The high-pitched metal shriek tore through the silence of the Eight-sided Entry hall like a blade drawn across glass.
Qiao Ming leapt to his feet, knocking the stone drafting stool backward against the Solitary Column. His hands moved by pure instinct, sweeping the ancient sheepskin fragment back into the star-copper metal tube and jamming the threaded cap tight before reaching for his instruments.
The sound was not coming from the ceiling vaults, nor was it the cry of a roosting petrel.
It came directly from the central brass gimbal of his Brass star-compass.
Mounted within the inner ring of the instrument, protected by a cage of slotted bronze ribs, sat an integrated liquid silver barometer. It consisted of a heat-softened rock-crystal tiny blood vessel tube, fourteen inches tall, filled with triple-distilled quicksilver resting over an ivory pool. The tube was tuned to measure the internal sky and water-pressure air-pressure of the Great Entry hall. For as long as Qiao Ming had carried the instrument, the silver knee pad had rested steadily between the twenty-eighth and thirtieth graduation marks, breathing with the gentle, rhythmic rise and fall of the daily tides.
Now, the quicksilver was in violent free-fall.
As Qiao Ming grabbed the instrument, the silver column plunged past the twentieth mark, past the fifteenth, past the tenth. Within the space of twenty heartbeats, the liquid silver collapsed into the lower bulb with a wild, frothing hiss.
A pressure drop of that size was never seen before in thirty cycles of records.
It didn’t indicate a weather front or a storm blowing through the high window row openings. In a closed, high-pressure stone megastructure, a sudden collapse of air pressure meant only one thing. A huge, total shifted weight of volume in the deep-sea basements leagues below. Millions of tons of water were being drawn out of the lower under-road drains, creating a giant suction vortex that pulled the air down through the drainage grates.
The thirty-six-day great conjunction tide was gathering twelve hours ahead of schedule.
Qiao Ming’s mind cleared of existential dread, wiped clean by the cold, immediate demands of survival. Whether he was Jiang Xuanji or Qiao Ming, whether he was a sovereign monster or a penniless caretaker, the flood was rising. If the water breached the middle terraces, his charts, his thick parchment, his seeds, and his life would be swept into the dark.
He snatched his survey belt from the bench. He slung the heavy ox-bone reel of his knotted lead line across his right shoulder—ten thousand deep-water lengths of braided deep-sea silk and star-fallen iron wire, weighted with his twelve-pound six-sided plumb-bob. He seized his horn lantern and dashed out of the Eight-sided Entry hall.
He didn’t take the lower stairs. He sprinted westward through the rows of stone pillars of Entry halls 076, 077, and 078.
His bare feet slapped against the cold banded limestone flags in a rapid, steady beat. The drafts in the halls had reversed their usual direction. Instead of blowing gently upward from the sea, a howling gale was being sucked downward through the archways, roaring through the fluted columns like air rushing into an iron fire. Loose kelp-fronds and dry sea-grass tumbled across the marble floors, whipped into spirals by the dropping draft.
As he sprinted through Entry hall 078, he glanced at the huge statues standing in the wall niches. The figures—warriors and judges carved from green snake-like and grey dark rock—seemed to hum. A low, low, deep shaking ran through their stone limbs. The water-marks on their stone stands, dry for months, were sweating beads of water drops that ran down their carved robes like tears. The entire stonework was alive with clockwork strain, groaning like an overloaded ship caught in a whirlpool.
He crossed the threshold of Entry hall 080—the great watching gallery known as the Overlook of the Drowned Deep gap.
Here, the middle tier ended in a massive stone railing carved with leaping sea-dragons. Beyond the low roof wall opened an upright void two hundred arm-lengths deep and five hundred arm-lengths wide, dropping straight down into the main drainage cross-halls of the Lower Basins.
Qiao Ming skidded to a halt against the stone dragon-heads of the low roof wall, gripping the cold marble carving to steady his body against the screaming gale.
He looked down into the deep pit.
What he saw made his blood run cold.
The Lower Basins were usually a dark, placid lake of green salt water, disturbed only by the sluggish swells of the six-hour tides. But tonight, the water had turned an oily, pitch-black hue. It wasn’t resting. It was boiling.
Massive underground blast waves were shuddering through the giant stone foundation piers. Millions of white foam-caps churned across the black surface like boiling rice inside a cooking pot. The sound roar that rose from the depths was huge—a clockwork thunder created by thousands of tons of tightly packed air and water screaming through narrow high-pressure valves beneath the floor.
Huge clouds of cold spray rose eighty arm-lengths into the air, drenching the stone railing in a stinging, freezing mist. The water tasted sharply of sulfur, deep-sea silt, and the bitter, unbending stone chill of the deepest ocean trenches.
Qiao Ming drew his twelve-pound lead weight from its leather holster at his hip. He checked the hollow animal fat cup at the bottom of the lead, ensuring the rendered fat was fresh and sticky.
He swung the six-sided lead out over the low roof wall and released the ox-bone reel.
Whirrrrrr—
The braided line screamed as it uncoiled, the horsehair marker-tallies flashing through his calloused fingers like whip-cracks.
Ten deep-water lengths. Twenty deep-water lengths. Forty deep-water lengths.
At fifty-five deep-water lengths, the lead struck the boiling surface with a dull smack. Qiao Ming clamped his thumb against the reel, feeling the tremendous drag of the currents through the star-fallen wire. The line shook wildly, humming with a high, dangerous pitch that threatened to sever his tendons if he lost his grip.
He hauled the lead up ten feet, letting it bounce against the churning surface to sound the surge speed, before reeling it back with furious, strained hard effort.
When the lead weight cleared the low roof wall, he checked the animal fat cup.
The animal fat was packed with black, gritty silt flecked with crushed mother-of-pearl, bits of stone-hard bone dust, and bright green copper flakes. The bottom current was wildly scouring the deepest foundation under-road drains—stripping the hardened floors down to the bare bronze keel.
He pulled his brass sighting side from his chest sling, holding its aiming cross over the line while the internal liquid silver sensor rattled against its rock-crystal casing.
The readings were terrifying.
The tide was already thirty-eight arm-lengths above the standard high-water mark, and it was climbing at a rate of one arm-length every three minutes. The thirty-six-day posture was not merely a seasonal surge. It was a sky-high convergence of the drowned cosmos. There, the gravity currents of dead star-patterns lined up to pull the deep-sea upward through the root of the Ark.
At this rate, the water would drown the Lower Basins fully. It would submerge the autopsy stone base of the Silent Anatomist in Entry hall 009. It would engulf the limestone throne of the Drowned Emperor.
And within forty bells, the black foam would reach the lip of the middle terrace. It would spill into Entry hall 080. It would rush through the rows of stone pillars and pour into the Eight-sided Entry hall.
The entire middle tier—the dry safe hall that had remained above the sea for three hundred years—was about to be swallowed.
Qiao Ming reeled in his lead line with furious, practiced speed, his muscles burning with the strain of fighting the current. He hauled the twelve-pound weight back over the stone railing and latched the reel to his belt. He could feel the spray wetting his clothes through to his skin, cold as liquid ice.
He turned and looked back along the dark row of stone pillars toward the Eight-sided Entry hall.
Through the long vista of fluted columns and shadowy arches, scarcely visible four hundred paces away, burned a solitary, motionless spark of amber light.
It was the animal fat candle he had placed upon the green red stone blade collar inside the Nineteenth Nook.
The flame burned small and frail in the vastness of the hall, but it didn’t waver. It stood as a lonely bright light of warmth in the heart of the stone maze—a light offered to an empty bed, a prayer whispered to a forgotten name.
The words of the ancient sheepskin echoed through Qiao Ming’s mind with chilling clarity:
If you find the Nineteenth, don’t tie the knot. Let the sky remain unstitched.
The tide was rising to meet the nineteen nodes. The stonework was groaning beneath an unbearable high-pressure load. The amnesiac custodian who swept bones had run out of peaceful seasons. The sea was coming to reclaim its builder, and the gates of the drowned world were about to break.
Qiao Ming tightened his grip on his brass instrument, wiped the stinging sea-spray from his eyes. Then he began to run back toward the solitary flame.