In his griping debut novel, Mai Jia reveals the story of Rong Jinzhwen, one of the greatest code-breakers in the world. A semi-autistic mathematical genius with a past shrouded in mystery, Jinzhen is abducted and recruited to the cryptography department of China's secret services, Unit 701, where he is assigned the task of breaking the elusive 'Code Purple', the most difficult code in history. Who is the mastermind behind the code? Why has Rong been chosen? Who can he really trust? His attempt to solve this enigma leads to him becoming China's greatest and most celebrated code-breaker - until he makes a mistake. Then begins his descent through the unfathomable darkness of the world of cryptology into madness.