The Contents of that Briefcase Henry Opens in the Hit Series?
During the bulk of season 5 of the popular Netflix show, the young Holly Wheeler and Max find themselves trapped inside a mental fortress constructed from the past of the villain Henry. The search for a way out in the pivotal sixth episode has them relive a traumatic incident from Henry's youth—a discovery that potentially carries the means to overcome him once and for all.
Spoiler Warning: This discussion details significant events for the second part of the final season.
Unearthing the Secrets of the Mine Shaft
After locating Max in the world called Camazotz, Holly discovers she is hiding out in a chamber that Henry avoids at all costs. By leaving the lens cap on a spyglass found in Henry's old home helps Holly understand that the source of fear lies not within the cave. When she lines up her view through the cap, she and Max plummet into a abandoned tunnel.
In this place, they observe a Henry as a boy find an injured and paranoid man. Attempting assistance, the man panics and shoots, wounding the boy in the hand. To protect himself, Henry kills the man with a rock. "Is this what corrupted him?" Holly questions through tears. Essentially, yes, but the act wasn't just a simple act of survival.
In keeping with mysteries of the final season, the truth about the encounter was first explored the stage play The First Shadow.
A Naval Mystery and A Spy's Mission
*The First Shadow* opens with the legendary naval test, which reportedly teleported a warship into a realm later called the Abyss. Demogorgons assaulted it, and the only one to return was the ship's commander, who returned in a catatonic condition with an entirely new blood.
This man's son, Martin Brenner, attempted to recreate this dimensional breach in Nevada. However, a treacherous employee took experimental components to sell to the Russian agents, who were eager to begin their own interdimensional projects. The man in the cavern is that employee.
The Briefcase's Contents
Considering what is revealed about his research, the container would assuredly have some of the unique blood type. As shown, Henry is already bleeding. He likely becomes contaminated upon opening the case, which triggered the origin of his telekinetic gifts—powers he would genetically impart to the children in Hawkins Lab.
A second theory, the box could have held strange particles that eventually found its way to Hawkins Laboratory, where it helps stabilize the Upside Down. *The First Shadow* reveals that Henry somehow wound up in the Abyss, coming back 12 hours later as a different person. From then on, he battles the whispers of a sinister presence, reminiscent of how the character Will was influenced by the entity in season 2.
Confronting Terror
His lasting fear of that cave shows how utterly horrifying the event was for him. Even as he commands the Hive Mind and attempts to pull the Abyss into Hawkins, a fragment of his psyche still exists. The villain weaponizes terror, and the series is building toward a climactic battle between Vecna and Will, who has deliberately faced his personal demons to fortify himself.
His confrontation has taken a weapon from Vecna. More importantly, Will now is aware of what the monster's own weakness, and this may grant a critical advantage in the endgame conflict ahead.
