Courtyard House: Starting with handing over the keys, the state helps me abuse birds.

When Duan Chengyi returned to the police station, it was already past 3 p.m.

He pushed open the office door, tossed his briefcase onto the table, and slumped heavily into his chair, letting out a long sigh. His experience with Xie Weihong today had left him with indescribably complex emotions.

In his twenty years as a police officer, he has seen all kinds of cases and all kinds of reactions from the victims' families: some weeping, some angry, some numb, and some even suffering mental breakdowns because they could not bear the blow.

But Xie Weihong was someone he had never met before.

That child was clearly overstimulated. Breaking iron shears with his bare hands? Leaving a fist mark on a brick wall? And saying something about "punishing evildoers to gain skills"?

Duan Chengyi rubbed his temples, a wave of sympathy washing over him. No wonder; seventeen years! His parents were murdered, their compensation embezzled, and he was kept and bullied daily by his enemy. Now that the truth had suddenly been revealed, no one could bear it.

He took out the manuscript of "Key Points of Short-Process Smelting Technology for High-Purity Special Steel" from his briefcase and casually placed it in the most inconspicuous corner of the table.

This manuscript… Duan Chengyi flipped through two pages, looked at the dense formulas and charts, and shook his head. He wasn't from a technical background and couldn't understand the technical content, but he was certain—this could never have been written by Xie Weihong, a child who had hardly any schooling and had grown up collecting scraps.

The most likely explanation is that Xie Weihong found some technical documents at a used bookstore or scrap yard, which triggered her delusions, causing her to believe that these things "emerged" from her mind.

"Sigh..." Duan Chengyi sighed, pushed the manuscript aside, and began to deal with other work.

He spent the rest of the afternoon organizing the case files for Yi Zhonghai, writing reports, and calling the branch office to discuss the arrest procedures. The manuscript lay quietly on the corner of the table, gradually covered with a thin layer of dust.

As he left work, Duan Chengyi glanced at the manuscript, hesitated for a moment, and ultimately didn't put it in his bag. "Never mind," he thought, "I'll deal with it tomorrow. The most pressing matter is Yi Zhonghai's case; this trivial thing can wait."

He locked the office door and rode his bike home.

Duan Chengyi's family lived on the third floor of an old-fashioned tenement building. The two rooms were a bit cramped for the family of four. After dinner, his wife was washing dishes in the kitchen, the two children were doing their homework, and he was sitting on the old sofa in the living room, flipping through today's newspaper.

But he couldn't concentrate on reading a single word in the newspaper.

My mind was filled with Xie Weihong's earnest face and those absurd words.

"Is Brother Duan home?" A familiar voice came from outside the door.

Duan Chengyi looked up and saw his old comrade-in-arms Xu Zhanqing push the door open and come in, carrying half a bottle of Erguotou liquor and a small bag of peanuts.

"Zhenhua? What brings you here?" Duan Chengyi stood up to greet him.

Xu Zhanqing was his comrade-in-arms when he was in the army. After retiring from the military, he went to a metallurgical research institute and is now a senior engineer. The two live not far from each other and occasionally get together for a drink.

"I got off work early today, so I just stopped by." Xu Zhanqing placed the wine and peanuts on the table and sat down opposite him. "You don't look well. Another tricky case?"

Duan Chengyi smiled wryly: "It's not just troublesome... it's downright awful."

He poured Xu Zhanqing a cup of tea and poured himself some wine, and the two chatted as they drank. Duan Chengyi briefly recounted Xie Weihong's story—of course, omitting the specific details of the case, only saying that she was the orphan of a martyr, whose parents had been murdered, and that the case had now been solved.

"That kid was too traumatized." Duan Chengyi took a sip of his drink. "He told me today that every time he punishes those who harmed his parents, his body becomes stronger and he gets technological inspirations."

Xu Zhanqing stopped shelling peanuts: "Huh?"

"I also think it's absurd." Duan Chengyi shook his head. "But he was very serious and even gave me a manuscript, saying it was the steelmaking technology that took shape in his mind after beating up the main culprit."

Xu Zhanqing became interested: "Manuscript? What's in it?"

"What's it called, 'Key Points of Short-Process Smelting Technology for High-Purity Special Steel'?" Duan Chengyi said casually. "I glanced at it; it's all formulas and charts, I can't understand it. I guess he found some old data somewhere and got a shock that made him delusional."

Xu Zhanqing's eyes lit up: "Short-process smelting? That's a hot research topic internationally lately. Brother Duan, where's the manuscript? Can I take a look?"

Duan Chengyi was taken aback: "In my office. You...you really want to see?"

"Let's take a look," Xu Zhanqing said with a smile. "What if it really is something good? Although what you said about 'gaining technology to punish evildoers' sounds unreliable, the technology itself might have some value."

Duan Chengyi thought for a moment, since the manuscript was useless in the office anyway, it wouldn't hurt to let Xu Zhanqing take a look.

"Okay, I'll bring it to the station tomorrow, you can come and see it."

"Don't go tomorrow." Xu Zhanqing stood up. "Let's go now. Anyway, the research institute isn't far from your police station. I can get there in ten minutes by bike."

Looking at his old comrade's excited expression, Duan Chengyi was somewhat amused and exasperated: "Zhenhua, do you really think that thing is useful? It's just something a kid did after being traumatized..."

"It's no trouble to take a look." Xu Zhanqing had already reached the door. "Come on, I'll give you a ride on my bike."

Unable to resist his old comrade's enthusiasm, Duan Chengyi said goodbye to his wife and went downstairs with Xu Zhanqing to ride their bicycles to the police station.

The police station was quiet at night, with only the duty room lit up. Duan Chengyi opened the office door, turned on the light, and walked to the desk.

The manuscript is still there, covered in dust.

"This is it." Duan Chengyi picked up the manuscript, dusted it off, and handed it to Xu Zhanqing. "Take a look, but don't get your hopes up too high."

Xu Zhanqing took the manuscript, his expression initially casual. He found a place to sit down and opened to the first page.

But after just one glance, his brows furrowed.

"This formula..." Xu Zhanqing muttered to himself, "is somewhat interesting."