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
'Every bit as smart, compelling and insightful as her debut' GYTHA LODGE
‘Balanced, nuanced, intelligent, provocative’ AMANDA REYNOLDS
'Jo Callaghan has done it again in this intricately plotted, humorous and incredibly moving thriller' LAURA MARSHALL
'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