In the utility room at the end of the corridor on the third floor of the teaching building, cleaning tools are carefully placed to create a hidden corner.

Mingqiao, wearing a mask, cleaned up the last piece of garbage on the ground and opened the window behind him which was only as big as a book.

"I told you not to clean up." Lao Jiang waved his hand to clear the dust in front of his face and sat down casually on the ground: "You told me before that you wanted me to try to shut down the phone, implant viruses and so on, but it was useless. This one on my phone should only be considered a semi-finished product. Apart from doing some small tricks, there is nothing else I can do. The pirated version can't be exactly the same as the original, so don't be too anxious."

Mingqiao squatted in front of Lao Jiang and pulled his mask down to his chin: "So I have to go to the principal's office to use their two computers?"

Lao Jiang sighed and said, "This is the only way for now."

Ming Qiao said solemnly, "But except for the time around 8pm on the 3rd, Sun Guiping and the old principal were in the office at other times, so I couldn't find a chance to do it. I tried many times on their computer before, and not only could I not open the 'Good Student' system, but I couldn't do anything except change the computer time to achieve time travel."

"Is it because there are other passwords that it cannot be opened?" Lao Jiang asked.

"I also thought that there might be other passwords, such as face and fingerprints that are not easy to detect, but I searched almost the entire office and couldn't find them," said Mingqiao.

"What if we don't start with this 'good student' system? What is the chance of successfully completing this exam naturally?"

Ming Qiao shook his head. "Combined with the information I've obtained during this period, in order to complete this exam naturally, all students must get the same score at the same time without dying. If a student dies during this period, they will return to a certain point and fall into a never-ending exam cycle. Only when the exam scores are consistent can no student be eliminated. It's difficult without cheating."

Lao Jiang stroked his chin and thought for a moment: "Then we are back to our original question, how can we use the 'good student' system on the principal's computer."

Mingqiao said: "Use violence to coerce them, or find an invisible code."

"Violence and coercion won't work," Lao Jiang said quickly. "I don't know about Principal Sun, but as for the old principal, he is very paranoid and may fight to the death."

Mingqiao couldn't help but feel depressed again: "But where can I find the password? I have no clues and I have no idea where to start."

Lao Jiang slapped his thigh and stood up from the ground, not caring about the dust on his pants, and pulled Mingqiao to walk out: "I will go with you to follow them this afternoon, there will definitely be some clues."

"No way." Mingqiao stopped Lao Jiang and said helplessly: "I have to supervise the exam this afternoon."

"Is it a big deal to be an invigilator, or is there something you need to do? I'll make two dummies for you to do it."

"It's nothing serious." Mingqiao knew he couldn't refuse Lao Jiang: "Leave a few tips for my little friend."

Lao Jiang said seriously: "The chief invigilator cannot help the students."

"I will find a good way." Ming Qiao said, "And since I can't help the students as the chief invigilator, I can help as an NPC. There is always a way."

Mingqiao and Lao Jiang monitored Sun Guiping and the other two in the office on the seventh floor for an entire afternoon. The two of them did not even leave their seats. Although only a computer screen could be seen from the outside, Sun Guiping had been playing the Zuma game the entire afternoon and had not opened the "good student" system.

"Every time I follow them, they are in this state." Mingqiao couldn't help but ask Lao Jiang: "Could it be that they already know that they are being monitored?"

"That shouldn't be the case." Lao Jiang said, "If they knew they were being followed, they wouldn't be so calm. If I were either of them, knowing that I was being followed and might be exposed, I would definitely catch the stalker and kill him. This is much simpler and more direct than playing games to cover up the truth, and there will be no consequences."

Ming Qiao frowned. "If we haven't been exposed, it means that staying in the office all the time and not going anywhere is their normal state. Then why was there no one in the office on the night of the 3rd? Where did they go?"

"Do you think the night of the 3rd will be a critical link?" Lao Jiang asked, "What if they just went to the toilet during that time?"

"Director Jiang, I don't think Sun Guiping and the old principal need to go to the toilet hand in hand. According to their cautiousness, someone must have stayed to watch the two computers." Ming Qiao said, "Something out of the ordinary will inevitably attract attention. Even if it's a trap, I have to jump in to find out if there is a secret passage at the bottom of the pit."

Although Chiang Kai-shek did not quite agree with Mingqiao's idea, he eventually stopped opposing it.

In his opinion, Mingqiao is an impulsive young man who does whatever he wants. Although Mingqiao is not thoughtful at times, the fact that he has made it all the way here is enough to show that his ability is still superior to that of ordinary people. As for whether Mingqiao will solve the mystery and escape with everyone in the school, or whether Sun Guiping and the old principal will achieve their ultimate goal of the exam selection, Lao Jiang thinks the probability is 50-50.

Mingqiao hugged Shi Xin back, patted his back gently, and finished telling him what had happened in the past few days: "This period of time is very chaotic, you must protect yourself."

"So have you figured out what happened on the night of the 3rd?" Shi Xin's muffled voice came from his ear: "How can I help you?"

"No, I can never go back to that night." Ming Qiao's voice trembled slightly: "Just like before, I broke into their office and knocked them out. When I tried to adjust the time back to the night of the 3rd, I failed."

Shi Xin's hand around Ming Qiao froze, and he also realized something was wrong: "But, today is the 3rd."

"That's right. For me, today is my seventh day here as an invigilator. But for you, you have been repeating number 2 for the first six days. You got a perfect score, so the time moved forward one day." Ming Qiao said, "This is the crux of the problem."

"Your time flow rate is right, but I'm wrong." Shi Xin murmured, "So, now it's me who can go back to the night of the 3rd, or rather, us students. So we influenced you, so I can see you here."

"Yes." Mingqiao nodded.

"So the reason why we were not caught by Sun Guiping and his men after our speech in the broadcasting room just now is because we were on the evening of the 3rd, and they were not in the office during this period."

"right."

Shi Xin said seriously, "I understand. Let's go in and look for clues now. If we fail tonight, I will tell all the students who can go back to that night that we will find it."

"That's what I mean, but I hope we can solve the problem today. I don't feel comfortable leaving it to others." Mingqiao took Shi Xin's hand and led him to open the door of the principal's office again.

"I had knocked them out, and when I was worrying about not being able to return tonight, they disappeared. That's when I guessed it would be you." Ming Qiao came to the computer and entered the password skillfully. "Jiang Su's speech was great. It reminded me of the student uprisings in history."

Shi Xin felt a little uneasy when he heard Ming Qiao say this: "Will the speech have any bad consequences?"

"Of course they will. A large part of the invigilators are from Sun Guiping's group. After tonight, they will definitely complain." Ming Qiao comforted him, "But don't worry. I discussed this with Director Jiang before I came here. Although he doesn't approve of me taking risks, he will give me some support and he will take care of these things."

Shi Xin saw that Ming Qiao had tried several times but still couldn't open the icon, so he took the initiative to say, "Let me try."

He took the computer and quickly created a run box. After a bunch of operations that Mingqiao couldn't understand, an input bar popped up under Shi Xin's cursor.

"password."

Mingqiao reported the power-on password, but Shi Xin said it was wrong after entering it.

"It doesn't look like a regular combination of numbers or letters and numbers." Shi Xin tilted his head and thought for a while, then looked around the computer: "This microphone..."

"Microphone?" Mingqiao followed Shi Xin's gaze and locked onto the microphone next to the computer.

"If this microphone is not used regularly, why is it so clean?" Shi Xin pointed at the switch on the microphone base. "The surface here is shiny and smooth, but the buttons are a bit patinated, which means they are pressed frequently. This is the case with keyboards and mice that have been used for a long time without daily cleaning."

"So you're saying that the password might be voice control?"

"Yes." Shi Xin said, "Excluding face and fingerprint unlocking, the only common unlocking methods I know of are voice control and iris. Iris and face both require cameras, so after that, voice control is the last option. For voice control passwords, you can't record them or imitate them. You have to say it in person."

"What if we can hold them back until Sun Guiping and the others come back?" Ming Qiao's heart was beating like a drum. "I'll hold them back at the door, and you stay here."

"Mingqiao." Shi Xin was anxious. He grabbed Mingqiao's hand and held it tightly, not daring to let go, as if the warmth of Mingqiao's palm was the last bit of strength he could hold on to: "This is undoubtedly suicide."

"I'm not afraid." Ming Qiao looked at Shi Xin and stared at him quietly: "I must stop them. Things can't go on like this."

Shi Xin was shocked by the determination in Mingqiao's eyes, but he liked Mingqiao and he couldn't just watch Mingqiao die.

"Shi Xin." Ming Qiao's tone was gentle but firm, "I am a teacher. When I chose this profession, I chose responsibility. I want to save all the students."

Shi Xin slowly let go of Mingqiao's hand. He liked Mingqiao. He could not accept Mingqiao's death, but he should also respect and stick to his choice.

Faced with this dilemma, Shi Xin compromised.

"What I need you to do is very simple. Destroy this system, delete the student data, and if possible, go back to the very beginning."

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The author has something to say:

It should be finished in a few chapters.