New DNA evidence appears to solve the murder of Tone, but Wisting still feels that something is amiss. Wisting and his colleagues must call on all of their skills and experience to avoid a dramatic and dangerous situation.

Wisting takes the help of a former colleague to solve Cecilia's murder, and to figure out who fiddled with the evidence. Line finds a video that links the charges against Wisting to Linnea's kidnapping.

Lines and Wistings investigations are linked, and the search for the serial killer becomes increasingly intense. At the same time, Wisting's worst nightmare becomes reality.

A new anonymous letter leads to fresh evidence, but not everyone is happy to see the old murder case back in the spotlight. Wisting realizes he is being opposed by powerful forces within the police, as he keeps searching for the secret messenger.

A new disappearance makes Wisting and Stiller fear that the killers are about to flee the country. But has the new victim really been kidnapped? A new clue causes the police to arrest a suspect.

Line's shocking findings overturn the police's theory of "The Other". The perpetrator gets rid of loose threads and time is running out. Wisting discovers the secret that his daughter has kept hidden from him.

A breakthrough in the case takes Wisting to Vilnius for a meeting with Interpol investigator Harriet Dunn. What is meant to be a simple questioning of a suspect becomes far more complex for both of them - both professionally and personally.

Line's obsession with Viggo's death leads to a quarrel with her father. Wisting and the FBI find more of Godwin's victims, and the FBI agent John makes a mistake that has serious consequences.

Six-year-old Clifford Greenwood vanishes from the family hotel Wildenvey and an employee is found dead. Detective William Wisting believes the boy was kidnapped. The Greenwood family is shocked, but Wisting discovers they have secrets.

An internal investigation of Wisting begins after his suspension. Torunn leads the investigation about a missing woman. Line runs into an ex when she works on her Ravneberg article.

Wisting is under pressure, still without leads. Clifford's parents await contact from the kidnapper but receive a mysterious message that leads them to a gruesome discovery. It's clear the kidnapper wants to tell them something, but what?

Clifford's family receives a ransom demand and a cryptic message. The clues suggest Clifford has been taken as a revenge against his grandfather. Wisting's daughter, Line discovers her ex, Tommy, has fallen into very bad company.

Wisting tries to save his reputation by conducting his own secret investigation into the Cecilia case. Torunn believes that Linnea is behind her own disappearance, but her parents are convinced that she is in danger.

Investigator William Wisting makes a frightening discovery: A corpse has been found among the spruce trees in a Norwegian Christmas tree field, and turns out to have links to a sought after American serial killer.

Wisting is under pressure, still without leads. Clifford's parents await contact from the kidnapper but receive a mysterious message that leads them to a gruesome discovery. It's clear the kidnapper wants to tell them something, but what?

Maggie is forced to share information, which she has previously kept secret from Wisting. The investigation takes a whole new turn, and leads Wisting and Maggie on a new hunt across the border into Sweden.