Here’s an illustrated view of how the Upside Down became one of tv's most terrifying alternate dimensions.
As the show progresses, parallels between elements of Dungeons & Dragons and the Upside Down become increasingly apparent.
Come season 2, Hawkins seems relatively peaceful, and heading back to some semblance of normality. Except for Will, that is. Emotionally and mentally scarred from his ordeal, Will’s everyday life is interrupted with stark, vivid flashes of the Upside Down and its "Queen" the Mind Flayer.
As was the norm in the 1980s, it’s the power-hungry Russians who are front and centre of the story here. After a failed test in their home land, they plot a course for Hawkins to utilise their latest piece of technology: a giant machine that can channel enough energy to slowly re-open the gate to the Upside Down.
Read the rest of the detailed breakdown of the progression of the upside down here