I pulled out a stack of rice paper from my bag and shoved it into Xiao Zhou's hands."Check it yourself. See if I tampered with anything."
Xiao Zhou glared at me, his face dark. To a nearby officer, he snapped, "Hurry up and bring my toolbox."
He opened it, took out some instruments and reagents, and began scanning the sheets. I ignored him and focused on the two palm prints. Meanwhile, Huang Xiaotao called over a tech officer to take photos for evidence.
The two palm prints were on the victim's shoulder blades. The killer must have pressed down hard, sucking blood from the victim, to leave such clear marks.
I compared the size to my own palm—the prints were significantly larger. Judging by shape and size, they belonged to a man in his twenties or thirties.
But then I noticed something odd, and Huang Xiaotao pointed it out too: "Song Yang, there are no fingerprints on these prints!"
"Why do you think that is?" I asked.
"Maybe the killer destroyed his own fingerprints or wore gloves," Huang Xiaotao guessed.
I shook my head and pointed out several details. "Look closely—these prints show clear skin folds at the joints. That means the killer wasn't wearing gloves. If he tried to damage his fingerprints, the prints would be messy, but these are clean and clear…"
…
…
"So what else could explain this?" Huang Xiaotao tilted her head, deep in thought.
By then, Xiao Zhou had finished testing my rice paper. His face looked even worse—like a purple eggplant.
Of course my rice paper was fine, but he stubbornly refused to admit it, trembling with anger."Those rustic methods could never beat my American equipment!"
I sneered, "It's not you losing to me or your fancy American gadgets losing to my old-school methods—it's your own arrogance that lost. You didn't fully learn the wisdom our ancestors left behind, yet you blindly chase foreign tricks."
"Here, fresh ash—eat it while it's hot." Wang Dali grabbed the ashtray from the bedside table and offered it to Xiao Zhou, who was too angry to reach out.
I took the ashtray and put it in front of him. "Come on, honor the bet. Eat it and I'll tell you why your tests failed."
Others in the room gathered around, mostly Xiao Zhou's subordinates. He shouted fiercely, "Everyone back off! No peeking!" Then grabbed the ashtray from me and dumped the ash into his mouth—most of it fell to the floor, but I didn't bother to mention that.
His mouth was full of ash and cigarette butts. The grim expression somehow looked comical, and I almost laughed—only held back to spare his dignity.
Wang Dali laughed, slapping my shoulder. "Yangzi, look at him. Does that ash taste good?"
Huang Xiaotao covered her mouth, trying not to laugh—probably to save Xiao Zhou's pride.
Of course it tasted awful. Xiao Zhou gulped it down with a stiff neck and wiped his mouth with his sleeve. "Alright, say what you gotta say. I'm listening."
"I've read all the Western forensic books. The principle of fingerprint detection is simple: human sweat glands secrete an invisible layer of oil that sticks to surfaces, revealing fingerprints when dusted with powder or exposed to UV light. But this killer is special…"
"How special?" Xiao Zhou couldn't help but ask.
"He has no sweat glands—or more precisely, his sweat glands don't function," I said.
Xiao Zhou gasped, "How can someone have no sweat glands?" The others were stunned and began whispering among themselves.
"Actually, I have to thank you," I said.
"Thank me?" Xiao Zhou was surprised.
"Huang Xiaotao said you're a top student returning from the US. I figured you wouldn't miss something as simple as fingerprints. That saved me some steps—I went straight to the 'oil paper overlay method.'"
"Wait!" Xiao Zhou said. "If he has no sweat glands, where did these two prints come from?"
"This is called 'Yin imprint'," I explained. "At the moment of death, the body's bioelectric currents dissipate through the pores. If something presses against the skin at that time, it leaves a clear imprint—whether or not sweat glands function. Why do people lose twenty-one grams at death? Some say it's the soul's weight. Actually, it's the total weight of the dissipated bioelectricity."
Xiao Zhou stared in disbelief, then sighed, "You really are something else. I underestimated our ancestors' knowledge. I owe you an apology."
His attitude was surprisingly good, unlike Qin, who's stubborn as a stone. I felt a bit of goodwill."No worries. You've studied science for years and it's normal not to trust me, a coroner. Hopefully, we can cooperate well from now on."
"I'll be humble and learn from you. No more arrogance." Xiao Zhou hesitated, then extended his hand. I shook it.
I waved to the watching officers. "Keep testing!"
"Still more to check?" Wang Dali asked.
This case was unusual. I didn't care about the cost of rice paper or camellia oil. With Wang Dali's help, we tested the victim's wrists, waist, thighs, and ankles.
The oil paper overlay method was time-consuming; the whole process took nearly an hour. We found binding marks on the wrists and ankles—like from cloth or silk—and pairs of handprints on the sides of the waist.
Xiao Zhou watched with fascination. He was completely convinced now.
I called to him, "Come help."
"Oh!" he ran over. "What can I do?"
"Lift the victim's arms slowly with Dali," I commanded.
As they lifted the arms, I placed listening bones on each shoulder blade, one at a time, and instructed everyone to keep quiet. If the victim was fixed in a position before death, the joint lubrication inside would solidify after death. When restored to that pose, subtle abnormal sounds can be heard.
This technique to restore the victim's final pose is called the "Art of Postmortem Examination"—an ancestral secret developed by Song Tianyang, a high-ranking magistrate. Legend says he reached such mastery that he could make corpses move into their death poses with acupuncture needles—terrifying enough to drive a court officer mad.
The ancestor once made a corpse "come alive" in court, point out the killer among suspects, and the culprit confessed on the spot.
After adjustments, we finally uncovered the victim's death posture:
Both hands raised high above the head, like a suffering Christ, nailed to the wall—at the mercy of the executioner.
I examined the wall carefully. There should be hooks to hold the victim's hands. I pressed the wallpaper and found it newly pasted. Behind it was a hole.
"Someone hammered nails here, then covered it up!" I exclaimed.
I activated my "洞幽之瞳" — my special insight — and inspected the wallpaper inch by inch. I found a subtle bulge and peeled the wallpaper off, revealing a black insulated wire behind it.
Wiring is usually hidden near the floor inside a plastic pipe for fire safety. This wire was clearly deliberately installed behind the wallpaper.
"Find out where it leads!" I urged.
"Come help!" Xiao Zhou called several tech officers. They tore open the wallpaper, pulled out the wire bit by bit, and finally found a pinhole camera next to the ceiling light, pointing straight at the bed below.
Everyone gasped. Huang Xiaotao said, "Hidden filming? That's disgusting!"
"But this means we've got a major clue," I said.
Huang Xiaotao nodded and called a policeman, "Go bring the hotel manager here!"