Chapter 5

The moment I opened the door, Zeng Ziming shot inside like lightning.

He glared at me.

“Fuck me, you're heartless. I'm working myself to death in Mingzhou while you hide at home sleeping in. Where's your decency? Your conscience? Have you no shame?”

I lifted my eyelids and gave him an unhurried glance.

Then I smiled.

“Screw you. I'm on leave. I'll sleep as long as I like.”

“Like hell you will. I've found something. We'll talk at the unit.”

He dragged me off. On the way, we picked up Qin Ming.

In the conference room, Zeng Ziming unveiled his news with an air of mystery.

“Yesterday I found out that on March 25, Zhang Jun bought several dozen pufferfish from local fishermen. Need I say more? Everyone knows pufferfish are extremely poisonous.”

He grinned, waiting for praise.

I poured cold water on his enthusiasm.

“Professor Qin's tests already showed that Li Zihan died of aconitine poisoning. Pufferfish toxin had nothing to do with it.”

“Damn it. Why didn't you tell me? All that work for nothing!”

He deflated at once.

What a waste of effort.

My mentor slipped into his usual comforting role, this time directing it at Zeng Ziming.

“You've done well, Zeng. You're young. Don't let a little detour discourage you.”

In the corner, Qin Ming clasped his hands in front of his chest. A gleam appeared in his eyes.

“Perhaps... this wasn't a detour. I have a bold hypothesis. I need to test it in the laboratory immediately.”

Before I could react, he was gone.

The three of us stood there, looking at one another.

What was the eccentric old man up to now?

Then his head reappeared in the doorway.

“Tiankai, what are you standing around for? Am I supposed to get back on my own?”

I snapped out of it.

“Oh! Right. Coming!”

At his request, we first went to the market and bought some pufferfish.

I could not understand it.

“Professor Qin, what do pufferfish have to do with this case?”

He deliberately kept me guessing.

“This could be a major discovery in pathology. If my hypothesis is right, you can call me Qin Conan.”

I shrugged and looked him earnestly in the eye.

“Qin Conan.”

Sincerity really was the ultimate weapon.

“For that alone,” he declared, “I'll finish the tests as fast as I can, even if it kills this old man.”

I gave him an encouraging look.

“You can do it, Qin Conan!”

After dropping him at the forensic medicine college's laboratory building, I stayed.

That evening, I lay in the car, staring up at the light still burning in his laboratory.

At some point, I fell asleep.

An excited shout woke me in the middle of the night.

“A genius! Zhang Jun is a fucking genius!”

I hurried upstairs and pushed open the laboratory door.

Qin Ming stopped short at the sight of me.

Then he began slapping the table in excitement.

“A major discovery in pathology! The perfect crime! Murder from a distance! For someone with only a high-school education to do this—he must be a genius!”

“Qin Conan!” I shouted impatiently. “Could you explain? What exactly have you found?”

But he could not calm down.

I lit a cigarette and put it between his lips.

There you go, Professor Conan. Have a smoke first.

By the time he finished it, he had recovered his composure.

“Let's go to the unit.”

It was four in the morning, but he remained wildly excited, pouring out technical terms none of us understood.

My mentor asked:

“Professor Qin, could you put it more simply?”

“Yes,” I added. “Plain language. Maybe a metaphor or a little personification. Something the rest of us can follow.”

He drank some water and tried again.

“It turns out the martial arts novels aren't entirely making things up when they talk about fighting poison with poison.”

“My experiments last night showed that when aconitine and pufferfish toxin are mixed, they can counteract each other to a certain degree.”

“Once combined, the two toxins begin holding each other in check. While that balance lasts, the poisoned person shows no symptoms.”

“I call that the stable period. Once the balance breaks—one toxin wins and the other disappears—the symptoms begin.”

“Clearly, in this victim's body, the aconitine defeated the pufferfish toxin.”

“That perfectly explains why she showed no abnormalities between six and eight on the evening of the crime, then became ill and died between eight and eight twenty-five.”

He let out a long breath, inwardly marveling at the sophistication of the killer's method.

As a researcher, he understood just how precise the calculations would have to be for such a plan to succeed.

Zhang Jun had also discovered that subtle relationship between aconitine and pufferfish toxin himself.

Setting aside its criminal use, the research alone was enough to earn a place in history.

Extraordinary.

Something that belonged in fiction had crossed into real life.

Zeng Ziming raised an admiring thumb.

“Brilliant.”

“Absolutely brilliant.”

“Beyond brilliant.”

After peeling away one layer of mystery after another, we had finally worked out how Zhang Jun committed the crime.

My mentor gave the order at once.

“Do it! Tiankai, contact Mingzhou immediately. We'll make a joint arrest.”

The arrest went smoothly.

Zhang Jun was still wearing a provocative smile when we caught him.

Once brought in, he refused to confess.

“If you have evidence that Li Zihan took aconitine and pufferfish toxin together, charge me whenever you like. If you don't, stop slandering me.”

He clearly knew that the pufferfish toxin had long since been consumed in its balancing struggle with the aconitine.

He used that fact to challenge us, accusing the police of making an unsupported allegation.

Everyone fell silent.

Once his method worked, it left behind a seemingly perfect, traceless murder.

The unit's leadership called a special meeting.

Everyone agreed that we could not let Zhang Jun go.

With his intelligence and utter lack of humanity, the danger he posed to society was obvious. We had to bring him to justice.

Ultimately, through close cooperation between the judicial authorities and the police, we brought him before a court.

The trial was held behind closed doors.

The court delivered its judgment:

“On April 1, 2007, at the Tengda Hotel, the defendant Zhang Jun intentionally killed the victim Li Zihan for the purpose of insurance fraud. His conduct violated Article XXX of the Criminal Law, and he shall bear criminal responsibility for intentional homicide.”

“The court hereby sentences the defendant Zhang Jun to life imprisonment for intentional homicide, with lifelong deprivation of political rights.”

The sun was unusually bright on the day of sentencing.

Unfortunately, the deaths of his first two wives had occurred too long ago. There was no evidence, and we could not secure convictions for them.

Fortunately, as matters stood, he was unlikely to have his sentence reduced. Spending the rest of his life in prison was at least some measure of retribution.

I stood on the balcony and looked up at the sky, feeling a happiness I had not known in a long time.

And there was more good news.

In recognition of my performance, the unit awarded me an Individual Second-Class Merit Medal.

The next day, someone anonymously sent a commendation banner.

It read:

“A detective to rival Di Renjie. A forensic examiner named Qin Conan.”

Enjoyed this story? Discover more completed short romance stories at NovelPotato.asia.