"But the most glaring shift, one that colours the book entirely, is tonal. In the book, King goes to great pains to stress that Jack Torrance is a good man. He was a teacher, and he developed a problem with drink just as his father had. When he accidentally breaks Danny's arm, Jack realises he has to change his ways. He's scared of the past and who he could become. He wants to make amends, and the hotel offers security and time with his family. King wants us to feel empathy for Jack. Everybody screws up, he wants us to say; everybody deserves a second chance.
In the movie, however, Jack Torrance is Jack Nicholson. He's crazy from the start, the man you saw in Easy Rider and One Flew Over The Cuckoo's Nest. He's got that manic grin and unkempt hair, and you don't trust him. He has a swagger and a temper, and there's a constant feeling that Wendy (Shelley Duvall) – so much more timid and subservient in the film than the novel, reduced to little more than a long face and a shrill voice – hasn't left him because she's just too weak. In the novel, she wants her husband back. And Danny …"
"In the novel, as in so many of King's early classics, location is all. The Overlook Hotel itself is alive; huge and vacant, with secrets hidden everywhere. Haunted bathrooms, the echoing memories of debauched parties, a topiary animal garden that seems to come to life, wasps' nests that feature a never-ending stream of hostile insects. The hotel wears its malevolence on its sleeve. It has a history of bringing power towards it, and of trying to grow by consuming that power. Jack hears the voice of the Overlook as the novel progresses – his own touch of the shining – and it gnaws at him, turning him away from his family. It wants Danny, because of his special ability and whether it gets him or not is down to Jack. As Wendy explains to her son, "It wasn't your daddy trying to hurt me … the Overlook has gotten into your daddy!" Jack's misdemeanours – his failings as a father and husband – aren't even his own. The primal thing that makes him who he is, which he's so desperate to supress, is what the hotel thrives on. In the movie, he's a monster. The hotel isn't alive: Jack might be possessed, he might not. Either way, he's a bad man. What happens would have happened anyway, even if they hadn't been able to see the hotel's ghosts; the memories of those it has left for dead"