The shadow murders

On her 60th birthday, a woman commits suicide. When the case lands on Detective Carl Morck's desk, he can't imagine what this has to do with Department Q, Copenhagen's cold cases division. It's a tragedy to be sure, but the cause of death seems to be clear. But his superior, Marcus Jacobsen, is convinced that this is not in fact a suicide, but a murder related to an unsolved case that has been plaguing him since 1988. At Marcus' behest, Carl and the Department Q gang-Rose, Assad, and Gordon-reluctantly begin to investigate. However, they quickly discover that Marcus is on to something: Every two years for the past three decades, there have been unusual, impeccably timed deaths with connections between them that cannot be ignored. As they dig deeper, it transpires that these 'accidents' are in fact murders by a very cunning and violent serial killer.