That is the new and excellent book by Kerry Brown. Almost all books on China are either bad or mediocre, but this one is the best book I ever have read on the exercise of power in contemporary China. Every page is good, here is a short excerpt:
More important than a cabinet in the Western system of government, yet ostensibly separate from day-to-day decision making, the Politburo owns the crucial function of dispensing ideological, spiritual and political leadership. This description means it covers nothing and everything. It has the broadest framework within which to operate, which means it can wander into every area of administrative and governmental life in the country. But like the ideal city described in Plato’s Republic, in a strange way China is really run on the model of philosopher kings.
Definitely recommended, one of my favorite non-fiction books of the year so far. I can readily imagine re-reading it.