I read this book a few years ago and was extremely happy with what I came away with. Some errors were made when it came to the purges of the Red Army, and at some points there were simply assertions that I did not agree with, but that should not take away from the excellent discourse this work goes into in regards to Stalin and the system that he was a part of. To us common sense has to dictate that killing millions of people is simply out of this world, even more so for one man to accomplish and do on his own.
This book is a framework that shows how in fact Stalin and the NKVD worked and what happened behind the scenes. It is my belief that in fact many of the deaths that occurred, happened indirectly from what Stalin had ordered done. The usual procedure was as follows, it is known as the 'snowball affect': When some of those arrested were interrogated they would give up names, those names would then be researched and found and brought in and interrogated, etc etc etc. This is how when Stalin signed away for the arrests of the top Marshals and Generals in the Red Army, those who suffered during the purge were also colonels, majors, captains, etc. Stalin most likely had no clue that they were involved in anything, but when torture is applied anything and everything will be reveiled.
This also explains that when Stalin realized where this was going he had to put a stop to it, he stopped it by blaming Yezhov, who was then in turn arrested, tortured, tried, and executed. One man most certainly was not responsible for what transpired throughout Stalin's reign. I am not an apologist, far form it, I hold him accountable for much of the suffering the Soviet Union and my great-grand parents had to go through. But more so I believe in knowing and understanding the truth, while much can be blamed on him it should be understood that this was a time of many crimes being committed by many people, this book goes far in showing that to be the truth.