🔗 Share this article

Throughout a large portion of the fifth and final season of the popular Netflix show, Holly Wheeler and Max Mayfield are imprisoned within a psychic prison constructed from the memories of Vecna. Their quest for a way out in the pivotal sixth episode forces them to experience a traumatic incident from Henry's early years—a discovery that potentially carries the secret to his downfall once and for all.

Spoiler Warning: This article reveals crucial plot points for the second part of the final season.

Unearthing the Secrets of the Cavern

When she finds Max in the mental landscape known as Camazotz, Max reveals she is hiding out in a grotto that Henry strangely fears. A clever observation a viewing device taken from Henry's old home allows Holly to realize that the true terror lies beyond the cave. Matching her view through the cap, she and Max tumble into a abandoned tunnel.

In this place, they observe a Henry as a boy encounter an man who is hurt and scared. As the boy offers aid, the man reacts violently, wounding the boy in the hand. In a desperate act of self-defense, Henry strikes the man down with a rock. "Is this what corrupted him?" Holly questions through tears. The answer is affirmative, but the event involved more than a simple act of survival.

Like many elements in volume 2, the significance of the encounter is detailed in the theatrical production Stranger Things: The First Shadow.

The Philadelphia Experiment and A Spy's Mission

*The First Shadow* opens with the 1943 event, which allegedly sent a vessel into a realm dubbed the Abyss. It faced creatures, and the sole survivor was the ship's commander, who returned in a catatonic condition with an entirely new blood.

This man's son, the future Dr. Brenner, sought to replicate this experiment in the Nevada desert. But a disloyal lab worker stole research materials to sell to the Communist spies, who were keen to start their parallel research. That traitor in the mine shaft is that employee.

So, What's in the Case?

Given what is understood of the doctor's experiments, the container almost certainly contained some of the unique blood type. As shown, Henry is already bleeding. Exposure likely occurred upon handling the contents, which triggered the origin of his telekinetic gifts—powers he would later pass on to the children under Brenner's care.

Alternatively, the container could have held strange particles that was destined to travel to the secret facility, where it helps stabilize the Upside Down. The prequel shows that young Henry somehow wound up in the Abyss, returning after half a day as a different person. As a youth, he fights the control of a malevolent force, reminiscent of how Will was possessed by the entity in season 2.

Confronting Terror

The reason Henry avoids the cave of that cave highlights how profoundly traumatic the incident was for him. While he controls the Hive Mind and seeks to merge the Abyss into Hawkins, a part of him still exists. Vecna uses fear, and the narrative points to a final confrontation between him and Will, who has deliberately faced his personal demons to become stronger.

This journey has effectively disarmed Vecna. Crucially, Will now is aware of what Vecna himself fears, potentially giving him a critical advantage in the series finale to come.