She suddenly burst into laughter, the Pear Blossom Rain Needle cylinder casting a cold glint in the moonlight. "Does Lord Xiao know that the true Armillary Secret Key..." The cylinder suddenly cracked open, revealing half a bronze fish tally. "It was never at sea! It is inside the scale weights of the Salt and Canal Yamen!"
The sound of war drums echoed from the heart of the river as the Red Horse Boat lowered its rope ladder.
Shen Xitang caught sight of the three cinnabar moles on the forearm of the lead boatman, finally deciphering the riddle her father had written in his own blood before he died—the Ryukyu merchants the Shen Family had saved twenty years ago were in fact undercover agents for the Ministry of Works.
The clapper sound of the midnight watch was swallowed by the tidal bore of the Qiantang River. Shen Xitang gripped the half-piece of the bronze fish tally, its sharp edges cutting bloody marks into her palm.
River winds laden with salt and brine swept over the ruins of the Salt and Canal Yamen. Twenty Red Horse Boats had already formed the Big Dipper Formation, and the bronze mirrors on their bows converged the moonlight onto the remnants of a stone mill in the cellar.
"A cunning calculation, Third Miss." Xiao Heng’s Steel Whip coiled around the axis of the millstone. "So, the patterns on this mill's handle are actually a rubbing of the Armillary Secret Key."
Shen Xitang pressed the bronze fish tally into the groove of the millstone; the tooth marks and salt stains fit together perfectly. "My Lord, you might want to look closely at the calibrations inside the mill’s eye."
She turned the handle, and the rusted iron shaft suddenly sprang open, exposing a concealed bronze gear. "This is a sixteen-tael scale weight mold specially crafted by the Ministry of Works' Bureau of Weights and Measures. Every three clicks of rotation corresponds to the salt tax on one shi of salt."
Several boatmen leapt down from the Red Horse Boats, each branded with three cinnabar moles on their arms. The scar-faced man leading them brought over a charred salt-weighing scale weight; beneath the verdigris, faint scroll-work patterns were visible.
Shen Xitang used her Silver Hairpin to scrape away the rust, and the weight split into three pieces, revealing half a scroll of the water-damaged Essentials of River Engineering hidden inside.
"The seventh day of the seventh month of the Guiyou year..." She pieced the remnants onto the stone mill; the missing sections perfectly matched the patterns on the millstone. "That day, the tide flooded the salt warehouse. My father was here, recalibrating the official scales, and discovered that the government scales were short by seven qian."
Xiao Heng’s Steel Whip suddenly lashed out at the stone mill, the sparks igniting the remnants of the scroll. As the charred paper felt the heat, it revealed an image: a map of the salt canal waterways, with a spot near a reef marked "Armillary Submerged Iron."
Shen Xitang suddenly remembered the iron anchor she had seen at the bottom of the Red Horse Boat three days ago; the pattern on its claws was identical to the Ministry of Works’ measuring tools.
"Set sail immediately!" She tore off the blood-stained silk ribbon from her wrist. "Since the Wojen know the location of the Armillary Secret Key, they will surely launch a fierce assault on Yanziji!"
At the third quarter of the Yin hour (4:45 AM), the warships quietly approached Yanziji. Shen Xitang stood on the observation deck of the modified tower ship, her telescope sweeping across the reef group.
In the moonlight, seven iron "water-suppressing oxen" were half-submerged in the river. The wear marks on the bronze rings of the oxen's horns matched the grooves on the salt scale weights perfectly.
"Deploy the sampans!"
Four men with cinnabar marks dove into the river, their iron chains coiling around the oxen's horns.
Shen Xitang turned the windlass, and the side compartment of the tower ship opened, revealing twelve modified Shenji Crossbows poised to strike. As the third frog call rang out, seven pillars of water exploded on the river’s surface—the iron oxen were hauled up by the chains, revealing fine iron keyholes in their bellies.
"It’s the Ministry of Works’ Four Symbols Lock!" Xiao Heng pointed with his Steel Whip; the patterns of the keyholes corresponded precisely to the star charts of the four seasons. "It requires the salt tax weights of the four seasons to unlock."
Shen Xitang unfastened her silk pouch and poured out four copper weights. The Spring Equinox weight was engraved with mulberry leaves, the Summer Solstice with rice ears, the Autumn Equinox with wheat awns, and the Winter Solstice with salt flowers.
She inserted the copper weights into the keyholes in the order of the solar terms, and a muffled sound of machinery rotating echoed from the riverbed.
"Retreat!"
Xiao Heng’s Steel Whip coiled around her waist, pulling her back urgently. The iron water-suppressing oxen exploded with a roar, and a bronze cabin surfaced from the river. The cabin door was covered in copper nails, their heads forming the wax seal of the Ministry of Works.
Shen Xitang pulled out the salt scale weight and pressed the protrusion on its base into the groove on the cabin door.
*Click.*
The moment the door swung open, twelve poisoned bolts shot through the air. Shen Xitang spun and dove into the bronze cabin, sparks flying as the bolts struck the bulkhead.
In the dim light, she saw the contents of the cabin: twenty fine-iron crossbows covered in oilcloth, the scroll-work at their trigger mechanisms matching the design of Xiao Heng’s Steel Whip.
"This is... the Yongle Shenji Crossbow!" She ripped off the oilcloth, the inscriptions on the crossbow arms glowing under the phosphorus powder. "These are the original blueprints for converting crossbows into weaving mechanisms from the third year of Xuande!"
Outside the cabin, the sound of clashing metal erupted; Xiao Heng’s Steel Whip and a Madao struck each other, scattering sparks.
Shen Xitang grabbed the crossbow’s rotating gear and discovered traces of sulfur corrosion on the springs.
She realized the truth instantly and grabbed an oil lamp, pouring it over the crossbows—the tung oil mixed with phosphorus powder ignited into a deep indigo flame, revealing a hidden fuse trailing across the cabin ceiling.
"Qingxing! Remove the third copper nail on the east side!"
The maid threw an iron chisel in response; the moment the copper nail flew off, the fuse snapped.
Shen Xitang kicked open a hidden window and saw the river surface covered in reed rafts soaked in rock oil, with Wojen warriors drawing their bows.
"Fire!"
The modified Shenji Crossbows roared in unison, the arrowheads wrapped in phosphorus powder cutting through the night sky.
The Wojen ships ignited upon contact with the fire, and dark patterns of the Shen family merchant flag emerged within the indigo flames. Shen Xitang gripped the half-piece of the bronze fish tally, finally understanding why her father had insisted on weaving phosphorus threads into every bolt of silk.
Amidst the chaotic battle, the bronze cabin suddenly shook violently. Shen Xitang steadied herself against the crossbows and saw a hidden compartment at the bottom of the cabin flip open, revealing boxes of classified Ministry of Works files.
The topmost mulberry-paper ledger read: "First year of Jiajing: Purchased three thousand jin of Wojen copper to cast as official scale weights."
"So that’s it!" She tore open the lining of the ledger, and the water-blurred ink appeared under the phosphorescence: "The seven-qian shortage in the official scales was actually caused by impurities in the Wojen copper!"
A conch horn sounded from the heart of the river; twenty Wojen ships formed a crane-wing formation. Shen Xitang caught sight of the glazed lamp on the mast of the flagship and suddenly grabbed a jar of phosphorus powder from the bronze cabin.
She scattered the powder into the river breeze, and in the moonlight, a glowing path appeared—pointing directly to the fuel depot in the hull of the Wojen flagship.
"Lord Xiao! The southeasterly wind!"
Xiao Heng’s Steel Whip lashed out, snapping the rigging, and the main sail of the tower ship turned with a boom. Shen Xitang triggered the Shenji Crossbow mechanism, and twelve sulfur-tipped arrows caught the wind, plunging straight toward the Wojen ship.
In the column of water kicked up by the explosion, she caught a glimpse of Shen Yanzhou leaping onto the deck, his python robe parting to reveal a fine-iron chest protector specially forged by the Ministry of Works.
"Must you still remain deluded, Brother?" She fired her final bolt. "The seams of chest protectors cast by the Ministry of Works are most vulnerable to moisture!"
The arrow pierced the seam of the chest protector, and Shen Yanzhou staggered, falling into the river. Shen Xitang threw down a rope ladder, only to see the gilded fish tally at his waist glinting in the moonlight—it was the other half of the Armillary Secret Key.
"Close the net!"
Xiao Heng’s Steel Whip coiled around the fish tally, the golden dragon on the whip’s tip biting into Shen Yanzhou’s wrist. Shen Xitang engaged the bronze cabin’s mechanism, and the iron chains on the riverbed tightened, crushing the Wojen ships into splinters.
As the first ray of dawn pierced the smoke, she watched the Shenji Crossbow blueprints in the bronze cabin spread out in the firelight; every annotation regarding the conversion of crossbows to weaving mechanisms matched the structural design of the Shen family’s ancestral looms perfectly.
"This is the true Exploitation of the Works of Nature." She pressed the two halves of the fish tally into the grooves on the cabin wall, and the fine-iron door swung open. "To end conflict with weapons, and to nourish the people with industry."
As the morning sun leapt above the river, twenty Shenji Crossbows stood in formation on the deck of the tower ship.
Shen Xitang stroked the scroll-work on a crossbow arm, then heard the sound of Xiao Heng’s Steel Whip falling to the deck—the silk bindings on the whip had snapped inch by inch, revealing the Ministry of Works' Tiger Tally hidden inside.
"Does Miss Shen know..." He picked up the half of the Tiger Tally, "that this military tally must be joined in two halves before it can mobilize..."
Before he could finish, a Red Horse Boat drifted toward them. The scar-faced boatman held out a gilded box, and inside, the complete volume of Creation of Heavenly Works sat soaking in tung oil.
Shen Xitang pressed the Tiger Tally onto the Big Dipper pattern on the cover, and the pages suddenly fell away, revealing the royal merchant’s gold seal hidden in the lining—the seven copper stars on the seal’s knob matched the lock of the Armillary Secret Key perfectly.