The nail scratches covered by the paint were concentrated on the lower part of the door. Chen Shi glanced back. The bedroom was located to the side of the door. He said, "The victims crawled here, desperately scratching the door to try and escape."

"People who are poisoned by gas are weak and can’t stand up at all."

"This doesn’t count as key evidence either... But the woman deliberately covered it up."

There seemed to be nothing left to check. The two opened the door and went out. An aunty saw them and hurried upstairs. Chen Shi said, "We’re not bad people. We are police."

"Oh, the police? What are you looking for? In the afternoon, you took the woman who lived there away. Did she commit a crime or something?"

"Do you know what her name is?"

"'The woman downstairs.'"

It seems that the aunty didn't even know the last name of the family. Chen Shi asked again, "I want to ask you something. On November 11th last year, did you see anything strange happen in this house?"

"Strange thing... I'll ask the neighbors for you!"

"Thank you so much."

Soon, a group of neighbors came together, talking about how this woman was a psycho. She often cried when she was teaching her child saying that the father didn’t want them anymore. And every time the man came, they would quarrel. They couldn’t possibly understand how the couple could get along with each other.

After listening to a lot of trivial matters that weren’t related to the case, a neighbor finally remembered something and said, "I don't know what day that was, but one day when I was finished walking the dog and came back, the dog kept barking at the door non-stop. Then, I heard a ‘cha-ra cha-ra’ scratching sound from inside the door."

"And then?"

"Then the woman came back and I said, ‘Sister, there seems to be some noises coming out of your house.’ She said that she bought two bamboo rats and was ready to kill them to eat them. She smiled and said that the two animals inside[1] were scratching the door in the house. Then, I left."

"Sorry, I want to ask you something alone."

After bringing the neighbor to the stairwell downstairs, Chen Shi asked, "Did you not smell gas back then?"

"Nothing at all. What's wrong? Did she have a gas leak?"

"Wait a minute!"

Chen Shi went and asked the neighbors all around and they all didn't smell the gas leak. He whispered to Peng Sijue, "This is very strange. The gas company will add a smell to the gas. It stands to reason that people outside the door would be able to smell it. Her doors and windows in the house aren’t completely enclosed either."

Peng Sijue muttered, "When we were checking just now, I found traces of glue on the edge of the window. Perhaps-"

"I see!" Chen Shi smiled. This was the proof of murder.

He said to the neighbor again, "Sorry, can you come back to the bureau with us later to cooperate with the investigation?"

"Huh? I have to go to the bureau? No, no. I have business at home."

"How about this..." Chen Shi took out three hundred yuan. "This is a small reward for providing leads. A car will pick you up and drop you off to ensure you won’t be delayed in your business.”

The neighbor smiled and was about to reach out and take it. Peng Sijue said sternly, "Giving witnesses money is bribery. If the defendant's lawyer knows that you are doing this, you’re turning valid evidence into invalid evidence!"

"It’s just a bonus for providing clues!"

"It’s a matter of principle!"

"I'm not a policeman."

"You’re working with the police."

"Okay, okay, I'm so sorry!"

The neighbor was also too embarrassed to ask for the money again and said, "Cooperating with the police to handle a case is the right thing to do. I’ll head back and feed the dog. Then, I’ll come down to find you later."

"Okay."

The two returned to the house, carefully inspected the doors and windows, and photographed the glue marks. Chen Shi said, "This woman must have glued things like rubber pads here in advance to make the entire room airtight. The room was then filled with gas! Afterwards, we can investigate what she bought over those few days. We finally have some evidence to go by."

"You think she thought about the whole plan from the beginning, including how to deal with the police today?"

"I don't know about this, but what is certain is that when the mother and son came to her door, she had the intent to kill."

The two took the witness back, and the police officers that were sullenly sitting in a room were suddenly full of excitement when they heard that there was new evidence. Peng Sijue immediately conducted the necessary tests. Everyone waited anxiously as time ticked by.

Peng Sijue walked out wearing a long white coat with a smell of medicine around him. He handed Lin Qiupu a report. "A trace amount of diazepam was found in the deceased's bone marrow, which is consistent with the drug composition in this bottle."

Lin Qiupu said excitedly, "Let's see what that woman says!"

They went into the interrogation room once again where Hao Jie's mother had been waiting impatiently, sitting in a chair and shaking her head. "You’re still not letting me go?"

Lin Qiupu put the drug test report in front of her face and said, "A sedative was found in the victim and it’s the same drug found in your home."

"They’ve already decayed to their bones. Don’t lie to me!"

"There are blood vessels in the bone marrow and the periosteum. Don’t you know of such common sense?"

Hao Jie's face suddenly turned pale. She explained, "That woman said she couldn't sleep and asked me for two sleeping pills."

"You mean she couldn’t sleep in a completely air-tight room? You bought glue and rubber pads online on November 6th and completely sealed the edges of your doors and windows. Do you still want to deny that?"

"Because it was cold at the time."

"The neighbors proved that you heard the scratching door in the house. Not only did you not open the door, but you left. You came back around 8:00. Why is that?"

"..." Hao Jie's mother lowered her head and said nothing. Her psychological defense was slowly disintegrating.

Lin Qiupu continued to give severe blows after blow. "If this evidence is put in front of the judge, what do you think they’ll think? Did you think you were flawless in your plan? Let me tell you something. There’s an eye in the world called ‘God’s eye’[2]. When you do something bad and wipe the traces clean, the ‘God’s eye’ might not take notice of you for a while. But as long as it notices you, it will slowly find all traces like a magnifying glass. There is no impenetrable wall in the world. If you kill someone, there must be traces that are left behind!"

"..."

"If you confess now, you might still get some leniency. Maybe you can see Hao Jie once more in your lifetime. If you continue to act like this, you might even lose this last opportunity."

Hao Jie's mother burst into tears. The dam bursting meant that her inner line of psychological defense had been completely breached. She slammed on the hand rest on the interrogation chair and said, "Your police are all beasts! You guys are willing to separate this mother and child. What did I do wrong? Is it wrong for a mother to love her son? If that’s the case, all the mothers in the world are guilty. Don’t you have a mother as well? Shouldn’t you have a little sympathy?”

Lin Qiupu suppressed his rage and said coldly, "If you really loved your son, you should have thought about the consequences before committing murder. You should have thought about the consequences it would bring to Hao Jie's life. He’ll be scolded by others in school as the son of a murderer. He’ll be discriminated against all his life! This is you loving him? This is not love at all. It’s just magnified selfishness! Your son is like a treasure to you and other people’s children can be brutally killed. What kind of positive example can such a mother give to their child?!"

Hao Jie's mother buried her face in her hands and burst into tears. Lin Qiupu was almost out of patience and said, "If you don’t want to talk about it, then you never have to speak of it again!"

"I’ll talk… I’ll talk..." She whispered through sniffles.

1. I believe the pun was intended.

2. You can also read this as “Sky’s eye”. People also call the surveillance cameras this since it’s so omnipresent.