So Jack—who has decided to give up on work in order, presumably, to not be a dull boy—ends this movie by freezing to death in the middle of a hedge maze, and Wendy and Danny get away in the snowcat machine.
But as if this movie weren't yet enough of a mindbender, Kubrick decides to throw in one final shot of a camera panning in on a photo on the wall of the Overlook Hotel. The photo is from 1921 and it shows an adult Jack Torrance partying with a bunch of people.
So now we're forced to ask if Jack Torrance is the reincarnation of some other guy who used to work at the Overlook. Or maybe he's been a ghost all along? In whatever case, he clearly has some investment in making sure he and his family can stay in the Overlook Hotel forever, and the only way that can happen is if they all die.
It's not easy to explain the ending of this movie, and you'll find a whole lot of arguments about it online. But in the end, it all seems to have something to do with Jack getting stuck in a time warp. After all, how else would he recognize Lloyd the bartender and all the other party-going ghosts who are supposedly from the 1920's?