The protagonist's golden finger is a "historical document", but the book is incomplete, and the content will only appear in the form of the protagonist's "dream return" or "epiphany". The protagonist must confirm the records in the book through his own real actions. The book gives some key "passwords" for solving crimes, such as the secret handle of a certain eunuch and the wrong and omitted evidence of an old case. The protagonist needs to find these evidences in reality and complete the comeback. The whole process is extremely real, there are no shortcuts, and every step is a huge gamble.
