One of the interesting things Flanagan does here is that he finds a way to bring Stephen King’s original “Shining” ending to the screen.
Kubrick’s film ends with Jack Torrance chasing his son through a snowy hedge maze outside of the haunted hotel. Jack is totally demented at this point, the evil of the hotel infecting him so deeply that if he catches his son he will definitely kill him.
King’s book paints Jack as a more tragic figure with a good man still buried deep inside there somewhere. The good side of Stephen King’s Jack Torrance fights back, wrestling control over himself long enough for him to blow the hotel’s boiler (and himself along with it), giving his wife and son a chance to escape.
The author has used the two endings to illustrate the difference in approach to the material between himself and Mr. Kubrick. The film ends with Jack frozen, the book ends with a roaring blaze. The former is cold, the latter is warm and according to King that’s all you need to know about the book and the movie.
Flanagan incorporates the original “Shining” ending into “Doctor Sleep” by giving Danny Torrance his father’s arc. Jack Torrance inflicted untold horrors on his boy’s psyche, traumatizing him but good for the rest of his life, but he also managed to teach his son by example. Danny Torrance knows what kind of monster he could become if the booze or ghosts or whatever problems he has gets the better of him because he’s seen it before, up close and personal.
You’ll notice this thread is developed visually and thematically on Danny’s journey to protect a young girl with “The Shine” from a band of near immortal transient monsters calling themselves The True Knot. He has a job interview that is framed and executed in exactly the same way as Jack Torrance’s interview to become caretaker of the Overlook. He has a moment of temptation with his very own Lloyd the Bartender. But in every mirrored moment where Jack Torrance gave into the darkness, Danny rejects it.
Could that be the lasting legacy of his father; the one good thing to come out of his struggle with his inner demons? He set an example for his son.
In that way, this story serves as a small redemption for Jack Torrance, both the highly tortured and complicated man that King wrote and the cracker jack loon that Jack Nicholson played in Kubrick’s film.