The Stranger Things Stage Play First Shadow Reveals How Vecna Got His Powers

Spoilers ahead for "Stranger Things: The First Shadow."

"Stranger Things" season 4 had many problems, including being overstuffed and derivative, but it also gave us the show's first truly great villain. Henry Creel, aka Vecna (Jamie Campbell Bower), is a psychic serial killer so evil that he killed his own mom and sister, mutilated their bodies, and framed his dad for the murders. This guy is seemingly behind every single bad thing that ever happened in the show — including bending the Mind Flayer to his own will. Or so it seems, until you watch the "Stranger Things" stage play.

In a rather bizarre move for cross-media storytelling, Netflix produced a stage play for "Stranger Things" that is not only canon to the show, but completely and utterly necessary to understand the final season. Stage plays of TV shows are nothing new — anime does it all the time! — but they tend to either just retell the story of the TV show or be a non-canon story unconnected to the main plot. With how much Marvel struggles to connect the TV shows that not many people watch with the theatrical films, it is quite bold that Netflix pulled this move. "Stranger Things: The First Shadow" premiered in London all the way back in 2023, two full years before the release of season 5, yet the show holds many key reveals that are only now becoming relevant in the main show.

One such reveal concerns how Vecna got his powers. No, not the enhanced abilities Vecna got when he became a monster after Eleven (Millie Bobby Brown) threw him into Dimension X, but the initial psychic powers he used to kill animals and people as a teenager. Turns out, it involves the original villain of "Stranger Things" — Dr. Martin Brenner (Matthew Modine).

"The First Shadow" tells the story of Henry Creel, his family moving to Hawkins, Henry befriending the parent of every main character in the show, and how he turned into the villain we know. Scripted by "Stranger Things" writer and co-executive producer Kate Trefry, "The First Shadow" starts with a seemingly unrelated prologue set in 1943, depicting the Philadelphia Experiment, in which the US attempts to turn submarines invisible during World War II but ends up accidentally sending the USS Eldridge to Dimension X. If that wasn't bad enough, demogorgons show up and kill the entire crew — with one exception.

The sole survivor is the father of Dr. Brenner, and his exposure to Dimension X caused genetic changes to his blood. That, alongside the stories he told his son, made the younger Brenner obsessed with this alternate dimension, leading to him establishing the Nevada Experiment to recreate the conditions of the Philadelphia Experiment. These are pivotal moments in the "Stranger Things" timeline, especially what happens after one of the scientists goes rogue, steals some equipment, and heads to a Nevada cave near where the Creel family live. By happenstance, a young Henry Creel is exploring the cave system when the scientist triggers a portal that transports both of them to Dimension X for 12 hours. During this time Henry is infected by the Mind Flayer, who gives him his powers and also corrupts his mind.

That's right: Henry did not create the Mind Flayer or even control an existing creature; it was the other way around. Henry was not born with psychic abilities, but was infected with them and driven insane by those powers.

It seems borderline foolish to make "The First Shadow" so hugely important to season 5 of "Stranger Things." While it is quite cool that the stage play is canon and intricately connected to the overall story, having so many big reveals happen in a show the vast majority of viewers have no access to is unwise. The stage play is connected to where Sadie Sink's Max is hiding at the start of season 5, how Noah Schnapp's Will got new powers, and even how Eleven got her powers.

Then we get the reveal of the Mind Flayer as the actual big bad, rather than Henry/Vecna. This is a major moment that reframes Vecna's entire story. Even if "Stranger Things" tackles this in the final season, some lucky audiences in London have known about it for two whole years.

"The First Shadow" is a spectacular stage production with some stunning VFX and creature effects, but it is also a story that is essential to the larger experience of watching "Stranger Things." Given that Netflix produced the show, it is not out of the question that the streamer will eventually film the show and add it to the platform. Hopefully audiences everywhere will get to see it one day, because it changes a lot of things we were giving for granted in the world of Hawkins.