Deep underground, below Valkyrien Square in Oslo, doomsday prepper Leif Lien arranges a place for Dr Ravn Eikanger to conduct his research in secret.

Ravn is clutching at straws, searching for something that can help Vilma. Against Leif’s will, Ravn decides to let Vilma’s research colleague, Unn, in on the secret. Teo is trapped underground.

The clinic is open. Leif provides the patients and Ravn and Unn treat them. They begin to make progress with Vilma’s treatment. But Vilma’s daughter, Siv, has begun to ask questions Ravn cannot answer.

Teo puts himself and the clinic at risk by seeking out his wife, Marit. A patient gives Ravn an idea that could help Vilma. But before he can give Vilma a new drug, he needs a test subject. Someone expendable.

A patient brings a deadly virus into the clinic. Vilma becomes infected, and Ravn must make the most difficult choice of his life. While Unn works hard to gain control of the infection, Leif implements his own plan.

Vilma has disappeared. Ravn and Leif must find her before someone else does. Police officer Per breaks into Leif’s tunnels and bomb shelters below ground. And in the clinic, Teo finds himself completely alone.