In the 26th year of the Republic of China, a second-hand bookseller in Shanghai discovered an iron box at a second-hand stall in the French Concession. It contained 20 handwritten files and had a red seal of "Historical News from the World" on the cover. The file records twenty strange cases scattered across the country from 1927 to 1937 - each of which uses "objects" as the mediators and "people" as the solvers, ultimately pointing to a hidden truth.
