This post first appeared on Quora March 15, 2020.

The embodiment of our worst nightmares as humans: being vulnerable and at the mercy of someone incapable of kindness.

Annie Wilkes is a nurse. We tend to trust nurses. Nurses are awesome (and I’m not just saying that because my mother was a nurse for 52 years and saved countless lives).

We place our trust in nurses every day when we’re ill, when we need help. They help us. Oftentimes they comfort us when we’re down. They make our hospital stays bearable. They put up with our blood, vomit, urine, feces, and our general crabbiness. The really good ones—the masters of their profession—help you not feel self-conscious about a sponge bath or that crappy rash you have all over you. Nurses hold your hand when you’re scared. They reassure you that they’ll do everything they can to help you.

Annie Wilkes? Not so much. She’s Nightmare Nurse. She knows exactly how to make you hurt (as RNs do) and goes through with it. A good nurse might want to give you 20 cc of air if you’re a particularly ornery patient, but he or she would NEVER do it. Wilkes would. She’d try to shut you up in a heartbeat (pardon the pun).

Perhaps it’s her obsessive devotion to her favorite writer that twists your mind. The relationship between writer and fan is an intimate one. Though the writer doesn’t know every reader by name, the readers often feel a sense of intimacy with the writer, as if they know the person through their writing. This twist here, with Annie being Paul’s “number one fan” means that Paul’s life is in danger. A person who should be kind to him, help him recover, and take care of him has turned on him because of her delusion that they have some kind of intimate relationship.

Annie is not stupid. Her linguistic skills aren’t the best but she catches on quick to subterfuge and is far more clever than people estimate. It is in this miscalculation of her intelligence that adds to her terror—she holds the element of surprise.

She is cunning, manipulative, and in control while Paul is vulnerable. This vulnerability is something that could happen to any one of us—and may the heavens forbid that we wind up under the care of someone like Annie Wilkes.

Representing the unexpected, the control over the vulnerable, and the loss of body autonomy is what makes Annie Wilkes so successful and terrifying as a villain.