Some really cool ideas, but meh...
For a start, there is no Douglas Adams connection here, apart from the presence of a coincidence engine that somewhat resembles the infinite improbability drive. Oh yeah, and the author is British. Once people start making comparisons like that, you might expect humour? Well, it isn't that kind of book.
Now we've got that out of the way, what is there here?
1. A very complicated, interconnected cast of characters and institutions, all in pursuit of said coincidence engine which is basically a bit of a mcguffin. Various forms of violence, scheming and subterfuge ensue though the point of most of them was never very clear to me. There are also a few coincidences, but no more than in your average novel and a bit of philosophy. Leith basically throws all this up in the air and tries to juggle with it, but instead of forming a nice arc, it comes out as random flying objects. One of the symptoms is the very rapid shifts of point of view, including a few where he suddenly turns round and starts addressing the reader. I can actually understand why he thought we might need a bit of stage direction.
2. A few interesting characters. I actually got the feeling that the author is a bit challenged when it comes to all that touchy-feely stuff of human subjectivity and relationships. His very best characters, the one I developed most empathy for was the one who was distinctly out of the ordinary in the way he processed human experiences. There were also some character based subplots which might well have proved interesting but for most of the book they seemed irrelevant, only manifesting as pointless coincidences right at the end.
All in all, it's a book that certainly had its fascinating moments, but it didn't quite gel.