Chen Shi said, "I heard that some people go to the scene to hold a memorial for Yan Qilin every year. When I was chatting with Zhang Jinlei alone just now, he said that he had been drinking himself into a stupor at the bar last night. I was just thinking that if it wasn’t him, could it be you?"

"Yes... It was me."

"Do you go there every year?"

"Yes! Since her death, her QQ has become like a tree hole. Many classmates who miss her will leave a message for her there. Once I left a message for her, but unexpectedly, she replied. It was actually Zhang Jinlei who had replied to me after logging into her QQ account. We were both very sad when we talked about this matter. I suggested that we should go and mourn her. Zhang Jinlei was afraid that he would be sad when he revisited the place, so he refused. So I go alone on Qixi to burn some joss paper for her."

"I’ll ask another question. How was the relationship between her and Yue Chao?"

"Yue Chao?" Xiao Ran recalled, "I don't know very well..."

"Do you have something that’s difficult to say? We’re only investigating, not trying to judge the behavior of the persons involved."

"Uh..." Xiao Ran lowered her head and said after a while, "I think Yue Chao and her were a bit too close. I often saw Yue Chao sending her home even though Yue Chao had already dropped out of school. Every time she stayed late doing self-study, he’d wait for her by the school gate leaning on his motorcycle. I asked her if she liked Yue Chao. She kept denying it and said she liked someone else. There are no airtight walls in the world[1]. In Zhang Jinlei's view, Yue Chao was harassing her, and the two had some conflict over it. Yue Chao didn’t reappear until the college entrance examination. But after the college entrance examination, I saw Yue Chao with her again..."

"Didn't you just say that you haven't seen each other during the entire summer vacation?"

"That was a chance encounter and I didn't step forward to speak to them."

"What were she and Yue Chao doing?"

"They... They..." Xiao Ran's expression changed. "I'm sorry. I don't think it has anything to do with the case."

"It's up to us to judge if it’s related or not."

"I don't want to talk about it. You can ask Yue Chao."

"Is it negative information about your friend?"

After a long silence, Xiao Ran recalled, "On July 24th, 2013, a case occurred on Guqiao Road. You can go and check that first, and then I will tell you after you have finished checking."

"Wait a while."

Lin Dongxue immediately sent a text message to the bureau. Five minutes later, the message came back. She handed it over to Chen Shi, who read the words out loud, "High school prostitution ring?"

"What great efficiency!" Xiao Ran praised. "There’s a place on that street where some high school girls and women dressed as high school girls will do dirty business. On that day, I was shopping with my cousin and saw a few police cars driving over. We went over to see what all the commotion was about. I didn’t expect to see Yan Qilin being arrested by the police. She was crying the whole time. Just when she was about to be taken into the police car, a motorcycle drove over. The driver jumped out and pushed the police away. He forcefully took Yan Qilin away. Although he was wearing a helmet, I still recognized that it was Yue Chao! After witnessing that incident, I was stunned. I didn’t know why she would do this kind of thing. Her family background wasn’t good, but she had always preserved her purity. Could she have done it to raise funds for university tuition? I don’t dare to dwell on it too much. And why did Yue Chao appear in such a timely manner? He had been fooling around in society after he dropped out, so would he have had something to do with it?”

"You chose to keep it secret?"

"Who else could I tell? The police? Tell Zhang Jinlei? I also wanted to question her, but I hung up the phone before I got through to her. I think that she wouldn’t have taken that step if she didn’t have some colossal problem. Honestly, I’m still shocked that my best friend would engage in this kind of business!"

Chen Shi and Lin Dongxue temporarily fell silent. Xiao Ran lowered her head as she stirred the ice in the cup with a straw. Chen Shi broke the silence. "This matter didn’t appear in your previous statement. It seems that you two are really good friends. Otherwise, you wouldn’t have kept it a secret.”

Xiao Ran seemed as though she received understanding. "Yes, the police came to me after the incident. They were totally talking to me as if they were facing a suspect. I know what they think. Could I have done it viciously because I wanted to snatch Zhang Jinlei away? The police always like to look at people in a negative light. I could only pretend not to know and answer every question of theirs truthfully."

After saying thanks, the two of them bid goodbye to her. Lin Dongxue asked, "Do you doubt anything?"

Chen Shi smiled bitterly. "It's quite tricky. Everyone's words are reasonable, and no flaws can be found."

"Then, should we shift the focus a bit and stop confining ourselves to the deceased's interpersonal network?"

"I want to see the crime scene."

"Didn't we just come back from there?"

"I mean the scene of the first case."

Lin Dongxue brought Chen Shi there. She walked to a spot in the housing district and said, "Here is the place where Yan Qilin was killed back then. The place is still the same but the people here have all changed.”

Chen Shi saw a pile of paper ashes on the ground. Lin Dongxue said, "This is the paper burnt by the person who came to mourn her last night."

"Let’s look at the surveillance footage!"

The footage from the property management showed that there was indeed someone walking in with a bag around 8:00 last night. The clothes they wore were very gender-neutral, and they couldn't see whether it was a man or a woman. If it weren’t for Xiao Ran's own admission, they wouldn't have thought that it was her.

Then the footage showed Yue Chao and his girlfriend. The two were wandering around the district. They were found by the patrolling police and subsequently taken away.

At around 11:00, the mourner left.

Lin Dongxue asked, "Do you want to go to the bar to verify things?"

Chen Shi nodded. "Of course!"

The bar owner had no impression of Zhang Jinlei, probably because he was there for the first time, and there were quite a lot of people last night.

Chen Shi took out Zhang Jinlei's picture, and a bartender remembered him. "He visited last night."

"What did he order?"

"Who would remember that?!"

"You use WeChat Pay here to settle bills. Can you give me a copy of last night's bill?"

Chen Shi got the WeChat bill from the bartender, went outside, and then looked around. He pointed to a traffic camera. "I want that footage. Since we’re verifying, we should verify things clearly.”

Lin Dongxue forced a smile. "Okay, boss."

After a day of running about, both of them were exhausted. Chen Shi drove the car to a Korean barbecue restaurant near his house. He ordered a bunch of pork belly, fatty beef rolls, and beef tongue. Drinking a big mug of draft beer while eating such fragrant barbeque, it seemed that the exhaustion of the day had been wiped out. "Ah, the hard work of the day is for this moment of happiness."

"It would be even better to have a drink with a sense of accomplishment if the case had been solved smoothly!" Lin Dongxue said as she flipped the beef tongue over with her chopsticks.

"You’re not embarrassed about saying that? I could have been sleeping at home today after solving the last case yesterday, but you stuffed a new case for me again.”

"Alright, great detective Chen, let me toast you, okay?"

The two raised their glasses, clinked them, and after putting them down, Chen Shi said, "I have a theory."

"What theory?"

"All three of them may be murderers."

1. Everything gets leaked eventually.