Castle Rock is deeply steeped in Stephen King's beloved writing. The worlds and characters that King has created serve not only as Easter eggs in the show, but important historical touchstones for many of the characters. They also provide clues for what's to come, and what's plaguing the Maine town this time around — and one of the most intriguing set of clues is the very sequence that introduces the series. The Castle Rock credits uses Stephen King excerpts to illustrate how rich this canon is, and maybe even point fans in a helpful direction as far as this mystery is concerned.
First in the sequence is a page from Needful Things, with some phrases and a psalm underlined, as well as "THE DEVIL" circled. (Fun fact — in an earlier version of Episode 2 released to press, the first page in the credits was a page from It, with some locations in Derry circled. The change itself might point to the significance of these credits. Was it important to the plot to include Needful Things in this sequence?)
The next snippet is a chapter from 'Salem's Lot — Jerusalem's Lot is another fictional Maine location in the Stephen King multiverse, found North of Castle Rock. Next is the table of contents from The Green Mile, the title page of Dolores Claiborne, and a selection from The Shining.
There's also a map of Maine that includes the fictional towns of Castle Rock and Derry, as well as references to The Mist and "Storm Of The Century." Towards the end, while some pages are too quick or out of focus to read, are larger excerpts from It and The Shining, again. Many of these pages have notes scribbled in the margins, as though someone is doing a deep study of King's world. For example, the page from It has "kidnapped" and "Ironworks explosion 1908" written at the bottom, referencing the atrocities in Derry. The words "PENNYWISE LIVES" also flash by right at the end, which is terrifying in and of itself.
Here's where it gets confusing — or at least inconsistent. There is a paper titled "Misery's Return," and Jack Torrance's "all work and no play" typed page from The Shining, as well as several handwritten notes about Cujo and a map of Shawshank Prison. These aren't novel excerpts. These are objects from the stories or characters in them. There's even what looks like a cast list floating by at one point. Plus, that "all work and no play" thing didn't happen in King's novel — it was added for the Stanley Kubrick film.
That said, the number "217" spotted in the credits is from the Shining novel. The film used a different number, 237. In fact, if you look really closely on the screen that reads "based on the characters and settings by Stephen King" (pictured below) you can see the number 217 a second time, crossed out and replaced by a handwritten 237.
So not only are the credits indicating a switch from King fiction to King fact, they're also adding in King adaptation.
What does this all mean? Is it capturing the feeling of Castle Rock, and how it treats Stephen King's multiverse like a playground of hallowed canon? Or is this somehow significant to the story? Jackie, the character played by Jane Levy, is super interested in Castle Rock history. So is Dale Lacy, the Shawshank Warden who captured Bill Skarsgård's mysterious character. Lacy actually had files and news clippings in his home that resemble the documents in the credits. He also believes that all of the town's woes are interconnected. That's why he kidnapped the Kid in the first place.
Or is this teasing some kind of meta reveal, where theses characters discover that they are part of a best-selling author's multiverse? Is reading Stephen King going to be what saves them? That might actually be too corny to be true, but every good mystery needs at least one conspiracy theory. Maybe this is a call to action for fans to start rereading King and taking notes of our own.
Most likely, the Castle Rock credits are just Easter eggs that remind us why we love King so much. There are so many stories that range from heartwarming to horrifying. So many characters we root and fear for in his works. The pages are torn up, creating sort of a collage, and that's kind of what Castle Rock is at the end of the day. Clues or not, these credits are super inventive, and you'll probably catch something new every time you see them.