"I really don't know. I fainted. Did the murderer really come in? That's too terrifying!" Facing the questions, Zhou Xiao answered in a flustered manner.

Chen Shi had already finished preparing the fish for the aunt. Standing with Lin Dongxue, Xu Xiaodong and two forensic policemen at Zhou Xiao's house, the small house which wasn’t large to begin with seemed even more cramped with all the people inside.

"I checked the door lock just now and there’s no trace of it being pried open. That is to say, you opened the door by yourself." Lin Dongxue said.

"Impossible! Impossible! I took a look from the peephole and I was shocked. How could I open the door? Right, could it be that he had a master key or something? When he came in, I fell to the ground with my whole body covered in urine, so he let me go?"

"Xiaodong, have you seen such a thing after being a policeman for so long? A witness is composing a story right in front of the police!" Lin Dongxue said.

"The so-called master key is nothing more than a professional lock-picking tool and using that would leave behind scratches." Chen Shi debunked his assumption.

"I really didn't lie!" Zhou Xiao was anxious and took out a pair of trousers from the sink in the bathroom. "Look, these are the trousers I wetted last night. I heard the footsteps and became incontinent over and over again, just like a fountain. How could I open the door? Wouldn’t I be crazy?!"

"Do you have a history of mental illness?" Chen Shi asked.

"Insane."

"So, you do then."

"I mean you’re insane!" Zhou Xiao said and seemed incredibly upset. "It's fine if you don't believe my testimony, but you’re even doubting my mental state. I'm very normal!"

"How do you explain the killing of the family of three next door then?"

"They’re dead!" Zhou Xiao's confident expression was like saying that one plus one equals two. "It's just because of some unknown power that they’ve resurrected, or they returned to the day before. The world is so big and there are so many unsolved mysteries. The mystery may have happened here!"

"Your remarks seem to me like you’re just avoiding problems."

"I remember it was true. They were silenced! It was the aunt who lied, not me! She shouldn't be alive! A dead person is alive, you don't doubt her, but you came here to doubt me!"

Chen Shi saw a movie poster on the wall and asked, "Do you often watch movies?"

"Not often. That is, I watch them every day."

"Talk about the lines of the movie that you’re most familiar with. It's best if everyone has seen it before."

"Uh..." Zhou Xiao thought for a while. "I'll just talk about Infernal Affairs. You’ve all seen it, right? When Andy Lau was on the rooftop, he said ‘I didn't have a choice before. If God could give me another chance, then I want to be a policeman. If I have to add a deadline to this choice, I hope it will be 10,000 years!’"[1]

Everyone at the scene laughed. Chen Shi said, "Recite a poem for us to listen to."

"Let me think about it. I'll just recite Li Mochou's [2]Shuidiao Getou[3] ‘When will the bright moon come, toast to the bright moon, feelings of sorrow in the wine, heartbroken people at the ends of the earth! Where... Aromatic grass!’" He recited passionately.

Everyone was dying of laughter as Chen Shi said, "Mr. Zhou, your memory seems to be really problematic... We’ll have to summon you back!"

Zhou Xiao thought he was going to be taken away, so he screamed as he was taken downstairs.

The purpose of the summoning was to investigate the house carefully. Chen Shi asked the forensic police to investigate the house carefully, especially the doorknob, to see if there was only Zhou Xiao’s fingerprints on it.

The name "Zhou Xiao" still sounded weird to say.

A few days ago, Lin Dongxue was still saying that Zhou Tiannan was dead, so why didn't his group of subordinates move? Chen Shi replied that it wasn't that there was no movement. It was because that group of people were all criminals with high intelligence. They wouldn’t leave behind traces when they committed murder.

Long’an had daily disappearances. There might have been victims from that group amongst them. However, this was time-consuming and labor-intensive to investigate, which was unrealistic.

Back in the bureau, the forensics department carefully compared the traces found in Zhou Xiao’s home. Zhou Xiao himself was taken to the interrogation room for questioning. He still insisted on the same rhetoric and didn’t change a single word. The inquiring police asked him to recite his multiplication tables, but the results were completely wrong.

Chen Shi stayed in the office waiting for the result. He played games on Xu Xiaodong's computer when he was free.

Lin Dongxue and Xu Xiaodong came in together. Lin Dongxue said, "I called his family. Zhou Xiao has a history of mental illness and was sent to a mental hospital, where he stayed for three years."

"When did this happen?"

"It seems that it happened when he was in university. He was forced to drop out of school because of a mental illness, and he has a very stiff relationship with his family, so he was sent there... Listening to the family's tone over the phone, it seemed that they were dealing with a piece of garbage."

"I guess he must not be the only child?"

"I just checked his household registration information. There’s a younger brother in his family. Zhou Xiao has been in Long'an for many years, and it seems that he’s never returned home."

"What's wrong with him?"

"I don't know. There was a big fire in that mental hospital a few years ago. All materials were burned. I heard that some mental patients ran away at the time and caused some trouble, but it has since subsided."

"Mental patient..." Chen Shi muttered.

Lin Dongxue casually conveyed the findings of the forensics department. Zhou Xiao only had his own fingerprints at home. This was the case for the door handles as well. The bloody footprints were indeed the same as the crime scene. There could be no other explanation other than Zhou Xiao opening the door to "welcome" the murderer in.

Xu Xiaodong also investigated some things. To be precise, it wasn’t investigating. He showed Chen Shi a printed picture. It was a man in a trench coat and a round hat with wrinkles on his face. However, this was not a photo. It was a CG screen.

"This can't be the computer sketch of the murderer, right?" Chen Shi asked.

"How can there be this kind of technology? Even if there was, it wouldn’t be so fast." Xu Xiaodong said, "When I first heard him describe the murderer's appearance, I felt like it was oddly familiar. After investigating, sure enough… Brother Chen, do you know what this is?"

"Don't act mysterious."

"The tyrant in the horror game ‘Resident Evil’. It’s a boss.”

Staring at the picture in his hand, Chen Shi said, "Zhou Xiao is also an otaku. He should have seen this character, so he confused his memory and filled his blank memory with things he had seen elsewhere."

"Then why does he think the neighbor's family was killed?" Xu Xiaodong said.

Lin Dongxue guessed, "I think that was his 'wish'. The neighboring aunt is very fierce to him, and it’s probably the same normally, so he hopes that this family would be killed."

"Is it possible that Zhou Xiao is the murderer?" Chen Shi's hypothesis was really shocking.

"Applause. Applause. Brother Chen is about to start his reasoning again!" Xu Xiaodong said excitedly.

"It's not reasoning. It's just guesswork! It's mainly because the footprint at the door made me suspicious. The footprints were directed towards the inside of the house. It was only found in that place. Was the murderer just standing at the door? Doesn't he have to turn around and leave? Could it be that he never left and is Zhou Xiao?! Zhou Xiao wore a pair of huge shoes and went out to commit crimes. After returning, he changed his shoes at the door. As for why he remembered wrong and why it’s so real to him as if he could vow that it was true, it’s because he has dual personalities. His main personality doesn’t know the existence of his sub-personality, so he made up some content in his brain to fill in these blank memories."

Chen Shi remembered one more thing. "By the way, aren't there fingerprints and hairs of the murderer at the scene? Ask Old Peng to compare them and we’ll get the answer!"

"I bet fifty yuan that you’re wrong this time." Lin Dongxue said, "The luminol reagent reacts very sensitively. If this is the case, there must be other blood stains on the scene, not just those bloody footprints."

"It's best to be wrong. That would mean that we can eliminate a wrong option." Chen Shi said indifferently.

1. The actual quote I retrieved online was "I had no choice before, but now I want to turn over a new leaf."

2. Character from The Romance of the Condor Heroes, The Return of the Condor Heroes, and Little Dragon Maiden

3. Shuidiao Getou is the name of a traditional Chinese melody to which a poem in the cí style can be sung.