"Sir, I'm here for the University Security Office."

With the help of the guards, Wu Tongguang talked with several students. At this moment, the zealous guard returned to his post, and since the young officer had warned himself that he must keep the secret for the time being, and wait for him to find out the case, then let him be, as long as he did not add burdens and responsibilities to himself.

He had just sat down, frightened, Professor Zhu was a good person, in the winter of last year, he lacked some supplies to keep out the cold, and Professor Zhu gave him some. How can you say that the onset of the disease is the onset of the disease. I really hope that this young officer can catch the murderer in time.

The phone rang. He first reported himself to his home.

"I'm Xu Bohao of the Secret Bureau." The other party said on the phone.

"Yes, yes, there is a man and a woman, and two officers are investigating the scene...... Well, one of our professors here died of a heart attack. ”

The other party seemed to be a little surprised, and paused, what kind of medicine is this Wu Tongguang selling.

The guard continued, "What do you mean by calling?" ”

Xu Bohao said: "Listen, I will solemnly tell you one thing now, these two people are not only people from the garrison headquarters, but also important fugitives, and the danger level is very high, you actually led them around, and they didn't report their lives to the authorities, this is a crime of collaborating with the enemy!" ”

The guard was so frightened that the three souls and seven spirits were gone, and it took a long time to squeeze out a sentence from his throat: "Please, ask the chief to show me a way to live." ”

Xu Bohao deliberately scared him and said, "It's late, you better hurry up and prepare for the future." ”

The guard had already heard of Xu Bohao's ruthless name, and he was even more afraid at the moment.

"If you want to live, it's not impossible to ......"

When he heard what the other party said, he was naturally much calmer, and hurriedly grabbed the last straw: "Captain Xu, you just command!" ”

"Well, you can report to me right away, who have they met and what they have done when they arrived at the university? Not a single detail can be missed. ”

The guard said, "I said, I said ......"

Xu Bohao quickly digested all the information, he thought about it quietly, and confirmed it to the guard: "Have you remembered all the people that the young man had seen?" ”

"Absolutely, I remember everything." He was referring to the four students Xu Zhihan, Bai Wenyu, Situ Wenwen, and secretary Wang Nianru.

A mysterious smile appeared on Xu Bohao's face.

"Sir, what should I do now?"

"You go and stabilize them, you can't let him look at the scene so quickly, once he has a conclusion, he will leave the university, and then you will have no way to live. We will come over immediately, only if we catch them, your family can be saved, even if you lose your life, you will delay Lao Tzu for forty minutes. ”

"Yes...... "The guard turned pale with fright.

Forty minutes is the fastest time for Xu Bohao to arrive.

At this time, it is about the same as Zhuo Shaoqing and Zheng Biwan, whether Wu Tongguang can escape in time is running out.

Wu Tongguang was standing outside the classroom where Professor Zhu was teaching the last lesson, he stood outside the classroom in a daze, the classroom was on the far left of the corridor, and there was a balcony at the door of the leftmost classroom, which extended about a meter to the outside, standing on the balcony on the third floor, just to see the vast place downstairs.

If Situ Wenwen had gone downstairs, she would have entered the secretary Wang Nianru's teaching office.

After Situ Wenwen asked the question, she went downstairs, and in the process, no one saw whether it was Situ Wenwen who lied.

The guard walked back and looked at Wu and Li from a distance, and Wu Tongguang greeted him politely.

Li Wutong asked, "Mr. Bao, is there something wrong?" ”

Mr. Bao said: "No, no, I am here, and the chief can command it at any time if necessary." The little ones are familiar with this place, and maybe they can provide some information. ”

If he didn't guard Wu and Li, he was afraid that the two would run away, and his family would inevitably be poisoned by Xu Bohao, so he didn't dare to leave.

Li Wutong saw that he was thoughtful, and he didn't rush him, as long as he didn't disturb Wu Tongguang's reasoning.

Wu Tongguang took two steps back and forth, imagining the scene at that time: after Professor Zhu finished class, Wang Nianru was already waiting at the door, informing the professor that a visitor had arrived. He suddenly remembered something: "Wutong, I ask you something." ”

"You say." Li Wutong couldn't help but get nervous.

Wu Tongguang said: "Now let's rehearse the scene that the three of their students said, I am Professor Zhu now, and you can help me time it." He handed a pocket watch to Li Wutong, which was still Shang Qingyuan's.

Li Wutong nodded and said, "Okay." ”

Wu Tongguang walked into the classroom and shouted, "Start timer." ”

Li Wutong pressed the chronograph button, and the hands clicked up.

Wu Tongguang opened the door of the classroom, walked out slowly, paused at the door, he stood for a while, his movements were like listening to the speech of the secretary Wang Nianru, and then he was about to move forward. He muttered, "Well, now the first student has come out." ”

He stopped again, waited for about 2 minutes, and began to step forward again, and when he reached the staircase, he stopped and looked at Li Wutong, who nodded—at this time the second student caught up and began to ask questions. After a pause, Wu Tongguang continued to walk to the right, and when he reached the door of the lounge, he waved his hand at the air, as if to ask the third student to hurry back. According to Szeto Wenwen, Professor Zhu seems to be in a hurry.

Wu Tongguang looked at Li Wutong, Li Wutong nodded, as if to say, "Don't worry, the time has been written down." ”

Wu Tongguang walked into the lounge – according to Situ Wenwen, it was open at the time. He closed the door casually. The lounge was suddenly silent, and even the air was heavy. What happened in the 7 or 8 minutes that Professor Zhu entered the lounge?

"If the whole reasoning is clueless, then it's better to take a closer look at the scene. If there are no more clues at the scene, take a closer look at the perimeter of the scene. Wu Tongguang said in his heart.

He walked slowly past the glass bookcase, and then walked past the two-seater, and a strong light came in from the window behind the sofa, and he walked to the window, just like Professor Zhu did at that time, and prepared to close the window.

"What is this?" Wu Tongguang made a major discovery, and he was so shocked that he could barely speak. He found that there were several tiny holes in the stone on the outward side of the window, which were extremely small, the same size as the wound on Professor Zhu's head.

Wu Tongguang didn't believe that Professor Zhu had a heart attack at all, were these holes the traces left by the murder weapon?

He stared out the window in a daze, and he remembered that according to the three students, the content of Professor Zhu's lecture today was about the basic concepts related to gravity.

"It's time!" Li Wutong shouted through the door. It's 15 minutes. If Wang Nianru killed someone, these 15 minutes would definitely not be enough for him to run around from the teaching office on the first floor.

Wu Tongguang opened the door of the lounge in disappointment, and Li Wutong smiled like a flower, as if he had made a major discovery: "Wu Tongguang, I found a problem." ”

"What's the problem?"

"It's not the right time......"

Wu Tongguang became vigilant: "What's wrong?" ”

Li Wutong looked at the pocket watch and said, "The time of the first two students is right, but the time of the third student is not right. ”

"What? You mean Situ Wenwen? ”

"Yes, that's her."

"Wutong, you hurry up and talk about it, this is very important."

Li Wutong frowned and said: "The third student said, that is, Situ Wenwen, she said: 'Half of the break has passed, Professor Zhu seems to have something urgent', Professor Zhu didn't answer her question, she returned in a huff, she had about 5 minutes left to rest after she asked Professor Zhu, this is not right. ”

"Oh?"

"Yes, when you get to the break room, there's a lot more time left than she said."

Wu Tongguang hurriedly said: "How much more?" ”

Li Wutong looked at the readings recorded in the pocket watch again and said, "Hmm...... About 2 minutes more. ”

Wu Tongguang asked, "Are you sure?" ”

Seeing his solemn expression, Li Wutong almost suspected that she had made a mistake, she confirmed it again, nodded at him, and then asked puzzledly: "Is there anything wrong with the extra 2 minutes?" ”

Wu Tongguang said word for word: "There is a big problem, and in these two extra minutes, I have figured out many problems." Come with me now, and we'll find the truth if we find something else!" ”

Hearing that the case was about to be solved, Li Wutong asked in surprise: "What is it?" ”

"Professor Zhu's bookcase!"

"Isn't Professor Zhu's bookcase in 'this' lounge?"

Wu Tongguang said with a smile: "This lounge is obviously Professor Zheng Jiaye's lounge, you look at the books and notes in the bookcase, and they are all Professor Zheng's name. ”

Li Wutong said: "You mean this is not Professor Zhu's lounge?" ”

"Yes, it's not."

"But...... Then why did Professor Zhu die in this lounge? ”

"That's the answer we're going to find, you can do something for me now."

Li Wutong nodded and said, "Okay, you say." ”

"We split up...... So ...... so."