Zen is in many ways a classic fictional dectective - middle aged, a loner, problems with relationships and authority. The Italy described is realistic, even in some of the later novels that are more ironic and playful. The characters are more memorable than is usual in dectective stories; suspects appear to have lives beyond their involvement in the events. As with many of the best crime writers, there is always a sense of things just out of vision, matters involving the rich and powerful that are handled in other ways. Not in a 'conspiracy theory' sense, the matters may be more squalid and banal than dangerous, but just because they know people. These are excellent books all round.
Although it is not really necessary to read the novels in order, doing so gives a much better understanding of Zen's evolving relationships with women, family, friends and employers as well as the changing political and cultural landscape of modern Italy.
Ratking unravels the dense knot of relationships binding members of a wealthy family in Perugia where Zen is sent to investigate a kidnapping. He quickly gets lost both in the labrynthine streets of the old city and the lies that the family tell to him and to one another.