SFTD -Chapter 88 Don’t Insult Beasts (Part 9)

“Send Zhang Chunyan’s fingernails to the center first. See if we can find any trace of tetramine. This type of poison is very stable— even if it’s wiped or washed, trace amounts can still remain.”

Zhou Hai pressed down on the accelerator and drove toward the center. After handing the samples over to Sister Zeng, he immediately headed back to the crime scene.

“Didn’t you already go there twice yesterday? Why are we going again?”

Zhou Hai shook his head and didn’t answer. At that moment, Captain Huang called.

“Where are you, Forensic Doctor Zhou?”

“I’m on my way to the 11.3 scene. What’s wrong?”

“Oh, I’m nearby. I’ll come find you.”

Shortly after, the two teams met. Captain Huang looked exhausted, his face covered in stubble. It was clear the three-day deadline pressure had worn him down—especially now that Liu Da was gone and no one was covering for them.

The three of them stood downstairs of the residential building, smoking. Huang let out a long breath.

“A wasted trip. There was nothing at all.”

“I just can’t figure it out. How did the killer ignite the room? Did he really manage to escape completely unscathed? What kind of damn calculation is that? Figuring out the exact timing for ignition?”

Xu Biao looked up at the scene and bumped Huang’s shoulder.

“Isn’t this just like figuring out how long it takes to fill a water tank? One side fills, one side leaks—at what concentration does it explode?”

He turned to Zhou Hai.

“Zhou Hai, do you know what concentration causes an explosion?”

“Between 3% and 11% gas-air mixture can explode.”

Xu Biao pressed on stubbornly.

“So after that, how much gas would still be left in the cylinder? How long could it burn?”

Zhou Hai understood what he was trying to do—Xu Biao was desperately trying to prove this wasn’t something a child could accomplish.

But all current clues still pointed to Zhang Chunyan. They simply lacked evidence. Even so, Xu Biao didn’t want to find it.

Zhou Hai had his own persistence too—because there was only one truth.

A long ringing sound interrupted their conversation. They stood up and looked toward a residential compound on the north side of the neighborhood.

A group of children ran toward the playground as the bell rang, and in an instant, the air filled with lively chatter.

“A school?”

Huang suddenly realized, “The neighbor said that girl, Zhang Chunyan, attends this primary school. What was the name again?”

“Liu Lidu Hope Primary School.”

Ten minutes later, the three arrived at the school, showed their identification, and entered the principal’s office.

Huang tried to keep his expression calm and forced a polite smile.

“Hello, Principal. We’re here to ask about a fifth-grade student, Zhang Chunyan. Could you call her homeroom teacher for us?”

The principal looked puzzled.

“Zhang Chunyan? Which class is she in? We have four fifth-grade classes.”

Huang shook his head. Zhou Hai recalled the name next to the homework book.

“Fifth Grade Class Three.”

The principal stood up. “Please wait a moment. I’ll go get the homeroom teacher.”

Shortly after, the sound of high heels approached. A teacher in her fifties entered the room.

Her hair was tightly pinned up, she wore a black suit, not a speck of dust on her shoes. Behind her black-framed glasses was a stern, unsmiling face, her eyes filled with suspicion.

“This is Zhang, the homeroom teacher of Fifth Grade Class Three.”

“You are…?”

Huang stood up and extended his hand. After a brief hesitation, the teacher lightly shook it.

“We’re from the East District Criminal Police Brigade. We’re investigating a case of arson. Zhang Chunyan’s mother and stepfather died in the fire, and she is currently hospitalized with injuries. We’d like to learn about her situation at school. Could you tell us something about her?”

A trace of disdain flashed in the teacher’s eyes, then she nodded.

“I saw the news. Of course I’ll cooperate.”

“This child—ever since I took over this class in fourth grade, for more than a year, she has spoken fewer than twenty times in total.”

“When asked questions, she either nods or shakes her head. I don’t know if she can’t speak well or simply doesn’t want to.”

“During parent-teacher meetings, no family members ever showed up.”

“She doesn’t interact with classmates either. She completely lives in her own world.”

“If you say she’s autistic, that might be too subjective on my part—but she’s just a child who barely speaks.”

“So I can’t help you much.”

Her detached smile clearly signaled she wanted to end the conversation.

Zhou Hai reached out and stopped Huang, who was about to continue asking. His expression turned cold.

“You remember she spoke fewer than twenty times. Then you must also remember what she said, right? Since the child is so unusual?”

The teacher paused and looked sharply at Zhou Hai. Meeting his cold gaze, she couldn’t hold it for even ten seconds before quickly looking away. This man was terrifying.

After thinking for a moment, she said: “It’s impossible to remember everything.”

“But I do remember that after the National Day holiday this year, we held a public safety education class.”

“The lecture was given by a fire department leader, teaching students how to prevent electrical fires, what not to do when gas is burning, and how to escape in case of fire.”

“It was mostly about fire safety.”

“At one point, he mentioned that you should not casually pour flour near a lit stove, because it could cause a fire.”

“Then Zhang Chunyan raised her hand and asked why flour could cause a fire.”

“That’s all I remember.”

Xu Biao’s eyes widened, slightly red, and he pressed urgently.

“And then? What happened next? What did he say after that?”

The teacher stood up, frowning deeply and looking increasingly impatient as she adjusted her clothes.

“Principal, I’ve already cooperated with the investigation. Why does this feel like I’m being interrogated now?”

Xu Biao also stood up, shook off Huang’s restraint, and stepped in front of her, pointing at her nose.

“You’re her teacher—her guardian at school! A child hasn’t spoken much for over a year, and you never once thought to ask what’s wrong? If she had difficulties?”

“This is how you teach? This is being a teacher?”

“You still have the nerve to act like this? What nonsense!”

“I don’t believe this is what your school stands for, or what these so-called ‘Hope Schools’ were built for!”

“Let’s talk this through properly!”

The teacher looked at him, stunned by his aggression. Her mouth opened and closed, but no words came out. Finally, she covered her face and ran out crying.

The principal spread his hands helplessly.

“Officers, please understand. These are retired teachers who were rehired. Their way of thinking is very fixed. Let’s all be a bit more understanding.”

Zhou Hai pulled Xu Biao away. Huang exchanged a few words with the principal before following them out.

“Huang, contact the fire department. Ask who gave that lecture, and whether they remember what Zhang Chunyan said—and how they responded.”

Huang nodded and immediately made a call. After a moment, he came back.

“I asked. They do remember Zhang Chunyan.”

“At that time, the lecturer talked about the September 23rd Anhui Huaibei flour plant explosion, and then expanded into dust explosions.”

Zhou Hai suddenly thought of the electric fan in the kitchen.

It all seemed to be beyond doubt now.

“Huang, do you still remember when we went to the hospital last time to take Zhang Chunyan’s statement?”