Dom is a numerate who comes to awareness of a bus in Utah with no memory of how he got there. All the numbers on his ID and money have been charred off, and there's another person inside his head. This person -- Billy -- is the crippled avatar of some long-dead numerate, memories of his corporeal life lost. He and his former host were chasing a powerful artifact in the desert when they encountered a much more powerful numerate, possibly inhabited by John Napier and Archimedes, and the ensuing duel killed Billy's host. Desperate for new accommodations, Billy fled to Dom's mind.
Thus begins Dom's adventures, fleeing from the powerful numerate who killed Billy's host and attacked him. He quickly teams up with Jenna, an untrained proto-numerate who spots him when he rubs the serial numbers off his money before buying lunch from her at a deli and pursues him and demands that he train her. They flee to Canada, and then to Scotland, and on the way, we are treated to glimpses of the numerate world, where coincidence is power, where prime numbers can defeat pursuers, where number-intensive pursuits like stock-trading and sports flare off raw power there for those who want it.
Murphy's vision of numbers as the secret, driving engine of the physical world is striking -- he plays right into the mind's own propensity to ascribe pattern to the patternless, significance to the random. The resulting mystical system feels very convincing, and forms the basis for as fun and intense an adventure novel as you could hope to find. The physical book, produced by Canadian specialty press ChiZine, is a smart and beautiful little package with striking, subtle use of embossing and type-design that makes it a fine artifact in its own right.