Human Remains by Jo Callaghan review

About The Book

Book: Human Remains
Author: Jo Callaghan
Standalone or Series: Book 3 in the Kat and Lock series
Publisher: Simon & Schuster
Publication Date (UK): 24th April 2025

🔍Standout Read. Awarded to books I highly recommend.

My Review

I must admit that, although I own the earlier entries, this third book in the Kat and Lock series is where I’m finally diving in.

The series features an unusual addition to the force: AIDE Lock, the world’s first AI detective. Callaghan does a fantastic job of reintroducing both Kat and Lock within chapter 2 (the first time we meet Kat within this book). She’s attending a potential crime scene where a fisherman has discovered some bones. As she assesses whether they’re human, she explains Lock’s role and how the hologram works. We’re brought up to speed so quickly and seamlessly that you can absolutely start the series here if you wish.

So, why the delay in picking it up? Honestly, I wasn’t sure how I’d feel about an AI detective. Despite my background in video games and being generally comfortable with tech, I wasn’t sure how it would be integrated into a crime narrative or if I wanted to read about AI. But it works brilliantly. If you’ve also been hesitant – don’t be. The AI element isn’t a gimmick; it’s woven into the story in a way that feels natural. That’s no surprise really, given that Callaghan is a senior strategist researching the future impact of AI and genomics on the workforce.

I was only three pages in when I welled up. Having seen Callaghan speak at the Theakston Old Peculier Crime Writing Festival, I know the personal loss she’s experienced – and this line hit hard: “But as a widow, now she was in charge of Absolutely Bloody Everything, and some days the relentlessness of it, the unfairness of it all, exhausted her.” Themes of loss and family thread poignantly throughout. But by page nine, I was laughing. Kat has such a sharp, warm sense of humour and is wonderfully written.

There are two main mysteries to unravel – who do the bones belong to and who is watching Kat? Alongside that, the book explores wider themes including perceptions of the police, justice versus prevention, current affairs, and the ever-evolving debate around AI. It’s smart, layered and thought-provoking thriller.

There’s also a mixed media element, including a true crime podcast focused on Kat’s old case, the Aston Strangler – and whilst it is relation to the location, how unfortunate is my surname of Aston?! You’ll also find a couple of newspaper articles, social media comments and formatted police interviews peppered throughout.

Overall, Human Remains is a compelling and surprisingly emotional read, even as a standalone. Callaghan has crafted intriguing characters and a thought-provoking plot that will keep you hooked.

Thank you to The Likely Suspects for a copy and also to Random Things Tours for kindly sending me a copy in order to take part in the book tour.