I have no idea what it was about this book but it was not for me.
The book was off to a great start with its unusual setting for a spy story that starts in rural Bulgaria, but then it seemed to loose its way for me.
It may have been Furst's attempt at writing a kind of panopticon that would show the different theatres of world history that were affected by the story in parallel that didn't work for me, or maybe it was because Furst's writing reminded me of Ken Follett's (who tried to pull of a similar overview of all the events in different locations in Fall of Giants ... God, I hated that book!) that put me off, but I just could not get invested in the story ... or the characters.
So, in the end, I finished the book, shrugged, and moved on.