In Shanghai in 1941, Shen Yan, a low-level military agent, was hiding in the market. He has an amazing eye for spotting Japanese spies and can spot enemies in the crowd; he is also a top operative, killing traitors in enemy-occupied areas at night. He wanders around teahouses and alleys, using his ordinary identity as a shield, using his blood and wisdom to dance on the tip of a knife, protecting his family and country, and writing the spy war legend of a little person.
