Rob Reiner and William Goldman are just about the last people you'd expect to team up to make a great horror movie, but Misery is not only one of the very best Stephen King adaptations, but also a truly unsettling and suspenseful piece of filmmaking. It may be Reiner and Goldman's backgrounds in other types of movies that allow them to make Misery so fascinating and disturbing; they're not concerned with goosing the audience or grossing them out, and the horror of the movie comes purely from the dynamic between the two main characters. Kathy Bates deservedly won an Oscar for her performance as obsessed fan Annie Wilkes, but James Caan provides the perfect balance for her as author Paul Sheldon, whose cynicism and pragmatism is a great contrast to Annie's delusions. It's easy to identify with his terror as he slowly realizes just what kind of person has "rescued" him from his car accident, but he's never a helpless or hapless victim.
That straightforward ingenuity works for the character, but it also means that Caan underplays while Bates steals the show as one of the best villains in the whole King canon. One of the scariest things about Annie is how close she is to being just a normal eccentric, the lonely middle-aged lady who buys romance novels at the grocery store and engages in pointless small talk with the clerk, then goes home to her empty house. Her fandom is recognizable, especially 20 years later in the age of J.K. Rowling and Stephenie Meyer, and Bates easily connects that creepy if innocuous obsession to the more deadly variety that consumes Annie. Reading about the kind of vitriol directed by "fans" at people like George R.R. Martin, it's easy to imagine someone taking a fairly small step to where Annie is.
Bates and Reiner both do a great job of showing Annie's escalating grotesquerie; one of the movie's wonderful touches is how often Bates is shot from below, putting the audience in Paul's perspective as she looms over him, taking up his entire field of vision. We're right with him when he finally takes Annie out, but Bates is able to give her enough sadness that we sort of feel bad for her, too. If she maybe got herself some psychiatric meds and had lived in the age of the internet, she'd be semi-stable and spending all her time on Paul Sheldon message boards pillorying her favorite author for killing off her most beloved character. As usual, it's the identifiable human element that makes evil that much more tragic and disquieting.
How far to Castle Rock:Misery takes place in King's second favorite state, Colorado, with no mention of the small Maine town.