Novel by Mai Jia.

In this book Mai Jia creates Unit 701, a top-secret intelligence agency in China whose sole purpose is counter-espionage, radio surveillance, and code-breaking. The protagonist of Decoded is an autistic genius called Rong Jingjen. He comes from the illustrious and highly educated Rong family, but was born deformed (with a big head). This is the tragic story of his rise as China's greatest code breaker, his almost mythic birth, the Rong family's role in China's modernization and education, of his leaving the world of mathematics and academia behind and his "recruitment" by 701. His greatest challenge is a set of highly classified codes called "The Purple Code" which is developed by China's chief enemy (unnamed throughout the book) and the mastermind behind the code is Professor Heath, a Jewish genius who is both Rong's teacher in university and his best friend.

Rong successfully breaks the Purple Code, but a new and more difficult variation awaits him. It's called the Black Code, and Rong becomes obsessed with breaking it. In the process, his notebook, which contains everything he's written about code-breaking, is stolen, and this accident eventually drives him insane…