Philosophers and scientists have yet to establish the point where mathematics meets metaphysics or where infinity becomes eternity. Such speculations and ruminations are not an obvious topic for a best-selling first novel. Yet “a novel” is boldly emblazoned beneath the title on the front cover of this extraordinary ­exploration of a fantastical reality by a long-term spymaster of the Chinese People’s Liberation Army’s intelligence unit.The fact that the novel itself is a rela­tively new literary form in the Far East makes the dazzling inventiveness of Decoded all the more striking. So much so that reviewers have had great difficulty in trying to situate the author within a more familiar tradition. Mai Jia has been compared to, among others, Franz Kafka, Aga