Introduction
The second installation of The Naturals Series, Killer Instinct has gripped the hearts of thousands with the return of the beloved teenagers as they face their newest challenge. Jennifer Lynn Barnes published this novel in 2014, yet with the announcement of a new addition to the series in November 2026, it’s the perfect time to read it.
A Summary
Killer Instinct throws us straight back into the world of the Naturals, where Cassie and the team are juggling their usual mix of profiling training, messy emotions, and the kind of danger only they could attract. This time, the stakes feel sharper, the atmosphere darker, and the mystery as devastating as ever. As the Naturals try to sneak behind the backs of their caregivers, they find themselves left with more questions than answers, and too close to the investigation to go unnoticed.
Writing Style
Barnes’ writing in Killer Instinct is wonderfully clean and direct, and honestly, that’s part of what makes it so addictive. She doesn’t drown you in unnecessary detail or try to over‑explain every clue; instead, she gives you just enough to keep your brain ticking without slowing the pace. It feels intentional, almost like she trusts the reader to keep up, and that confidence makes the story flow so smoothly. The dialogue snaps, the internal monologue stays sharp, and the darker moments land without feeling overly dramatic. It’s the kind of writing that lets you inhale chapters without realising how far you’ve gotten, which is exactly what a YA thriller should do.
What I Loved
The first book in this series had me captivated, but I also had a lot of worry that Killer Instinct wouldn’t compare in its amazingness. Having said that, I was not disappointed at all. I fully felt myself delve into the world, and embrace it wholeheartedly. There was some subtle character development that I adored, not just from Cassie, but every single character present had some form of transformation, no matter how small. It’s so easy for character arcs to lack progression when they are part of a series, so for Barnes to manage to succeed with every character is incredible. The plotline was once again, super interesting, and allowed us to understand Dean more, as well as the other character’s relationships with him. As well as the plot twist at the end that I did not see coming, I was completely enamoured by it.
I also (surprisingly) adore how straightforward the writing style is. The book tells you what you need to know, and doesn’t waste its time with unnecessary details. Typically, thrillers that I read are chock-a-block with descriptions and details which I love because it gives me more information to guess with, but it simply isn’t needed here.
What I Didn’t Love
There isn’t a lot I didn’t like about this novel, but The Naturals is still my favourite, because I did like the plot more than in *Killer Instinct, *simply because I didn’t guess what was going to happen in the first novel, but in this one I did guess the initial twist (not the end one though, that had me floored).
Series Order
The Natural series consists of 4 released novels, a novella and a 5th novel set to be released later this year.
1) The Naturals
2) Killer Instinct
3) All In
4) Bad Blood
4.5) Twelve (Novella)
5) Dangerous Impulse (Release Date - 05/11/26)
Recommendation
If you loved the first one, this is a definite must-read! And if you haven’t read the first one, what are you doing?!
Songs
Songs that I find reminiscent of the book:
Bury A Friend by Billie Eilish
Team by Lorde
Everybody Wants To Rule The World by Lorde
Better Luck Next Life by Unlike Pluto
(P.S. We made them links so feel free to click on them and get teleported straight into the vibes.)
