You thought you were alone. Think again. The groundbreaking fifth thriller in Lars Kepler's bestselling series featuring Joona Linna. Perfect for fans of Stieg Larsson and Jo Nesbo. IF THE LIGHTS ARE ON, THEY CAN SEE YOU A film arrives at the National Criminal Investigation Department in Stockholm. It shows a woman, alive, being filmed through the window of her house. She does not know she is being watched. The police don't take it seriously. Until she is found dead. BUT IF THE LIGHTS ARE OFF. When the next video arrives, Detective Margot Silverman frantically searches for any way of identifying the victim. But it is already too late. Because at the time the video was sent, the subject was already facing the terrifying final moments of their life. And without anything to link the victims, the police are powerless to help them. IT'S ALREADY TOO LATE Soon Stockholm is in the grip of terror. Who will the Stalker target next?