Chen Shi rushed into the autopsy room and saw The Silent Man’s body lying on the table. Peng Sijue was sitting on the ground. Several interns were shaking him. "Captain! Captain!"

"Old Peng, what's the matter with you?"

Peng Sijue’s eyes widened as if his soul was gone. It took a full minute before he said, "Who did it?"

An intern said guiltily, "I put my phone on the test bench to charge in the morning and I was so busy I forgot about it. It exploded somehow."

Another intern scolded him, "I asked you to change your phone long ago but you’re still using that brand? Didn't you read the news?"

"Go and check if there’s any damage to the equipment." Peng Sijue stood up with Chen Shi's help, clutching his chest. "I was scared to death."

"Haha, you also have times when you’re so cute." Chen Shi smiled as it was just a false alarm.

"Who let you in like this? Get out!"

Chen Shi saw an extremely conspicuous scar on the corpse's abdomen and asked, "What's going on?"

"If you want to see it, change into a sterile suit."

Chen Shi put on a sterile suit and went in. As Peng Sijue was about to open it, Chen Shi said, "Wait, look at his bulging stomach. It wouldn't be an explosive, right? This corpse passed through the hands of those people, so be careful just in case. Is there a metal detector?"

"What day and age is it? A metal detector?" Peng Sijue rolled his eyes and ordered his subordinates, "Go to the fourth floor to borrow a drug detector."

Peng Sijue inspected the surface of the body first. There were six stab wounds on the right shoulder of the deceased, but none of them were fatal. There were some bruises on the body, which seemed to have occurred in a fight. The time of death should have been two days ago. It had been discovered that there was a needle hole in the leg of the deceased and his pupils were constricted, so it was suspected that the injection of drugs caused the death.

Chen Shi said, "It seems that he, like Zhou Xiao, didn’t accept the invitation, so he was killed."

"How do you know?" Peng Sijue asked.

"Zhou Xiao told me. Don't be scared when you hear about it, but I saw that serial killer at his house... It's a pity that he ran away."

Peng Sijue was silent for a long time before he whispered, "You must be prepared to expose your identity."

"It won't be too long. It won't be too long." Chen Shi murmured. With Zhou Tiannan's accidental death, his group of subordinates would go crazy for one last time, but they would definitely be destroyed.

Soon, Peng Sijue’s subordinates fetched the instrument that Peng Sijue wanted. The full name of this apparatus was a drug bomb detector, which could detect trace particles of drugs and explosives. After inspection, it was confirmed that it was safe. Then, Peng Sijue cut the sutures on the abdomen of The Silent Man.

His bloody internal organs were exposed, and Chen Shi instinctively resisted the urge to throw up. He furrowed his brows and looked in, but found no foreign matter.

However, Peng Sijue had seen the structure of the human body countless times and found something wrong at the first glance. He picked up the kidney with tweezers and said, "Look, this kidney was already dead. This kidney was sewn in afterwards... and here, this liver was also sewn up."

"This kidney is definitely not his own. I seem to understand that the person who killed him replaced the lost organ for himself. This is a kind of respect. A criminal's respect to another criminal, leaving him with a complete body.”

"Whose kidney and liver does this belong to?"

"I guess it's Qin Wanmu who is still missing at this time. No, I can't bear this imagery. Bye-bye..." Chen Shi patted Peng Sijue on the shoulder when he left. "When the case is over, let's go out to relax."

"I'm free on Saturday." Peng Sijue replied without looking back.

"See you then."

After Chen Shi left, Peng Sijue and his assistants went to work. They separated the deceased’s abdominal cavity. Peng Sijue saw that the deceased’s liver was very dirty, showing signs of edema and necrosis. He ordered, “Take a pathological section of the liver.”

The organs of the deceased were taken out and weighed. Pericardial blood, urine, and gastric contents were all taken. The cause of death may have been poisoning. Finding the target organ was the same as succeeding half-way. He noticed that the main cardiovascular system of the deceased was dilated and his pupils were contracted. Acute kidney failure and severe liver disease.

There was no pungent odor in the stomach contents. The poison was injected into the body and acted on the liver and kidneys. He thought of arsenic compounds and ordered his subordinates, "It may be arsenic poisoning. Do an X-ray diffraction analysis.[1] We’ll also need to take samples of his hair and nails for testing."

Half an hour later, the subordinates came in and reported, "Captain, the analysis result shows that it’s not arsenic poisoning."

"How was the blood test?"

"Blood potassium and white blood cells were above average."

Peng Sijue immediately thought of something and murmured, "Snake venom?" He said, "Take a urine test to see if myoglobin is positive."

He examined the lymphatic organs of the deceased, but the pathological features didn’t match that of snake venom. He suddenly thought of something. The deceased was once a mental patient. He should have taken phenothiazines for a long period of time. The liver had long been necrotic, so it couldn’t be used as the index to analyze the poison.

The increase in white blood cells may have been caused by the deceased's struggle and injuries before his death.

How could he explain the increase in blood potassium? He suddenly thought about how the pupils of the deceased were contracted. This was an abnormal phenomenon because the pupils of dead people would usually dilate. Could it be drugs?

A subsequent urine test confirmed that it wasn’t snake venom. Peng Sijue calmly ordered, "Chromatography analysis[2]!"

He continued to check all the organs of the deceased. One hour later, his subordinates reported excitedly, "Captain, there’s cocaine in the urine of the deceased."

"Let me have a look."

He took off his gloves, handed his current task over to his assistant, and personally checked the identification results. There were indeed drug residues in the urine, and the amount was still high. In order to verify this, he performed liquid chromatography tandem mass spectrometry identification[3] on the blood.

The results showed that not many drugs were injected into the deceased's body, and the dose was far from lethal. Because the deceased had no history of drug use, cocaine had a strong effect on his organs, which successfully interfered with the judgment of forensic medicine on the poison.

This can be said to be a technical level of anti-investigation, where the killer sets up interference objects to make the real poison "invisible".

Peng Sijue remembered his teacher's teachings. There was no undetectable poison in the world, only undetectable methods. So, he made a decision. "Craniotomy and brain dissection!"

A few hours later, Peng Sijue fell into confusion. All the methods were used. Metal poisons, biological poisons, plant poisons, drugs, alcohols, anesthetics... all of these weren’t comparable. The things that every forensic doctor had imagined in his student days happened. An unknown poison!

If there was an unidentifiable poison, it meant that the murderer could kill as he pleased but could not be prosecuted because it could be interpreted as an ordinary sudden death.

"Make another-"

Peng Sijue didn't give up. However, when he turned his head, he found that his several assistants were all leaning against the wall or staggering, asleep.

He woke them up and an assistant rubbed his eyes and said, "Captain, it's 12:00!"

There were no windows here. He didn't notice that he’d been working for ten hours without eating, drinking, or even sitting. Peng Sijue said tiredly, "Head back and write an appraisal report tomorrow morning."

"How should we write it?"

"Acute poisoning... The poisoning substance is unknown!"

1. https://pubmed.ncbi.nlm.nih.gov/14216681/

2. Analytical technique commonly used for separating a mixture of chemical substances into its individual components, so that the individual components can be thoroughly analyzed

3. Enables Large Scale Molecular Characterization of Dissolved Organic Matter