Finnish police Nina Kautsalo makes a horrific discovery in the basement of wilderness cabin. Soon the find brings German virologist, Thomas Lorenz, to work on the case.

National Bureau of Investigation joins the investigation and Nina is forced off the case. Tracks in the snow give her a new lead, however.

Raunola, the man suspected for the murders is leaving the investigators confused. The virus investigation takes a bad turn, and Nina and Thomas find each other in surprising place.

Both crime and virus investigations are progressing slowly. Work and personal life are starting to mix for both Nina and Thomas.

Virus investigation becomes even more topical. Police track down the fourth victim.

Nina gets a chance to interrogate the fourth woman. Esko gets into trouble with the police. The first victim wakes up from coma.

Nina and Thomas are in danger when Raunola returns to Ivalo. Marita gets bad news in quarantine.

Nina and Thomas get new information from a surprising source. Thomas has to fight for his daughter's custody. Virus infection takes a frightening turn.

Nina and Thomas participate in an illegal expedition to Murmansk. Venla is fighting for her life.

Nina and Thomas return to Finland. Venla gets help from unexpected source. Nina will have to step into the darkness once more.

Nina Kautsalo has returned to Ivalo as she is set to become the new Chief of Police. When a local pharmacist is found murdered, Nina is assigned to investigate the case as her last assignment with her old partner Aikio. Meanwhile, an American car manufacturer's test car is attempted to be hijacked.

Nina continues as Ivalo's police chief. Her son Santeri is with her. Stenius comes to ensure security for an international conference. Nina investigates a major accident that turns out to be a mass murder.

They want to keep the mass murder investigation a secret. Aikio smells a burnt cart. A terrorist suspect arrives in Ivalo. The threat of terrorism, mass murder, and a brilliant comet in the sky seem to be connected.

Old events related to the religious sect are beginning to unravel. Nina interrogates Ossi about the past. Marita is warned about the prophecy. Aikio is shot. The police find out who is behind the mass murder.

Aikio's condition is serious. Nina identifies the terrorist wanted by the FBI. The motive for the mass murder is confirmed. In Ivalo Visiting astrophysicist Jonathan Sprout's life is in danger

Nina finds out about 40-year-old events and who the last representative of the Taimenen family is. Jarmo and Esko drive to the wilderness church. Tuomas kidnaps Santer. A desperate Nina decides to trust the guidance.