Right of the bat this is an intriguing book, offering a mystery and dollops of info on Jewish culture and holocaust history. This could have been an excellent, thought provoking read, unfortunately the writing is fairly didactic, a little dry and it failed to stir much more than mild curiosity in me.
A good deal of the book involves interviews and research, which did bog down the first 60% of the text. As this is not a real life investigation, merely inspired by real life events, I feel that a good deal of this research time could have been cut down. There is similarly little feeling to any of the characters. I couldn't tell you if I found Samuel nervous or excited because there was little emotion to the writing. The characters were bland and flat and there was no feeling of urgency or even why he wanted to know. If I was to travel across the globe to discover something, I would have some desire or emotional reaction for this, but I could not understand the main character's motivation. Was it academia? Had he always been eager to know? The fact that I couldn't fathom his reasons were a big problem. In addition, he met the love of his life at some point during the last 40% of the book and I can't tell you a thing about her, which is poor when you consider I finished reading about 45 minutes ago.
The mystery itself was intriguing and the effort put into writing the diary entries was impressive but this is not enough to carry the rest of the text.
In conclusion, it's an able mystery but not written compellingly enough for my tastes. I recommend taking back the text and injecting a little more life into the characters.