As the final season of Stranger Things unfolds, fans are clinging to every clue, theorizing about every shadow in the Upside Down. But some of the most explosive revelations aren’t hidden in Hawkins’ latest crack in reality—they’re on a stage in New York and London. Stranger Things: The First Shadow, the officially sanctioned Broadway and West End play, isn’t just a fun side story. It’s the essential origin code for the entire series, and it holds the definitive explanation for one of Season 5’s biggest moments: Will Byers’ shocking new psychic abilities.
For those who haven’t seen the play, the connection might seem distant. But the Duffer Brothers and writer Kate Trefry have woven a narrative thread so tight that the stage show directly fuels the television series’ endgame. It all revolves around one brutal correction to our understanding of the show’s villain: Henry Creel did not create the Mind Flayer. The Mind Flayer, from a place called Dimension X, created Vecna.
What Happens In The First Shadow?
The First Shadow opens with a terrifying 1943 military experiment gone wrong, where a submarine is attacked by Demogorgons in a strange dimension. This place, dubbed Dimension X, is the primordial source. The story then jumps to 1959, where a young Henry Creel, exploring a Nevada cave system with a rogue scientist, is accidentally flung into Dimension X for twelve horrific hours. There, he isn’t just attacked by the particle-cloud entity we know as the Mind Flayer—he is infected, corrupted, and mentally shattered by it. This infection is the sole source of his psychic powers. Henry didn’t discover his gift; it was a violent, parasitic implantation that drove him insane. This is why, in Season 5, Max finds a memory of a cave that Henry is too terrified to enter. That cave is his ground zero, the place where he was unmade.
This fundamental rewrite of the show’s mythology has a ripple effect that reaches every powered character. Dr. Brenner, learning of Henry’s infected blood, uses it as the basis for the MKUltra “Indigo” program. The psychic children—One through Ten, at least—are not natural mutations or Firestarter-style accidents. They are biological offspring of the Dimension X infection, their abilities branching from Henry’s tainted bloodline.
Which brings us to Will Byers.
At the end of Season 5’s fourth episode, “The Sorcerer,” a determined Will raises his hand and psychically slams a door shut to protect his friends. It’s a triumphant, jaw-dropping moment that seems to come from nowhere. But The First Shadow provides the missing scientific logic. Will has no innate powers of his own. However, in Season 1, he was the first victim taken to the Upside Down, where he was inundated with the very essence of that place—a place intrinsically connected to Dimension X’s influence. He was forcibly connected to the Hive Mind, a network powered by Vecna, who is himself a conduit for the Dimension X entity.
Will’s power-up isn’t a sudden mutation. It’s a hijacking. He is, for a fleeting moment, tapping into the same corrupted network that fuels Vecna, because he is still spiritually and physically connected to it. He’s not generating power; he’s redirecting a current that was forced into him years ago. The play confirms that all psychic phenomena in Hawkins stem from that one source. Will’s ability is a heartbreaking echo of his trauma, a weapon forged from the very thing that tortured him.
The play’s revelations extend beyond Will. They explain why Max’s consciousness is hiding within Henry’s sun-drenched memories, and they suggest a final strategy for the Hawkins gang. The First Shadow paints a surprisingly sympathetic portrait of young Henry, a boy who fought the corruption within him, even finding love with Patty Newby (Bob’s sister). This adds profound depth to the theme that “love is more powerful than hate,” which has been the emotional core of the series since Joyce communicated with Will through Christmas lights.
What This Could Mean For Vol. 2
Knowing that Henry was a victim before he became a monster changes the endgame. The final battle may not be about killing Vecna, but about saving Henry. The key to victory could lie in cutting the connection to Dimension X, severing the Mind Flayer’s influence, and curing the infection—perhaps through the power of the memories and love that Max and Holly are discovering. It would be the ultimate expression of the show’s heart: fighting not with bigger weapons, but with greater understanding.
So, is The First Shadow important? It’s more than important—it’s the master key. It transforms Vecna from a singular evil into a tragic patient zero, recontextualizes the powers of every character, and turns Will Byers’ defining trauma into his greatest strength. As we head into the final episodes, the play assures us that the answers were never just in the past; they were waiting in the wings, under the stage lights, all along.
