Veteran prosecutor Duan Hongshan of the Municipal Procuratorate is assigned to handle a case involving a woman who killed her husband after suffering domestic abuse. Fang Lingyuan, a young prosecutor from the Provincial Procuratorate, is appointed to assist with the investigation. During their investigation, they discover the case's close ties to a "campus excessive self-defense case" from fourteen years ago, which involved Li Mufeng, Mei Zheng, and Jiang Ting. It was also an earlier case handled by Duan Hongshan. Guided by facts and the rule of law, and carefully weighing moral principles, human sentiment, and national law, the two work together to arrive at an accurate and fair legal conclusion.