During the Wanli period of the Ming Dynasty, a wordless secret scroll set off an undercurrent concerning the fate of the country. In the premise, the criminal officer Song Yan was entangled in an unjust case and his future was ruined, but he was forced to become the only "living key" that could unlock the volume - only his blood could make the last edict written by his mentor with special ink reappear in the world.
The edict refers directly to the "Hollow Man", a huge spy network that infiltrates the government and the public. The hands that used to break prisons and examine wounds now have to be stained with blood. Amid the open and covert attacks of all forces, they have formed a life-or-death partnership with Liu Qingmei, a Qianhu of Dongchang who has ulterior motives.
As the decryption deepened, they discovered that what the "Hollow Man" sought was not simple power, but a "Sea Power Map" that could overturn the world structure in the next three hundred years. From the far reaches of the rivers and lakes to the top of the Forbidden City, a desperate game surrounding the secrets of navigation and the change of imperial power quietly unfolded. The injustice of the past intertwined with the general trend of the world. When the truth was finally laid out in blood, Song Yan faced not only his own innocence, but also an imperial crisis that could destroy everything.
