Today is Sarah Lund's last day of service. Tomorrow she leaves her post as homicide inspector for the Copenhagen Police Department, moves to Sweden and begins a new, civilian life. But, as you know, man proposes, but the devil disposes. The body of a nineteen-year-old girl was discovered in the forest on the outskirts of the city. Sarah is forced to temporarily postpone her departure and, together with her colleague Inspector Jan Mayer, take up the murder investigation. The trail leads to the city administration, where there is a serious struggle for the post of future mayor of the capital of Denmark. Politics gets involved, and the hunt for the killer turns into a deadly balancing act on the edge of a knife, when any wrong move can lead to death.