A breath-taking thriller with twists you'll never see coming. The start of a new series from international bestseller Arne Dahl. Soon to be the subject of a series adaptation from the producers of Killing Eve 'Brilliant visceral writing with terrific pace, this book grips you like a vice from the very first line and never lets you go' PETER JAMES Someone is watching. At each abandoned crime scene there's a hidden clue- a tiny metal cog. Someone is sending Detective Sam Berger a message, someone who knows that only he will understand the cryptic trail. Someone knows. When another teenage girl disappears without trace, Sam must convince his superiors that they're dealing with a serial killer. As the police continue the hunt to find the latest victim, Sam is forced to unearth long-buried personal demons. He has no choice if he is to understand the killer's message before time runs out. Somebody is killing just for him.