This book, although it starts pretty slowly with a symbollic rather than believeable setting (a huge secret library in a land where there are no secrets), is written as a mystery with very good character development. One comes to know the main characters pretty well. The setting is Franco Spain, and the main effect conveyed repeatedly is the absolute horror of living in a fascist regime where the police can beat or kill you at will and then face no ill consequences. The police inspector, appropriately, is a psychopath.
Aside from quite a few sentences whose length would satisfy a Hegelian philosopher, the German translation is a apparently a very good one.