The trade-offs of a surprise twist in The Intruder by Freida McFadden

I chose Freida McFadden’s The Intruder for Novel Study because her books are bestsellers among bestsellers. In 2025, she had three of the twenty bestselling books in the US and sold more than six million print copies (Publishers Weekly). What’s the secret to her success with readers? Are there craft tools she’s using that you could apply to your own work? Some of the key attributes of her books—like her surprise twists—will not work for every story or every author. Other techniques, like her rhythm of opening and closing story questions and the way she strategically positions cliff-hangers, are more widely applicable.

Let’s start by looking at my intensity graphs for the novel, which give a good snapshot of what it feels like to read a McFadden novel.

We get a couple of sharp jolts at the beginning to hook us: layered over the baseline suspense about a coming storm, McFadden deploys the hook of the titular intruder. Casey sees a face outside the window of her remote cabin in chapter 3, then discovers a girl in her shed brandishing a knife in chapter 11. The overall intensity of the action dips slightly through the middle as we spend more time in the “Before” strand we think belongs to the girl in the shed, but we still get regular spikes of higher intensity material, and then in the final stretch, nine of the last twenty-three chapters are at the maximum external intensity level, in which the stakes are life and death. In many of those chapters, the internal intensity is just as high.

McFadden is also good at using story questions to make sure readers always have something to be curious about. This graph shows the rhythm at which she first opens and then resolves story questions such as Will the roof of the house collapse? or Why is Ella going hungry?

Notice that many of the early questions can’t be resolved until the very end of the book, but that McFadden also establishes frequent short-term questions that are quickly resolved, sometimes just in the next chapter, like Who’s at the door? in chapter 5 or Is Ella going to go inside the Carters’ house? in chapter 39. Notice, too, that McFadden makes sure that at least one high-stakes story question is open at all times. For example, at the end of the novel our concern shifts from Casey to Lee to Nell’s mother; as soon as one of these characters is out of danger, the next one is under threat.

This particular technique is one that can be used for many genres and styles. For example, Liz Moore uses a similar strategy in God of the Woods, which is also a thriller and even covers some similar territory (a missing child, parental abuse) but with a much slower, more literary pacing.

McFadden also uses her chapter endings strategically, to either open a brand new question, which then operates as a cliff-hanger, or using her “resonators” to remind readers about a question that is still open. For example, at the end of chapter 8, before she’s discovered the girl in the shed holding a knife and covered in blood, Casey is evaluating the heightening storm, debating whether she should try to make it to the cabin of her neighbor Lee before deciding to stay put. The chapter ends with the line, “I only hope I survive the night,” which reminds us that the storm could be a life-or-death threat in its own right.

This graph shows the pattern of McFadden’s chapter endings, as well as providing a snapshot of her POV shifts.

Notice that very few of McFadden’s chapters have a neutral ending: only twelve out of sixty-one (20 percent). The cliff-hangers pull readers forward into the book, while the resonators draw their attention to a previous source of tension. This kind of scaffolding for readers operates a bit like the old teaching adage to preview, deliver, then review or like the “previously on…” recap that opens a TV episode. When combined with her short chapters, this technique means that busy and distracted readers can consume McFadden’s books in snackable chunks or while multitasking (for example, listening on audio while commuting or cooking or running errands).

Now, let’s discuss McFadden’s signature surprise twist, which is a feature of all of her books and I think one primary component of her popularity. Readers and critics treat the twist as her signature: in one ranking of twenty of her thrillers, the reviewer docks a novella simply for having “no big twist — which, let’s be real, is what we've come to expect from Freida McFadden.”

Crafting twists like these is harder than it may look. The entire novel must be crafted around the twist; this is not a game for discovery writers unless you are willing to commit to multiple drafts to uncover your surprise, followed by meticulous revision to weave it into the manuscript. To pull off a twist, you also have to walk a very fine line between plausibility and surprise. You have to drop just enough breadcrumbs and red herrings, in just the right places, so that readers won’t spot the twist before you reveal it, but will readily accept it once you finally do.

For example, in The Intruder, the surprise twist is that Casey, whose POV strand is labeled “Now,” and Ella, whose POV strand is labeled “Before,” are actually the same person. McFadden lures us into the assumption that the Ella POV strand is telling us the backstory of how the girl ends up in Casey’s shed, wearing bloody clothing and holding a knife with the inscription “Eleanor.” The first Ella chapter is positioned right after Casey spots “a pale face” staring at her through her window, leading us to make the connection. Then McFadden has Casey observe details that cement the connection in our minds, like the cigarette burns on the girl’s arm (chapter 17), which we soon after see enacted in the “Before” strand (chapter 22), or the green lighter Eleanor pulls out of her backpack (chapter 26), which we later see Ella receive from her friend Anton (chapter 28).

However, on a second read, you can see the buried details that make the surprise twist feel right once it’s revealed. For example, we learn in chapter 1 that Casey is sensitive to the smell of cigarette smoke (as Ella, her childhood home reeked of it) and that she has recurring nightmares about fire (as Ella, she burned down her home, killing her abusive mother).

If you do want to write an action-focused novel centered around a surprise twist, it’s worth taking the time to chart out The Intruder or another McFadden novel on a spreadsheet (here’s my template) and list every clue and red herring, as well as where she positions them. Plan out a similar progression in your own novel.

That said, there are costs to a twist like this one. The primary one is that we aren’t as deeply invested in McFadden’s characters as we could be. Because we spend almost the entire novel thinking that Casey’s backstory belongs to Eleanor/Nell, and because McFadden has to limit what she reveals about Casey to obscure the connection, it’s hard to see her as a fully realistic and coherent person.

McFadden compensates for that, I think, by hinting that Casey might be an unreliable narrator, something that comes through more clearly on a second read. For example, the Ella strand has a small subplot about her neighbor, Mrs. Fleming, who accuses Ella of stealing money from her. We’re empathetic to Ella at this point, having just seen her principal give her detention for stealing another student’s lunch rather than recognizing that she did so because she is going hungry at home. But later in the novel, Ella mentions, “A few days after I took out [Mrs. Fleming’s] trash, she slipped and fell during the night, and she hit her head really badly. She's in the hospital now, and they're not sure she's going to get better. In other news, I've had money for lunch for the entire week.” McFadden buries this aside in the midst of a high-tension scene in which Ella is, against her better judgment, going to allow her schoolmate Anton to see the inside of her house, revealing that her mother is a hoarder. It’s a clever technique, but for readers who notice it, I think the effect is to make us suspicious of Ella—a suspicion that eventually transfers to Casey.

McFadden’s choice to use first-person present narration makes us feel close to the POV characters, but in truth these characters don’t reveal very much and we can’t entirely trust them when they do. As a result, Casey’s character arc feels flatter than we might expect from someone who has experienced this much trauma. McFadden makes it clear early in the novel that Casey thinks therapists are “quacks” and the end of the novel shows us that she has converted her trauma into barely suppressed rage that occasionally breaks out into vigilante justice.

The logic holds, but the flatter character arc doesn’t move us as deeply as being in the POV of a character who experiences a more dramatic arc. (I’m thinking, for example, of the devastating ending of SA Cosby’s King of Ashes, whose protagonist shares certain similarities with Casey but who has a much more extreme arc.) McFadden’s goal is to thrill us, not to shake us or move us deeply. And that’s a fine goal and clearly popular among millions of readers, but you should be wary of using McFadden as a model if that is not your own goal for your work.

My favorite moment of the whole book is chapter 34, when Eleanor asks Casey to tell her a scary story when she can’t sleep. Casey tells a story that is laughably bad—a random collection of horror tropes held together by coincidence rather than cause and effect. Eleanor pronounces it terrible, and when Casey challenges her to do better, she nails it with a story that seems to be about Casey and Eleanor in this moment, but with a terrifying ending in which the Eleanor character cuts off the limbs of the Casey character while she’s sleeping to prevent her from telling anyone about her. The story very effectively raises the stakes—is this girl, already covered in what seems to be someone else’s blood, capable of killing Casey?—while at the same time being quite funny, especially when Eleanor patronizingly explains to Casey why it works: “What's good about that story . . . is that what’s happening in the story is similar to what’s happening here—right now. And it makes you worried that maybe those things could happen to you. Do you understand?”

This is a fun wink from McFadden to her readers, who can turn to fiction for safe thrills that may skirt the edges of truths or situations they could plausibly encounter in their own lives, even if they aren’t ready or able to confront them.

So are McFaddens’ novels useful models for your own work? That’s the first question to ask. If you want to write this kind of book—a fast, surprising read that thrills rather than moves—then it’s worth studying her closely, because there are things you’ll have to nail (the twist above all) and things you’ll have to be willing to sacrifice (the character depth that a buried backstory makes impossible). But if your goals are different from hers, there’s still plenty to learn from her novels. No matter how literary your book is, it can benefit from some of McFadden’s craft techniques—her rhythm of story questions, her strategically placed cliff-hangers, her short chapters—especially if you have a character-heavy story that drags in the middle or a plot that isn’t yet hooking or holding your readers.