The grown-up Dan Torrance, a recovering alcoholic, just like dear old dad, now uses his ability to "shine" to help the dying cross over peacefully. He is contrasted with a young girl named Abra, who may shine even more strongly than young Dan ever did. Complicating matters are a bunch of creepy supernatural folks who seem to thrive on the energy of young shiners. Uh oh.
All of the literary links and in-jokes relating to The Shining aside, the central compelling story of Dan's link to Abra, and their desire to use and understand their abilities while staying human is what really works in Doctor Sleep. King has always got people, and how they talk and interact. The spooky stuff is actually the least interesting aspect of this novel.