PINTEREST
BLOGLOVIN
GOODREADS
Human suspicion. AI manipulation.
Who can you trust when truth has no meaning?
DCS Kat Frank returns to work at the Future Policing Unit after a tragic loss, only to find herself thrust into a new high-profile case. On the night of Halloween a local MP is found murdered, with a taunting message written in binary code that seems to target Kat specifically: Catch me if you can.
The victim’s anti-AI sentiments suggest a political motive, and as Kat investigates with her partner AIDE Lock – the world’s first AI detective – she finds herself once again battling her own prejudices about the technological future he represents. But when a cyberattack takes out the National Grid, Kat and Lock have to race against the clock to track down the hacker before thousands die.
Tangled in a web of suspicion and deception, Kat must choose who and what to believe when the truth seems to defy both instinct and logic.
Can she set aside her old doubts and put her faith in her AI partner one last time?
Or will this case send Lock down a path she just can’t follow – a path that will leave humanity behind for good?
MY THOUGHTS
Body of Lies is the fourth and final instalment of the Kat & Lock crime series, published by Simon & Schuster on 21 May 2026. Available in ebook, audiobook and hardback with the paperback to follow.
I’ve been a huge fan of this series, have loved every book and although I know every series does have a natural end, I’m so sad that this is the final outing for DCS Kat Frank and her hologram partner AIDE Lock.
Body of Lies begins a few months after the ending of Human Remains. Kat has returned home and to work but it is clear that she is still haunted by traumatic events and questions her own judgement at every turn. She is still heading the Future Policing Unit but the team are struggling. Her AI partner, AIDE Lock is again by her side, via the wrist bracelet Kat wears, but its quest for a human form makes Kat uneasy and as much as she relies on Lock, there are trust issues.
The murder of an outspoken MP, vocal against the development of AI, thrusts the team not only into an investigation to find a killer but when a cyberattack threatens the entire country Kat and Lock are against the clock to discover who is behind it before more lives are lost.
The author superbly navigates the emotional struggles of Kat and other members of her team, not only in dealing with trauma and loss but also showing a thought provoking view of both the benefits and dangers of the AI revolution which adds a level of relevance and authenticity.
The final part of the story was gripping and dramatic. With the suspense racking up, there was shock at the revelations and ultimately the sad realisation that this was indeed the end. Jo Callaghan has created a fantastic crime series that has both heart and intelligence, all with a touch of dark humour. I really took these characters to my heart and I shall miss them, especially Lock. It (I still want to say he) could be infuriating but there was an endearing quality too and I did enjoy the bond that formed between Lock and Kat. I look forward to seeing what comes next by this very talented author.
My thanks to Tracy of Compulsive Readers for the tour invite and to the publisher for the ecopy to review.
Jo Callaghan works full time as a senior strategist, carrying out research into the future impact of AI and genomics on the workforce. She was a student of the Writers’ Academy Course (Penguin Random House) and was longlisted for the Mslexia Novel Writing Competition and Bath Novel Competition. After losing her husband to cancer in 2019 when she was just forty-nine, she started writing In the Blink of an Eye, her debut crime novel, which explores learning to live with loss and what it means to be human. She lives with her two children in the Midlands, where she spends far too much time tweeting as @JoCallaghanKat and is currently working on further novels in the series.
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