Policeman Salmander loses his job in Oslo and must spend dismissal time in Hellfjord, a shit hole of a place far north in the country. As soon as he arrives, strange things start to happen in Hellfjord, and the seemingly quiet place turns out to conceal dark secrets.

Salmander and Johanne sneak into Hellfish at night and come across something strange. They overhear Bosse Nova talking about the infamous serpent Tulla, and despite Salmander's chronic seasickness he decides to defy his fear and look into this phenomenon.

Salmander's notice period is over and he is sent back to Oslo. He continues to investigate the murder mystery as a civilian. Meanwhile in Hellfjord, Johanne finally gets to the bottom of Bosse Nova's hidden activities by herself, and reveals a conspiracy that is bigger than they ever could have imagined.

Salmander and Johanne have each on their own exposed Bosse Nova's drug business. Without police help, but armed with confidence and a machine gun, Salmander comes back to Hellfjord for a final showdown with Bosse in the fish factory Hellfish.