In the summer of 1991, a rape case broke the peace of a small town. The fathers of two girls in the local middle school were the policemen in charge of the case. Nevertheless, they had very different working styles: QU's father was a stubborn legal medical expert always insisting on ironclad evidence, while ZHANG's father, a retired soldier, handled cases relying on his intuition and often extorted confessions through torture. The supposed criminal was caught by ZHANG's father yet similar cases kept happening. Nobody noticed ZHANG's disappearance since she was kicked out of class.