Dali noticed how I ignored him yet answered Xiaotao’s question immediately.

“Jeez, dude! I’ve been asking you so many questions and you didn’t even bat an eye,” he complained. “But Xiaotao-jiejie only had to say a few words and you answered her immediately? Dude, are your ears selectively deaf?”

“Okay, okay, I’ll answer your questions later!” I told him. Then I turned to Xiaotao and said, “The handprints on the body and the fingerprints on the plastic bag look very similar to each other. I wonder if there is any possibility that the murderer and the one who discarded the body are the same person?”

“The same person?” Xiaotao raised an eyebrow. “But one is cautious and efficient while the other is sloppy and messy. How could they be the same person?”

I took off my gloves and took a pair of Vernier calipers from my handbag and compared the handprints and fingerprints. The fingerprints on the bag were muddled and fuzzy. I could only find three complete fingerprints. But the results were clear—the three fingers and the ones left on the body were of the same length!

But this was all very curious. When the murderer killed the victims, he was calm and cautious, and he wore gloves. Yet when he discarded the bodies, he became careless and left a lot of fingerprints on the plastic bag. It was obvious that the person who threw away the bodies was scared and nervous.

Xiaotao’s doubts were exactly the points in this case that I couldn’t figure out the solution for. I had a hunch that this was the key to everything, but it was now shrouded in a thick fog. It nagged at me like the way a fish bone stuck in one’s throat might.

“Do you want to continue examining the corpse?” asked Xiaotao.

“No, there’s nothing left to do here.”

I took out a piece of yellow joss paper and burned it. I chanted a Reincarnation Mantra in honor of the victim. A gust of wind blew from under the bridge and carried the ashes into the river while the police officers looked on.

Xiaotao seemed to have become accustomed to this scene, and she barely batted an eye at it.

“You should go back first, Song Yang,” she suggested. “I’ll stay here to clean up the crime scene. There’s nothing to investigate for the time being. We’ll just summarize all our findings together tomorrow morning.”

I wanted to offer to stay and help, but there really was nothing else I could do here. Plus, I had been busy working since four in the morning, and I was dog-tired. So, I agreed to go back to my dorm, all the while admiring how strong and resilient Xiaotao was compared to me.

Once I returned to college, I skipped afternoon class and went to the library instead, looking for more information. I stayed there until the library closed at night.

Even when I went back to my dorm room, I lay in bed and pondered about the case. Dali sat on the edge of my bed and asked, “You’re still thinking about the case, aren’t you? You shouldn’t overexert yourself, dude. You should go to bed early tonight. We’ve got to hurry to the police station for the meeting tomorrow morning, right?”

“Yeah, okay. I’ll stop thinking now.”

“By the way, you didn’t fetch some water from the water room, did you? I got a kettle of hot water for you, and there are a few packets of instant noodles in my drawer. You can cook them up if you’re hungry.”

Dali’s words warmed my heart. I realized that he didn’t just tag along with me because he wanted the bonus money. In fact, I realized that he had been taking care of me since the beginning of our freshman year. I had always been this way, too. I’d often forget about sleeping and eating whenever I get serious about something. Dali was always there to fetch water for me and bringing me food. I thought of how lucky I was to have made such a good friend in college.

I thanked Dali, to which he replied, “Come on, dude. We’re bros. There’s no need to say thank you!”

I lay in bed and thought about the case until finally falling asleep at around three in the morning. I had strange nightmares that night, and it made me wake up in a confused daze.

The next morning, Dali and I arrived at the police station early. Some police officers weren’t there yet. Xiaotao bought breakfast for everyone as usual. I noticed that Wang Yuanchao wasn’t there, so I asked Xiaozhou about it. He told me Wang Yuanchao came very early this morning and had gone to Ma Jinhuo’s house to investigate the case.

At about eight o’clock, Xiaotao officially began the meeting.

First, we summarized the overall progress of the case and the clues that we gathered. The rope used by the murderer to tie the bag had been traced to a certain manufacturer. However, this rope was sold in different places in Nanjiang City, so we needed to investigate all these places to hone in on where the murderer might have gotten it.

The second important finding was that no hospitals in Nanjiang City used nitrous oxide anymore. Even the veterinary hospitals no longer used it. In fact, there were no manufacturers in all of China that produced nitrous oxide at that point. Hence, it was speculated that the murderer had bought the raw materials for it and produced it himself.

Some officers raised doubts about this. Wasn’t the suspect Ma Jinhuo a high school dropout? Could someone with that level of education produce his own laughing gas?

Another police officer countered with the fact that everything could be found on the internet now. Criminals could glean a lot of knowledge from films and TV dramas too. There had been a case where an illiterate criminal imitated what he saw on TV to produce homemade explosives and robbed a vehicle that was transporting cash with it.

“Laughing gas is a simple inorganic substance that can be obtained by thermal decomposition of ammonium nitrate in chemical fertilizers,” Xiaozhou explained. “As long as someone has a little knowledge in chemistry and access to the internet, they can easily produce it themselves.”

Xiaotao stopped their argument by continuing to talk about the clues I found on the dead bodies and some information we gathered from the residences of the victims. When everyone heard that there might be a new victim in two days’ time, the whole room grew tense and silent. We were working against the clock.

The case was currently in a stalemate. The whereabouts of Ma Jinhuo was still unknown, and no connection was found between the victims. What should we do next?

Xiaotao said that all the surveillance videos near where the rope was sold had been obtained. Today, everyone should do nothing else but watch these videos to find clues to the murderer.

Then she asked me what advice I had. I thought about it and suggested, “The murderer must have kidnapped the victims with a car. This car should appear near the houses of the three victims. It may be helpful to look at the surveillance videos of the intersections around the area, including the videos from the community security guards.”

“Right!” She then immediately ordered several policemen to retrieve the surveillance videos.

After the meeting, she told me, “Song Yang, the third victim’s body has not been found yet. You can go back and rest for now.”

“No, Dali and I will stay and help you check the surveillance videos.”

“Good!”

Throughout the morning, we all watched various surveillance videos at the police station. Xiaotao asked people to move the TV and video recorders into the conference room. When the equipment in the police station was not enough, they went to the nearby electrical stores to rent them. Everyone occupied a corner and stared at a monitor. From time to time, someone stopped to put eye drops in their eyes or to smoke. The curtains in the room were drawn, and smoke filled the room. If someone suddenly walked in, they might think that they had entered a cinema.

All the videos added up to thousands of hours, and we viewed all of them at twice the speed. I stared at a TV set with Dali. It was an eye-wateringly dull and boring task. It took all the strength we had not to fall asleep.

Finally, Dali had had enough. He slumped into the chair and groaned, “Ah, this is so boring! If only we could watch some Korean drama instead.”

“This is what a police investigation is like,” I tried to comfort him. “Even if the clue is as small as a sesame seed, it must not be overlooked. Come on, get up and get back to work!”

Under my urging, he sighed and continued to watch the video.

In the end, our efforts still paid off. A policeman found a white van from the community surveillance. The car also appeared in the residence of the other two missing persons, and it appeared exactly the same time as the victim’s disappearance.

Xiaotao immediately sent someone to investigate the car with this license plate number!