Warning: There are spoilers ahead for Stranger Things season 5, volume 1.Stranger Things creators Matt and Ross Duffer confirm how season 5’s cave connects to The First Shadow prequel play. The production, which has been performed in the West End and on Broadway, explores Henry Creel’s origins before he is transformed into Vecna.
In Stranger Things season 5, it is revealed that Max Mayfield is alive and trapped within the memories of Vecna’s mind. One of these memories includes a cave that Vecna is unwilling to enter and seemingly terrified of, which makes it the perfect refuge for Max.
During an interview with Variety, the Duffers were asked if this is the same cave that is referenced in The First Shadow. Matt Duffer confirms that it is the same and details how season 5 and the play had to be careful not to spoil one another. The Duffers tease “more overlap with the play” while clarifying that viewers can still fully understand season 5 without having seen the stage production. Check out their comments below:
Variety: In “The First Shadow,” the prequel play that’s on Broadway and in the West End, there’s a reference to a cave in Nevada near an army base where a young Henry Creel first encountered something connected to the Upside Down. Is that the same cave?
Matt Duffer: Yeah. When we were working on the play with Kate Trefry, we had Henry’s backstory worked out. There was always a balance that we had to find in terms of how much we were going to put in the play. [The director] Stephen [Daldry] and [the produce] Sonia [Friedman] were always pushing for more and we were pushing back and saying, “Well, we have to wait to reveal that in the show.” You’ll see, especially as you reach the final episode, there’s more overlap with the play.
Ross Duffer: And, like, Max finds that “Oklahoma” poster, which people who haven’t seen the play are maybe like, “Why is Henry in ‘Oklahoma’?” But I think it’s nice for us to start to tie those two together.
Matt Duffer: But you absolutely do not have to have seen the play to understand. They’re Easter eggs more than anything.
The First Shadow reveals that when young Henry was exploring these caves in Nevada near an army base, he was accidentally transported to Dimension X, an alternate dimension that predates the Upside Down’s inverted version of Hawkins, and this is when he first came into contact with the Mind Flayer.
Beyond being a massive connection to The First Shadow, the Duffers’ confirmation offers a possible explanation of why Vecna is unwilling and too afraid to enter the cave in his memories. Because this is where he was first exposed to the Mind Flayer and to alternate dimensions, this memory may be too traumatizing for him to enter, and he may even fear the Mind Flayer’s power.
While season 4 and season 5, volume 1 have positioned Vecna to be the show’s ultimate villain, The First Shadow emphasizes how the Mind Flayer manipulated Henry. His fear of the cave memory could be a hint that the Mind Flayer is still the ultimate villain after all.
Even though the cave is a significant connection to the play, the Duffers’ comments indicate that the mystery behind it will be explained in season 5’s remaining episodes. They ensured that the mystery wasn’t spoiled in the play and so all audiences could learn the answers at the same time.
In terms of smaller connections, they mention the memory Max encounters where a young Joyce Byers is handing out flyers for a production of Oklahoma! starring Henry. This is an Easter egg since Henry is cast in Oklahoma! during his time at Hawkins High School in The First Shadow.
Another Easter egg that the Duffers don’t mention here involves Stranger Things season 5’s cast. The military’s Lieutenant Robert Akers, who Eleven and Jim Hopper take captive in the Upside Down, is played by Alex Breaux. He is the same actor who plays Dr. Martin Brenner in The First Shadow.

