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Leave No Trace

The new thriller from the author of BBC 2's Between the Covers pick In the Blink of an Eye

About The Book

DCS Kat Frank and AIDE Lock return in the provocative new thriller from the Sunday Times bestselling author of In the Blink of an Eye.

'A smart, agile, immaculately plotted and moving thriller that is unswervingly gripping and scary, and at the same time beautifully tender and humane' NICCI FRENCH
'Chilled me to the bone and I couldn’t turn the pages fast enough. Callaghan writes with such intelligence; interspersing humour with moments of utter heartbreak' NIKKI SMITH

One detective driven by instinct, the other by logic.
It will take both to find a killer who knows the true meaning of fear . . .

When the body of a man is found crucified at the top of Mount Judd, AIDE Lock – the world’s first AI Detective – and DCS Kat Frank are thrust into the spotlight as they are given their first live case.

But with the discovery of another man’s body – also crucified – it appears that their killer is only just getting started. With the police warning local men to be vigilant, the Future Policing Unit is thrust into a hostile media frenzy as they desperately search for connections between the victims. But time is running out for them to join the dots and prevent another death.

For if Kat and Lock know anything, it’s that killers rarely stop – until they are made to.
PRAISE FOR LEAVE NO TRACE:

‘A detective working with an artificial intelligence character is such a brilliant premise!’ PRIMA, 3 of the best sequels to read this month
‘Callaghan, who is a professional researcher into the effects of AI, has a great talent for making the benefits and limitations of the technology comprehensible. Her account of Lock’s ability to absorb information about human relationships and to provide a sense of empathy and humour is fascinating' LITERARY REVIEW
‘Jo Callaghan’s debut novel In The Blink of an Eye might have been released over a year ago, but it’s still making waves… startlingly original, working as a compelling procedural, an examination of how far artificial intelligence has come – and could go – and an exploration of very human grief' CRIME MONTHLY
'With Leave No Trace, Jo Callaghan cements her status as a crime fiction force to be reckoned with' CAZ FREAR
'Seeing the return of Kat and Lock is like returning to old friends. A brilliant rapidly paced and plotted thriller. Couldn’t put it down. But a thriller with the added extra of being really very original. Executed perfectly. Another masterpiece' IMRAN MAHMOOD

About The Author

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.   

Product Details

  • Publisher: Simon & Schuster UK (March 28, 2024)
  • Length: 400 pages
  • ISBN13: 9781398511224

Raves and Reviews

‘A smart, agile, immaculately plotted and moving thriller that is unswervingly gripping and scary, and at the same time beautifully tender and humane’ Nicci French

‘As brilliantly plotted and innovative as In The Blink Of An Eye, AIDE Lock & DCS Frank are back in Leave No Trace. This time attempting to solve horrific murders in the dead of winter; the story chilled me to the bone and I couldn’t turn the pages fast enough. Callaghan writes with such intelligence; interspersing humour with moments of utter heartbreak’ Nikki Smith


‘Seeing the return of Kat and Lock is like returning to old friends. A brilliant rapidly paced and plotted thriller. Couldn’t put it down. But a thriller with the added extra of being really very original. Executed perfectly. Another masterpiece’ Imran Mahmood


‘I am rapidly becoming a huge Jo Callaghan fan. Leave No Trace was every bit as smart, compelling and insightful as her debut, and where these books really excel is in the emotional weight they bring to the thriller genre. A terrific read!’ Gytha Lodge


‘With Leave No Trace, Jo Callaghan cements her status as a crime fiction force to be reckoned with. Emotional and enthralling, with great dashes of humour throughout. It also includes one of the most heart-stopping yet satisfying endings I've read in a long time. More please, Jo!’ Caz Frear


'Jo Callaghan has done it again in this intricately plotted, humorous and incredibly moving thriller. As well as being a gripping, fast-moving story in its own right, it has so much to say about the complementary roles of logic and emotion in policing (and life!), the complexities of grief and what it means to be human. I absolutely loved it' Laura Marshall

‘Another exciting and thought-provoking book from Jo Callaghan that combines cutting-edge tech with a classic police procedural that is hugely human and big-hearted. Brava!’ Sarah Hilary

‘Balanced, nuanced, intelligent, provocative’ Amanda Reynolds


‘A terrific, immersive read! I found it utterly believable, and it's rare to find a crime novel that captures the AI zeitgeist, with so much authority and verve. The plot is devilishly clever too. I loved it!’
Kate Rhodes


‘I don’t know how, but Jo manages to explore huge societal questions through the medium of a pacy thriller. There’s tension by the bucketload. It’s tough and tender, and is a masterclass in persuading a reader to keep turning pages. Chris McDonald


It goes without saying that a crime thriller should keep you on the edge of your seat, but when it also makes you laugh out loud AND cry, you know you’re in the hands of an amazing writer. An absolutely brilliant read’ Frances Quinn

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More books from this author: Jo Callaghan