Kat and Lock

SUNDAY TIMES BESTSELLER Two detectives: one human, one AI. And a case that will test them both. “Wildly original, heartfelt, funny, and properly thrilling, this is the kind of fresh and fearless debut I just adore.”—Chris Whitaker, author of All the Colors of the Dark, a Read with...

DCS Kat Frank knows all about loss. A widowed single mother, Kat is a cop who trusts her instincts. Picked to lead a pilot programme that has her paired with AIDE (Artificial Intelligence Detective Entity) Lock, Kat's instincts come up against Lock's logic. But when the two missing person's cold cases they are reviewing suddenly become active, Lock is the only one who can help Kat when the case gets personal. AI versus human experience. Logic versus instinct. With lives on the line can the pair work together before someone else becomes another statistic?

From the bestselling author of In the Blink of an Eye comes an inventive thriller that pits algorithms against experience, logic against instinct, and one undetectable killer against two extraordinary detectives. “Unswervingly gripping and scary, and at the same time beautifully tender and...

When the body of a man is found crucified at the top of Mount Judd, DCS Kat Frank and her partner, AIDE (Artificially Intelligent Detecting Entity) Lock, of the Warwickshire Future Policing Unit, have their work cut out for them. Previously only dealing with cold cases, the FPU are thrust into the spotlight as another body is found – also crucified – and it appears as though there is a serial killer on the loose. But why these victims? And who will be next?

Pre-order BODY OF LIES, the brand-new thriller featuring DCS Kat Frank and AIDE Lock from the award-winning and Sunday Times bestselling author Jo Callaghan, coming Spring 2026. From the author of In the Blink of an Eye, the Sunday Times bestseller, winner of the CWA ILP John Creasey (New...