Qin An's condition worsened and he was diagnosed with poisoning. Some people were suspected to be eager to silence him.Yan Chi and Qin Wan began to suspect that the reason for Qin An's poisoning might be related to the previous murders in the Qin Mansion, and believed that these murders might be revenge of the victim's family.Qin Guan and Yan Chi excavated a total of thirteen corpses. At the same time, they began to check the missing person files sent by various provinces and found the fire in the Yang family and the information about the two daughters of Aunt Yang.

Qin Guan and Yan Chi suspected that Aunt Yang's eldest daughter might be the murderer or the commander, so they decided to find her.Yan Chi and Qin Wan discussed the case in the Qin Mansion Garden, believing that stealing the demon-slaying stone was the first case of the murderer and the first step in revenge. Qin Wan discovered a method of using bamboo to move the demon-slaying stone. This method only requires two people, even if one of them is a woman.
Qin An confessed that he had secretly bought girls through Qingyuan Pawnshop. Yan Chi decided to seize the pawnshop immediately to find information about Yang's eldest daughter.Qin Guan found out from Qin Li that Qin Chen had an affair with the old lady’s maid Caihe, and Caihe should be the daughter of Aunt Yang!At the same time, Yan Chi learned that Yang's husband was color blind, and immediately realized Caihe's identity.Qin Wan went to find Yan Chi, but was stopped by Qin Chen. Qin Wan revealed all the things Cai He had done for revenge, including poisoning Yao Xinlan, which Qin Chen could not accept.At the same time, Caihe was taking Yao Xinlan to the Buddhist temple.