In the autumn of 1938, the Shanghai Concession was still singing and dancing. Chen Shu is a piano tuner at the Paramount Cinema, and his fingers can hear the tiniest out-of-tune of the strings. That evening, after he finished tuning the Steinway piano for the new Belarusian luthier, he discovered a roll of microfilm hidden in the interlayer of the soundboard in the bass area. When the film was developed, it was half a map of the Japanese army's troop deployment in East China, as well as a list of seven lurkers marked with code names. That night, the piano player died at the Suzhou River Pier with a piano tuning wrench stuck in his chest - exactly the same as the one in Chen Shu's tool box. When someone from the patrol house in the concession knocked on the door, Chen Shuzheng used tweezers to pick out a small piece of bloody velvet from the gap in the wrench. It was the lining material of the Belarusian luthier's coat.
