Zhao Yu had been involved in criminal investigation for a long period of time, so when he found a large number of numeric symbols in the book, he did some quick research and figured out some clues.
First, he searched the Internet and found out that these numeric symbols were a kind of phonetic symbol used during the period of the Republic of China. It represented the Chinese Pinyin during that period. According to the Internet, as the usage of Mandarin was not popular during that time, the Chinese Pinyin was not the same as today. Instead, it was made up of forty symbols that looked like Latin alphabets.
Next, Zhao Yu made a comparison between the numeric symbols and a previous hexagram. Very quickly, he found a matching symbol.
As this was a phonetic symbol, only the correct pronunciation of the hexagram poem mattered, not the exact meaning of the words.
