Why HBO's It: Welcome To Derry Is Crucial Viewing For Fans Of Stephen King's Other Novels

This post contains major spoilers for Stephen King's "It."

Andy Muschietti's "It" (and his 2019 follow-up, "It Chapter Two") make a spirited attempt to flesh out Stephen King's complex horror multiverse as portrayed in the eponymous novel. However, these entries barely scratch the surface in terms of the surreal origins of Pennywise the Clown, along with the multiversal implications that have connections to some of King's novels. This urge to delve deeper necessitates Muschietti's highly anticipated "It: Welcome to Derry," which will serve as a (potentially) multi-season prequel series unraveling the eerie reality of living in Derry, Maine. Per November 2025's issue of SFX Magazine, showrunners Andy and Barbara Muschietti intend to cement the basics of this world in the first season and use subsequent seasons to "look into all the bigger questions" about the titular monster, It.

While the films offer a rather streamlined explanation of Pennywise's origins, it doesn't explain its homeworld — known as the Macroverse — and how it's connected to our own. "What I want the audience to feel is that everything they know about It is just the tip of the iceberg...," Muschietti explains in the interview, while also stating that the show's lore will tie into key multiversal figures from King's other novels:

"It is not only revealing the lives and struggles of people in Derry in the past and their connections with the characters that we know, but also it will be a breach into and towards the other side, the Macroverse, the other dimension that Stephen King talks about in so many of his books [...] That line that crosses across so much of his work, which is basically the world on the other side – the Macroverse, the turtle, Gan, the Crimson King, and the Dark Tower and the pillars around it."

The name Maturin might not ring a bell in relation to Muschietti's "It" movies (despite some blatant Easter eggs), but this is "the turtle" that the director is referencing in the abovementioned quote. Maturin is no ordinary turtle, as he is said to have vomited out King's fictional universe (!) that is supposed to mirror our own, and is considered Pennywise's mortal enemy. Maturin's moral allegiance seems to be leaning towards benevolence, and he either appears or is mentioned in some of King's novels, including "Wizard and Glass" and "The Dark Tower." Moreover, it is known that the giant turtle communicates directly with Bill Denbrough in King's "It," where he urges the child to stand by his friends and perform the Ritual of Chud.

Maturin is an integral part of the Macroverse, but there's much, much more to this extra-dimensional space that Muschietti wants to dissect in his upcoming show. The true nature of Pennywise's evil can only be understood if we peer deep into the abyss, which might explain what It truly wants and why it chooses to terrorize Derry, of all places. "What does It want? Why is It here? All the cryptic elements of It, we're going to ruin and explain, Muschietti humorously states, making it clear that the scope of the story is far beyond Pennywise and his earthly reign of terror.

It goes without saying that die-hard King enthusiasts who are enamored by the Macroverse and its associated elements will find "It: Welcome to Derry" especially intriguing. This doesn't necessarily exclude complete newcomers or casual viewers, as the series could serve as an entry point into King's dense worldbuilding and the terrifying primordial creatures that are a part of it.