'Stranger Things' play may have already revealed season 5's ending, and Vecna's story might hold the clue
Fans who have already made the trip to see 'Stranger Things: The First Shadow' on stage may be holding a major advantage heading into the Netflix series’ final chapters. The companion play, which debuted in London's West End in December 2023 before arriving on Broadway in April 2025, appears to quietly lay the groundwork for how 'Stranger Things' will ultimately conclude. Written by Kate Trefry, a longtime writer on the Netflix series, 'The First Shadow' has been described as an essential piece of the franchise's larger mythology. Trefry herself has called the production the "missing puzzle piece" of the 'Stranger Things' story.
The Duffer Brothers have confirmed that the connection is intentional. Speaking to The Hollywood Reporter, creators and showrunners Matt and Ross Duffer revealed that the play and Season 5 were developed side by side to ensure continuity across mediums. According to Ross Duffer, "The play starts to tee up some things that are going to be big reveals in Season 5." Set in 1959, more than two decades before the events of season 1, 'The First Shadow' revisits Hawkins, Indiana, when familiar faces like Joyce Byers, Jim Hopper, and Bob Newby were still students at Hawkins High. However, the story centers on a new arrival: Henry Creel, who fans know better as Vecna.
In the series, Henry is introduced in season 4 as the main antagonist. Through flashbacks, viewers learn that Henry was once a gifted but troubled child who murdered his family after discovering his abilities. He was later taken to Hawkins Lab, becoming Dr. Martin Brenner's first test subject and the genetic source for later children like Eleven. The show largely frames Henry as inherently monstrous, a born predator who eventually becomes Vecna after Eleven banishes him to another dimension in 1979. The play, however, complicates that story. Rather than presenting Henry as pure evil, 'The First Shadow' humanizes him and offers a detailed explanation for how his powers originated.
The production opens with a startling flashback to 1943 and a secret U.S. military operation known as the Philadelphia Experiment. In this version of events, a battleship is accidentally transported to a hostile alternate dimension, where most of the crew is killed by a creature resembling a Demogorgon. Only the captain survives, returning to the real world infected and mysteriously altered. His blood type changes, and scientists later extract inter-dimensional particles from his body. Further experiments on those particles are derailed when a Russian spy infiltrates the program, stealing advanced technology and a vial of the particles.
The spy’s body later turns up near a cave in Nevada. It's the same cave that an eight-year-old Henry Creel unknowingly wanders into while living nearby. Inside, Henry accidentally activates the stolen technology and is briefly transported to Dimension X, the realm where the Mind Flayer originates. In an interview with Variety, the Duffer Brothers confirmed that this cave also appears in season 5. In volume one, Max Mayfield hides there after her consciousness becomes trapped within Henry's memories. She chooses it deliberately, noting that Henry refuses to enter the cave and theorizing that he's terrified of that particular moment from his past.
This revelation flips one of the show’s biggest assumptions on its head. While Vecna claimed in season 4 that he shaped and controlled the Mind Flayer, the play suggests the opposite. Henry was invaded by the Mind Flayer during his exposure to Dimension X. The entity uses Henry as a vessel, gradually asserting control as the boy struggles and fails to resist its influence. So, for fans paying close attention, 'The First Shadow' may already have revealed that Vecna isn't the final enemy.
