Law of Return brings together many of my favorite elements: interesting and complex characters, World War II in Europe as a setting, well-researched historical detail, and a Jewish refugee in need of help. Carlos Tejada has been promoted to lieutenant and transferred to Salamanca from Madrid. It's 1940, the Spanish Civil War has ended and we know who won: Tejada's boss.
In Salamanca Tejada meets a young woman whom he met in Book 1 of the series, Elena Fernandez. She is from Salamanca, where he father was a professor at the university. He has had political problems during the war and is now on probation and under surveillance most of the time. Her father had a German Jewish colleague who is now trapped in France and needs help getting to Spain. Professor Fernandez cannot travel to Biarritz, France, which is near the Spanish border, so Elena and her mother plan to go to San Sebastian and sneak into France. At the last minute her mother is injured so Elena goes alone. At the same time Carlos Tejada is going to San Sebastian to investigate the disappearance of another university professor who is also on probation, Manuel Arroyo Diaz. He has a house and a boat in San Sebastian, so it is suspected that he escaped there with the intention of fleeing the country. But where and why?
The tension in these books is fueled by the strange political situation in Spain. There don't seem to be many good guys and lots of bad guys. However, Lieutenant Tejada is an enigma. Ostensibly on the side of Franco (super bad guy), Tejada is a good man and fair-minded policeman, which seems to be an oxymoron in this context. Elena seems to be fairly a-political at this point, but her brother is a Communist who fled to Mexico after the war. Elena and Carlos seem to be destined to fall in love, but continue to fight about politics.
This book also passed the Wikipedia test for me: It prodded me online to find out more information about Spain after the Civil War ended and about the cities of Salamanca, San Sebastian, and Biarritz. Despite Spain's official neutrality during World War II, Franco and Hitler were thick as thieves, so it was a very dangerous place to be. The title of the book refers to a law passed in Spain stating that Jews of Spanish descent, Sephardic Jews, who can prove their lineage, may return to Spain. But our German Jewish Professor Meyer is not Sephardic. He seeks another solution.