The Mystery Within that Briefcase Henry Opens in the Hit Series?
Throughout a large portion of the fifth and final season of *Stranger Things*, the young Holly Wheeler and Max are imprisoned within a psychic prison built from the past of Vecna. Their mission for a way out in the pivotal sixth episode has them experience a life-altering moment from Henry's childhood—an event that may just hold the means to overcome him permanently.
Editor's Note: This discussion reveals crucial plot points for *Stranger Things* season 5, volume 2.
The Discovery in the Cavern
When she finds Max in the mental landscape known as Camazotz, Holly discovers she is hiding out in a grotto that Henry strangely fears. By leaving the lens cap on a viewing device found in Henry's old home lets Holly see that the true terror lies outside of the cave. Matching her view with the shape, she and Max tumble into a abandoned tunnel.
They watch a young, eight-year-old Henry encounter an injured and paranoid man. When Henry tries to help, the man fires a gun, striking Henry in the hand. In a desperate act of self-defense, Henry ends the threat with a rock. "Was this the turning point?" Holly asks tearfully. It was a factor, but the trauma involved more than a defensive killing.
Similar to other plot points this season, the significance of the mine shaft incident is detailed in the theatrical production Stranger Things: The First Shadow.
An Interdimensional Incident and A Spy's Mission
This backstory explains the infamous Philadelphia Experiment, which transported a warship into a dimension dubbed the Abyss. The ship was attacked, and the only one to return was the captain, who returned in a unresponsive state with an entirely new blood.
That survivor's offspring, Martin Brenner, wanted to repeat this dimensional breach in Nevada. One of his scientists took experimental components to sell to the Communist spies, who were eager to begin their parallel research. The man in the mine shaft is the one who stole the materials.
Unlocking the Mystery
Given what is known about Brenner's work, the briefcase almost certainly contained some of Captain Brenner's infected blood. At that moment, Henry is wounded and bleeding. It's probable he was infected upon contact with the blood, which triggered the origin of his telekinetic gifts—traits he would later pass on to the kids in Hawkins Lab.
A second theory, the container could have held exotic matter that eventually found its way to Hawkins Laboratory, where it maintains the stability of the mirror dimension. The prequel shows that Henry was transported in the Abyss, coming back hours later with a new blood type and personality. Throughout the play, he battles the whispers of a dark entity, much like how the character Will was controlled by the Mind Flayer in the past.
The Power of Fear
The reason Henry avoids the cave of that cave demonstrates how utterly horrifying the event was for him. Even as he orchestrates the collective consciousness and seeks to merge the Abyss into Hawkins, a piece of the scared boy still exists. Fear is his tool, and the narrative points to a final confrontation between Vecna and Will, who has overcome his personal demons to become stronger.
Will's growth has effectively disarmed Vecna. Furthermore, Will now understands what Vecna himself fears, potentially giving him a decisive edge in the ultimate battle to come.
