Zhou Ning followed Xu Dayuan and ran towards a building behind the office building, and came to a room on the third floor, where the door had been opened.

The room is full of all kinds of test equipment, obviously this is a laboratory, seeing a few familiar criminal policemen squatting in a corner, Zhou Ning hurriedly stepped forward, Zhou Xiaoyu was lying on the ground, and the person had fainted, his mouth was taped, and white ties were tied to his hands and feet.

Zhou Ning hurriedly squatted down, cut the cable tie, raised his hand and tried Zhou Xiaoyu's carotid artery, his heartbeat was normal, and as his fingers skimmed over his hair, a blow wound on the back of his head was revealed, but it was just a crescent-shaped skin injury, such an external injury, not to coma.

Zhou Ning's heart had already risen to his throat, and his eyes were a little sour.

Hurriedly hugged the person in his arms and gently patted Zhou Xiaoyu's cheek, Zhou Ning called.

"Xiaoyu, Xiaoyu wake up!"

Zhou Xiaoyu slowly opened her eyes, and when she saw her open her eyes, Zhou Ning's hanging heart was put down.

"Brother, why are you here? How am I here? ”

"Do you remember what happened?"

Zhou Xiaoyu held his head and sat up, as if he was still a little dizzy.

"I don't know, wait...... Cui Guanglin smashed me with a water glass, and when I fell, he pounced on me and covered my mouth, and then I don't remember. ”

Zhou Ning checked the back of Zhou Xiaoyu's neck again, pressed the periphery of the wound, made sure that the injury was not serious, and there were no fingerprints on her neck, seeing that her lipstick was a little rubbing, she quickly used a cotton swab to extract Zhou Xiaoyu's lips and nasal cavity, put the cotton swab away, and then comforted:

"Okay, it's all over, now recall, when and where did you meet Cui Guanglin today?"

Zhou Xiaoyu rubbed her wrist, some of the strangulation marks on it had been broken, and she took a breath in pain.

"As soon as I arrived at school in the morning, I saw Cui Guanglin in the corridor of the office building, he waved at me, I put my bag back in the office, I felt that you were right, there was something to say clearly, so I went out of the office and saw him at the corner of the corridor.

He said that no matter whether he continued to prepare for marriage in the future, or broke up, at least he had to make it clear that there were too many people here, and it was better to go to the laboratory to be quiet, so I followed him to the laboratory on the third floor of the science and technology building.

But as soon as the door opened, he smashed the back of my head from behind, and then he covered his mouth and nose, I was very panicked, I didn't know what Cui Guanglin was going to do, I struggled a few times, but I didn't have the strength to do it, and then I didn't know anything, what was going on, brother? ”

Zhou Ning hugged Zhou Xiaoyu, who was still trembling, and felt a little afraid in his heart, patted her on the back, and comforted:

"Don't be afraid, brother is here, you and my colleague will go to the hospital for a check-up first, as for Cui Guanglin has been caught by us, as for his matter, the investigation here will be completed later, I will tell you, Da Zhao, you can help me find someone to send Xiaoyu to the hospital!"

Da Zhao had already come over and helped Zhou Xiaoyu up.

"Don't worry, I'll ask Sister Feng to send Xiaoyu to the hospital, and you can call Director He."

Zhou Xiaoyu took Zhou Ning's hand, and his face looked a little anxious.

"Don't tell my mom!"

"Don't worry, I won't say it, if I say it, I will make them worry, but you have to listen to me, go and check it out."

Zhou Xiaoyu nodded, followed Da Zhao downstairs, Zhou Ning glanced at the position where Zhou Xiaoyu was sitting on the ground just now, under a table next to him, there was a cabinet, the doors were all open, there were traces of rubbing and trampling inside, Zhou Ning squinted.

"Xiaoyu is stuffed into this cabinet?"

Xu Dayuan patted Zhou Ning's shoulder, he could feel Zhou Ning's anger, if it was him, I am afraid he would not be able to control his emotions.

"Not only did I stuff Xiaoyu inside, but I also locked it, this laboratory has been searched, the second search, I opened the inside of the cabinet to check it, and then I found Xiaoyu, fortunately, people are fine."

Zhou Ning nodded, this sentence is the key, fortunately, people are fine, if Xiaoyu has something, Zhou Ning doesn't know how to blame himself.

"I should have let Xiaoyu rest for a few days last night, it was all my carelessness."

"Come less, don't be sad with me, so many teachers are in the multi-purpose hall, I'll deal with it first, Cui Guanglin will take it away, you check it here, and go back to the team, Da Zhao stayed to help, in fact, I don't understand, why did Cui Guanglin control Xiaoyu?"

Zhou Ning shook his head, he couldn't understand this, if Cui Guanglin was really the murderer of the 3.10 case, there was a high probability that he might also be the murderer of the red-clothed serial murder case, such a person has a serious obsessive-compulsive disorder, and he is so rigorous, the only thing that is missed is the angler, but what happened today?

Is it because of the reflection of the Zhou family?

Still, if you can't get it, you will destroy it, thinking of this, Zhou Ning is even more afraid, and takes a deep breath to control his emotions.

"Xu Da, go get busy, I'll let Xiaoqu check the monitoring in the building, as for here, for a chemistry teacher, it's not difficult to make some chemical preparations that make people comatose for a short time."

Xu Dayuan waved his hand and led the people away, and Da Zhao ran back quickly.

"Sister Feng sent Xiaoyu to the hospital, with the 120 car, did you call?"

Zhou Ning took out his mobile phone and dialed He Shancun's number.

"He Shancun, I'm Zhou Ning."

"Talking, I'm busy!"

"My sister Zhou Xiaoyu was sent to your hospital by 120, and I will arrive in a while, I hit the occipital wound, check for fractures and concussions, and I suspect that she was stunned, I collected her nasal cavity and the edge of her lips, but I don't know if there can be any residue, you help me give Xiaoyu a careful examination."

According to what Xiaoyu said, she was stunned before eight o'clock, and she was just woken up by me, if it wasn't an anesthetic, then what chemical agent could cause such a long coma? ”

He Shancun paused, obviously shocked by Zhou Ning's words.

"What, your brother-in-law-to-be? I remember you said last night that he teaches chemistry, right? ”

"Well, you give me directions, I'm in their school's chemistry lab."

"Don't worry, as an inhalation anesthetic, we commonly use sevoflurane and desflurane, but there are many similar halothanes, enflurane, and isoflurane, which can also be used as anesthetics.

I remember reading in a magazine that as long as you can use hexafluoroisopropanol to react with dimethoxymethane in the presence of a catalyst, and then add any strong acids or the like, you can get sevoflurane, as long as you are a master of chemistry, these are not difficult things.

However, this thing is a gas and is not easy to preserve, and halothane is an aromatic liquid, but this thing is not very stable. ”

Zhou Ning was a little confused, but he remembered these names.

"Understood, I found these chemical agents, if there are Cui Guanglin's fingerprints on them, it's fine."

"Well, that's pretty much what it means, by the way, look for the trash can, if he has used it, he can at least throw away bottles of gauze and something like that, this thing will metabolize into hydrohalic acid when exposed to light or heat, this can be tested."

"Thank you, Xiaoyu handed it over to you."

Hanging up the phone, Zhou Ning looked at Da Zhao.

"Let's start looking, Cui Guanglin's fingerprints have been collected just now, we need to look for bottles and gauze in the trash can, if we find halothane, hexafluoroisopropanol and dimethoxymethane here."

Da Zhao nodded.

"Don't worry, I heard it, and I found out what words it was, let's do it!"

As he spoke, he began to search on all the test benches, Zhou Ning took a look, went straight to the trash can at the door, and as soon as he opened it, he saw a piece of gauze and a brown glass bottle thrown on the top, and he directly took out the two things.

The fingerprints were collected on the brown bottle, and without comparing Zhou Ning, it was found that there was a mark on the edge of the fingerprint, which was obviously a trace left by a band-aid.

"Da Zhao, I found it!"

Da Zhao came over and put the cable tie into the evidence bag.

"It seems that this man was in a hurry and didn't have time to deal with these things."

Zhou Ning nodded, put all the physical evidence bags into the investigation box, and stood up.

"In the first class at eight o'clock, Cui Guanglin brought Xiaoyu here, and stuffed her into the cabinet in a daze, too much time has been wasted, go and see if there is anything new to find out about Xiaoqu."

The two went downstairs and drove towards the doorman, it was lunch break, many students were looking at them, and the police car was still too conspicuous in the school.

When I came to the guard's guardhouse, I saw Xiaoqu waving his hand as soon as I entered.

"This Cui Guanglin seems to be very familiar with the surveillance on campus, he avoids the surveillance when he goes to and from class, even if he can't avoid it, he is hidden among the students, I found a few pictures, you see 8:45 here, he went out through the side door and followed a few students.

Then at 8:59, he entered the staff dormitory building, but there was no surveillance here, and the guard on duty just said that the floor surveillance of their faculty and staff had been broken for a long time, and he didn't know where he was during the period from 8:59 to 11:50. ”

During the three-hour window period, what can Cui Guanglin do?

"Let's go, let's go to the dormitory building, isn't the master already gone."