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The novel’s teenage character Ella, who holds her own against the threat closing in on her family’s remote cabin, was not invented from whole cloth. McFadden was watching someone very close to home while drafting her.
One of my biggest inspirations for this book was my own daughter, who is about the same age as Ella, and in my opinion, just as much of a badass.
McFadden has written cruel mothers before, and the pattern is not accidental. She has a clear theory about what that particular wound does to a person over a lifetime, and it keeps drawing her back as a starting point for her most complicated characters.
A childhood plagued by a cruel mother is the perfect ‘origin story’ for a villain or antihero.
The mother-daughter axis gave her the right container for something she has felt strongly enough to repeat across her catalog: that life fails to balance the ledger, and fiction is where she gets to correct that. She named the book specifically when making the case.
My general feeling is that in life, people rarely get exactly what they deserve. But in art, you can dole out that poetic justice, which I enjoyed doing again in The Intruder.
That phrase, ‘again in The Intruder,’ is worth pausing on. The satisfaction she describes is not new to this novel; she has been building toward this kind of reckoning for years, and here she found another vehicle for it.
Before a word goes on the page, the book has already been living in her head for a long time. The speed readers see in her output comes from compressing the visible phase, not the thinking phase.
I spend a lot of time planning the book in my head and the physical writing is quick. I’ll think about a book for months and then I like to blow through the first draft really fast because once I’m writing, it’s all I can think about.
That mental orientation toward catastrophe, which she named in a Reader’s Digest interview specifically in the context of discussing The Intruder, is not a skill she had to cultivate for this genre. It is simply how her imagination runs.
I’m always the person who imagines things going wrong. So it’s not hard for me to get in that frame of mind.
When a concept stalls before the drafting sprint can begin, she has one main tool for breaking the logjam. Her husband is a sounding board of last resort, and she describes his contribution in a way that admits it is as much about her needing to externalize the problem as about any advice he gives.
If I have a seed of an idea and I’m struggling with it, I’ll talk to him about it, and he’ll kind of spit ball things — he’ll make fun of me, usually, because he can’t help himself — but I think just the act of talking it out to somebody helps so much.
The twist problem is structural for the whole genre right now, not just for McFadden personally. She articulated the arms race facing any thriller writer: readers who have consumed enough of the form have internalized the moves, so the bar for surprise keeps rising. The example she gave is deliberately absurd, but the underlying pressure is real.
You have to step out of the box of: ‘The suspects were A, B, C, D, and A is the killer.’ It’s not even enough to say E is the killer. It has to be E is the killer because he is actually B and was the victim’s mother and his daughter, and also was dead the whole time.
She noted that reaching a concept that clears this bar can be frustrating, but satisfying when it finally clicks. For The Intruder, which pivots on revelations about who Casey and Eleanor actually are to each other, the frustration clearly paid off.
McFadden wrote her thrillers anonymously for years, keeping her legal identity as Sara Cohen, a physician specializing in brain injury, entirely separate from her pen name. She disclosed her real name publicly in April 2026. That long gap between the private self and the public author sharpens what she said on Jenna Bush Hager’s Open Book podcast in December 2025, when she described how exposed the books themselves have always made her feel.
These books come from inside my brain. It’s almost like, when people are reading it, it’s like they’re reading my diary, and it’s a little embarrassing.
Casey and Eleanor, the novel’s two central figures, are not set up as heroine and villain. McFadden has described this as a deliberate construction, not a side effect, and her reasoning is about what makes a character worth following for three hundred pages.
I love writing morally grey characters. I’m intrigued by the idea that a person can be good deep down but still do bad things. Or a person can be mostly ‘evil’ yet still have sympathetic qualities. Someone who does nothing but good things is not interesting to read about, in my opinion!
The darkness in her books is not the whole picture. McFadden is consistent on this point across interviews: she runs a counterweight of humor through even her most unsettling scenarios, and she treats that as a feature of her sensibility, not an occasional relief valve.
I don’t like to take myself too seriously, and that translates into my books.