In 1900, Fei Yanggu, a Manchu official of the Qing dynasty (1644–1911), on the orders of Empress Dowager Cixi, led two bodyguards to San Francisco to capture the revolutionaries Sun Wen and Zheng Shiliang. The daughter of U.S. Congressman Grant, Alice, was disemboweled and murdered in San Francisco’s Chinatown. An elderly Native American man was also killed at the same time. The suspect was Bai Zhenbang, the son of Bai Xuanling, the leader of Chinatown’s Xiesheng Hall. Since Grant hates Chinese people in the United States, he is planning to push for a stronger Chinese exclusion bill in Congress. In order to save his son and prevent the Chinese from suffering large-scale persecution, Bai Xuanling invited Qin Fu, a young reasoning master, to help solve the case and find the real murderer.

On the other hand, Ah Gui, a Chinese-Native American hunter, came to San Francisco to avenge his adoptive father and met Qin Fu. The two began to work together to find the truth, but later two young women were disemboweled and killed. Since Zheng Shiliang is a good friend of Bai Zhenbang, the young master of Xieshengtang, Fei Yanggu’s arrest operation did not go smoothly. In order to prepare for the revolution, Zheng Shiliang and Bai Zhenbang stole a batch of firearms from the Irish gang, thus offending the Irish. Zheng Shiliang and Bai Zhenbang hid the firearms in the Chinese Theater where their friend, the Chinese magician Jin Lingfu, worked. Following this, they were caught in the machinery, causing the show to be a success.

After that, Qin Fu meets with Bai Zhenbang, and Bai Zhenbang tells him that he was trying to elope to Europe. After that, they visit the autopsy of Alice, finding that the killer was good with a knife and also discovering wood in Alice’s head and hair. Qin Fu proceeds to question Congressman Grant, but does not receive any information. After being removed from the premises, Ah Gui and Qin Fu look in Grant’s house. They find a banister matching the wood in Alice’s hair.

Meanwhile, Fei Yanggu makes an alliance with the Americans, after a brawl in a bar.