Warning: SPOILERS ahead for Doctor Sleep.
Doctor Sleep, the film adaptation of Stephen King's sequel to The Shining, introduces a frightening new antagonist: Rose the Hat (Rebecca Ferguson), who leads a tribe of near-immortal creatures that feed on children with psychic abilities. These "shine vampires" are people who had the shining themselves before their transformation, and maintain their psychic abilities - which include everything from astral projection to mind control.
Danny Torrance (Ewan McGregor) is a grown man in Doctor Sleep, and after struggling with drug and alcohol abuse manages to get clean and even find a benevolent use for his abilities: working as an orderly in a hospice, and providing comfort to people before they die. He also develops a "penpal" relationship with a girl called Abra Stone (Kyliegh Curran), who has extremely powerful psychic and telekinetic abilities. Unfortunately, her shine makes her the new prime target for Rose the Hat and her gang, the True Knot, and Danny is forced to emerge from his peaceful life and do battle with the forces of evil once again.
But what exactly are the forces of evil? Let's dig into what the True Knot are, how they feast on children with the shining, and how the Overlook Hotel and its ghosts fit into the mythology.
Rose the Hat's Origin
Much of Rose the Hat's past is left deliberately shrouded in mystery, though in her first scene she tells her poor unsuspecting victim, Violet (Violet McGraw), that she earned her nickname because she has always worn her hat. King's novel reveals that her original name was Rose O'Hara, and her accent gives away the fact that she's from Ireland. Though she's not the oldest member of the True Knot - that honor goes to Grampa Flick (Carel Struycken) - she is the leader of the group, and is centuries older than she actually appears. Like everyone else in the True Knot, Rose started out as a child who had the shining, but at some point underwent the Turning and began feasting on others in order to live longer. Rose is capable of far-reaching astral projection and of peering into other people's minds - though her abilities pale in comparison to Abra's.
How Shine Powers, Steam & Vampires Work
"The shining" was the term that Dick Halloran used for his and Danny's psychic powers, but the True Knot instead call it "steam," and this steam is the substance that they consume to prolong their lives. Some people are more "steamy" than others; for example, Bradley "Baseball Boy" Trevor (Jacob Tremblay) has just enough steam to be able to read the intentions of a pitcher, and for others their shine/steam can be as low-key as knowing instinctively when to bring home flowers for an unhappy spouse. Rose and Crow Daddy (Zahn McClarnon) have a discussion about how the world is a lot less "steamy" than it used to be, making it harder and harder to find food sources. They prefer to feast on children because, as Rose explains to Danny in the movie's final act, the steam becomes corrupted as people grow up
While the shining usually manifests as some kind of psychic ability, it can vary from person to person. Snakebite Andi (Emily Alyn Lind), for example, is a "pusher" - someone who can control people by giving them instructions on what to do or feel. Danny can get psychic readings from people by touching them, and can also see ghosts. Abra, however, is the most powerful of all: able to sense the True Knot's attack on Bradley from hundreds of miles away; able to locate Rose the Hat and from a similar distance and explode the glass door in front of her; and capable of building complex psychic traps. In addition to extending their lives, shine vampires can also heal rapidly by consuming steam - but they can be killed in all the same ways as humans (no stake to the heart required).
So, how does a person with the shining become a shine vampire? The True Knot offer a demonstration when they put Andi through a ritual called "the Turning," in which she consumes some of Violet's steam from a canister. The cannibalistic nature of eating another person's steam turns Andi into a shine vampire, which works in a very similar way to traditional vampire mythology. She gains extremely long life, but only for as long as she can continue to find food sources, and when she dies she collapses into nothing but steam, leaving neither a body nor a ghost behind (similar to how vampires have no souls, and turn into dust when they die). We also get to see what happens when a member of the True Knot dies from old age, as Grampa Flick's funeral ends with the rest of the tribe feasting on his steam.
Grampa Flick, it's revealed, was able to live for thousands of years by feeding off children with the steam, and the True Knot offer a gruesome demonstration of exactly how they feast when they lure in Bradley Trevor. They stake him out on the ground, and Rose the Hat tortures him with a knife in order to release the steam (as Rose explains, "pain purifies the steam, so does fear"). As with vampires, it may be possible to consume just some of the steam and leave the victim alive, but the True Knot do not do this. Instead, they torture their victims until every last bit of steam has been released, at which point the child is dead. They then bury the body and move on, storing part of the steam in canisters decorated with souvenirs from the victim.
The Overlook and its Ghosts Also Feed on Steam
Shine vampires aren't the only creatures out there that prey on children with the shining. The Overlook Hotel itself is a hungry monster that consumes psychic energy, trapping the souls of people who die there and turning them into twisted spirits that, like the True Knot, feast on steam. When the rest of the True Knot have been eliminated in Doctor Sleep, Danny and Abra are left facing Rose the Hat, who is more powerful than the rest. Danny decides to stage a trap for her at the Overlook Hotel, but in doing so knows that he'll be putting both himself and Abra in danger.
The Overlook can take possession of people who have the shining, which is why it wasn't able to control Wendy Torrance, but was able to take hold of Jack Torrance. However, it appears that the hotel can only possess people whose steam has been weakened or corrupted somehow, lowering their psychic defenses, which is why both Jack and the adult Danny Torrance were tempted to drink in the hotel bar. Most frightening of all, the ghosts that inhabit the Overlook can leave if a particularly tasty meal tempts them away, which is how they end up following young Danny and, later, Abra.
Given all that we learn in Doctor Sleep, it's easy to see why the True Knot are running out of food, and why the world is getting less "steamy": there are a lot of predators out there. Both The Shining and Doctor Sleep offer a metaphor for how being sensitive and talented can make a person vulnerable - not only to others who want to prey on them, but also to corrupting influences like drugs and alcohol. And while Rose the Hat was not the last shine vampire in the world, the movie ends on a hopeful note as Abra prepares to banish the old lady ghost in the bathtub who has followed her home. If anyone can resist the shine vampires of the world, Abra can.