In the Shadows - Arnaldur Indridason - book

A sales representative is found in a small Reykjavik apartment, shot dead by a Colt bullet and branded with the word “SS” in blood on his forehead. Suspicion quickly falls on the foreign soldiers milling about the city in the summer of 1941.
Two young men are in charge of the investigations: Flovent, the only investigator in the Icelandic criminal police, a former trainee at Scotland Yard, and Thorson, the Icelander born in Canada, designated as an investigator by the military because he is bilingual.

The influx of British and American soldiers is shaking up this island of fishermen and farmers, which is rapidly evolving towards modernity. Women are becoming emancipated. The Nazis, despite the dissolution of their party, have not given up on finding traces of their myths and Aryan purity on the island. Moreover, a visit from a great man is secretly awaited.

The investigation's many twists and turns paint a fascinating picture of Iceland during the "Situation," the occupation of young soldiers who sow unrest among the female population. They also reveal tenacious investigators, despised by the military authorities but determined not to allow themselves to be subjected to the expected culprits.
In this gripping and addictive novel, the reader is as fascinated by the world embodied by the characters as by the unpredictable plot.