Body of Lies by Jo Callaghan review

About The Book

Book: Body of Lies
Author: Jo Callaghan
Standalone or Series: Book 4 in the Kat and Lock series
Publisher: Simon & Schuster
Publication Date (UK): 21st May 2026

🔍Standout Read. Awarded to books I highly recommend.

My Review

There are no spoilers here. I always make sure not to include any but as this is the final book in the series I wanted to make that explicit.

Body of Lies picks up from the events of that explosive ending to Human Remains. This is a unique police procedural series that is absolutely worth your time. I personally was foolish and ignored my friends’ praises of Callaghan’s debut In the Blink of an Eye. They told me I would love it, but being aware one of the detectives was AI, I assumed I would not get on with it. I see this criticism a lot, so if you are in the same boat then please know I wholeheartedly recommend this series and hold my hands up that I was very, very wrong.

Yes, there is an AI element to the series, but it’s done incredibly well and it’s about so much more than that. Kat is such a well-written character, so believably human and incredibly relatable. Heck, I even love (love to hate or hate to love?) Lock.

Body of Lies features DCS Kat Frank and her holographic assistant AIDE Lock as they investigate the murder of a local MP. At the scene, they uncover a coded message that seems to be targeting them. They are also preparing for a public hearing regarding the roll out of AIDES in the force. The series feels timely and resonant, in real life earlier this year CrimeOwl AI launched to help investigators process thousands of files in minutes, making it easier to connect evidence, uncover hidden patterns and generate new leads. It’s no surprise that Callaghan pre-empted this in her novels, as she has a background as a senior strategist researching the future impact of AI on the workforce.

Throughout the series there has been ambiguity surrounding Lock. Is it possible for the AI to have its own alternative motives and do a Skynet? There’s a knife-edge uncertainty throughout and I loved the resulting tension.

As mentioned I won’t go into too much more of the plot to avoid spoilers. I will say that there was a part that gave me Fight Club vibes and that the ending was superb. What a ride this masterpiece series has been.

Thank you to Simon & Schuster for the proof copy.