A shocking attack on a politician in Reykjavik means Chief of Police Andri has to return to his hometown in the north of the island, and to working with his former colleagues Hinrika and Asgeir, to investigate a suspected link between the case and far-right nationalists. Things are changing in the countryside. Heavy industry is taking over, to the deep resentment of local farmers and environmentalists, with fears of untold damage to both their livelihoods and their landscape. With Andri’s family life still fractured since the dark events three years ago that sent him to Reykjavik, he is going back to a place that still feels strange to him.
Gisli’s links with the far-right organisation, Hammer of Thor, lead Andri and Hinrika to suspect two young local farmers – Torfi and Skuli – of involvement in Finnur’s murder. But rather than face questioning, Skuli escapes into the mountains on horseback. In his absence Torfi confesses to Finnur’s murder, but Andri does not believe him. Thorhildur will still not talk to Andri and has begun going out without telling her aunt so that she can hang around with Finnur’s son Aron.
Ketill is released, but his sons Torfi and Skuli remain the best lead the police have. With Skuli still on the loose, a full search-and-rescue operation is mounted. Torfi drops a hint that his group, Hammer of Thor, are planning something big, but do Andri and Hinrika have time to work out what it is before it’s too late? Asgeir helps them make a breakthrough. Meanwhile Mayor Hafdis is still being threatened by a mysterious opponent, but is determined to conceal it from the police until the investment deal is signed.
Andri was too late to save Mayor Hafdis from being kidnapped and now she is in the Hammer of Thor group’s clutches. And after leading police on a wild goose chase, Skuli has at last been found, but he is in no condition to talk to police. Could exposure have done this to him or did something else happen out in the wilderness? While still no closer to finding Finnur’s killer, the team must use what little information they have to save Hafdis.
The police have foiled a terrorist plot but they’re left no closer to having solved the mystery of who killed Finnur, or why Gisli took the actions he did. Now his sister and victim, the Minister for Industry, is coming back home for his funeral. Half the town will also be in attendance, and Andri and Hinrika are on the lookout for any signs of family tension. Meanwhile Asgeir follows up on his suspicions about Finnur.
Ketill has been finding dead animals up by the lake and has his own suspicions about why Skuli became so ill when he was hiding out in the mountains. Ebo is beginning to feel in danger at the plant – his foreman knows what he’s been up to with Vikingur and does not have Ebo’s best interests at heart. Thorhildur is still taking impetuous risks and keeping secrets; when Andri discovers the full extent of her youthful indiscretions there are consequences she has failed to consider.
In the aftermath of another killing at the plant, Vikingur is found covered in blood, and with his fingerprints on the murder weapon. It is all Hjortur can do to keep the other workers from tearing him apart until the police arrive, and now he is in custody at the station for a murder he swears he did not commit. The shock is felt by Vikingur’s troubled family, and by Andri and Hinrika, who clearly must charge Vikingur. Ebo, alone and in danger without Vikingur to protect him, looks for sanctuary with Vikingur’s friends. Meanwhile Asgeir has agreed to investigate the mystery of the dead animals Ketill has been finding up at the lake.
The polluted lake has been discovered and the town’s water supply has been turned off to prevent further cases of sickness. Now it is no longer a secret, people are starting to think the whole place is cursed. Under pressure to provide answers, Andri and Hinrika are chasing up leads all over town, but in their haste Hinrika worries they might be becoming slapdash. With a dubious suspect still in custody they need progress fast, so Andri decides it is time to put more pressure on the management of the aluminium plant. Meanwhile Thorhildur is still sitting on her secret discovery from Finnur’s bag.
Thorhildur’s confession to Asgeir brought a new sense of hope, but with everyone chasing down different leads and being too busy to speak to each other events take a catastrophic and disturbing turn. When everyone recovers from the shock, tracking down the killer has become not just a matter of public safety, but a personal vendetta. Meanwhile Andri has to contend with keeping Thorhildur safe. Now she has handed the police the lead they so desperately needed, he must get her out of town before the killer realises what has happened.
Having found the true reason for the chemical pollution at the lake, the true identity of the killer is now clear to Andri and Hinrika but it’s not enough. Once more they are one step behind and it is a race against the clock to stop even more harm coming to the people they love. By the time they can finally lay the case to rest, darker family secrets still will have floated to the surface.