The train driver in the courtyard

Li Aiguo had just finished speaking.

The cave fell into a deathly silence.

All the security officers' eyes were fixed on him.

Zhou Ke was also stunned: "Aiguo, this sulfuric acid can detonate explosives?"

Li Aiguo shook his head: "No, this thing is essentially a delayed detonation device."

As he spoke, he squatted down and laid out the wire and glass shards on the ground.

He explained the principle by gesturing: "This bottle contains sulfuric acid. The iron wire is bent into a buckle and placed at the bottle opening, firmly pressing against the matchbox's eraser and the match head, so that the match is in a critical state where it will ignite as soon as it is pulled."

Then seal the bottle with wax, leaving only a tiny opening aligned with the wire; this is the key.

Zhou Ke finally realized what was going on and immediately asked, "But how do we control the detonation time? The enemy's goal is clearly to collapse the mine and damage the coal cutter with ore. The timing must be extremely precise."

"That's simple. Just adjust the sulfuric acid concentration and the size of the glass opening. The higher the concentration and the larger the opening, the faster the corrosion rate. As long as we do a few more tests, we can accurately calibrate the detonation time."

The people in the equipment department of the weather station also came up with something similar, although it wasn't sulfuric acid + bottle + iron wire, the principle was about the same.

After the words were spoken, the cave fell silent once more.

The security officers frowned as they pondered and digested this seemingly simple yet ingenious design.

"Controlling the corrosion rate with sulfuric acid, this method actually seems to work..." someone muttered.

"It's not just feasible, it's absolutely brilliant."

"Yes, after the explosion, only a few shards of glass and bits of wire were left, so no one would suspect anything."

"That dog Dieter is too cunning."

"No matter how cunning an old fox is, he's still afraid of running into a good hunter. Look, he was still seen through by the comrades at the Qianmen Locomotive Depot."

The way everyone looked at Li Aiguo had changed.

Previously it was merely out of respect for his position, but now it has been mixed with heartfelt admiration.

That's how it is in security work. You don't submit to whoever has the highest rank. Only those who can genuinely solve cases and overcome difficult problems deserve true respect.

Zhou Ke was also a little discouraged at this point. They were brothers who had grown up together, how come he hadn't noticed?

One of the security officers leaned forward and asked, "Aiguo, tell me, what's the background of this Dieter who's hiding here?"

"Ahem. There's been a major breakthrough in the case. Let's have a meeting to discuss it." Section Chief Wu interrupted at the right moment, his tone serious.

The staff immediately understood.

The case involves Dieter and is too confidential to discuss here, so everyone nodded in agreement.

Section Chief Wu arranged for several staff members to stay at the entrance of the cave, strictly prohibiting anyone from entering or leaving. He then led Li Aiguo back to the conference room.

In addition to Section Chief Wu, the two heads of the Security Section were also present at the meeting; both were reliable comrades who had been tested and proven.

Once the meeting room door was closed, the noise was completely shut out.

Section Chief Wu took out a cigarette and handed it to him: "Aiguo, although we have figured out Dieter's detonation method, glass bottles, sulfuric acid, and iron wire are too common in the mining area. It will be extremely difficult to trace the person through the materials."

Li Aiguo took the cigarette, lit it, and slowly said, "The materials are common, but the person who came up with this method must have a solid foundation in chemistry. Many people may know that sulfuric acid can corrode iron wire, but to precisely control the corrosion rate and calculate the detonation time is something that ordinary people cannot do."

Upon hearing this, Section Chief Wu's eyes lit up instantly: "So, the target should be people working in the chemical industry?"

He immediately turned to the deputy head of the security department and gave the order.

"Contact the General Affairs Department immediately to find out who in the mining area has access to chemicals and who has chemical knowledge, the sooner the better."

"Yes!" The deputy section chief turned around and picked up the phone.

After the call was connected, the comrade from the General Affairs Department wanted to consult with his superiors, but the deputy section chief's tone turned serious: "Comrade Chen Xiaoquan, this is a confidential mission from the Security Department, and you are the only one who is allowed to know about it. Report the situation truthfully immediately!"

"Understood!" Chen Xiaoquan on the other end of the phone was startled and quickly replied.

He was in charge of the allocation of chemical raw materials in the factory area, so he knew the matter very well and immediately explained it in detail.

In addition to two departments that frequently handle chemicals, there are two other departments within the mining area.

Only two departments in the mining area regularly come into contact with chemicals.

One is the ventilation department, responsible for mine ventilation and gas control, but they never come into contact with sulfuric acid.

The other is the explosives preparation workshop.

This is a special workshop found only in large mining areas, where sulfuric acid is used to adjust the acidity and alkalinity of ammonium nitrate explosive raw materials.

“I think that ‘rat’ must be hiding in the explosives preparation workshop! He understands chemistry, can do hands-on work, and can easily get his hands on explosives. There’s no other place like it.”

Zhou Ke said impatiently.

Li Aiguo frowned slightly.

Logically, explosives preparation workshops are high-risk and critical departments, and their management should be strict. How could such a loophole appear?

However, he was unclear about the specific management of the explosives workshop at Linxi Mine and therefore could not draw any conclusions rashly.

Subsequently, the investigation team divided up the tasks.

Li Aiguo, along with a deputy section chief, was responsible for studying the files and preparing for the interrogation. Once the person was brought back, the interrogation would begin immediately.

Section Chief Wu then led a team of security officers to the explosives preparation workshop to conduct an investigation.

"Old Wu, the rats are in the dark, and we're in the light. We need to be careful."

"I understand!" Section Chief Wu nodded emphatically, went out the door, gathered the team members, and drove a jeep and a truck to the explosives preparation workshop.

Li Aiguo then had the deputy head of the security department transfer the files of all personnel in the explosives preparation workshop and the ventilation department.

"Didn't the ventilation department already rule out suspicion?" the deputy section chief muttered under his breath, but still turned around and brought the file over.

The two departments have a total of two to three hundred people, and the files piled up on the table are like a small mountain.

There was still no news from Section Chief Wu, so Li Aiguo wasn't in a hurry. He lit a cigarette, poured himself a cup of tea, and slowly began to peruse the book.

After leaving the security section, Section Chief Wu immediately led his men to the explosives preparation workshop.

Due to its extremely high risk, this workshop was deliberately located in a remote area in the northwest corner of the mining area, separated from other areas by a safe distance.

His decision to exclude Li Aiguo from the arrest operation was based on his own considerations.

If Dieter was indeed an explosives manufacturer, the workshop was full of explosives, and a slight mistake could cause an explosion.

He absolutely could not allow Li Aiguo, a national model worker who was able to develop a coal cutting machine, to put himself in danger.

"I hope everything goes well." Section Chief Wu looked up at the pale sun in the sky, then pushed the bullet into the chamber.

The convoy stopped outside the preparation workshop, and smoking was strictly prohibited within a 500-meter radius.

When Section Chief Wu and his men pushed open the door and rushed into the workshop, there were two people talking quietly at the entrance.

Workshop Director Cao, and a thin middle-aged man in his forties.

Upon seeing Section Chief Wu and his entourage arrive fully armed, a barely perceptible hint of surprise flashed across both of their faces.

"Section Chief Wu, what brings you here?" Director Cao was the first to greet him.

"Old Cao, did anyone in your workshop ask for leave today?" Section Chief Wu asked directly, without any pleasantries.

Director Cao noticed his anxious expression and then glanced at the security officers behind him.

They were all fully armed, and some had their fingers already on the trigger. Suddenly, their hearts sank, and they realized in an instant that something was wrong.

"When I take roll call in the morning, everyone is there and no one has asked for leave."

"Okay, immediately take control of everyone in the workshop—the batching workers, pressing workers, sealing workers, and all the general staff—and bring them all to the conference room for centralized supervision!"

Before Director Cao could react, Section Chief Wu waved his hand, and a team of security officers rushed into the workshop. Soon, the sounds of tables and chairs clattering and shouts of "Stop!" could be heard from inside.

"Stay where you are, don't move!"

"The one with the explosives box, put it down slowly and gently!"

"From this moment forward, anyone who dares to act recklessly will be punished in the same way as Dieter!"

Before long, the team leader strode out of the workshop to report that the situation was basically under control.

Section Chief Wu was about to follow them in when he suddenly stopped and looked at the middle-aged man standing behind Director Cao.

"What's wrong with this comrade?"

"This is Technician Bai; he's from the ventilation department."

Director Cao sensed something big was about to happen in the workshop and said to Technician Bai, "Old Bai, your idea for purifying explosives is indeed insightful, but today's situation is special. Let's discuss it in detail another day."

Technician Bai nodded at the opportune moment: "That's good. I was just about to go to Well No. 3. I just received a report that there was an unusual smell down there, which may be due to excessive gas levels."

Section Chief Wu had already signaled the security officers to take the man into custody, but upon hearing this, he hesitated.

The gas accident was urgent; if it was delayed, the lives of hundreds of miners in the mine would be hanging by a thread.

At this point, Director Cao added, "Old Bai never went into the workshop; he just chatted with me for a couple of minutes at the door."

Section Chief Wu then called out to the security officer, saying, "Our mission is to inspect the explosives preparation workshop. Let him leave."

The two security officers stopped, and Bai Jishu nodded to the group before pushing his bicycle out of the explosives preparation workshop.

His movements were very natural, like those of an honest technician who, when faced with an unexpected situation, would slightly distort his movements, but it was just right.

Section Chief Wu stared at his back for a long time until the clerk beside him urged him softly, then he turned his gaze away and stepped into the workshop.

As soon as he was out of Chief Wu's sight, the white-clad technician, who was riding his bicycle on the streets of Linxi Mine, turned extremely pale.

"Why would the security department be targeting the explosives workshop? How much information do they actually have?"

"Could it be that Chen Liushui confessed? Impossible, he had no idea about my real identity."

This was the first time he felt the situation was out of control, and a strange anxiety welled up inside him.

Back at the ventilation department, colleagues greeted him from time to time along the way.

I just entered the office.

An officer stood up and said, "Old Bai, you said last time that there was a file that needed to be revised. I just went to the archives and asked, and the file has been taken away."

Bai Jishu's heart skipped a beat: "Who took it?"

"Then I don't know. You know the rules in our mining area. If I hadn't asked, the people in the archives wouldn't have told me." The clerk's tone carried a hint of pride.

"Thank you so much, Xiao Chen. I'll definitely treat you to drinks sometime."

Bai Jishu was no longer in the mood to deal with him. He went into the office, closed the door, and his face turned ashen.

"First they checked the explosives preparation workshop, and now they're investigating the ventilation department. Could they really be targeting me? That shouldn't be happening."

"No, we can't just sit here and wait to die. I was originally planning to stay in the mine a little longer, but it seems it's too late now. But before I leave, I want to give you a big gift."

The technician pretended to be busy at his desk for a while, then asked the section chief for a requisition slip, claiming he was short of pens and ink, and went straight to the logistics department.

The logistics staff were already familiar with him; he frequently came to apply for office supplies, so the young women weren't surprised to see him.

"Xiao Pan, Technician Bai from the ventilation department is here." Someone called out towards the warehouse. Pan Jinyue, who was in charge of distributing office supplies, came out. When she saw Technician Bai, a flash of surprise crossed her eyes, which she quickly concealed.

She turned and went into the storeroom to get a few pens and notebooks, handing them to him and indicating that he should sign the requisition form.

After signing the form, the technician left with the items. Shortly afterward, people from other departments came to collect their stationery.

It wasn't until nearly noon that Pan Jinyue said to the officer next to her, "I'm going to the restroom. Can you keep an eye on things for me for a while?"

"Don't worry, no one will come to collect their stuff now," the clerk waved his hand.

Pan Jinyue walked out of the logistics department, seemingly heading towards the restrooms, but stopped abruptly after turning a corner and quickly disappeared into an abandoned office building next door.

Not far away, two plainclothes security officers exchanged a glance and quickly followed.

But once inside the building, Pan Jinyue had already disappeared.

Where is Pan Jinyue?

He was being gagged and huddled in a corner by the door of an office.

Pan Jinyue was so frightened that cold sweat broke out on her forehead. Just as she was about to bite the hand covering her mouth, a cold voice came from beside her ear: "Fool, you don't even know you're being followed!"

Hearing the footsteps approaching, Pan Jinyue's expression changed drastically, and she quickly held her breath.

The footsteps outside grew closer, and Pan Jinyue froze, quickly holding her breath.

"Where is the person? Why is he missing?"

"They must have escaped through the back door, hurry and chase them!"

The footsteps gradually faded away, and after another two or three minutes, the hand covering her mouth was finally released.

Pan Jinyue looked up and saw that the person in front of her was Bai Jishu.

"Don't speak, come with me!" Bai Jishu glared fiercely at Pan Jinyue.

Pan Jinyue followed obediently behind like a child who had done something wrong.

The two left the house one after the other.

Bai Jishu was very familiar with the surrounding terrain. He led Pan Jinyue through a series of twists and turns, out through a hole in the wall, and they arrived at a hillside.

Below were several mine shafts of the Linxi Mine, where the cage cars were buzzing and extremely busy.

The technician in white stood on the slope with his hands behind his back, staring at the mine shaft below, before speaking after a long while.

“Jin Yue, we may be exposed. I plan to evacuate as soon as possible and head overseas.”

“Teacher, that’s wonderful! I’ve wanted to go back to my hometown for so long. My mother said that cherry blossoms are blooming everywhere in my hometown, and it’s so beautiful.” Pan Jinyue’s eyes lit up.

"But there's one more thing to do before I leave."

Pan Jinyue pricked up her ears.

Technician Bai suddenly pointed downwards, his tone ruthless: "Everyone in the mine is an enemy, they must be eliminated!"

“Teacher, there are at least several hundred people in a mine.” Pan Jinyue was startled.

“Those are enemies, not people. Besides, why do you think our family abandoned us back then, and now they’re willing to take us back?” Bai Jishu’s tone was icy.

A gust of wind blew by, and Pan Jinyue couldn't help but shiver: "They told us to sabotage the mine."

"Not only the mine shaft, but also the coal cutter, and take care of that train driver from the Qianmen locomotive depot as well."

“But how can we do that? You know, Mine No. 6 has been protected by the security department, and no one can get close.” Pan Jinyue frowned.

“Fool, Mine No. 5 and Mine No. 6 are connected. When the ventilation equipment was installed, the mine had someone seal off the entrance. As long as we can get into Mine No. 5, we can complete the mission.”

As he spoke, Bai Jishu turned to look at Pan Jinyue.

“The No. 5 mine shaft is under the jurisdiction of the production department, so we need to get Deputy Section Chief Chen to handle it.”

"he"

When Deputy Section Chief Chen was mentioned, a hint of disdain flashed in Pan Jinyue's eyes.

That person was a filthy pig.

"Jin Yue, I know you've been wronged, but we're doing this for the greater good of the empire. As long as we complete the mission and return to our homeland, perhaps His Majesty Tianhuang will even grant you an audience!"

White technology guides and inspires.

"This isn't the first time you've done something like this. One more time won't make a difference. Besides, don't you want to rescue Chen Liushui?"

These words struck Pan Jinyue's weak spot precisely. She looked up abruptly: "Teacher, are you willing to save Liushui?"

"Of course, although Liushui is not from our side, he is your lover. I have already talked to the people above. As long as he can complete the mission, they are willing to accept Liushui."

Upon hearing this, Pan Jinyue hesitated for a moment and bit her lip.

"Teacher, I will listen to you."

"Okay! Wait for me." Bai Jishu waved to Pan Jinyue, and after Pan Jinyue came closer, he whispered a few words in her ear.

"Understood, teacher. Don't worry, I will definitely complete the task."

"Loyalty to Tianhuang, for the great cause of the empire!" Technician Bai raised his fist, his tone fervent.

"Loyalty to Tianhuang, for the great cause of the empire!" Pan Jinyue also raised her fist in agreement.

A gust of wind swept in, sending up clouds of dust that completely obscured the already pale sun, casting a dark gloom over the world.

****
"What? You guys lost them?"

Around noon, Section Chief Wu, who had just returned to the security department, received two pieces of bad news.

One of the technicians and workers in the explosives preparation workshop, after initial questioning, had no problems.

The second was the security officer sent to follow Pan Jinyue, but Pan Jinyue slipped out of sight, although she returned to the logistics department around noon.

Seeing that Section Chief Wu's face was frighteningly pale, a plainclothes security officer quickly stepped forward to explain: "Section Chief Wu, Pan Jinyue only disappeared for twenty minutes. Logically speaking, it's impossible for her to have done anything underhanded."

"Don't even mention twenty minutes! Even if it's only ten minutes, Dieter could blow our mine to smithereens!" Section Chief Wu roared in anger, pointing at the two men, about to reprimand them furiously.

Li Aiguo, who was standing nearby, quickly stepped forward and grabbed his arm: "Brother Wu, it's already commendable that they were able to report the situation in its entirety."

Li Aiguo was not trying to excuse the two plainclothes security officers.

The security officers were less disciplined than the meteorologists.

If these two deliberately concealed the fact that they had lost track of the person, no one else would have known.

As for the failure to follow up, it was more of a technical oversight; the two individuals' positions and ideas were by no means problematic.

Section Chief Wu paused for a moment, then softened his tone: "The responsibility lies with me. If I had known Pan Jinyue was so cunning, I should have sent two more people to assist you."

The two security officers breathed a sigh of relief and looked at Li Aiguo with gratitude.

Li Aiguo changed the subject, turning his gaze to the two of them: "Before Pan Jinyue disappeared, besides the people from the logistics department, who else did she see? Did you write them all down?"

“I’ve written it down. I’ve met quite a few people.” An officer quickly handed over a list.

The document not only listed names but also detailed the recipient's department and the reason for their visit to the logistics department, clearly indicating that thorough preparation had been done in advance.

"The last person to see her was this one, but we checked, and there's nothing wrong with him," the officer added, pointing to the last name on the list.

Before he could finish speaking, Li Aiguo's finger pointed to another name: "Bai Jishu, have you checked this carefully?"

The officer was taken aback, then quickly replied, "Huh? Bai Jishu left more than thirty minutes ago, and Pan Jinyue left after him, so it shouldn't have anything to do with him, right?"

"What if Bai Jishu is deliberately delaying his departure to avoid your sight?"

Li Aiguo spoke calmly.

The words were like a stone thrown into a calm lake.

The two security officers' expressions changed drastically.

Logically speaking, the person most likely to be suspected is the last person to have met with Pan Jinyue!

Dieter must have known about this situation.

What if Dieter did the opposite?!
"Besides, he's a technician in the ventilation department, so he must be well-versed in chemical engineering," Li Aiguo added, hitting the nail on the head.

Section Chief Wu suddenly exclaimed, as if he had just remembered something: "That's right! I also saw Bai Jishu this morning. He was chatting with Director Cao outside the explosives preparation workshop. The two seemed to have a close relationship."

Upon hearing this, everyone in the meeting room changed their expressions.

"Bai is proficient in chemical engineering and has a good relationship with the explosives preparation workshop. Could it be that he blew up the mine?"

"There is a possibility."

Li Aiguo stood up and pulled out a file from the table that he hadn't had time to look at yet.

Bai Jiju, whose real name is Bai Jian, is from Weixian County, Da Cong Province. He was sent here by the Kailuan Coal Mine Bureau during the Japanese occupation. He is 48 years old and was once married. His wife died of illness.

Aside from these, there was no other information in the file; it was quite rudimentary.

“Patriotism? There’s nothing to see in the file. How about I take some people to investigate the ventilation department?” Section Chief Wu said.

"Section Chief, you absolutely mustn't! This will only alert the enemy and cause trouble for Bai Jian," Deputy Section Chief Zhao quickly advised.

Li Aiguo threw the file on the table: "If I'm not mistaken, Deputy Section Chief Zhao, your actions of retrieving the file today have already alarmed Bai Jian."

Deputy Section Chief Zhao froze, stunned on the spot.

He repeatedly recalled the details of retrieving the files, and the previously scattered clues quickly connected in his mind, his face turning deathly pale in an instant.

“It was my oversight! Although I instructed the archivist to keep it confidential, the news still leaked out... Patriot, I made a big mistake.”

"No, no, no, not only did you not make a mistake, but you also unintentionally helped Section Chief Wu to complete a brilliant 'beating the grass to scare the snake' strategy."

Li Aiguo clapped his hands and said.

Section Chief Wu was also taken aback for a moment, but then he remembered seeing Bai Jishu at the entrance of the explosives workshop and immediately understood.

"No wonder! Bai Jian first ran into me, and then realized that his file had been transferred. It's no wonder he panicked and went to see Pan Jinyue."

As he said this, Section Chief Wu felt a pang of sadness.

When Li Aiguo asked someone to keep an eye on Pan Jinyue, Section Chief Wu thought it was unnecessary, since Pan Jinyue was just Chen Liushui's cousin and there was no suspicion against her.

Section Chief Wu only cooperated with the work because Li Aiguo was the head of the investigation team.

Now, this seemingly idle piece has become the key to breaking the deadlock.

He was completely impressed by Li Aiguo's strategic planning skills.

This goes beyond the capabilities of a detective; it requires a holistic perspective on the entire case.

"That's right. Mice are hard to catch because they hide in the shadows. Once they're alerted and start moving, that's our chance."

Before Li Aiguo could finish speaking, a security officer approached and saluted: "Reporting, Team Leader Li! Our comrade on surveillance has reported back. Pan Jinyue just made an appointment with Deputy Section Chief Chen to go to the Workers' Cinema tonight!"

Li Aiguo stood up: "The show is about to begin."

(End of this chapter)