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. “[An] interesting dichotomy of instinct and algorithm.” —TODAY “A thrilling ride with a twist of tech . . . this book is your next obsession.” —The Seattle Times “Compelling.” —Criminal Element “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? “Jo Callaghan has done it again with this intricately plotted, humorous, and incredibly moving thriller.” —Laura Marshall, Sunday Times bestselling author of A Good Place to Hide a Body “A brilliant, rapidly paced and plotted thriller. Couldn’t put it down. Another masterpiece.” —Imran Mahmood, author of Finding Sophie “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 Jo Callaghan works full-time as a senior strategist, carrying out research into the future impact of AI and genomics on the workforce. 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 British Midlands. Atherstone, Warwickshire, 7 December, 5.55pm He doesn’t turn to check that he’s not alone. He doesn’t cross the street to where there are more houses, more lights. He doesn’t even pretend to ring someone or hold his umbrella like a truncheon. He just walks through the night: through the absence of fear. He doesn’t see me watching. He stops at his front door, fumbling for the key he hasn’t gripped all the way home. He enters the hallway, not even glancing over his shoulder as he kicks the door shut. Imagine feeling that safe. Imagine being that stupid. A dull yellow light splashes from his bay window, staining the frost-white drive. That’s him in the front room now, not caring to close the blinds against the dark of night and threat of snow. He stands in front of a pale-grey settee and points a remote at a large screen above the fireplace. Flickering pictures fill the room. I bunch my frozen fists, and through the wooden shutters I spy the sleek, luxurious furniture, the high Georgian ceilings and framed paintings lining the walls. How did someone like him end up in a lovely home like that? I force out a breath so long and hard that for a moment I imagine disappearing in a puff of ice-white smoke. It clears in seconds. And yet still I am here: alone in the cold, dark street. The dead chill of night presses through my trainers, draining the heat from my body. I shift my weight from one freezing foot to the other. It’s not too late to walk away. I almost do. But then snow begins to fall, ghostly white in the dark of night. Memories flash through me: my face distorted in a glittered bauble, the thud of distant music; snow against snow. Blood beats fast through what’s left of my heart as I lift my face to the sky. A snowflake lands in my eye and I embrace its icy sting. I will no longer be haunted by the Ghosts of Christmas Past. I am here to reclaim my future. I turn back towards the window, where he sucks at a bottle of beer, legs spread as he stares at the TV, oblivious to the darkness beyond. I tuck my thumbs under my shoulder straps, feeling the weight of my rucksack and all that it contains. Tonight, he will learn about fear. CHAPTER ONE DCS Kat Frank’s home, Coleshill, Warwickshire, 8 December, 5.44am ‘I’m going to count to ten,’ DCS Kat Frank warned. ‘And then I’m coming up.’ She pointed her torch at th