‘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