Chen Shi’s smile vanished and he gazed sternly at Yan Ke’s eyes. “The mastermind behind the scenes directed you to do this, right? Has he promised you that even if the police suspected you, there wouldn’t be any evidence to arrest you, because his magic is boundless, and he can make people who are already dead stand up, talk and die the next day? But he wouldn’t have helped you for nothing. If you don’t have money to give him, he must want you to do something for him. You need to know that agreeing to his terms is to be truly consigned to eternal damnation!"

Facing Chen Shi's questioning, Yan Ke was so scared that he even fell off his chair. He gasped as if he was facing a fierce beast, and then covered up his panic with anger, "This is intimidation. This is intimidation. I want to sue you guys!"

"That’s enough from you. Do you really dare to do so?" Chen Shi sat back down. "It's not a formal interrogation right now. All our conversations are informal. I am just reminding you that there are no good outcomes if you make deals with the devil."

Yan Ke wanted to talk but stopped again, fearing that a single word would also let the cat out of the bag. He pretended to say angrily, "I can't understand what you’re saying, is it your style to frame innocent people?"

"Well okay, Mr. Yan, I believe we will meet again."

After leaving the school, Lin Dongxue reproached Chen Shi, "You went overboard just now."

"Sorry, I was a little out of control."

"I know you hate evil!" Lin Dongxue smiled. "Do you really suspect him?"

"What about you?"

"About ninety percent!"

Teacher Liu came up and asked, "Yo, you two, are you still investigating the case? I would like to ask when the office will be cleared? We have been squeezing with other teachers in their offices over the past two days, or we would have to correct homework in the classroom. It’s too inconvenient."

"We’re really sorry. The forensic police will come over again this afternoon and review it. It should be available for you guys to use tomorrow."

"That’s great. By the way, is there any progress in the case?"

"This is not something convenient to disclose."

"Just reveal a little. What percentage has been investigated? 30, 60 or 90?"

Chen Shi smiled and shook his head. "Investigating the case is not the same as completing work. Sometimes, when a clue appears, it’s 100%, and before this clue appears, it’s 0%."

"This means that there’s currently no key clues yet?"

"By the way, I have something to ask you. Do you live alone?"

"Yes, I do. I live in an apartment near the school. Just above the window with the ‘XX Tutoring School’ billboard."

"Does the school worker who provided the eyewitness testimony live alone as well?"

"Old Zhang? He’ll sleep in the duty room if he’s on duty at night. So of course he’s alone."

Chen Shi thought for a while and asked again, "Let me ask some unimportant questions. Did you have any special experiences on the evening of September 30th?"

"You mean that happened to me?"

"Correct!"

"I can't remember anything. It was a very ordinary day. I went home and drank some beer, watched TV, and then went to bed."

"Okay, thanks!"

When the two walked away, Teacher Liu suddenly chased after him and wanted to talk to Chen Shi alone. He glanced at Lin Dongxue and whispered, "I'm a little embarrassed to talk about it. I had a dream that night, and I dreamed about... Teacher Lin!"

"Was it that kind of dream?"

"Aiya, look at what you’re saying." Teacher Liu's cheeks were red. "To be honest, I think it's very strange. The age gap between Teacher Lin and I is so large. I rarely talk to her normally. I'm a teacher who serves as a role model and never thought of her like that. But I don’t know why, I had a dream about her that night, and it was very realistic. I haven’t had it before or after... I don’t know if it’s considered private or not. I hope that the case can be solved as soon as possible, so I told you. I suppose it can’t really be considered a clue, haha. Don’t tell the female police officer."

"Okay, I’ll definitely keep it a secret."

After Teacher Liu walked away, Lin Dongxue asked, "What did he say to you?"

"He said he dreamed of Teacher Lin on the night of the 30th. Is it strange?"

"Could it be tuomeng? [1]?"

"The so-called tuomeng phenomenon is just due to psychological suggestions..." Chen Shi's eyes widened. "Psychological suggestion!?"

"Psychological suggestion?"

Chen Shi suddenly ran outside. Lin Dongxue finally caught up with him with some difficulty. After getting into the car, Lin Dongxue asked, "Are you going to look for Miss Gu?"

"Yes!"

He didn't go directly to the clinic, but called Gu You, and they agreed to meet downstairs below the agency. After half an hour, Gu You arrived, fresh and sharply-dressed as always. She greeted them with a smile, "Miss Lin, we haven't met for such a long time. Why didn’t both of you go up?"

"Gu You, I have something to ask you. If I have a pear in my hand, can I make a person think that it’s an apple by hypnotizing them? No matter how it looks like or tastes like, it’s an apple. It was also an apple when you recall the event.”

"Oh, that's easy. Anyone who knows a little hypnosis can do so. Not to mention pears, even if it was an onion, it can turn into an apple."

"What about a person?"

"A person?"

"Changing them from one person to another through suggestion."

Hearing this, Lin Dongxue suddenly realized that the eyewitness testimonies of the three people were based on meeting Teacher Lin when they were alone, and no physical evidence had been left behind. Were they hypnotized?

But how did that person do it?

Gu You thought about it and asked, "What case is it this time?"

After finding a coffee shop, Chen Shi recounted the case, including his own conjectures. Gu Yu muttered, "Zhou Tiannan has started up his activities again? It’s faster than expected."

"I remember you mentioned that he has a psychologist under him with skills comparable to yours - Ling Shuang."

"I wouldn’t describe my skills as comparable to hers. Ling Shuang is a master in the field of behavior control. Do you know the term ‘reflex regulation’?"

"I’ve heard of it." Chen Shi said but Lin Dongxue looked blank.

Gu You took out a cube from a jar and placed it on the table. "This is a piece of sugar. No matter how it looks and tastes in your mouth, it’s sugar, because your brain has already established a reflex arc that correctly provides feedback. But if I hypnotize you deeply and keep telling you that it’s a piece of salt, and re-establish a new conditioned reflex: When you eat it, it will really taste salty."

"Can this be done?" Lin Dongxue asked in surprise.

"Because the human brain is too sophisticated, it’s also easy to deceive. Such examples happen everywhere in life. You just said that through reflex regulation, one can make a person think of target A as target B. The key is the process of the hypnosis which must be concealed and not be detected."

"The three witnesses all lived alone."

"That was easy to carry out then. She snuck into their homes in the middle of the night on the 30th, hypnotized them in their sleep and kept telling them, 'The person that you see now is Teacher Lin'. That person must have been Ling Shuang. She has all these skills!"

Lin Dongxue suddenly realized, "No wonder Teacher Liu dreamed of Teacher Lin that night. It was because someone kept saying her name in his ear."

Chen Shi thought for a while, "So if you show them Ling Shuang's photos now, will they still regard her as Teacher Lin?"

Gu Yu shook his head, "Zhou Tiannan is cautious when he acts and wouldn’t leave behind such a major weak point. If it were me, I would release them from their hypnotized state after October 1st. The tampered memories would remain in their minds, but they wouldn’t know anything at all."

1. Chinese supernatural concept of a ghost appearing in one’s dream to make a request.