This article contains spoilers for Stranger Things Season 5, including the finale, and the stage show, Stranger Things: The First Shadow.The Duffer brothers have confirmed that the upcoming Stranger Things spin-off will fully address and explain the purpose of the mysterious rock in the briefcase obtained by Henry Creel in the flashback sequence during the Season 5 finale.

Matt Duffer regrets doing those post-mortem interviews for the Stranger Things finale, saying he was "fried" when answering interviewers' questions.

I'm, like, fried,' Matt Duffer explained in the wake of the Netflix hit's big finale, which we can certainly understand.

During the "Stranger Things" finale, the origin of Vecna and Henry was finally revealed. During a moment in the second volume, where Holly stumbles on a memory involving a young Henry killing a man with a gun, it essentially explains how he came about his violent nature.