Warning: SPOILERS for Castle Rock up to episode four.
The fourth episode of Castle Rock - titled "The Box" - ends with a deadly twist inside Stephen King's infamous Shawshank State Prison. In fact, the deadly end of the episode not only derails one of the budding subplots revolving around Shawshank prison guard Dennis Zalewski (played by Noel Fisher), but the plan for André Holland's Henry Deaver to leave Castle Rock and return home.
In Castle Rock, Hulu's original series based within Stephen King's literary multiverse and inspired by some of the author's most beloved stories and characters, death row attorney Henry Deaver returns to his hometown (the fictional setting of several King stories, including Needful Things, Cujo, and The Body) at the request of a mysterious Shawshank inmate known only as "The Kid" (played by Bill Skarsgård). In fact, Dennis Zalewski makes the call himself, in hopes of exposing Shawshank's shady (and often illegal) history and shutting the prison down for good. After he personally discovers "The Kid" in a cage beneath one of the prison's abandoned blocks, Dennis is confident that it's incriminating enough for Henry and him to personally blow the whistle on Shawshank. And even though everything appears to be going according to plan well into the fourth episode of the show, the final moments of the episode change the trajectory of Castle Rock completely.
Related: Castle Rock Cast & Character Guide
By episode four, Dennis has made it perfectly clear that he wants nothing more than to tear Shawshank to the ground (either figuratively or literally), even telling Henry that he feels like "a prisoner in there, too." Unfortunately, some personal drama surrounding Henry prompts him to prematurely jump ship on Castle Rock and return to Houston, TX, where he lives. Dennis listens to a voicemail from Henry while preparing to clock in at Shawshank, and he's told that Henry won't pursue the hearing in "The Kid's" defense, instead opting to encourage his client to take the settlement offer from Shawshank and wipe their hands of the entire situation. This cues Dennis' unexpected turning point.
Moments after Dennis relieves another guard from her shift, Dennis stares vacantly at the ongoing abuse against Shawshank's prisoners through a set of security monitors (he also spots Henry Deaver waiting outside the warden's office), then draws X's over the screens with a marker, removes a handgun from the office's gun safe, and proceeds to carry out a mass shooting within the prison against his fellow guards. When he finally reaches the warden's office and approaches Henry, he says, "I wanna testify," just as a flash-bang grenade is thrown at his feet and he's shot dead by an onslaught of guards.
The episode ends on this cliffhanger, hinting at the unexpected direction in which the show is heading. It strikes a nasty, defeatist tone that contrasts former Shawshank inmate Andy Dufresne in The Shawshank Redemption, where he famously insisted that "Hope is a good thing; maybe the best of things." In this show - following this particular episode - calling hope a long shot is an understatement. Dennis' killing spree and death was clearly meant to get audience's attention, but it's impossible to tell in which direction that attention will ultimately lead.
Henry clearly needed motivation to stick around and solve the mystery that's not only been haunting himself but all of Castle Rock; and it's certainly no coincidence that the last thing Dennis said to Henry was, "How many times has one f***ing town looked the other way?" Henry Deaver has unfinished business in his hometown, and he's ignored it long enough. Now, whether digging deeper into the past leads to closure or catastrophe, Dennis' desperation signaled that things in Castle Rock are so bad, they might be worth dying (even killing) for.
Castle Rock releases Wednesdays on Hulu.