What's Inside the Briefcase Henry Opens in the Hit Series?
During the bulk of the concluding season of the popular Netflix show, Holly Wheeler and Max are imprisoned in a realm of memories forged from the recollections of Vecna. Their mission for an escape route in episode 6 has them relive a life-altering moment from Henry's childhood—a moment that may just hold the secret to his downfall once and for all.
Heads Up: This article reveals crucial plot points for the second part of the final season.
A Journey Into the Mine Shaft
Upon meeting Max in the mental landscape dubbed Camazotz, Holly discovers she is sheltering in a grotto that Henry avoids at all costs. By leaving the lens cap on a telescope pilfered from Henry's old home helps Holly understand that the true terror lies not within the cave. When she lines up her view with the shape, she and Max plummet into a subterranean passage.
They watch a child version of Henry find an wounded, fearful individual. When Henry tries to help, the man fires a gun, wounding the boy in the hand. In a desperate act of self-defense, Henry kills the man with a rock. "Was this the turning point?" Holly questions through tears. The answer is affirmative, but the event involved more than a defensive killing.
Like many elements in volume 2, the truth about the events in the tunnel originates in the theatrical production The First Shadow.
The Philadelphia Experiment and Secret Science
This backstory explains the legendary naval test, which allegedly sent a vessel into a dimension later called the Abyss. Demogorgons assaulted it, and the lone returnee was the captain, who returned in a unresponsive state with an entirely new blood.
That survivor's offspring, a young Martin Brenner, attempted to recreate this experiment in the Nevada desert. However, a treacherous employee pilfered lab samples to sell to the Russian agents, who were eager to begin their parallel research. This spy in the tunnel is the one who stole the materials.
The Briefcase's Contents
Considering what is revealed about his research, the case would assuredly have samples of Captain Brenner's infected blood. As shown, Henry is already bleeding. It's probable he was infected upon opening the case, leading to the development of his psychic abilities—traits he would genetically impart to the kids under Brenner's care.
A second theory, the box could have held exotic matter that later made its way to Hawkins Laboratory, where it acts to anchor the parallel world. The prequel shows that young Henry somehow wound up in the Abyss, reappearing 12 hours later with a new blood type and personality. As a youth, he struggles with the whispers of a sinister presence, reminiscent of how the character Will was influenced by the entity in an earlier season.
The Power of Fear
The reason Henry avoids the cave linked to that memory demonstrates how utterly horrifying the event was for him. While he orchestrates the army of monsters and attempts to pull the Abyss into Hawkins, a part of him still exists. The villain weaponizes terror, and the narrative points to a final confrontation between him and Will, who has overcome his greatest terrors to gain strength.
His confrontation has effectively disarmed Vecna. Crucially, Will now is aware of what Vecna himself fears, and this may grant a decisive edge in the series finale to come.