Detective William Wisting makes a terrifying discovery: a corpse among the spruces at a Norwegian Christmas tree farm is connected to a wanted American serial killer.

Aided by FBI agents Maggie and John, Wisting tracks American serial killer Robert Godwin to a remote farm, but can they keep it secret from the press before Godwin bolts?

Wisting and the FBI suspect Godwin is linked to 12 other cases in Norway. Convicted killer Vidar Haglund is released from prison after 17 years and confronts Wisting.

Line’s obsession with the Viggo case leads to a fight with her father. With the press hot on their heels, Wisting and the FBI agents discover more corpses.

The Viggo and Godwin cases cross paths, and the hunt for the serial killer intensifies as Wisting’s worst nightmare becomes a reality.

Just as Wisting is hailed a hero for solving the Caveman case, he faces accusations of evidence tampering in a prior murder case, leading to Vidar Haglund’s conviction.

Internal Affairs investigate Wisting, and following his suspension, Torunn heads the inquiry into the disappearance of a young woman. Line runs into an old flame.

Wisting fights for his career and reputation by conducting his own investigation into the Cecilia case. Torunn suspects Linnea is responsible for her own disappearance.

Suspended detective Wisting resorts to desperate measures to prove his innocence, while Internal Affairs puts his police department under intense scrutiny.

Wisting and Robekk join forces on the Cecilia murder case, but will they figure out who was behind the evidence tampering? New clues point to Linnea’s abduction.