There is something particularly effective about a mystery that refuses to give you a trustworthy person to stand behind. Usually, when a thriller introduces multiple suspects, the fun comes from trying to work out which one is guilty. Killing Sadie, Rachel Peterson’s debut YA thriller, makes that question a lot messier. What if everyone has a reason to lie?
The novel opens with a nightmare already in progress. At a notorious barn party, seventeen-year-old Sadie Cooper has been stabbed. Beside her is Mason Vreeland, the boy everyone assumes is responsible. Before the situation can become an open-and-shut murder case, Sadie’s boyfriend, Ben Carrera, kills Mason during a confrontation. Two teenagers are dead, and pretty much everyone has a version of what happened. The problem is that those versions don’t match.
Book Overview: Killing Sadie
Content Warnings: murder, stabbing, gun violence, death of a teenager, grief, blood and injury, bullying, mental health struggles, auditory hallucinations, underage drinking, and manipulation and gaslighting
Summary: Here’s what we know: there was another infamous barn party at the McClain family farm last night, and things went horribly wrong. By the end of the night, there were two dead bodies in the old barn: seventeen-year-old Sadie Cooper and her killer, Mason Vreeland. The murder was heartbreakingly witnessed by Sadie’s twin sister, Jayne, and Sadie died in her arms. Mason was killed by Sadie’s boyfriend, Ben, in an attempt to save Sadie.
Aside from figuring out Mason’s motive, it should be an open-and-shut case.
But it’s not.
The story unfolds just after the murders, and Jayne, Ben, and Sadie’s best friend, Liz, are telling the cops what transpired at the party and the events leading up to it. But little details don’t match. And those little details start to add up to big discrepancies. But who’s lying, and why?
The shocking truth is revealed in the third act, when the POV shifts to Sadie herself in the days leading up to the party. Witness exactly what happened—and see if you can piece it all together. Because poor Sadie totally missed what was right in front of her.
So Who Do We Actually Believe Here?
Peterson builds the story around three narrators. There’s Sadie’s identical twin sister Jayne, her best friend Liz, and Ben. Each one recounts the events surrounding the party, including the days leading up to it, and each perspective introduces new information that makes the previous one harder to trust. A conversation happened differently. Someone was somewhere they claimed not to be. A relationship isn’t quite what it seemed. A detail that initially feels insignificant suddenly becomes suspicious.
And then there’s Sadie.
Peterson wisely saves Sadie’s perspective for the third act, appropriately titled “Dead Girl Talking.” We think this is one of the novel’s strongest structural choices, because the entire book is built around the question of who gets to tell the truth. Sadie is the person at the center of everyone’s story, yet she’s the one person who cannot correct anyone else’s version of events. Giving her a voice only after her death doesn’t just add another perspective. It forces us to reconsider everything that came before.
That is where Killing Sadie is at its most interesting.
The Real Question Was Never Who, It Was Why
The novel’s central idea isn’t really “who is lying?” Peterson has essentially answered that before we can even ask it. Everyone is. The more interesting question is why. Every narrator has something to protect, and every character has a perspective shaped by grief, jealousy, guilt, loyalty, resentment, or fear. Truth becomes less like a fixed point and more like something everyone is constantly bending to protect themselves or someone they love.
Jayne, for example, is devastated by losing her twin, but grief doesn’t make her objective. Her fierce protectiveness of Sadie exists alongside resentment toward Liz and a need to control how people understand her sister. Liz is the impulsive “party girl,” but reducing her to that stereotype misses the complicated loyalty and emotional vulnerability underneath. Ben initially appears to be the protective boyfriend who stepped in when Sadie needed him, but his anger, trauma, guilt, and secrecy make that heroic image increasingly unstable.
None of them are particularly easy to like. That’s a compliment.
Peterson understands that a thriller becomes much more compelling when its characters are allowed to be messy. These aren’t perfectly innocent teenagers waiting to be cleared of suspicion. They’re teenagers with grudges and secrets and complicated relationships who happen to find themselves in the aftermath of a horrific crime. Their flaws aren’t simply obstacles between us and the solution. They’re part of the mystery itself.
Sadie Deserved To Be More Than A Body
Sadie herself is perhaps the most fascinating example. Before her death, she appears to be the quintessential popular girl, all charisma and confidence and social power, sitting right at the center of her community. But the later revelations about her private struggles complicate that image. Her narration adds an unsettling dimension to a girl whom everyone thought they understood. It also changes the emotional weight of the murder.
A weaker thriller might treat Sadie primarily as a body around which everyone else gets to have a story. Killing Sadie eventually gives her back some agency. Her voice reminds us that the victim isn’t simply the answer to a mystery. She was a person with fears, secrets, relationships, and an interior life that the people around her couldn’t fully see.
The Ohio setting adds another layer to all of this. The rural barn-party backdrop feels distinctly Midwestern, and the relatively close-knit community amplifies the sense that everyone knows everyone, or at least thinks they do. Social hierarchies, class differences, bullying, and assumptions about outsiders all shape how the characters interpret Mason and Sadie’s death.
Mason is particularly interesting here. He’s initially easy for everyone to categorize as the strange outsider, the loner, the obvious culprit. The novel gradually asks us to examine how quickly people decide who someone is based on reputation. In a story where nearly everyone is concealing something, the character who seems easiest to understand may be the one we should be questioning the most!
The Structure Is The Whole Magic Trick
Structurally, Killing Sadie is at its best when it leans into that uncertainty. The interrogation-room framework keeps the story moving while the flashbacks steadily fill in the gaps. Instead of giving us one complete version of the night and then revealing that it was false, Peterson layers competing accounts on top of one another. The result is a narrative where every new piece of information can either solve the puzzle or make it significantly more complicated.
That approach also makes the book extremely readable. Short chapters, shifting perspectives, and frequent revelations create the kind of momentum that makes “just one more chapter” a dangerous proposition. The book clearly understands the appeal of the modern YA thriller. Give readers a murder, surround it with secrets, add several emotionally complicated teenagers, and then keep moving the goalposts.
Does the book reinvent the YA murder mystery? Not exactly.
This is probably the biggest weakness of Killing Sadie. Readers familiar with Karen McManus, Holly Jackson, Natasha Preston, or the broader wave of YA thrillers built around secretive teenagers and multiple perspectives will recognize the blueprint. The popular girl, the outsider, the complicated friend group, the party, the unreliable narrators, and the revelation that everyone has something to hide are all familiar territory. But originality isn’t the only measure of a thriller’s success. The more important question is whether Peterson can make familiar ingredients feel compelling, and for the most part, she does. The novel’s strength isn’t that you’ve never seen these pieces before. It’s in the way they’re assembled, and specifically the decision to make deception itself the organizing principle of the story.
That Final Act Really Does Earn Its Gamble
The final act is where Peterson’s gamble with structure pays off. By waiting until so late to let Sadie speak, the novel turns the traditional murder-mystery formula inside out. We spend much of the book trying to understand Sadie through other people’s memories, assumptions, resentments, and affection. Then we finally get the chance to hear from her directly.
And suddenly, the question isn’t simply who killed Sadie. It’s whether anyone ever really knew her!
That distinction gives Killing Sadie more emotional resonance than its premise initially suggests. Beneath the murder mystery is a story about how people construct versions of one another: the perfect girl, the jealous sister, the reckless friend, the angry boyfriend, the weird outsider, and how dangerous those assumptions can become when nobody has the complete picture.
For fans of twisty YA mysteries, this is an easy recommendation. If you like books where every character seems suspicious, every conversation might contain a clue, and every new revelation makes you rethink what you thought you knew, Killing Sadie should keep you turning pages. Fans of A Good Girl’s Guide to Murder, One of Us Is Lying, How to Survive Your Murder, and similar teen thrillers will feel immediately at home.
A confidently plotted debut that turns its own unreliable narrators into the murder weapon, Killing Sadie understands that the scariest question isn’t who did it, but why nobody could see it coming.
What did you think of Killing Sadie? Did you clock the culprit before the final act, or did Sadie’s chapter catch you completely off guard? Be sure to let us know in the comments below or over on Twitter, Instagram, or Facebook!
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