In the autumn of 1938, the Battle of Wuhan was in full swing. A top-secret strategic plan named "Sakura" by the Japanese army was quietly delivered to Shanghai Super High School. This plan is related to the ultimate plan of "disintegrating the Chongqing regime within half a year" set by the Japanese Imperial Council - once implemented, China will lose all foreign aid channels and the national destiny will be in danger.
Shen Jinghong, a mathematician-turned-military code-breaking expert, was ordered to sneak into the occupied Shanghai, using his identity as an employee of a foreign bank as a cover, in an attempt to contact the mysterious informant "Zhong Kui" lurking within the Japanese cabinet intelligence agency. However, the connection failed and the informant was killed. The only clue was a seemingly meaningless set of digital codes.
At the same time, Gu Xiangjun, an underground member of the Communist Party of China, accidentally obtained half an account book written in charcoal shorthand. The two went from confrontation to joining forces, and in the strangulation net pressed step by step by Masao Watanabe, the super high school class, they peeled off the cocoons and got closer to the truth. They gradually discovered that the "Sakura Project" was not a simple military deployment, but a comprehensive war involving finance, diplomacy, and people's hearts. What's even more surprising is that someone within Chongqing's top leadership is paving the way for this plan.
The ups and downs of the spy sea, the thought of life and death. When faith and country hang by a thread at the same time, how can a small person hold up the backbone of a country that is about to collapse in the dark night of history?
