I found this to be a rather odd book. Much like The Immortal Life of Henrietta Lacks, it has two distinct plot lines. One is the story of the rise of Hitler and Rosenberg's role in developing and disseminating toxic and vicious anti-Semitism for the Nazis; the second is the discovery of Rosenberg's diary and how it was smuggled out of Germany by Kempner (a prosecutor at the Nuremberg Trials), concealed, misplaced multiple times, chased down across the Atlantic, and finally preserved in the Holocaust Museum.
I find I have to read books about Nazi Germany in small doses; the horrifying events and the descriptions of the viciousness of the individual Nazis are just too much to take in and too disturbing to read in long swaths. But this book provides one of the best overviews I've seen with respect to the rise of the Nazis, the terror they instilled, the wishful thinking by so many, the overwrought pretexts and lies the Nazis used to justify their actions, and the "logic" that underpinned everything from the looting to the killing. A well-researched, careful book.