Rong Jinzhwen, perhaps one of the great code-breakers in the world is a semi-autistic mathematical genius recruited to the cryptography department of China's secret services, Unit 701, and assigned to break the elusive 'Code Purple'. He rises to be China's greatest and most celebrated code-breaker, until he makes a mistake and descends into madness. The author, pseudonym of Jiang Benhu, worked for decades in Chinese secret security.