The brutal assault on a politician in Reykjavik prompts Chief of Police Andri to return to the quiet solitude of his childhood home. The landscape there holds the lingering shadows of past tragedies, a weight he has long carried.

Andri and Hinrika harbor a suspicion that Torfi and Skuli, two young farmers from the area, are involved in Finnur's death.

Torfi and Skuli remain the primary suspects in the chief of police's investigation. And Skuli is still at large.

Now that Skuli is removed from their investigation, and Mayor Hafdis is held by the Hammer of Thor, has the team jeopardized their chances of rescuing him through this delay?

Authorities have thwarted a terrorist plot, yet the circumstances surrounding Finnur's death and the motivations behind Gisli's actions remain unsolved.

Near the lake, Ketill discovers the remains of dead animals, and a grim suspicion takes root in his mind regarding the cause of Skuli's debilitating illness during his time in the mountains. Simultaneously, a growing sense of unease settles…

Following the latest death at the factory, Vikingur was discovered coated in blood, his prints starkly visible on the weapon used in the killing.

The source of the lake's contamination has been identified, and the town's water supply has been shut down as a precaution against further illness. Andri and Hinrika are now pursuing every available clue throughout the community.

With the crucial information Thorhildur has provided, Andri now faces a pressing task: to spirit her out of the city before the killer learns of her cooperation.

The killer's true identity is unveiled, plunging Andri and Hinrika into a desperate struggle to safeguard those closest to them.