Set two years after Season 3, this fourth and final season starts with the discovery of a woman who was brutally murdered at the base of the bridge. Henrik seeks Saga's help, but being imprisoned, there's nothing she can do.
Henrik and his new colleague, Jonas, continue to investigate Margrethe Thormod's murder. Their two main leads are the radical leftist group, Red October, and the missing refugee, Taariq.
Taariq recognizes a car related to the case. He wants to push the owner for money, but is himself accused of robbery. Saga fears that will be more murders and Henrik's efforts for the homeless girls ends up in disappointment.
The taxi driver who drove Margrethe Thormod and was the last person to see her alive, turns out to have connections to another victim as well, while suspicions about the Sonning couple also grow.
Henrik believes he found the connection between all victims and an unexpected finding ends up on the investigation board. At the same time, the crack between him and Saga is greater than ever.
The investigation on Tommy continues but his mother, who is still in police custody, refuses to cooperate. Niels Thormod comes up in the investigation again.
The homeless girls know who the killer is and try to get in contact with Henrik, but the killer is after them and the girls have to run for their lives. Meanwhile, Saga finds a match for the killer's fingerprint.
