I agree with an earlier comment that this falls into the category of mysteries/crime novels with a slight supernatural tinge. Stylistically, it reminds me of Nicholas Freeling, in that I had often to re-read sentences to understand what van Greenaway was saying. This is particularly the case where the subject of a sentence is something abstract.
This is also a very clever novel, with some very clever imitations of Nostradamus-like quatrains. The book assumes an educated and literate reader and makes no concessions to those that are not.
Overall, I thought this book was terrific and I strongly recommend it.