It: Welcome to Derry is more than just an exploration into Derry’s lore. It shows how Pennywise came to be and how Derry became a feeding ground for the evil. One of the clearest ways the show does this is through Dick Hallorann, a character long associated with The Shining.While this allusion may make many viewers think Hallorann’s inclusion was a direct nod to Stanley Kubrick’s 1980 film, the series has drawn rather heavily from Doctor Sleep, Stephen King’s 2013 sequel.It: Welcome to Derry was not inspired heavily by The Shining but by Doctor SleepDick Halloran's internal, mental struggle emerges as the emotional backbone of Derry’s story and not just a passive easter egg. To take a deeper look, one must first understand King’s mythology.In 'King macroverse', psychic abilities, recurring symbols, and overlapping characters connect otherwise separate stories. This shared framework allows characters and ideas to echo across stories without collapsing into flat storylines or as mere crossovers.Dick Hallorann was first introduced in The Shining as the head chef of the Overlook Hotel. In the movie's lore, Halloran instantly recognizes Danny Torrance’s psychic abilities and teaches him how to survive them. View this post on Instagram Instagram PostIn the series, Hallorann keeps his touch with the culinary arts as a chef in the Black Spot. This ties him to Derry decades before Pennywise’s notorious rampage. Welcome to Derry takes that small connection and turns it into a full character study, with Chris Chalk playing a younger Hallorann in the early 1960s.In The Shining, Hallorann functions as a guide to Danny, who explains 'the shine' to him and even risks his life to help in Danny's escape. These moments not only speak about Halloran's character, but also offer limited insight into how Halloran learned to live with his powers.That missing context is provided years later in Doctor Sleep, and it is that novel, not The Shining, that the HBO series grounds itself in.The Doctor Sleep influence on IT: Welcome to DerryDoctor Sleep shows how Halloran was abused as a child and taught to lock his powers in his mind. This idea of a mental “lockbox” is woven into the narratives. It will determine how Danny and Halloran will both lock away their psychic ability.This framework resurfaces in It: Welcome to Derry, where Chris Chalk’s younger Hallorann uses 'the shine' reluctantly aware of its good side and bad. In one such scene, Hallorann instinctively knows that Leroy Hanlon has a son, a scene that briefly recalls The Shining.It: Welcome to Derry (Image via YouTube/@hbomax)Yet the emotional weight of the moment is different when Leroy confronts Halloran about using his powers without consent. This tense, grey area aligns far more closely with Doctor Sleep’s treatment of psychic awareness as something ethically fraught.A more poignant moment appears sometime later when Hallorann is coerced into opening a mental lockbox during a vision induced by It. The imagery of sealed trauma being violently released mirrors Doctor Sleep almost directly.The co-creator and showrunner of IT: Welcome to Derry, Jason Fuchs, has addressed this. He said,"You see the battle that's been waged in his mind for the entirety of his life: is this a gift or a curse? Hallorann is one of the most compelling characters in Stephen King lore, but certainly within the context of this season, there is a real battle waging for his soul. He starts out cynical and deeply selfish and goes on a journey where he has to confront all that."Instead of becoming simply powerful, Halloran is forced to decide whether his shine will continue to control him or if he will control it. By the finale, we know the source of wisdom he imparts to Danny. Thus, IT: Welcome to Derry is not recreating The Shining, but showing the psychological groundwork that makes Doctor Sleep possible.It: Welcome to Derry is streaming on HBO Max.