'Nyk nen's twist on Nordic crime fiction may be the most inventive of the year. Ariel Kafka, a middle-aged bachelor, is a detective in Helsinki (think early Harry Hole) and, as far as he knows, the only Jew on the entire Helsinki police force, which is why he's picked to head up the investigation of a series of murders that began with two Arabic-looking men who may have been shouting Jewish obscenities as they died. Set during the days leading up...