Tang Ren was swaying on his fishing boat amid the reeds of Taihu Lake. Qin Feng unfolded the bronze model map: "This wave pattern is the lake shoreline, the waterway in the Song Dynasty's "Pingjiang Map"!" The old fisherman at the bow suddenly cast a net and caught a bronze box tangled with water plants, the surface of which was covered with pinhole-sized air holes.
"This is an incense box for raising silkworms!" Su Chen scraped off the rust on the copper, "but the pattern is imitating the longitude and latitude of silk thread craftsmanship." Tang Ren used the eight crab pieces to pry open the copper box, and a ball of black silkworm silk rolled out from the fishy smell, with half a jade-carved silkworm pupa wrapped around the silk thread - the pupa's belly was engraved with a gourd seal of "Lu's Workshop".
The sound of engines came from afar, and a speedboat opened its mist. The leader raised a spear gun with a silencer: "Hand over the copper box!" Tang Ren grabbed the incense box and smashed it into the water. The vents made a sharp whistle when they hit the water, startling the flock of egrets.
---
When Tang Ren found the abandoned mulberry garden following the silkworm pupa mark, his trouser legs were covered with weeds. Qin Feng pushed aside the spider webs and saw the four characters "Lu's Silkworm Room" glowing phosphorescently on the broken plaque. In the drying stove were piled up burnt account books, and the remaining pages recorded the record of the Lu family exporting "special silkworm breeds" to Japan in 1956.
"This silkworm cocoon is really strong!" Su Chen picked up the charred shell of the cocoon, "Normal cocoons are oval, but these have edges." Tang Ren kicked over the bamboo plaque, and a metal box rolled out - it was filled with microfilm rolls, and after the film was developed, it turned out to be a military map of Taihu Lake mapped by the Japanese army, with the "Jiaolong shipwreck" marked on it.
Suddenly, a faint green fire lit up in the darkness, and dozens of fireflies gathered in the shape of an arrow, pointing to an ancient well deep in the mulberry garden. A half-broken stele was embedded in the moss on the well wall, and the part where the inscription had been chiseled away revealed fresh chisel marks.
---
Qin Feng used well water to wet the stele, and the weathered words suddenly became clear: "In the tenth year of Showa, Lu presented a treasure..." The second half was splashed with a fishy liquid. Su Chen dipped his nose and smelled it: "It's chicken blood mixed with cinnabar. Someone wants to cover up history."
There was a metallic clang from the bottom of the well. Tang Ren lowered himself down with a hemp rope around his waist, and found a Japanese general's sword in the mud. The handle of the sword was tied with a faded kimono belt, and on the inside was a phrase: "On a moonlit night in Suzhou, silkworms turn into silver threads and bind a dragon."
"This knife is the key!" Su Chen compared the pattern on the blade with the bronze mold map, "The pattern on the scabbard spells out the coordinates..." As soon as he finished speaking, the hemp rope suddenly broke. Before Tang Ren fell into the undercurrent at the bottom of the well, he caught a glimpse of Mr. Lu's face.
---
The flashlight on the diving suit penetrated the turbid lake water, and Qin Feng felt the bullet hole on the mast of the sunken ship. The cabin was scattered with fragments of blue and white porcelain, and the bottom of each piece was marked by the Lu family. Tang Ren used a harpoon to pry open the safe, and what came out was not gold bars, but bundles of silkworm seed files - a top-secret record of the Lu family's crossbreeding of Taihu wild silkworms with Japanese silkworms in 1937.
"This is an ordinary silkworm!" Su Chen put the file close to his mask, "Genetic modification experiment... They want to use silk to make a parachute!" Suddenly a giant catfish swam by and smashed the cabin, revealing a rusty weapon rack. A skeleton was wrapped in silk into a coil, with copper movable type pinned on its chest - spelling out "Those who sell out the country will be punished."
---
When he returned to the old house of the Lu family, there was a bowl of raw silk rice on the altar in the ancestral hall. Qin Feng used a silver hairpin to test the poison, and the hairpin head turned black instantly: "The silk has been soaked in arsenic. This is the last sacrifice." The sound of a loom came from behind the secret door. Mr. Lu was weaving gold silk into the loom, and the woven product was a complete Taihu military map.
"In order to protect this secret, Grandpa personally poisoned the tribesmen who participated in the project." Mr. Lu stroked the loom, "These silk threads are mixed with tungsten and gold threads, invisible to radar..." Suddenly he swung out the shuttle to extinguish the oil lamp, and in the darkness, the silver threads covered everyone like a spider web.
Tang Ren picked up the copper incense burner and smashed it against the loom, splashing the wooden thorns and cutting the silver thread. Su Chen took the opportunity to pull out the silk thread, and the Morse code hidden between the longitude and latitude lines: "The truth is in the cocoon."
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Amber silkworms were neatly stacked in the cellar freezer. Qin Feng opened the shells and found a baby corpse curled up inside each one - the experimental subjects destroyed by the Japanese army before the withdrawal in 1945. The tattoo on the back of the corpse's neck was the same as the burn mark on Lao Xu's palm, both of which were silkworm-shaped codes.
"The Lu family relied on these children to experiment with cold-resistant silkworms!" Su Chen dug out the yellowed birth records, "all the women giving birth were wives and daughters of silkworm farmers back then..." A white silk thread suddenly fell from the beam of the ancestral hall, and Mr. Lu was dangling in the air, holding tightly in his hand half a jade silkworm pupa - the address of a laboratory in Nanjing was engraved on the back of the pupa.
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### **The aftermath of the final chapter**
The day after the case was closed, Tang Ren was eating plum cakes on Guanqian Street. Qin Feng stared at the jade silkworm pupa: "This genetically modified silkworm is still breeding somewhere..." Su Silently unfolded the last piece of silk from the Lu family, and the embroidered code appeared in the sunlight: "The silkworm slept for ten years, and the world was shocked when it was broken."
The wind chimes on the eaves of Xuanmiao Temple suddenly rang, and Tang Ren looked up and cried out in surprise - the lost movable type with the word "broken" embedded in the gap of the plaque of the Qing Palace cast a shadow in the wind, like a flapping moth.