Zen is the ultimate outsider, a man for whom nothing seems to go right even before it goes wrong. In this first book of the Zen series we can see a pattern emerge which will be developed and elaborated upon in this book and those that follow. Zen is assigned a case concerning the kidnapping of a very unsavory but powerful business tycoon. Perhaps what is more unsavory than Signore Miletti is his family and his retainers.
The "ratking" refers to a tangle of rats bound by their tails through circumstance that operates in a symbiotic manner in order to survive. Mr. Dibdin uses this analogy to explore not only the Miletti famly but Zen's entire world, his mother, girlfriend, fellow detectives, the political system, indeed the entire society in which he must live. If not for the worldly resignation of Zen and his lack of interest in his career this would be truly a rather too bleak world to bear or read about.
But it is Zen's perceptions and realism that keep driving him on and his own self-preservation. The psychological dimensions of the story are immense and yet do not get in the way a a tautly written murder mystery. The cast of characters is lush with villains, neurotics, freebooters, venal degenerates, incompetents, all living in a world of lush luxury.
While Zen himself is not total anti-hero and is truly misanthropic, he is an admirable realist or as Wycherley wrote, a "plain dealer. This is a thinking man's mystery.