Warning: There are spoilers ahead for Stranger Things season 5, Volume 1 and The First Shadow.

The first four episodes of Stranger Things 5 dropped last week, and many viewers are wondering why Henry Creel/Vecna/One looked downright terrified of one mysterious cave in episode 4. These four episodes, comprising Stranger Things 5, Volume 1, contained a host of surprises.

In addition to the action-packed ending of Stranger Things 5, Volume 1, which saw Will wielding newfound powers, Max had a shocking on-screen return in these first few episodes, not solely trapped in a coma, lying in a hospital bed, but up and about in Henry’s memories, helping Holly discover the truth about Henry’s identity and his intentions.

Within this plot was the revelation that Max managed to escape from Henry’s clutches—as he hunted her like a horror movie—by running into a cave that he was unwilling to enter. It was immediately clear something much deeper was going on, particularly given the extent of Henry’s reaction, so why exactly is Henry so scared of this cave?

Henry Refuses To Follow Max Into The Cave During Stranger Things Season 5

The scene in which Henry stalks after Max is jarring for multiple reasons. For one, Henry’s appearance is perhaps its most terrifying yet (at least in terms of when he’s in his Henry form), as he has the hand of Vecna and blood splatters across his clothing but otherwise looks human/normal, as he did in Hawkins Lab at first.

However, the most unsettling part of this scene is actually how Henry reacts to the cave. He isn’t merely afraid of it—he looks utterly terrified, complete with wide eyes and trembling lips, which is something we’ve certainly never seen from this character before. What could possibly cause this reaction? Stranger Things’ prequel play, The First Shadow, has the answer.

Stranger Things’ First Shadow Play Explains Why Henry Is Afraid Of The Cave

Although Stranger Things’ creators, the Duffer Brothers, have assured audiences that The First Shadow is not essential viewing to understand this final season of the show, it certainly helps to solve this mystery because The First Shadow explained the connection to this cave. Specifically, it was revealed that this cave led to Henry’s first interaction with the Mind Flayer.

This response to the cave isn’t just fear, then; it’s effectively a trauma response. This suggests an entirely new layer to Henry/Vecna’s story, wherein he, not unlike Will, is a victim of an evil that corrupted him. It’s true that Henry was an odd little boy even before this encounter, but could it be that he is somewhat misunderstood?

What The Cave Means For Vecna’s Story In The Rest Of Stranger Things Season 5

This cave could mean major changes to Vecna’s story in Stranger Things. Throughout season 4, and for the most part in season 5, Volume 1, Vecna seemed like the overall ‘Big Bad’ of the show. Yet, if Henry is having such a visceral reaction, could it be that it’s the Mind Flayer, not Vecna, who is the greatest evil?

It’s entirely possible that this will be a reveal in the finale, if not in Volume 2, which will forever change what Vecna/Henry Creel/One represents in Stranger Things. Sadly, for those anxiously awaiting answers, the next three episodes will not be released until Christmas Day—so, for now, we wait.