The protagonist carries a "global deduction sandbox" that can deduce future intelligence variables and travels back to the 26th year of the Republic of China when the Battle of Songhu was defeated. He does not rely on force to sweep the battlefield, but engages in a zero-sum game with the top Japanese agents in intelligence warfare, psychological warfare, and deception warfare. The deduction sandbox can simulate the flow of data, but it cannot directly tell him the answer - he must find a way to break the situation among countless pieces of false information.
