Qiao Yan remembered and asked, "Hasn't the murder weapon been found yet?" ”

Wei Chihong shook his head deeply, "In such a short time, if he wants to deal with knives, he can only deal with knives in the area from the rental house to the factory, which is very small, but the area has been thoroughly searched, and no knives have been found." ”

"Could it be, he brought it back to the factory to deal with?" Qiao Yan thought that it was really easy to destroy a knife in the hardware machinery processing factory.

But Wei Chihong overturned her idea. "In that factory, there were people who had come to the factory with knives to make trouble, and there were many times when metalworking products were lost, and it was suspected that employees had smuggled things out of the factory. Later, a metal detector was installed at the entrance of the factory, and when entering and exiting, as long as there were metal items on the body, it would be detected. According to the security guard guarding the door, Cai Weimin was not detected when he entered the factory. There were two security guards on duty at the time, and the possibility of perjury was largely non-existent. ”

Qiao Yan couldn't think of a reason, and was still thinking about it, the Red Star Hardware Machinery Processing Factory had arrived.

Wei Chihong showed his ID and asked the two security guards on duty at the guard office whether Director Cai had not been detected by the metal detector when he passed through the security gate that night.

One of the security guards said no, and had already told the police who had come to investigate. Another security guard also said no, but when Wei Chihong and Qiao Yan were about to leave, he suddenly remembered the details that had been overlooked. "There was a knock at the security gate, but it wasn't a prop, just a metal kettle. Director Cai brought a kettle with tea in it, he likes to drink tea very much, everyone knows it. ”

Wei Chihong nodded thoughtfully.

In the deputy factory director's office, Wei Chihong and Qiao Yan saw Cai Weimin for the first time, his appearance and the description of the portrait are basically the same, tall, fat, a little wooden, and honest.

"You may be seated." After the two revealed their identities, Cai Weimin behaved politely and politely, "The police have already come before, and I have said everything that should be said." Do you have any questions? ”

"We're either here to ask questions, or we're just passing by, coming in and sitting." Wei Chihong said, his eyes wandering around the office, "Can you take a visit?" ”

Cai Weimin was stunned for a moment before saying, "Of course you can, you can do it, I'll make tea." ”

Yu Chihong then paced slowly indoors.

Qiao Yan secretly paid attention to Cai Weimin's actions, he was boiling water with an induction cooker, and his demeanor was very calm.

The office is neatly organized, with a large bookcase filled with a variety of books and materials. Yu Chihong opened the glass door of the bookcase and saw a metal handicraft placed in the top compartment, a bit of installation art style. He reached out and took it. "This is a craft, it's quite exquisite."

Cai Weimin turned around, and Qiao Yan could see from his face that there was a subtle expression of fear for 0.25 seconds. But he regained his dull expression in an instant. "I'm doing it for fun, and the officer is interested in crafts?"

"I love art, and I do sculpture and stuff like that." Wei Chihong was quite interested, "Can you lend me two days, I want to refer to it." ”

"Yes." The corners of Cai Weimin's mouth twitched slightly, and his answer was short and stiff.

"Thank you." Wei Chihong's gaze stayed on the bubbling kettle beside Cai Weimin for a few seconds, and said quietly, "We should go, and I will return the things to you in two days." With that, he took the artifact with him.

Qiao Yan was puzzled, she knew that it was absolutely impossible for Yu Chihong to really create art, he had another purpose, but what connection would that handicraft have with the case? When leaving the office, Qiao Yan glanced back at Cai Weimin, his face was stiff, and his gaze was fixed.

As soon as she got in the car, Qiao Yan couldn't wait to ask: "Is that handicraft related to Fang Hong's murder?" ”

"When you were studying, you didn't study physics, right?" Wei Chihong asked rhetorically.

"What do you mean?" Qiao Yan was confused, what does this have to do with not learning physics well?

Wei Chihong replied: "The knife used by the murderer contains bismuth and indium. Indium-bismuth alloys, which are fusible alloys with low melting points, are often used as solders and are also widely used to make molds using casting methods, such as lens molds. Low melting point alloy is used in molding, with short mold making cycle, less machining man-hours, and obvious advantages. ”

"The knife that killed Fang Hong was made of this alloy? Could it be, this craft was made of that knife? How? Qiao Yan speculated wildly, and her vague thoughts began to become clear.

Wei Chihong glanced at her. "Well, it's not too stupid. Follow me to meet someone, and you'll know it all. ”

"Not too stupid?" How does this sound so ...... Frivolous? Qiao Yan gritted her teeth secretly, this guy is getting more and more presumptuous! But she responded with silence, and if she said too much, she would lose it, and she had already seen how powerful he was.

Wei Chihong drove into Haidu University. Haidu University is a high-level university under the national "211 Project" and "985 Project", and is also a comprehensive university with a complete range of disciplines, strong faculty, first-class in China and extensive influence in the world.

Qiao Yan really couldn't think of who Wei Chihong came to this school to see and for what purpose.

After getting out of the car, Wei Chihong walked like a fly, Qiao Yan had to trot all the way, followed him into the building of the School of Physical Science and Technology, and climbed to the fifth floor in one breath. Obviously there is an elevator, but he said that waiting for the elevator is a waste of time, and it is fast to take the stairs. Fortunately, since she sprained her foot in a container coffee shop in distress in wearing high heels last time, Qiao Yan has learned to be obedient and no longer wears high heels.

"What the hell do we want to meet...... Who is it? Qiao Yan crouched on the stairs panting.

Wei Chihong walked back in great strides, looked down at Qiao Yan, and replied simply and clearly: "Lu Xipeng, associate professor of the Department of Physics of Haidu University." ”

Associate professor, still in the Department of Physics, Qiao Yan has preconceived the stereotype for others - the image of an old-fashioned old pedant. Therefore, when she walked into the physics laboratory and saw only a young man with his head down and fiddling with the instrument, she immediately said to Wei Chihong, "Professor Lu is not here. ”

"Whoever said no, this is Professor Lu." Wei Chihong corrected.

The young man raised his head in Qiao Yan's surprised gaze, and Qiao Yan's eyes lit up. This man is so handsome! Heroic and upright. The smiling eyes are shiny and gentle, the eyebrows are thick and dark, and the bridge of the nose is straight. I didn't expect the professor who studied physics to be so young and handsome.

In this way, she unconsciously compared this Professor Lu with Wei Chihong, if it is about the handsomeness of appearance, the two are comparable. But Yu Chihong is always cold, rejecting people thousands of miles away, like an iceberg that can't be melted, and even rare laughter seems so weird. And Professor Lu has an elegant demeanor and a charming smile, which is obviously more in line with the image of Prince Charming in women's hearts.

However, although she came to such a conclusion, Qiao Yan's whole attention was on Yu Chihong, she peeked at Yu Chihong, but found that he was looking down at her, his eyes flashing and strange.

Qiao Yan's heart suddenly skipped a few times. It's over, it could be that he was a nymphomaniac with Professor Lu just now, and it happened to fall into his eyes, and this time he really lost face.

"Show me something." Lu Xipeng didn't have any extra nonsense and went straight to the point.

Wei Chihong took out the metal crafts he brought from Cai Weimin and handed them to Lu Xipeng.

Lu Xipeng held it in his hand and looked at it for a while. "If indium and bismuth are mixed in the right proportions, they can be made into a metal with a melting point of 70 degrees. The temperature of boiling water is 100 degrees, which means that the metal can melt in boiling water. It is entirely possible that the prisoner used that metal as a knife beforehand, and after committing the crime, he melted it down and took it away. ”

"It seems that my speculation is correct, this metal artifact is the murder weapon." Yu Chihong was visibly relieved.

"You still have to check it to be sure." Lu Xipeng shook the artifact slightly, "Are you sure you can melt it?" ”

Wei Chihong definitely said yes.

"That's not good." Qiao Yan couldn't help but interject, "You told Cai Weimin that you would return it to him in two days, if it melts, how can you pay it back?" ”

Wei Chihong disagreed. "No problem, it's a big deal to lose money." He spoke with a lot of confidence, giving people the impression that if the handicraft was expensive, he would definitely be able to afford it.

Qiao Yan had nothing to say.

Lu Xipeng smiled and said, "I will try my best to restore it to its original state, and there should be no need to lose money." He quickly put into work, melted the metal, dipped a little molten metal with a cotton swab, put it into a small bottle, cut off the bamboo skewer, leaving only the cotton head, and then sealed the bottle and handed it to Wei Chihong, who took it back to the Public Security Bureau for inspection.

"The rest of the work will be troublesome to Professor Lu." Wei Chihong looked at the clock in the laboratory, it was almost half past 12 noon, "Let's go to lunch together." ”

Lu Xipeng declined. "Next time. Today, my wife has prepared a bento box, which can be eaten after heating it up. ”

These words gave Qiao Yan another surprise, he actually had a wife, and the heart of the admirer must have been broken. She was suddenly curious, what kind of woman would be his wife with such an outstanding man?

Wei Chihong was naturally not reluctant, and made an appointment with Lu Xipeng to come the next day to get the restored handicrafts and say goodbye.

The two of them still took the stairs and went downstairs. The noon sun shone brightly on the campus, and they walked out onto the boulevard, where the winter trees of Haidu were evergreen, and the sunlight through the dense leaves was like a shining golden thread. When she came here just now, she was in a hurry, but now she walked back leisurely, and Qiao Yan's mood was also illuminated by the sun, and she jumped up childishly and grabbed at those shining gold threads.

Wei Chihong was originally walking in front, but when he heard the footsteps behind him disappear, he turned around and saw Qiao Yan holding a handful of sunshine in his hand, and his body was also bathed in golden light, flashing and moving. A warmth spread out from his limbs, how long had it been since such a sunny picture appeared in his life?