During the War of Resistance against Japan, Chen Zhensheng, a civilian guardian of books, uses Tingyuzhai as a front to protect China's national treasures. He unexpectedly acquires the Ming-dynasty unique manuscript The Chenhao Proclamation, which contains firsthand historical records of the Prince of Ning's rebellion. Rumors also claim that the book conceals a treasure map left by the Prince of Ning. After the news leaks, the Japanese army covets the ancient book and its treasures, seeking to steal historical records and sever China's cultural heritage. Meanwhile, agents from 'Unit 76' want to seize the book to curry favor with their superiors and distort history. Intelligence operatives from both sides launch a hunt for Chen Zhensheng. Su Yanqing, his childhood sweetheart, returns from studying abroad as an underground Communist Party member. The two move from mutual suspicion to entrusting their lives to each other. In the face of danger, Chen Zhensheng activates the 'Moving Mountains Plan,' igniting a silent war amid the darkest hour.