This article is a suspense reasoning theme under the background of the Republic of China. In the midsummer of 2018, He Shuo, the owner of a second-hand bookstore, saw a novel called "The Great Treasure" in a newly acquired magazine of the Republic of China. The novel tells the story of August 1945, the eve of Japan's surrender. The four sects of the secret organization "Tiandi Xuanhuang" in Fengtian City learned that the Japanese army was going to transport a batch of national treasures looted from the Forbidden City back to China. In order to prevent the national treasure from falling into the hands of the Japanese, the Four Gates planned an extremely arduous "battle to regain the national treasure." The masters of the four gates each showed their talents, and finally successfully sniped the Japanese treasure transport team and intercepted the national treasure, but also paid a huge price for it. However, when everyone was celebrating their victory, they discovered that three national treasures were not included in the delivery list. As a result, surrounding the three missing national treasures, the masters of the four gates, Japanese detectives, revolutionary martyrs and Kuomintang spies all appeared, and the city of Fengtian was once again turbulent... This article is narrated by two timelines of the present and the past, divided into four relatively independent chapters. Each chapter is an exquisite mystery case and an exciting suspense adventure story. The author also combines reasoning with traditional Chinese magic and acrobatic elements, which is refreshing. In terms of subject matter, this article takes the retrieval of national treasure as its theme, has patriotic feelings, and can convey strong empathy and good guidance to readers.