In 1939, Shanghai during the isolation period became a battleground for various intelligence forces. Japanese and puppet spies, military commanders, the CCP's underground communication lines, the Youth Gang and foreign companies were intertwined. On the surface, the protagonist is just a photo studio owner with his daughter in the concession, but in fact he was a well-trained lurker. He lost his wife and identity due to a failed operation, and could only hide himself in the world of fireworks as a "nanny". The Japanese army is secretly promoting a Yangtze River defense intelligence plan code-named "Kurotide". Once completed, tens of thousands of soldiers on the front line will be passive. In order to protect his daughter, investigate old cases, and block the enemy's intelligence network, the protagonist is forced to play the game again. Under the shell of pretending to be a coward, he overturns the most vicious intelligence chess game in Shanghai step by step.
