Leave No Trace

A Novel

By: Jo Callaghan

Narrated by: Rose Akroyd

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 humane.”—Nicci French, author of Has Anyone Seen Charlotte Salter?

When the body of a man is found crucified at the top of a hill in the British Midlands, AIDE Lock—the world’s first AI detective—and Detective Kat Frank are thrust into the spotlight as they are given their first live case. When a second body is found, the police issue an extraordinary warning to local males aged between thirty and forty years old:

• Avoid drinking in pubs.

• If you insist on going to a pub, do not leave alone.

• And definitely do not leave a pub with a stranger.

With the national media and local men in an uproar, Kat and Lock have to combine their instincts and algorithms to catch the killer before they can strike again.

©2025 Jo Callaghan (P)2025 Random House Audio

Critic reviews

“Callaghan’s riveting sequel to Blink of an Eye . . . tweaks the traditional British detective story just enough, freshening up a well-worn formula without attempting to fix what isn’t broken. This series deserves a long life.”—Publishers Weekly

“[The] big reveal is unlikely to be foreseen by even the AI-abetted reader. This thriller may feature state-of-the-art AI, but its solid craftsmanship is timeless.”—Kirkus 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, internationally bestselling author of Has Anyone Seen Charlotte Salter?

AI and it’s meaning in our lives

I really enjoyed the story and the mystery as it pays attention to the abuse of women. It really shows the awfulness of society which is eye-opening but real. My favorite part is the discussion of AI in the larger mystery.

Great series

The plot is engaging and I enjoyed watching the growth of Kat and Lock as they both worked on solving a complex case. Hard to put down. I also liked that it wasn’t yet another mystery in which women were being imprisoned and slaughtered. Looking forward to the next book in the series.

Even better than the first !!

It has been said that the second book is the hardest. I think this is particularly true where the first has been a great success. Can't just repeat, can't change too much, basic canon is fixed. All of which made this book such a delight--the characters become more three-dimensional, and the author probes even closer questions along the rim of the uncanny valley. But most important by far is the GREAT mystery and the procedural plotting. CANNOT wait for a third.

Great Story and Well-Researched

The story was compelling and hard to put down. I was impressed with the author’s research about AI and how Lock was portrayed in the story. The narration was excellent. The transition between characters was seamless with just one narrator.

Well Done

It is a good second, looking forward to the next. I do Callaghan is not going to establish a formula where tension is created because the team is going to lose the case for not solving soon enough.