an image that promises the Mind Flayer - named after a Dungeons & Dragons character that can control people's minds - is not yet done making life miserable for the (mostly) good people of Hawkins. As a means of supplying the series with Lovecraftian baddies, the Upside Down is a useful conceit that the Duffer Brothers are obviously in no hurry to abandon. They also clearly understand the potential danger of revealing too much about the workings of the Upside Down and killing the mystery.

The Upside Down works also as a metaphor for every inexpressible fear, every childhood demon that refuses to stop haunting us. That metaphor works much better if the universe remains this place that is always just beyond reach, operating under its own impossible-to-grasp nightmare logic. As the show continues and Netflix keeps inevitably upping the budget, there may be a temptation to go back to the Upside Down with greater frequency and try to visualize its horrors in more shiny, vivid CGI detail. It seems that, for the time being, the Duffer Brothers are resistant to the idea of over-explaining the Upside Down, and wish to remain true to their original, elusive, classically Lovecraftian concept.

MORE: Stranger Things Still Has A Timeline Problem

Source: THR