A report of a rare and unusual gun - a type favoured by assassins - being smuggled into the country sparks Detective Harry Hole's interest. Then a former WW2 Nazi sympathizer is found with his throat cut. Next, Harry's former partner is murdered. Why had she been trying to reach Harry on the night she was killed?

As Harry's investigation unfolds, it becomes clear that the killer is hell-bent on serving his own justice. And while the link between the cases remains a mystery, one thing is certain: he must be stopped.