The candy factory was relatively small in size. It was perhaps more appropriately called a workshop. When we reached the residential area neighboring the factory, we got out of the car. It was an old area that was sparsely populated and it had no neighborhood watch. Xiaotao knocked on a door and asked the resident which building housed employees of the candy factory, and the resident replied that it was Building C.

We headed to said building. Yuanchao was about to turn on a flashlight, but I quickly stopped him. We stopped in front of the buildings and observed it. There were only a few rooms where the lights were on.

“Why don’t we just bring in a police dog?” muttered Dali.

“We don’t have Xu Gang’s scent, so what use is a police dog, you idiot?” snapped Xiaotao.

Her words gave me an idea. “I remember that the rich lady smelled heavily of perfume. Perhaps her scent still lingers on in Xu Gang’s car!”

I went on to sniff at the cars parked near the apartment buildings, and just as I expected, there was indeed an SUV there that had a strong perfume smell on one of its doors. It smelled just like that rich lady. I wasn’t a police dog, though, so that was all I could confirm. I couldn’t follow her track straight to the house where the murderer was, neither could I use the tracking method I used in the previous case because I hadn’t prepared the elixir.

I looked around the car. There was a black thread in the crack of the door.

“Do you recognize this?” I asked Yuanchao.

He held it between his fingers then lit it up with a lighter.

“It looks like a soundproofing material found on the walls of night clubs!” he stated.

“Soundproofing?” My eyes lit up. “I see it now. Xu Gang must’ve trapped the rich lady indoors. He was afraid that the sound of her crying for help would give out her location, so he covered the walls with a layer of soundproofing material.”

Xiaotao followed my line of thought and added, “He’d want to make it oblivious to people’s eyes too, so he won’t nail the material to the wall. Rather, he’d use the wallpaper glue instead.”

“Yes!” I agreed. “Which means that his house must smell of wallpaper glue!”

DaIi glared at us and said, “How did you guys find out all that just from a strand of fiber?”

“It’s just the basic skill of deduction, you idiot!” Xiaotao laughed. “You should learn it too sometime.”

We then split up to find a house that smelled of wallpaper glue, but we agreed not to act or cause alarm if any of us found it. Instead, we should just keep in touch through our mobile phones.

I smelled each house from door to door. When I reached the top floor, I finally detected a house that was emitting a distinct scent of glue. I got excited and was about to call Xiaotao, but before I could do that, the door opened. Out came Xu Gang, who walked out casually towards me. We stood there silently regarding each other for a while, then I politely asked him, “Excuse me, does Wang Dali live here?”

“Drop the act, Detective Song!” sneered Xu Gang. “You really are as good as the rumors suggest. I never expected you to find me so soon.”

I was taken aback. I dialed Xiaotao’s number discretely while my phone was still in my pocket, then deliberately spoke loudly, “You’re pretty good at hiding yourself! It took me a lot of effort to climb up to the top floor just to find you!”

“There’s no need for that little trick, detective,” said Xu Gang, glancing at my hand. He then shouted, “I know the police are downstairs! Xu Gang lives in Unit 603! Why don’t you hurry up here and catch me?”

I was quite embarrassed about the blunder. I observed Xu Gang’s face and found that he was completely calm. He didn’t look like a criminal at all. In fact, he was just a middle-aged man wearing pyjamas—the picture of banality.

Xu Gang turned around and headed back into the house. He stopped at the door and said, “I’ve heard of you, Detective Song. I know you’ve solved many difficult cases. It’s an honor to be one of your subjects. Why don’t you come inside and have a chat with me before the police arrive?”

That didn’t sound like a good idea at all. Xu Gang noticed my hesitation, so he added, “You’ll regret it if you don’t come in.”

“Okay,” I said. “Lead the way.”

I followed him into the house. It looked exactly as I had imagined. The walls were covered with black soundproof material. The furniture in the room was covered with plastic film and looked very new.

“I’d planned to move here with my wife after we got married,” Xu Gang explained. “But she was gone too soon…”

“Was your wife’s death related to the hibernation drug?” I asked him.

He sat down on the sofa with a wide grin on his face and replied, “Why don’t you tell me? I’d love to hear what the great Detective Song thinks!”

“You joined the research team to develop the hibernation drug because your wife was terminally ill,” I began. “You wanted to put her in deep cryogenic sleep before she died, but something happened which slowed down the development of the drug. That made you resent your colleagues and employer because their incompetence indirectly caused your wife’s death.”

Xu Gang nodded and crossed his legs. “You’re mostly right, but you’ve got a lot of the details wrong.”

“Correct me then!” I said. “Tell me exactly what happened!”

He then began recounting his tale. The hibernation drug was his life’s work. He started working on it when he was still studying at Harvard University. When he returned to China, the rich lady recruited him to help her company develop new drugs. She provided the funds; he provided the brains. When the time came for the drug to be marketed, the rich lady promised him that he would be paid 30% of the drug sales.

And so, Xu Gang worked his ass off day and night to develop the groundbreaking drug. He believed that it would revolutionize modern medicine and make history. Perhaps, he might even be awarded the Nobel Prize for it too! But just when things were looking up, his wife was diagnosed with a terminal disease which was practically incurable based on the current medical knowledge. This motivated Xu Gang to work on the hibernation drug even harder because he believed that it could save his wife’s life.

Tragedy struck again, though. Just as the drug was in its final phase of development, there was a fire in the lab and it burned everything down, dashing all hopes that the drug could ever be marketed. Xu Gang collapsed to his knees and wept bitterly as he watched the fire consume the whole lab. After that, he had no choice but to send his wife abroad to be euthanized.

After losing his wife, Xu Gang was completely heartbroken. He fell into depression and remorse for a whole year, not having the will to continue with his research. Then one day, he was reading a foreign medical journal when he saw a report about Chinese researchers who had successfully developed a hibernation drug and was now in the final clinical trial.

He almost couldn’t believe his own eyes. He started to investigate the matter and discovered the shocking truth. The rich lady colluded with the other researchers to cause the fire in the lab. The purpose was to steal all the research data and publish it themselves so the rich lady would get all the profits from the sales of the drugs. The other researchers received generous rewards for their cooperation, of course. They all betrayed him, and it was all just for money!

Xu Gang was furious. Their avaricious greed caused him to lose everything that mattered to him. He vowed to take revenge on those scums!

He found himself a new laboratory to cook up the hibernation drug, then injected all the researchers with it and trapped them in wooden crates to leave them for dead. He left the best parts of his plan for the rich lady. He wanted her not to die, but to suffer as much as possible and pay for what she did!

As he was speaking, Xu Gang clenched his fists and gritted his teeth, barely able to hold in his anger. I thought he looked like a wild beast raring to go in for the kill.

Then I heard footsteps coming from downstairs. It was clearly Xiaotao and the rest finally arriving. This gave me courage to ask Xu Gang, “Why did you have to kill Chen Da too?”

He laughed. “Chen Da was involved in the conspiracy too. He secretly transferred the materials to their lab. His sins weren’t so terrible, though, so I let him die a relatively quick death. But that woman is different. I lost my family because of her. I want her to taste the misery and despair that she caused me! I want her to die slowly and painfully!”

“Where is the lady?” I asked.

Xu Gang burst out in laughter. “Do you think that I’ll just tell you, Detective Song? No, it’s your job to find out where she is. Anyone who was injected with the drug can survive for two years without food and water, even if they’re in an environment where oxygen is scarce. So take your time, Master Detective!”

The footsteps from downstairs were getting closer and closer.

“Xu Gang,” I pleaded, “you don’t need to do this! Technically you haven’t committed a murder yet. Please tell me where the lady is, and perhaps you’ll receive a lighter sentence! It’s not too late to turn back from the path of evil!”

Xu Gang pulled out a dagger from his pocket and coldly replied, “Turn back? From the moment my wife died, there’s been no turning back for me!”