Episode 13 recap: Jin Manfu took out Doudan's toy gun.

Guo Guizhi knew that her daughter had been arrested, and in order to seek a chance to contribute, she voluntarily confessed the matter about Doudan from that year. Wang Shitu received the news and learned that there was a cotton spinning mill in Zhaoyang County back then, owned by someone surnamed Jin, who had found her through an intermediary, hoping she could arrange for someone to go to the designated place to take away a young boy wearing a police uniform.

Wang Shitu went to Jin Manfu's office to find him, but he did not admit it. Unexpectedly, Wang Shitu actually believed the words of a criminal. Wang Shitu did not obtain any valuable information from Jin Manfu, and he returned home in low spirits. Xiaosi noticed his abnormality, but no matter how he questioned, Wang Shitu did not say anything.

Jin Manfu thought that as long as the designated detention time for Yan had passed, she would be released, so he didn't even think of making a deal with Wang Shitu. But he didn't expect that the police had obtained new evidence. Yan, in order to prevent her father from defending her again, confessed that she had hidden the nail with blood on it in the crystal ball.

Qin Yong led people to search Jin Manfu's house, and he carefully observed the furnishings and environment of Jin Manfu's home. Later, Qin Yong opened the crystal ball and found the bloodied nail inside, which made Jin Manfu greatly alarmed. He didn't expect that Yan would keep this nail, as he had asked Yan about the nail's whereabouts before, and Yan had said she had thrown it away.

Through forensic analysis of the nail's blood trace and the information provided by Jin Manfu, the police confirmed that the nail had once scratched Biejie's hand, and the school teacher also knew about this incident. But later, after repeated inspections, they found brain tissue on the nail, which could prove that Biejie's head had indeed hit the nail.

Jin Manfu couldn't go to Wang Shitu's house. Xiaosi opened the door and saw him with a serious expression, questioning why he had come back. Jin Manfu said he had come to find Wang Shitu, and according to the regulations, Wang Shitu and the family members of the criminal suspect were not allowed to meet privately, but Jin Manfu said he wanted to discuss the unfinished matter from the office.

Wang Shitu knew he was going to talk about Doudan, so he agreed to go out with him. Xiaosi was surprised, but couldn't stop them. In order to make Wang Shitu believe that he really knew Doudan's whereabouts, Jin Manfu took out Doudan's wooden toy gun from back then, which was made by Wang Shitu, so he recognized it at a glance. But Jin Manfu proposed a deal - as long as Yan could be released, he would reveal Doudan's whereabouts. If Jin Manfu was forcibly detained, he would just claim the toy gun was picked up on the road, and then Wang Shitu would never know Doudan's whereabouts.

Wang Shitu knew he had the responsibility of a police officer, but he was also a father. He didn't know what to do and didn't sleep all night, sitting in Doudan's room. Early the next morning, Wang Shitu looked at his wife Lu Lu's portrait and murmured a few words. Xiaosi hadn't slept and heard it, but didn't catch what Wang Shitu said.

So Xiaosi angrily went to find Jin Manfu, questioning whether he was threatening Wang Shitu with Doudan's case. Jin Manfu tried to drive Xiaosi away, when Bian Meiizhen appeared and persuaded Xiaosi to leave quickly. Xiaosi listened to "mother" and left without further confronting Jin Manfu.