A GUARDIAN BOOK OF THE YEAR'Gnomon is an extraordinary novel, and one I can't stop thinking about some weeks after I read it. It is deeply troubling, magnificently strange, and an exhilarating read.' Emily St. John Mandel, author of Station Eleven'Nick Harkaway's most ambitious novel yet. [A] story of near-future mass surveillance, artificial intelligence and human identity ... An amazing and quite unforgettable piece of fiction.' Guardian'Harkaway dazzles.' Daily Mail'Wonderfully good.' Sunday TimesNear-future Britain is not just a nation under surveillance but one built on it.Every action is seen, every word recorded.So when Diana Hunter inexplicably dies in police custody, there are questions that cannot be asked. How is a glitch like this possible? How can the System, the most perfect of governments, have made such a tragic mistake?Charged with discovering what happened, Investigator Mielikki Neith enters Hunter's mind using a machine that reads memories from your brain. But instead of uncovering the truth, Neith finds within Hunter's brain the lives of 4 others - none of which can possibly be there.As Neith is drawn deeper into the case, the 4 stories begin to combine, and one question stands above the rest: who will live, and who will die? Immersing herself in neural recordings of the interrogation, what she finds isn't Hunter but rather a panorama of characters within Hunter's psyche. Embedded in the memories of these impossible lives lies a code which Neith must decipher to find out what Hunter is hiding.