The enigmatic nature of the Upside Down has long served as the central puzzle of Stranger Things. Although the core cast has become seasoned veterans at traversing this mirror dimension, the fundamental “why” and “how” of its existence remained largely obscured. This veil is finally lifted during the high-stakes Christmas Eve episodes of Season 5, where a reconnaissance mission to the spectral version of Hawkins Lab provides Dustin (Gaten Matarazzo) with the missing pieces of the puzzle. True to form, he contextualizes these cosmic revelations using the familiar vernacular of Dungeons & Dragons.
[Warning: The following contains significant plot revelations for Stranger Things Season 5, Volume 2.]The groundwork for this revelation is laid in the third episode, “The Turnbow Trap,” as the group recruits Erica Sinclair (Priah Ferguson) for an ambitious abduction gambit. Erica’s frustration stems from being pulled away from Mr. Clarke’s (Randy Havens) science lecture on the mechanics of wormholes—theoretical bridges that allow matter to bypass vast distances between galaxies or dimensions. As is typical for the series, this academic lesson serves as a crucial narrative foreshadowing.
Upon realizing that the Upside Down is contained within a perimeter centered on Hawkins Lab, Dustin initially suspects the existence of a physical anchor or shield generator. However, his search yields something far more profound: the clandestine journals of Dr. Martin Brenner (Matthew Modine). Brenner’s research confirms that the Upside Down is actually a wormhole tethering Hawkins to a far more ancient, primordial realm. Dustin christens this terrifying source “the Abyss,” a D&D-inspired moniker for a plane defined by unadulterated malevolence and entropy.
While Jim Hopper (David Harbor) remains weary of yet another tabletop gaming analogy, the comparison is strikingly accurate. In the D&D multiverse, reality is comprised of various campaign settings like Ravenloft and the Forgotten Realms, alongside inhospitable “Outer Planes” such as the Nine Hells. The Abyss is a particularly apt title, as it serves as the spawning ground for demons, including the infamous Demogorgon.
The lore behind this connection was previously teased in the stage production Stranger Things: The First Shadow, which depicted a Navy vessel inadvertently breaching a “Dimension X.” Series co-creator Ross Duffer recently shared that this concept—the Upside Down acting as a bridge to a deeper dimension—has been a cornerstone of the show’s mythology since the first season.
“We didn’t call it the Abyss in our early notes,” Duffer explained. “The working title was Dimension X, a nod to the Teenage Mutant Ninja Turtles lore. We toyed with revealing this back in Season 2, but the narrative was already overflowing with ideas. It feels more impactful to save this definitive unmasking for the grand finale.”
The origin of Henry Creel’s power is traced back to his exposure to volatile materials salvaged from Brenner’s Nevada facility. Brenner later exploited Henry’s biology to cultivate a generation of psychic prodigies, Eleven (Millie Bobby Brown) among them. Following Henry’s brutal purge of the lab, Eleven cast him into the Abyss, a realm so toxic it physically warped him into the entity known as Vecna. Years later, when Brenner coerced Eleven into a psychic probe of Vecna’s mind, the resulting contact manifested the “Upside Down” as we know it—a corrupted snapshot of Hawkins that allowed Vecna to begin his slow invasion, starting with the disappearance of Will Byers.
Vecna’s ultimate endgame is the total convergence of the Abyss and our world. He has spent years weaving these dimensions together, using psychic assassinations to tear rifts and kidnapping sensitive children to amplify his influence. This mirrors the narrative stakes of Out of the Abyss, a prominent D&D adventure where demon lords spill into the material plane. According to modern D&D guides, the corruption of the Abyss is so pervasive that any portal opened to it will eventually begin to digest and terraform the surrounding environment.
Venturing into the Abyss is a suicidal endeavor for all but the most powerful “high-level” heroes. It is a world where the atmosphere itself is a weapon and demons lurk in every shadow. For the Hawkins survivors, it represents the ultimate crucible—a place where they must apply every lesson learned since 1983 to prevent their world from being consumed by eternal darkness.
The initial seven chapters of Stranger Things Season 5 are currently streaming on Netflix, with the series conclusion set to debut on New Year’s Eve.
Source: Polygon
