'Stranger Things' Season 5 finally reveals the Upside Down's secret, pointing to Eleven's ultimate choice
Ever since 'Stranger Things' debuted in July 2016, one of its biggest mysteries has been the Upside Down. Throughout the show, the Upside Down is established as a parallel version of Hawkins, which was created when Eleven (Millie Bobby Brown) accidentally broke open a barrier between worlds during experiments at the Lab. However, the question remains: What is the true purpose of the Upside Down, and how will it help Vecna (Jamie Campbell Bower) achieve his twisted goals?
In 'Stranger Things' Season 5 Volume 2, episode 'The Bridge', Dustin Henderson (Gaten Matarazzo) explains that the Upside Down is actually a wormhole, an interdimensional bridge linking the real world to the realm Vecna hides in, which he calls the Abyss. This bridge is held together by unstable exotic matter above Hawkins Lab, and Vecna plans to collapse it to merge both worlds, using Holly (Nell Fisher) and the other kids. When Holly attempts to escape the Abyss and appears to fall through the Upside Down's sky, she is, in fact, falling through the wormhole itself, as per Screen Rant. Notably, 'Stranger Things' Season 4 also clarified the origins of the Upside Down.
After the 1979 Hawkins Lab massacre, Eleven banished Henry Creel (Jamie Campbell Bower) to the Abyss, where he became Vecna among creatures like the Mind Flayer and Demogorgons. Created unintentionally when Eleven made contact with a Demogorgon while searching for Henry, the Upside Down functions as a mirrored passageway frozen in 1983, allowing creatures from the Abyss, including the Mind Flayer and Demogorgons, to reach Hawkins. Exotic matter at its core holds the bridge together, and Vecna plans to collapse it to merge both worlds.
The finale of 'Stranger Things' centers on whether destroying this wormhole can end the threat for good, even if it may require Eleven's ultimate sacrifice. The stage play 'Stranger Things: The First Shadow' reveals a key backstory about the Upside Down by confirming that the Abyss is actually Dimension X, an alternate world Henry encountered as a child long before Eleven banished him there. After being accidentally sent to Dimension X through stolen experimental equipment, Henry first comes into contact with the Mind Flayer, an experience that permanently alters his personality and awakens his powers.
This encounter sets off the chain of events leading to Project Indigo, Eleven's involvement, and the eventual creation of the Upside Down wormhole in the series. Talking about the last episode of 'Stranger Things', RadioTimes.com revealed that the 'Stranger Things' finale, titled 'Chapter Eight: The Rightside Up', runs for 2 hours and 8 minutes and premieres on Wednesday, December 31 (Thursday, January 1, in the UK).
