What's Inside that Briefcase Henry Unlocks in Stranger Things?

Throughout a large portion of the concluding season of the popular Netflix show, the young Holly Wheeler and Max Mayfield find themselves trapped within a psychic prison forged from the recollections of the villain Henry. Their mission for a way out in "Escape from Camazotz" forces them to relive a life-altering moment from Henry's youth—a moment that could contain the means to overcome him once and for all.

Editor's Note: This discussion reveals crucial plot points for *Stranger Things* season 5, volume 2.

The Discovery in the Mine Shaft

After locating Max in the mental landscape called Camazotz, it becomes clear she is hiding out in a grotto that Henry is terrified of. By leaving the lens cap on a viewing device found in Henry's old home allows Holly to realize that the source of fear lies outside of the cave. By aligning her view to the cut-out, she and Max tumble into a abandoned tunnel.

They watch a young, eight-year-old Henry find an wounded, fearful individual. As the boy offers aid, the man panics and shoots, striking Henry in the hand. In a desperate act of self-defense, Henry ends the threat with a rock. "Is this what corrupted him?" Holly wonders aloud. The answer is affirmative, but the event involved more than a defensive killing.

Similar to other plot points in volume 2, the significance of the mine shaft incident originates in the theatrical production the prequel play.

An Interdimensional Incident and Stolen Research

The play reveals the infamous Philadelphia Experiment, which transported a U.S. Navy ship into a dimension dubbed the Abyss. Demogorgons assaulted it, and the sole survivor was the captain, who emerged in a vegetative state with an altered blood type.

That survivor's offspring, a young Martin Brenner, attempted to recreate this phenomenon in remote Nevada. But a disloyal lab worker stole research materials to sell to the Communist spies, who were eager to begin their own interdimensional projects. That traitor in the cavern is that employee.

The Briefcase's Contents

Based on what is understood of his research, the briefcase almost certainly contained samples of Captain Brenner's infected blood. In the scene, Henry is already bleeding. It's probable he was infected upon opening the case, which triggered the origin of his telekinetic gifts—powers he would later pass on to the kids in Hawkins Lab.

A second theory, the container could have held strange particles that was destined to travel to Hawkins Laboratory, where it acts to anchor the parallel world. The stage play explains that Henry somehow wound up in the Abyss, reappearing hours later fundamentally changed. Throughout the play, he fights the whispers of a malevolent force, similar to how the character Will was possessed by the entity in the past.

Confronting Terror

His lasting fear linked to that memory demonstrates how deeply scarring the event was for him. While he controls the collective consciousness and seeks to merge the Abyss into Hawkins, a fragment of his psyche remains. Vecna uses fear, and the series is building toward a climactic battle between Vecna and Will, who has confronted his own deepest fears to fortify himself.

This journey has neutralized a key tactic of Vecna. Furthermore, Will now is aware of what Vecna himself fears, which could provide a key upper hand in the series finale ahead.