In the spring of 1940, Wang Jingwei, formerly vice-chairman of the Chinese Nationalist Party, brokered peace with the Japanese government and established a new “National Government” in Nanjing. From that point on, the War of Resistance Against Japan entered a new “three‑power” phase: Wang Jingwei’s Nanjing National Government, Chiang Kai-shek’s Chongqing National Government, and the Shaanxi–Gansu–Ningxia Border Region Government led by Mao Zedong—each standing as an equal pole, governing independently while mutually checking one another. Upon assuming office, Wang Jingwei launched three major policies: building up his military within his sphere of influence, carrying out pacification campaigns to suppress the Communists, and simultaneously enticing disgruntled Kuomintang military and political figures to join his cabinet.

　　On October 10, 1942, the Wang Jingwei regime held a grand ceremony to celebrate the thirtieth anniversary of the founding of the Nationalist Government. During the event, a high-ranking official of the Wang regime was assassinated, drawing serious attention from the Japanese authorities. Takeda, head of the Imperial Army’s intelligence unit, suspected that this series of assassinations had been orchestrated by “Old Gun,” an underground Communist leader, and sought to seize the opportunity to dismantle his organization. Takeda’s investigation revealed that “Old Ghost,” who was responsible for transmitting orders, was hiding within the Anti‑Bandit Command Headquarters. Accordingly, he brought five suspects—those most likely to have access to telegrams—to the secluded Qiu Zhuang: Wu Zhiguo, commander of the puppet army’s anti‑bandit unit; Bai Xiaonian, aide-de-camp to the commander of the puppet army’s anti‑bandit corps; Li Ningyu, head of the translation and cipher‑breaking section at the anti‑bandit command headquarters; Gu Xiaomeng, administrative clerk in charge of correspondence at the same headquarters; and Jin Shenghuo, director of the military‑communications department of the puppet army’s anti‑bandit corps.

　　With the investigation limited to just five days, Takeda must resort to every means at his disposal—even brutal torture—to uncover the “Old Ghost.” Meanwhile, the five under house arrest, desperate to save themselves, meticulously scrutinize the other four, each hoping to expose the “Old Ghost” as quickly as possible so they can slip away from Qiu Zhuang unscathed.