Spoilers ahead for "The Box" episode of Castle Rock. There are plenty of mysteries to unravel in the fictional Maine town that gives Hulu's new thriller series its name. Where did Molly get her powers? Who is the Kid? But almost all of those mysteries eventually circle back to the question of Henry Deaver's past. Did Henry kill his father on Castle Rock? The death row attorney may have no memory of the 11 days he went missing back in the winter of 1991, but the show is slowly starting to parcel out answers, and connect his disappearance with the present-day unrest in his hometown.
The biggest clues so far came in Castle Rock's fourth episode, "The Box," as Henry starts to remember flashes of his captivity in dreams, and Sheriff Alan Pangborn drops one hell of a bombshell on the befuddled prodigal son. According to Pangborn, Reverend Matthew Deaver wrote him a note on his deathbed the day before he passed away, scrawling his final statement on the back of a bank slip since he couldn't talk due to the breathing tube in his throat. "HENRY DID IT," the note read.
So did Henry really kill his own father after all? Castle Rock's citizens viewed Henry with suspicion on his return, assuming he was the one who lured his father into the woods and pushed him off a cliff before faking his own disappearance to cover his tracks. It's natural for the viewer, as an outside observer, to take the protagonist's side and assume that the townsfolk are just being mean gossips. But what if they're right? What if the twist lying in store is that Henry really is a killer?
If that's the case, it's possible that Henry could even have returned home to finish the job. A previous episode showed Molly remembering walking across the lawn to the Deaver house and unhooking the Reverend's life support. But Molly is a psychic — one with an especially potent connection to Henry, at that — and viewers have already seen her feeling what he's feeling, both emotionally and literally. When he got angry, she clenched her hand at the same time as his; when he was cold, she breathed out fog in her own warm bedroom. What if her memory of murdering Reverend Deaver wasn't her own memory, but Henry's, which felt so real it was like she was there doing it herself?
Henry's brief flashbacks to his captivity could support this theory as well. In them, the young boy can be seen lying on a dirt floor behind bars… as though he's been locked up in a cage, much like the one in which Warden Lacy was holding the mysterious Kid underneath Shawshank. Lacy thought he had received instructions from God to lock the Kid up; being a man of God himself, could the Reverend have also received similar instructions himself? Is Henry evil like the Kid? Or, at the very least, could he once have been host to the same evil that now resides inside the Kid's body?
Of course, there could be another explanation for all of this; the Reverend's note to Pangborn didn't exactly specify what "it" was that Henry "did." Pangborn assumed the Reverend was talking about his killer, but it's possible that Henry's father was referring to something else entirely. Viewers will have to wait to find out... but it would be a twist worthy of Stephen King if it turned out that Castle Rock's seemingly sympathetic protagonist turned out to be the ultimate personification of evil after all.