In the year 1995, the National Police of Barcelona faces a series of accidents and suicides that have the peculiarity of occurring on terraces of buildings where the deceased did not live. These deaths, initially unrelated, give the Homicide Group 3, led by Inspector Bellido and Sub-inspector Mónica, a headache. With the imminent deployment of the Autonomous Police, the August vacation just around the corner, the increasingly precarious financial resources of the National Police, and the accumulation of cases, following the trail of these seemingly random deaths becomes a true torment for the investigators. But the biggest surprise for the police comes when, collecting the data, they discover that all these deaths occur on the same day of the week: Thursday. And between one event and another, there are usually five to six months. In all cases, there is always a witness who claims to have seen the victim in the company of someone they have never been able to recognize.