For several nights, Song Chi couldn't sleep. He couldn't figure it out, Zhang Yulin's father's strange eyes and behavior that day, and he always felt that there was some ulterior secret between him and Professor Tan, who fell from the building.

On the other hand, he is Zhang Yulin's father, and he is the father who wants to confess his girlfriend, so he shouldn't have such doubts.

Suffering and unsolvable, it was like a hinge wrapping around Song Chi, leaving him at a loss.

weishenme is he? An elder in his own heart, dignified.

Song Chi knew in his heart that the real cause of Professor Tan's death from the building was only the clue of Zhang Yulin's father, and if he even gave up on this, the truth of Professor Tan's death would be nonsense.

No matter what, we must also find out the truth of the matter! Song Chi secretly made up his mind.

After thinking about it again, he called his cousin Song Ruotong's phone. "Ruotong, I'll ask you about something."

Song Ruotong was making facial masks and maintaining her skin in the dormitory, and when she heard her cousin's call, she hurriedly responded: "Why do you keep telling me to do things, but I have to collect taxes!" ”

"Zhang Yulin's father, is his name Zhang Zhihong, that is, Dean Zhang who taught you the "Western Classic" class?" Song Chi urgently needs to be confirmed.

Song Ruotong was stunned and replied: "It's terrible, this time chasing Zhang Yulin, you want to check her household registration book?" It's Dean Zhang, he is very haode, knowledgeable, and approachable, and we girls think he looks like Chen Daoming! ”

Sure enough, it was him, Song Chi frowned. "Then do you remember that on the 26th of last month, that is, the morning of Professor Tan's fall, I seem to have heard you say that you heard the sound of the fall, are you in class in the teaching building?"

Song Ruotong couldn't answer this question, she looked at the calendar, thought about it for a long time, and then replied to Song Chi. "The 26th was Wednesday, right...... I was in that teaching building, taking a big class on "Western Longitude", and of course I heard the sound of Professor Tan falling from the building. ”

What the! Song Chi was horrified in his heart, his cousin was taking the "Western Longitude" class that day, that is to say......

"Isn't the teacher of your "Western Classic" class Dean Zhang? Was there anything unusual about him in class that day? Song Chi kept asking questions, so that his previous judgment could be coherent.

These boring questions are quite repulsive to Song Ruotong. "Why are you asking this? It's annoying! The "Western Longitude" class that day...... Oh, I remembered...... After the bell rang for the fourth period, Dean Zhang did not show up, and after about 5 minutes, he returned to the lecture hall, and some of the boys in the class booed......

The fourth class in the morning of the university usually starts before 11 o'clock, and Professor Tan's fall time is about that time. There was about 10 minutes between the third and fourth classes, and Dean Zhang was 5 minutes late for the fourth class, of which 15 minutes were there.

From his cousin's description, Song Chi came to two clear conclusions, one is that on the day Professor Tan fell from the building, Dean Zhang was teaching in that teaching building; The second is that Dean Zhang was 5 minutes late before the fourth class!

And what is he doing in the past 5 minutes?

In all likelihood, Dean Zhang went to the rooftop and then had an argument with Professor Tan...... This affected him to attend the fourth class.

Song Chi didn't dare to think about it further, because it would involve a lot of problems. Although he was full of suspicions in his heart, he still leaned towards Dean Zhang's integrity and innocence. All this is just a coincidence, how can intellectuals have the evil idea of killing.

"By the way, I saw that it was written in the newspaper that Professor Tan was evaluating the title of professor before his death, saying that he was under a lot of pressure and had a competitor ......" Song Chi suddenly remembered something and asked without saying a word.

"That's Dean Zhang!" This time, Song Ruotong blurted out. "Both of them are bound to win, but I heard from the teachers in the department that Dean Zhang has a better chance of winning."

What the! Song Chi's heart shook again. How could there be so many things entangled between the deceased Professor Tan and Zhang Yulin's father Zhang Zhihong. And once these things are concentrated, it makes people have to be suspicious.

It's normal to evaluate a professor in the university, who is up and who is down, but weishenme happens to be the two of them this time?

On the day of the fall, Dean Zhang was in the teaching building, and he was late for the fourth period; He also competed with Professor Tan for the title of full professor, and Dean Zhang was at Professor Tan's house, all kinds of strange behaviors...... This made the doubts in Song Chi's heart even heavier.

"Ruotong is a good sister, you can do one more thing for your brother. This week...... It's too late, next week, you go to the school library and borrow a book on calculus. Song Chi suddenly thought of the small envelope stuffed in the calculus book with "Zhang Zhihong received" written on the front. Perhaps there will be some unexpected answers to the contents of the envelope.

That day, he hid in the bookcase and heard Zhang Zhihong mention that the books were to be donated to the school library. As long as this calculus book is in the library, it can be borrowed. But he couldn't remember the name of the book for a while, only that it was a calculus book.

"What, you're going to graduate school?" Song Ruotong looked very surprised, she couldn't understand that her brother Weishenme wanted a math book. "What calculus? Which one? ”

After his cousin said this, Song Chi was really asked, only blaming himself for being careless, and even forgot the title of the book. "That calculus book looks old, it's pretty thick......"

"You better go buy one yourself, there are so many Xinhua bookstores. I don't know which one you want, but I guess there are hundreds of calculus books in the library. Song Ruotong persuaded.

Hundreds? It's like looking for a needle in a haystack. But there is no other way, and the envelope in this book should be a very important clue. "Okay then...... Can you help me borrow all the books on calculus......"

"You're crazy!" Song Ruotong tore off the mask on his face and yelled hysterically: "Did you stay in that newspaper and be brainwashed by those old guys?" Last time I asked for the phone number of the dead man, this time it was even more exaggerated, and he actually asked me to borrow all the calculus books in school, are you my brother? ”

These reactions of my cousin are also human nature, but strong curiosity has repeatedly driven Song Chi to find out the truth of the matter. The process of finding out a truth that has been covered up must be very painful, but if you don't stick to it, you can't do anything.

"Ruotong, I know that you have great powers and can do anything in school. With your sharp teeth, what else can't be done? "Song Chi tried his best to encourage his cousin to help him." Don't you want to get a new Apple iPad? I have friends who can buy parallel goods in Hong Kong. ”

As soon as he heard the Apple iPad, Song Ruotong's eyes suddenly lit up, and even his tone of voice became gentle. "Can you really do it? Okay, leave the library to me, I'll be active. But as for whether I can find the book you want, I can't guarantee it. ”

"You can rest assured, as long as you do it, no matter the result, the Apple iPad is yours." This time, Song Chi has made a bloody investment.