As the troop marches towards the Protectorate Camp of Lin'an Prefecture, the doctor explains that the bodies of three soldiers have recently been found. The soldiers were killed within two months of arriving at the camp, and the doctor needs to begin an autopsy. He finds bite marks on the soldiers' faces, bodies, and legs. He wonders if the soldiers were practicing martial arts, and wonders why they would use their teeth to bite. He wants to open the brains of the dead soldiers to see if they have suffered from mental illness. The doctor explains, "for ancient people, frontal lobes and temporal lobes were normal size, but those who suffered from a mental illness, such as patients with manic depression, had shrunken organs. It's like they have been bitten by something