The author, who is a well-known award-winning author in China, supposedly worked in the Chinese intelligence service himself. Moreover, it is written in a pseudo-scholarly style, including footnotes, transcribed interviews with key characters, and pages copied from notebooks. So, you would expect the story to seem quite realistic. In fact, however, Jinzhen's personal story feels more like an allegory about genius, the Rong family history is like a fairy tale, and the intrigue/political turmoil during the Cultural Revolution is so Kafka-esque as to be almost unbelievable.

Several of the characters are mathematicians, including more than a few Rongs and a European colleague who serves as a mentor to the young Jinzhen before becoming something of an adversary. In a vague sense, the book certainly conveys the sense that math is interesting and important. Rong Jinzhen himself is, for a time at least, considered a great hero for having broken a code named PURPLE.

No mathematical details are given regarding the codes PURPLE and BLACK which are central to the plot. We only know that they are in some way diabolical as well as mathematical. The few times that the book tries to be more specific about mathematics are its worst moments. One explicitly mathematical part is when a young Jinzhen tries to determine how many days there were in another character's life. That part is, unfortunately, a bit boring. . . but at least I did not see any errors in it. Later, we are told that Jinzhen writes a proof that artificial intelligence is impossible which is based on the irrationality of the number π. That doesn't make any sense to me, but it gets worse. The other mathematicians are supposedly critical of this proof because it assumes that π is a constant, and (we are told) mathematicians do not actually know whether it is. (This is so ridiculous, I am left wondering whether it is an error introduced by the English translators.) Look, start with a circle of radius 1 and define π to be the ratio of its circumference to its diameter. One might imagine at first that a different circle would lead to a different ratio, but it is obvious that scaling the size of the circle will change all lengths by a factor of some number k. Since this applies to both the circumference and the diameter, it is clear that the ratio of the circumference to diameter of any circle in the Euclidean plane is a constant, and that's the number that we call π. It is not quite as easy to see that this ratio is an irrational number, but by the 1950's this also was no longer an open problem in math.

For me, this book was worth reading because it gives a bit of a glimpse into Chinese culture. It did not seem to have anything interesting to say about math itself. It does seem to be trying to say something about the nature of genius, about its fragility. However, at least on a first reading, I didn't really get it. So, it is difficult for me to strongly recommend that others read this book. But, I would ask this favor: if you do read it and understand it better than I did, please come back here and post some comments using the links below. Thanks!

The book first appeared in Chinese in 2002, but was translated into English and published by Farrar, Strauss and Giroux in 2014.