"There are many Oxfords ..." begins John Gielgud (several times) as University Chancellor during Colin Dexter's The Twilight of the Gods. I had a similar sensation while reading this book.
It's an original and entertaining tale of an Argentinian graduate student who, on arriving in Oxford, becomes embroiled in a series of murders seeming to centre around logician Professor Seldom. Of course, being a novel, there must be a twist: the murderer's calling card takes the form of a mathematical sequence, challenging those involved to solve the puzzle. Martínez elegantly weaves various mathematical ideas (Gödel, Wittgenstein, Pythagoras, Fermat) into the tale while never getting too heavy, and the reading was much lighter than I expected. There are the requisite number of plot twists, red herrings, and facts you couldn't possibly have known, but all in such a clever way that you don't really mind. It's odd that crime fiction should prove to be so entertaining when you stop to consider the reality of violent death, but perhaps it's just a more extreme form of escapism from the real world.
I'm not sure of his intented audience, but Martínez has slipped up with his research in a few places. I would have thought it was common knowledge internationally that the British police are armed only in exceptional situations. Perhaps it's just psychogeography, but anyone who has spent time in Oxford (and particularly those "living in") would not consider it a short walk from Cunliffe Close to the Mathematical Institute on St Giles. The Eagle and Child is not on Magdalen Street. Finally, the Mathematical Institute is not a uniquely hideous piece of modern architecture: it's just around the corner from Nuclear and Astrophysics. Though they do perhaps indicate a little sloppiness, none of these really detract from the book, even to a relatively knowledgeable observer.