Anne Marie "Annie" Wilkes was the hidden main antagonist of Misery. She was Paul Sheldon's arch-nemesis.
Wilkes is a former nurse, living in the mountains near Sidewinder, Colorado. She seemingly has deliberately chosen to live there because her favorite novelist, Paul Sheldon, often retreats to the area to write his books in seclusion at a cabin he rents. Paul is the bestselling author of the Misery series, a collection of 19th century romance stories starring Misery Chastain, a young woman whose adventures in love and the culture of the times have great appeal to readers everywhere. The latest book in the series, Misery's Child, ends with the death of Paul's heroine in childbirth, a career move Paul had been working toward for years; wanting to "kill off" the character and cease the series in favor of writing about other subjects and characters.
When Sheldon finishes his latest novel, Fast Cars, about urban car thieves, he drives out from the cabin and is caught in a sudden snowstorm. Before he left his cabin, Paul had been drinking champagne in celebration, which impairs his driving skills. His car slides badly on the snow-covered mountain road and crashes down an embankment. Paul is severely injured; both his legs are badly broken. Before he dies, he's pulled from the car by Annie Wilkes, who takes him to her secluded farmhouse. She feeds him and tends to his injuries, giving him a heavily codeine-based (fictional) drug called Novril to help him with the pain. Paul is initially unconscious for several days and he has vague recollections of Annie having to perform CPR on him when she gives him too much of the drug, which represses his respiration.
When he wakes up, Annie introduces herself but Paul realizes very quickly that Annie has him trapped in the guest room of her house -- she tells him the storm is too severe to call an ambulance or take him to a hospital -- that he's become addicted to Novril and that Annie, a religious fundamentalist, is psychotic and keeping him in her house for her own purposes. She tells him she's his "number one fan" but it becomes very apparent that she's obsessed with him. She has read all the Misery novels and is currently at work on Misery's Child which she'd bought only a few days before.
When Paul gives Annie his permission to read the manuscript for Fast Cars, she tells him that she dislikes it, believing it to be too profane. While feeding him soup, she becomes increasingly agitated while Paul tries to explain that the language in the book is typical of urban street kids. Objecting loudly, Annie has an outburst of pure rage and throws the soup bowl at the wall, making a mess she blames Paul for. She spends a solid hour cleaning the mess and denying Paul his medication. When she finally does bring it to him, she forces him to wash it down with the rinse water from the bucket she'd been using.
Annie also flies into a rage when she finishes reading Misery's Child and discovers that her beloved heroine is now dead. After ranting at him for several minutes and manhandling him, causing him extreme pain, she locks him in the room and leaves the house for two full days. Unfed, dirty from wetting the bed and without his medication, Paul suffers horribly until Annie returns. She continues to withhold her care of his injuries, refuses to feed him and withholds Paul's medication until he burns the manuscript for Fast Cars as a penance. After several more hours in agony, Paul willingly burns Fast Cars and she gives him his medication. Paul drifts off vowing to eventually kill her.
A few days later, Annie surprises Paul with a used wheelchair and a Royal typewriter. She tells him he'll write his next novel in her home, Misery's Return, where he'll bring Misery back to life and that it will be an exclusive: they'll have it bound and Annie will own the only copy. When he tells her that the paper she's bought for him is unsuitable for his needs because it smudges easily, she again becomes enraged, pounds his shattered left knee, and storms out to get him better paper. Despite again being in extreme pain and weak from being sedentary, Paul is able to escape the room with a bobby pin that had fallen out of Annie's hair. He finds her stash of Novril, taking some for himself, along with a small amount of food from her pantry. When he tries to use the phone to call for help, he discovers that the line is dead. He quickly returns to the room when he hears Annie approaching, barely making it in time. Annie's attitude has changed from when she left; she blames herself for Paul's suffering while she was gone and treats him well.
Paul spends the next weeks and months writing the book under Annie's hawkish eye. She isn't fooled by any literary tricks he tries to use in bringing Misery back to life but, at one of Annie's suggestions, he eventually figures out a story angle involving a near-fatal bee sting. Annie is delighted with the new turn and even becomes pleasant, not showing her usual symptoms of psychotic rage. Paul realizes that without his usual lifestyle of smoking, drinking, parties, bars and casual sex, he is more productive than he's been in years. One recurring annoyance however, is that the typewriter she gave him keeps dropping it's key strikers: it was missing the "N" when she presented it to him and it later drops it's "T" and "E", which constitute the most frequently used letters in English. Paul does find a good use for it as a weight to exercise his arms.
Paul notices a period where Annie becomes extremely depressed. She becomes increasingly inattentive to his needs and her physical appearance suffers. She tells him she's leaving for a few days. Paul sneaks out of his room a few times during her absence, stealing food and Novril. Eventually he finds an old scrapbook of hers; in it are personal items, photographs and many news clippings. To Paul's horror, he pieces together Annie's past: she was a registered nurse who secretly killed patients who were suffering from chronic or deadly illnesses. She'd been brought up on charges several times but was never convicted for lack of evidence. Paul now believes the only way he'll survive is to kill her himself. He takes a kitchen knife and hides in between his mattresses. When Annie returns, she waits until he's asleep and injects him with a heavy dose of morphine and straps him to the bed before he can kill her. She tells him she figured out how he escaped his room -- she'd found a small piece of one of his bobby pins behind the doorknob plate. She tells him she's going to punish him by "hobbling" him: she uses an axe to cut off one of his feet. Before Paul can bleed to death, she cauterizes the stump with a propane torch.
Weeks later, a local sheriff shows up at Annie's house. At first frozen with fear, Paul takes an ashtray Annie had given him for his work and throws it through the window, drawing the sheriff's attention. Though he recognizes Paul immediately, he's too late to react when Annie, on her riding lawnmower, stabs him viciously with a cross she'd made while burying one of her dead cows. She repeatedly stabs the sheriff with the cross, rendering him barely able to move or defend himself. When he's finally able to grab his dropped revolver, Annie drives her lawnmower over his arm and then over his head. Annie comes up with a plan: she'll take the sheriff's body and his car up to a remote cabin she calls her "laughing place", the same spot she went to when she left Paul alone. From there, she'll ride a motorcycle she has stored there. However, she refuses to leave Paul alone in his room and locks him in her basement. While he's down there, he steals a can of charcoal starter fluid.
Paul tells Annie he's nearly finished with the book and he'd like to celebrate in his traditional manner: by smoking a cigarette and having some champagne. She agrees and surprises him with a large plate of expensive caviar, which Paul enthusiastically devours. She gives him his cigarette and a single match. When she leaves to get the champagne, Paul soaks the manuscript with the starter fluid and lights it on fire when Annie returns. Like Paul predicted, Annie seizes the book to douse it with water. He clubs her with the Royal typewriter and tackles her when he's able to stand on one of his broken legs. After a brief struggle where Paul stuffs burned and charred paper down her throat, she trips on the Royal typewriter and knocks herself cold when her head connects with the fireplace mantle. Paul escapes from the room just as the police arrive. Screaming a warning to the cops when they check out the room, they find she's gone, having jumped out the window. Paul is panicked but they later find out she'd reached her barn and died of hemorrhaging from a fractured skull. The police find her with her chainsaw in her hands.
Months later, Paul is living in New York City and suffering from writer's block. His doctors have promised he'll one day walk without crutches but Annie continues to haunt him and he drinks heavily to escape the trauma. He suddenly remembers seeing a boy on the streets with a skunk in a box and becomes inspired and furiously begins to write again.