TL;DR
Guess Again by Charlie Donlea is a fast-paced, high-stakes psychological thriller that’s currently blowing up on BookTok. It’s got everything older teens love: a cold case, a missing "all-American" girl, and more twists than a Wisconsin backroad. However, it’s definitely an adult thriller. Expect themes of serial killers, "black heart" branding (yes, it’s as dark as it sounds), and some mature sexual content.
Recommended for: Ages 16+ (or mature 15-year-olds who already handle the Riley Sager or A Good Girl's Guide to Murder vibes).
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If your teen is suddenly obsessed with a book that has a black-and-white cover and a lot of buzz about "the ending you won't see coming," it’s probably Guess Again. Released in 2025, it’s the latest from Charlie Donlea, a master of the "popcorn thriller"—books you can finish in a weekend because the chapters are short and the cliffhangers are relentless.
The story follows Ethan Hall, a former hotshot detective who quit the force after getting burned out by the "kid crime" division (heavy stuff). He’s now an ER doctor, but he gets pulled back into a 10-year-old cold case: the disappearance of Callie Jones, a high school volleyball star and the daughter of the now-Governor.
It’s being pitched as Silence of the Lambs meets Cruel Summer, and honestly, that’s a pretty fair assessment. It’s dark, it’s atmospheric, and it deals with some very adult psychological games.
If you’ve spent any time on #BookTok, you know that the "twist" is the currency of the realm. Teens aren't just looking for a good story; they’re looking for a "book hangover"—that feeling of being so shocked by an ending that you can’t function.
Guess Again delivers on that. The short chapters (some only 2-3 pages) are perfect for the TikTok-era attention span. It feels like a Netflix binge-watch in paper form. Plus, it features a teenage protagonist (Callie) in the "past" timeline, which makes it feel relatable to high schoolers, even though it's technically written for adults.
Learn more about why BookTok trends influence teen reading habits
Let’s get into the weeds. If your kid is asking to buy this at the bookstore, here is what you actually need to know before you swipe your card.
Mature Themes & Sexual Content
Right from page one, the book lets you know it’s not Nancy Drew. The opening line literally describes a girl realizing she's about to lose her virginity. While the book isn't "smutty" in the way some BookTok romances are, it deals with adult relationships, sexual pressure, and the darker side of attraction.
Violence and The "Gore" Factor
This is where parents might want to pause. The villain, Francis Bernard, is a serial killer who branded his victims with a black heart on their breasts. There are descriptions of torture and the psychological "allure of evil" (hybristophilia). Because the main character was a "kid crime" investigator, there are references to crimes against children that can be pretty unsettling.
Digital Safety & "The Anonymous Client"
One of the subplots involves a psychologist who runs an online counseling platform called "The Anonymous Client." It’s a great jumping-off point for a conversation with your teen about digital privacy and the reality of "anonymous" apps. In the book, secrets shared online become dangerous. In real life, we see this with apps like NGL or Tellonym.
At Screenwise, we don't believe in "banning" books—that usually just makes kids want to read them more under the covers with a flashlight. Instead, we look at readiness.
- Ages 13-14: Probably a bit too heavy. The themes of child crime and the specific nature of the serial killer's violence are a lot for a middle schooler. If they want a mystery, try The Inheritance Games instead.
- Ages 15-16: This is the "maybe" zone. If they’ve read Holly Jackson or Karen M. McManus, they can likely handle this, but you might want to mention the darker themes first.
- Ages 17+: They’re the target audience for the "YA-to-Adult" crossover. They’ll likely appreciate the complex plotting and the medical/detective procedural elements.
Ask our chatbot for a comparison between Guess Again and A Good Girl's Guide to Murder
If you decide to let your teen dive in, here are three things to keep an eye on:
- The "Dark Cloud" Effect: Some kids (and adults!) get really bogged down by thrillers involving crimes against children or intense trauma. If your teen seems more anxious or is having trouble sleeping after reading, it might be time to pivot to something "lighter" (like a cozy mystery).
- The "Hybristophilia" Conversation: The book explores why people are attracted to serial killers. With the rise of true crime podcasts and Netflix docs about Ted Bundy, this is a real-world cultural trend. It’s worth asking your teen, "Why do you think people get obsessed with 'villains' in these stories?"
- The "Anonymous" Trap: Use the "Anonymous Client" plot point to talk about how they handle their own data. Do they think "delete" actually means "gone"? (Spoiler: It usually doesn't).
If Guess Again feels a little too "adult" for your household right now, here are some Screenwise-approved alternatives that hit the same mystery/thriller notes:
Ages 14+ This is the gold standard for teen thrillers. It has the "missing girl" and "cold case" elements but stays firmly in the YA lane. It’s smart, twisty, and much less "gritty" than Donlea.
Ages 13+ Basically "The Breakfast Club" but with a murder. It’s a great "entry-level" thriller for younger teens who want the drama without the serial killer branding.
Ages 14+ If your teen likes the "detective" side of Guess Again, they will love this. It’s about a group of teens who use their unique skills to help the FBI solve cold cases. It’s basically "Criminal Minds" for the YA set.
Ages 13+ A great atmospheric mystery set at a private school with a 1930s cold case that mirrors a modern-day disappearance. Very clever, very bingeable.
Guess Again is a well-written, genuinely gripping thriller. It’s not "brain rot"—it actually requires a lot of attention to keep the timelines and characters straight. However, it is dark.
If your teen is a seasoned thriller reader who watches Stranger Things and isn't easily rattled by mentions of violent crime, they’ll probably love it. If they’re still sensitive to "scary" content or aren't ready for adult themes, maybe steer them toward the Holly Jackson section of the library for another year or two.
Next Steps:
- Talk to them: Ask if they’ve seen the book on TikTok.
- Set a boundary: If you’re unsure, read the first chapter together (it sets the tone immediately).
- Check the stats: 62% of parents in the Screenwise community allow their 16-year-olds to read adult thrillers, while only 15% do for 13-year-olds.
See more community data on teen reading habits
Stay intentional, parents! You've got this.