Bai Song, who was about to leave the office, stopped abruptly.

Standing at the door of the office, Bai Song's brain was working rapidly.

What exactly is wrong?

"Hey, Bai Song, why are you..."

Ma Xi was passing by and saw Bai in this state. Not knowing what was wrong with him, he came over to ask Bai Song. However, Bai Song simply stretched out his hand, put his left index finger to his mouth, and signaled Ma Xi not to speak.

Ma Xi naturally understood the meaning of Bai Song's gesture and immediately shut his mouth.

Bai Song maintained this action and retreated step by step from the door.

Seeing this, Ma Xi didn't know what was wrong with Bai Song, and slowly followed Bai Song into the house.

Bai Song thought about everything that had just happened, replaying the scene in his mind, slowly walked to his seat, and then took out the piece of white paper that had been put away.

White Paper didn't ask...

Bai Song was just thinking about it when he suddenly discovered that there were only two handwritings on the white paper.

That’s right!

That's what's wrong.

Bai Song experimented three times with three pens. There should be three different handwritings, but now there are only two!

Phew~

The adrenaline that had just been secreted in large quantities was now receding like a tide, and Bai sat limply on the chair.

Yes, fading pen.

One of these three pens is a fading pen, or a UV highlighter.

If this is the case, then Scarface should have written something with this "invisible pen", but we don't know what he wrote exactly.

Whether it is an invisible pen or a fading pen, how do you make the image appear?

What we see most often in our daily life is ultraviolet light imaging. This anti-counterfeiting mark is similar to the one on money. Bai Song immediately searched the Internet for a lot of information.

Bai Song checked and took notes on the relevant paper website.

"Does this pen disappear after writing?" Ma Xi picked up the pen curiously and observed it: "This is a bit like the one my son uses for calligraphy practice."

"That would be troublesome if that were the case." Bai Song said casually.

"What's the difference?" Ma Xi asked curiously?

"Look at this," Bai Song held the phone in front of Ma Xi, "This is a fading pen for practicing calligraphy. The mechanism is that the color-developing substance in the ink reacts with oxygen, carbon dioxide or water vapor in the air to become a colorless substance. And this reaction is usually irreversible.

For example, this photosensitizer, whose scientific name is indoline benzopyran sulfonic acid, is an open-ring structure when dissolved in water and shows color. Under the action of ultraviolet light, it forms an invisible closed-ring structure, which is colorless. However, we don’t know how it turns into a colored substance... This is beyond my understanding of chemistry...

Unless this is a UV developer pen, there is no hope."

"Don't say it, I don't understand what you mean, but I understand now, go buy a small ultraviolet laser lamp and try it, and you will know the outcome." Ma Xi said, "This is easy, it's sold at the stationery store next to our institute, I'll buy one for you later."

Unconsciously... Ma Xi began to think of himself as a soldier and Bai Song as the sheriff...

“No, no…” Bai Song was a little embarrassed: “I’ll go.”

After saying that, Bai Song didn't think any more about it. He just put the things down and ran out.

Ma Xi watched Bai Song run out and thought that this young man was sensible and would rush to do something like this. But when Ma Xi was about to leave, he suddenly found that Bai Song had not packed up his things. Could it be that he wanted him to help look after them?

Forget it, just stay at home. Ma Xi was too lazy to touch these things, so he just sat quietly waiting for Bai Song to come back. He also wanted to see what the ending would be.

Bai Song ran back very quickly. After running several hundred meters back and forth, sweat appeared on Bai Song's head.

"I hope it works. If it's really just a fading pen, it will be troublesome." Bai Song held up a small toy ultraviolet lamp.

Bai Song carefully looked at the open pages of the notebook horizontally and diagonally. Such careful observation revealed that there were indeed traces of writing on the paper, but without any color.

After shining the ultraviolet lamp on the book for a long time, there was no word. Bai Song continued to shine the light on the book, but there was still no word.

Bai Song took out a RMB note and shone the light on it, but found that the anti-counterfeiting mark on it was clearly visible, so there was no problem with the small light, which meant that this was not a UV fluorescent pen.

"No?" Ma Xi asked.

"Well, no. However, it can be seen that some words were indeed written on this notebook, but they are gone. It is probably written with a fading pen. I don't know what this scarred face wants to express." Bai Song pointed to some traces of handwriting on the notebook.

"Are you sure there are words on it?" Ma Xi also saw what Bai Song meant. "Then don't worry. My old classmate is in charge of handwriting identification at the Municipal Institute of Criminal Science and Technology. As long as there are words written on it, it will be no problem to hand it over to him."

"Is this possible?" Bai Song was a little surprised.

"Leave professional matters to professionals. Have you forgotten this?" Ma Xi felt much more comfortable when he saw that Bai Song didn't understand. It must be said that it was a very happy thing to educate and guide Bai Song.

Bai Song nodded to show that he understood.

Solving crimes in modern times is the result of cooperation among all parties, and with the development of science and technology, technical means are becoming more and more important. However, due to confidentiality reasons, Bai Song does not understand many technical means.

With the filing procedures in place, the handwriting identification procedure was not difficult, and Bai Song habitually handed this matter over to Ma Xi.

After Ma Xi agreed, he started to go through the formalities. Halfway through the formalities...

Suddenly discovered?

???

Who is the sheriff? Who arranges who to do the work? This is...

Is this a trick?...

Bai Song didn't think so much about it, he had other things to do.

It is not far from Dabei Vegetable Market to East Third Hospital. This is why Scarface, Fei Ming and others live here. After all, these people don’t care much about the housing environment.

Bai Song parked his car in front of the Dabei Vegetable Market and slowly walked towards the East Third Hospital.

On the way, Bai Song looked around and soon saw a bookstall.

This is what Bai Song is looking for. If we recreate the scene and cross-analyze the various clues that are both true and false that we have at hand, we can roughly come up with something like this.

1. There is a suspected tomb or "treasure" place, located near Dashan City, Dashan Province;

2. Fei Ming, Fei Peng and others were aware of the matter and discussed it with Scarface, but no specific agreement was reached;

3. Scarface took care of the matter himself and abandoned all these people, but these people kept it a secret;

4. Scarface did some research on this matter, probably bought some random books, and also had some plans of his own;

5. Scarface had already made up his mind not to come back, and took all his belongings with him;

6. Scarface is missing.