Salonika, Greece (now Thessalonika), is Greece's second largest city, after Athens. However, it is located in the northeastern part of Greece, much closer to the Balkan nations than to Athens. And it is here where Alan Furst, author of so many excellent WW2 novels, has based his new "spy thriller".
The summer and fall and winter of 1940 was the end of the "Phoney War" in Europe. Hitler had invaded west and had taken France and the Low Countries, and were threatening the Balkan States, some of whom were already "allied" with Germany. Greece had just been invaded by Mussolini's Italy, jealous of the success of Hitler's Germany and all the land they had conquered. The Greeks were able to hold off Italian advances, but everyone was waiting for Hitler to come to the aid of his Axis-partner, and finish off Yugoslavia and then Greece. (Understanding the politics of the Balkans is way above my pay-grade, but I can sort of appreciate the machinations of all involved).
Costa Zannis is a "special" police officer in Salonika, assigned to the city's "special" cases - those involving high-ranking officials and foreign dignitaries. "Special cases" which needed tact and discretion to handle. He has a small squad at his disposal, and extra funds from the government to help him along with his job. Furst has Zannis handle many cases, from aiding a refugee underground devoted to getting Jews from Germany to safety in Turkey and Egypt, to helping sneak a shot-down British scientist trapped in Occupied France escape back to England by taking him down the Balkans to Greece. Zannis is not an ambiguous hero. He does what he does from an honest belief in helping those who need it. He is quite honestly a good man.
Furst writes quite a nuanced book here. The plot is sometimes a little pot-boiler, but only a little. It's all in all a great read, particularly for those of us WW2 "junkies".