In the winter of 937, Shanghai fell after the Songhu Battle, but the French Concession remained prosperous on the surface. In an inconspicuous tailor shop, Chen Yanqiu, a young tailor who had returned from studying abroad, measured the figures of his customers with a tape ruler and scissors, and also recorded the edges of documents inadvertently exposed in their pockets with his eyes. He didn't know that three days later a customer's forgotten pocket watch would drag him into a password war involving hundreds of lives.
