Gun Machine is a story working on two layers. The first layer is a well written thriller where a policeman and a serial killer stalk each other across Manhattan. The second layer is more interesting to me- the ghost maps of modern life. "Ghost Maps" is a term Ellis introduces midway through the book, describing things like the old paths of rivers running across the island, the geographical distribution of surveillance cameras, police precinct boundaries, informational lag time in information networks as a measure of distance versus geographical distance and many more ideas of a similar nature. It is the informational overlay we place over our environment, and how that environment is shaped by forces invisible to us, that forms the intellectual backbone of Ghost Machine. It is a highly sophisticated view of cities and very thought provoking. It is a particularly unusual way to frame a murder mystery.And more than brainy- Gun Machine is funny. Bleakly, blackly, horribly funny. Warren Ellis established his gift for a searing turn of phrase back in his graphic novel days and it's put to good use here! His description of Sumo should see the sport spike in popularity in bars across America. I won't spoil the jokes, but oh god are they funny. Ellis is clearly a firm believer in the theory that tragedy and comedy are best deployed proportionately and in conjunction.The characters are well rounded and interesting. They live in a plausible world, and they behave with a pleasing degree of rationality. This may be an overreaction on my part, but I seem to have read a great number of books recently where many plot defining challenges would have been overcome by a reasonably emotionally stable seventh grader. The obvious exception to this is the psychopathic serial killer, but the point of that character is that he functionally lives in another world. Our hero, Detective Tallow, is a deeply flawed and lonely character, so lonely that he does not even realize that he is lonely and unloved. His CSU sidekicks are weird as hell, but weird in a very human way. Big city weird that argues with a spouse over the cost of steak sandwiches and leaving coats on the back of the couch. For all that they make what I will bowdlerize as a coitus-bot and other offences to the gods of HR.It's a good book. The plotting is tight, the pacing is swift but pleasantly varied, and the dialog is sharp and real. Gun Machine is packed with ideas and trivia. It makes you think. And when you learn what the Gun Machine actually is, how it works and the why of it... well. It's worth reading the book to find out. I read it in a day, staying up much too late to finish it. I recommend this book unreservedly.