Killer Instinct is the second book in the Naturals series and picks up about six weeks after the end of the previous novel. The Naturals (Cassie, Dean, Michael, Lia, and Sloane) all have gifts that allow them to read people and situations, which is an obvious benefit to an agency such as the FBI. Cassie and Dean are natural profilers, Michael can read emotions, Lia is a human lie detector, and Sloane is a wealth of knowledge and statistics.
After putting their lives on the line to catch a serial killer in The Naturals, the teens have been instructed to only work on cold cases. To ensure they stick to the plan, Agent Sterling (the Director's daughter and Agent Briggs's ex-wife) moves into the residence to supervise and evaluate the program. Her opinion could lead to the disbanding of the program, but that doesn't stop the team from investigating a local murder with the same MO as Dean's incarcerated serial killer father. As the number of bodies begins to add up, the FBI agrees to officially pull the naturals into the active investigation.
Throughout the story we learn more about Dean, his relationship with his father, and the events he was exposed to as a child. It is also revealed how the love/hate relationship between Michael and Dean developed. I felt like both of these characters came a long way towards strengthening their relationship, which will only help the group dynamic moving forward. When push came to shove they had each other's back and even extended themselves to help one another, which was a huge step in the right direction.
This is the first YA murder mystery series that I have found that I thoroughly enjoy. The characters are very unique and the stories are engaging from start to finish. I looked forward to reading this book each day and simply did not want to put it down. The only aspect that I could do without is the love triangle between Cassie, Dean, and Michael. It was beginning to wear thin during the first book and continued for the majority of Killer Instinct. I believe we have worked past it, which should relieve some of the tension between the characters in All In, which is the next installment in the series.
It was announced in the closing chapters that there will be a change in how The Naturals program will operate moving forward. I don't want to give anything away, but it will definitely open up the possibilities for the series moving forward.