Though the main character in Assouline's La Cliente comes across as a very judgemental, even busybody person, he did not bother me once. In his search to understand the 'absolute evil' - people who denounced others anonymously in occupied France - he learns once more there is no black and white, only shades of gray - which is another way of saying that it is not so difficult to understand why people acted the way they did, though the consequences of their actions were horrid - in this case, sending jewish French citizens to their certain death. The main character's inquisitiveness brings forth a fascinating story.
Assouline's prose is fine - like a finely chiseled landscape etching - and refined.I did not know quite a number of the words he used ('scuse my French). I have not found an english edition, though La Cliente has been translated into other languages.