Spoilers ahead for all of Castle Rock Season 2. Castle Rock Season 2 may only be loosely connected to Season 1, but it still has plenty of Stephen King Easter Eggs. In the three episodes released thus far, it primarily draws from three of King's novels: 1991's Needful Things, 1975's Salem's Lot, and 1987's Misery, the last of which is most prominent, considering Season 2 follows Misery villain Annie Wilkes (played by Lizzie Caplan). However, the story unfolds before the events of Misery, instead functioning like a prequel.
Season 2 also features Pop Merrill (played by Shawshank Redemption's Tim Robbins), a character mentioned in Needful Things, as well as his nephew Ace, who is a major character in Needful Things but may be best remembered as the antagonist of the movie Stand By Me, based on King's short story "The Body." Finally, Season 2 introduces the neighboring town Jerusalem's Lot, also known as Salem's Lot, which is a King novel about vampires.
Like Season 1, there are some meta references too. The Castle Rock opening credits highlight pages from King's works that inspired the series. As for the rest of the Easter eggs, here's a detailed breakdown (which will be updated throughout the season).
Episode 1, "Let The River Run"
- When Annie Wilkes is introduced, she's decorating her nurse's uniform with pigs. In the novel Misery, Annie has a pet pig that she names after her favorite character — and a statue version of said pig plays a role in her ultimate death.
- The fact that Annie's daughter is named Joy, the emotional opposite of misery, is also a callback to the book.
- Annie and Joy are searching for "The Laughing Place," a concept taken from Joel Chandler Harris' Uncle Remus tales that Annie references in Misery.
- Annie's car crashes in Castle Rock, and Misery begins with a car crash too.
- Ace calls Annie "Nineteen" after her cabin number, and 19 is a significant number in the King canon.
- The Merrill family owns the junk shop Emporium Galorium, a key location in Needful Things that also shows up in Pet Sematary and a novella called "The Sun Dog."
- Joy tells her mom that she feels "cabin fever-y" after being cooped up in Star Gazer Lodge. The psychological effects of cabin fever is a major theme of The Shining, as well as Misery.
Episode 2, "New Jerusalem"
- Killing Ace Merrill didn't totally stick, which may have something to do with the haunted construction site where Annie dumped his body — and could be a reference to Pet Sematary, in which a burial ground brings dead pets (and people) back to life.
- After dumping Ace's body, Annie winds up in a long tunnel that leads to the Marsten House, a key location in Salem's Lot.
- There were a number of Cujo references in Season 1, so keep an eye on Ace's dog just in case.
Episode 3, "Ties That Bind"
- Joy's new friend Chance knocks on her door and asks if she wants to go look for a dead guy. Teenagers hiking in pursuit of a dead body happens to be the plot of Stand By Me/"The Body." In King's story, Ace Merrill trails the young heroes, and in Castle Rock he's the dead guy in question.
- Actually, if the Wil Wheaton-esque haircut didn't already give it away, it's blatantly apparent by Episode 3 that Chance is the Castle Rock version of Gordie LaChance, the protagonist of Stand By Me. Her friends Vera and Timothy are therefore Vern and Teddy, respectively.
- In self-defense, Joy drugs her mother and ties her to the bed — which is what Annie does to an unsuspecting author in Misery. She even enters a scene asking, "Are you ready?" which is a reference to Annie asking. "Are you ready for the next chapter?" in Misery.
- When Ace returns from the dead, he tells his dad that he's been in Derry, the town plagued by a murderous clown named Pennywise in It.
- Back at the Marsten House, a real estate agent mentions Hubie Marsten, who infamously killed his wife prior to the events of Salem's Lot.
- Greg Grunberg's appearance as a cop isn't a Stephen King Easter Egg, but Grunberg is a JJ Abrams Easter Egg. Abrams is an executive producer on Castle Rock, and his pal frequently appears in his projects.
Episode 4, "Restore Hope"
- This episode calls back to Castle Rock's first season with the return of Pastor Drew, played by Aaron Stanton. His new role may be a twist on a character named Father Callahan from Salem's Lot and the Dark Tower series.
- Nadia finds some letters from Dale Lacy, the former warden of Shawshank who was played by Terry O'Quinn in Season 1. In the first episode of the series, Lacy died by suicide, and his headless body was found at the bottom of Castle Rock lake — an incident that Chance and her friends referenced in Season 2, Episode 3.
- Annie is watching The Wizard of Oz, which is a favorite cultural touchstone for King. He references The Wizard of Oz multiple times in the Dark Tower series.
- This is maybe a stretch, but is Councilwoman Pinto's name a nod to the Ford Pinto from Cujo?
- Ace, or whoever/whatever is speaking through Ace, takes Chris to the Church and gives him a history lesson about the true founders of Jerusalem's Lot. In the short story "Jerusalem's Lot," a prequel to Salem's Lot that you can find in the collection Night Shift, King reveals that the town was founded by a cult that split away from the Puritans, which practiced both witchcraft and incest.
Episode 5, "The Laughing Place"
- Annie's dad calls her his "number one fan," which is how Annie introduces herself to her victim in Misery.
- Annie's tutor (who later becomes her stepmother and Joy's birth mother) is named Rita K. Green, which is quite possibly a reference to Rita Desjardin, one of the teachers from Carrie. The name "Desjardin" means "of the gardens" in French, which is a similar enough parallel to "Green." In King's novel, Miss Desjardins is sympathetic towards Carrie, but laughs at the prank the mean girls pull on Carrie at the Black Prom. Carrie feels betrayed and attacks her. This parallels how Annie feels betrayed by Rita at the end of the episode. However, also like Miss Desjardins, Rita survives.
Episode 6, "The Mother"
- King has talked extensively about his struggles with drug and alcohol misuse — especially in his memoir On Writing — which came to an abrupt end when his family intervened in the '80s, per the Guardian. As a result, alcoholism often shows up in his work, so it's not surprising to see Rita struggling with her own sobriety.
- Insects are a motif that King has employed with the scorpion-flies in The Mist and the can-tam Insomnia, and they come into play again here with the cicada-like bugs following Ace around town.
- Perhaps this is looking too much into it, but the name on one of the coffins underneath Castle Rock, Amity Lambert, could be a reference to Mary Lambert, who directed 1989's Pet Sematary.
Episode 7, "The Word"
- As mentioned, "19" is a common motif in King's work, and "The Word" includes several flashbacks to the year 1619. That's when Amity Lambert converted the entire town into a Satanist cult, burned any dissenters at the stake, and went on to kill everyone in town with the assurance that they would be resurrected in 2019 — on the 400th Anniversary of Castle Rock/New Jerusalem.
- After the hooded figure hypnotizes the parade attendees, Pop sees the wooden statue through the reflection of a helium balloon. It may have been gold and not red, but balloons are a reference to It.
- In the final moments of the episode, it's revealed that the hooded figure is in fact Bill Skarsgård's mysterious "Kid," who was locked up below Shawshank at the end of Castle Rock Season 1.
Episode 8, "Dirty"
- Annie goes into the basement in Marsten House, which looks an awful lot like the one in Misery. Vulture also pointed out that you can see a sledgehammer in the corner (which she later uses as a murder weapon). This is the tool Annie uses to break Paul Sheldon's feet in Stephen King's 1987 book and the subsequent 1990 movie.
Episode 9, "Caveat Emptor"
- Ace hypnotizes nearly all the townspeople, leaving the streets eerily empty. As the official Castle Rock Twitter account pointed out, an evil force corrupting a small town is a common motif in King's works, appearing in Needful Things, Salem's Lot, and The Tommyknockers.
- After Jamal is tied down to a hospital bed, Annie sticks two syringes into his eyes. Both being strapped down to a bed and being threatened with syringes are reminiscent of what Annie would do to Paul in Misery when he didn't cooperate.
Episode 10, "Clean"
- Ah yes, the pièce de résistance. After Annie and Joy flee town, the nurse finds a book called Misery's Quest by one Paul Sheldon. This is, of course, what begins her obsession with the author in King's book. Later, she and "Joy" go to a book signing, where the author reads from Misery's Love. In the audience, Annie informs her daughter that she's Paul's number one fan.
- Annie finds Joy's sketchpad, which is filled with disturbing drawings likely inspired by her hypnotism. As she flips through the pages, Annie becomes more and more upset, which might be reminiscent of Shelley Duvall's character in The Shining finding Jack Nicholson's pages, which just read, "All work and no play makes Jack a dull boy," over and over again.