The trial process of Zhang San's case

Xue Pan and Jiang Yuhan were drinking in the hotel, and they had an argument with the waiter Zhang San, who deliberately killed Zhang San. At the first trial, Xue Pan admitted that it was intentional homicide. Later, Xue Dou bribed the county magistrate and turned over the case. This shows the social reality of reversing right and wrong at that time. Investigate the mastery of the plot of the work and its role in the theme expression.