Warning: SPOILERS for Castle Rock up to episode five.
The fifth episode of Castle Rock - titled "Harvest" - reveals the true identity of one of its main characters in a surprising twist, connecting directly to one of Stephen King's most beloved novels, The Shining. However, in a series ripe with references to Stephen King's literary universe, it's unclear whether or not this reveal will at all play into the season's overarching story.
In this episode of Castle Rock, "The Kid" (played by Bill Skarsgård) is finally released from Shawshank State Prison following a plea deal (as well as the prison's recent mass shooting). He's grudgingly looked after by his lawyer Henry (played by André Holland), and he ends up crossing paths with a number of locals, including Melanie Lynskie's real estate agent Molly Strand (who offers him a place to sleep inside her realty office) and Jane Levy's Jackie Torrance, a taxi driver and horror enthusiast. In fact, despite The Kid's trail of death that's already begun sweeping through town, he listens politely to Jackie's monologue about Castle Rock's seedy past; and, in doing so, the audience discovers an unexpected revelation pertaining to Jackie's identity that ties all the way back to The Shining.
After explaining that she wished she was alive to witness some of Castle Rock's darkest moments (referencing Cujo and The Dead Zone), Jackie explains that the only personal connection she has to anything overtly macabre is the fact that her uncle once "tried to axe-murder his wife and kid at some fancy ski resort." She then explains that her parents refuse to even acknowledge that it happened, and that she "took his name just to piss them off." She reveals that her real name is actually Diane (which may or may not be a throwaway nod to Stanley Kubrick's co-writer on The Shining, Diane Johnson).
So, even though it's unlikely that the ghost of Jack Torrance will end up strolling through Castle Rock any time soon, Jackie's connection to The Shining opens up some exciting speculation. Not only does it reinforce the fact that the shine is, in fact, an ability that characters in the show can be imbued with (see: Melanie Lynskey's Molly Strand, who just so happens to be close friends with Jackie), it posits the possibility (not likeliness) that someone like Danny Torrance (the only surviving member of the immediate Torrance family in The Shining, as well as the lead character in the sequel Doctor Sleep) can potentially make an appearance. At the very least, audiences might get a chance to personally meet Jack's older brother Mike (or his older sister Becky, assuming she kept the Torrance name).
As exciting as this scene might have been for fans, it's likely that this reference is just some offhand fan-servicing with no real narrative pull, but in a series as predicated on paving the way for major, unexpected twists as Castle Rock is, speculation never hurt. In fact, this isn't the only Stephen King reference in the episode. When Ruth Deaver is helping tie Alan Pangborn's tie, she refers to a rabbit going through a hole (like the rabbit that led Cujo to the rabid bat hole); in another scene, two young characters are named Gordie and Rennie, referencing Gordie Lachance in The Body and possibly referencing "Big Jim" Rennie from Under the Dome; Henry mentions both the Bangor Strangler (from The Dead Zone) and Juniper Hill, an asylum that's appeared in several King stories, including IT, Needful Things, The Dark Half, and Gerald's Game; and Alan refers to the fact that he's an amateur magician, which is common knowledge for readers.
Now, Stephen King himself mentioned that he'd rather audiences not dig too deep into the show's easter eggs, and simply enjoy it for what it is, so maybe Jackie's familial ties to The Shining are just that and nothing more. That said, Castle Rock could certainly use some help with the wildfires spreading over on Black Mountain, and given that the Torrance's certainly have a knack for cutting down doors with axes, Jackie may well turn out to be Castle Rock's unexpected hero after all.
Castle Rock releases Wednesdays on Hulu.