The Contents of the Briefcase Henry Opens in Stranger Things?

For much of the concluding season of the popular Netflix show, the young Holly Wheeler and Max Mayfield find themselves trapped in a realm of memories built from the recollections of Vecna. Their quest for an escape route in the pivotal sixth episode leads them to witness again a defining event from Henry's childhood—a moment that could contain the secret to his downfall for good.

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

Unearthing the Secrets of the Cavern

After locating Max in the mental landscape dubbed Camazotz, Max reveals she is hiding out in a cave that Henry avoids at all costs. By leaving the lens cap on a telescope found in Henry's old home lets Holly see that the source of fear lies beyond the cave. Matching her view through the cap, she and Max plummet into a deep mine shaft.

There, they witness a Henry as a boy encounter an injured and paranoid man. When Henry tries to help, the man fires a gun, striking Henry in the hand. Fighting for his life, Henry ends the threat with a rock. "Was this the turning point?" Holly questions through tears. Essentially, yes, but the event went deeper than a defensive killing.

In keeping with mysteries in volume 2, the truth about the encounter originates in the stage play The First Shadow.

A Naval Mystery and Secret Science

*The First Shadow* opens with the 1943 event, which reportedly teleported a warship into a realm dubbed the Abyss. It faced creatures, and the lone returnee was the ship's commander, who emerged in a catatonic condition with an altered blood type.

That survivor's offspring, Martin Brenner, sought to replicate this experiment in Nevada. But a disloyal lab worker took experimental components to hand over to the Russian agents, who were keen to start their own interdimensional projects. That traitor in the tunnel is that employee.

The Briefcase's Contents

Considering what is known about the doctor's experiments, the case most likely held some of the unique blood type. At that moment, Henry is already bleeding. He likely becomes contaminated upon handling the contents, causing the development of his psychic abilities—powers he would inadvertently transfer to the kids Brenner would experiment on.

Another possibility, the container could have held exotic matter that was destined to travel to the secret facility, where it maintains the stability of the Upside Down. The prequel shows that Henry somehow wound up in the Abyss, coming back 12 hours later fundamentally changed. As a youth, he fights the whispers of a sinister presence, similar to how the character Will was influenced by the shadow monster in an earlier season.

Confronting Terror

The reason Henry avoids the cave linked to that memory demonstrates how deeply scarring the incident was for him. While he controls the Hive Mind and works to collapse the Abyss into Hawkins, a piece of the scared boy remains. Fear is his tool, and the narrative points to a final confrontation between Vecna and Will, who has confronted his greatest terrors to gain strength.

Will's growth has neutralized a key tactic of Vecna. Furthermore, Will now understands what the monster's own weakness, and this may grant a critical advantage in the series finale to come.