The wind eighty-four arm-lengths above the floor was clean, brisk, and carried the thin, chilling moisture of cloud-mist.
Qiao Ming stood upon a projecting top stone ledge of white Pentelic marble scarcely two handspans wide. Behind him rose the sheer upright cut stone wall of Entry hall 006. Before him fell an empty drop that ended upon the distant, chequered marble stone floor below. Yet his stance was relaxed, his shoulders low and balanced. His bare feet, hardened like horn from thousands of leagues of stone walking, curved over the outside lip of the top stone ledge. His toes gripped the fluted egg-and-dart moulding with prehensile familiarity, reading the tiny texture of the marble as easily as a hand might hold a walking staff.
Around him, the upper tier was alive with the beating of wings.
The silver terns of the high vaults were small, pale birds with black caps, red beaks, and wings so slender they seemed carved from shaving flakes of mica. Unlike the scavengers of the lower tide-pools, the terns lived entirely within the Stratum III nimbus. They nested in the sheltered hollows of the high friezes, inside the deeply carved acanthus leaves of the Corinthian capitals, and within the braided beards of the massive stone sovereigns whose shoulders pierced the lower cloud-track.
As Qiao Ming edged along the top stone ledge, a pair of terns wheeled past his face, their sharp, piping whistles cutting through the rushing drafts. They didn’t attack or flee in alarm. To the flock that inhabited the northern vaults, the tall land-mapper in the amber oilskin coat was as familiar as the stone props themselves—a quiet, permanent feature of their upright world.
“Patience, little sisters,” Qiao Ming said softly, leaning his shoulder against the relief wall.
He reached into a greased pouch at his belt and drew out a handful of dried white bait-fish. Tiny, semi-clear smelts he had salted and dried on the sunny steps of the roofed porch three days prior. He extended his open palm against the wind.
Within three breaths, the air stirred with a delicate fluttering. A mature tern, its breast feathers glistening like mother-of-pearl, dropped its webbed orange feet and settled lightly upon his calloused index finger.
The bird was virtually weightless, scarcely heavier than a dried pine cone. It cocked its dark eye at Qiao Ming, uttered a low, deep-throated clicking sound from the back of its throat, and daintily plucked a dried smelt from his palm.
“You have been flying through the northern high window row vents,” Qiao Ming murmured. He watched the bird tilt its head back to swallow the fish. “Your feathers smell of frost and high dark rock. The outside clouds are gathering dark above the seventh tier.”
The tern ruffled its silver mantle and remained perched upon his knuckle, its tiny, needle-sharp claws pressing into the yellow callus of his skin without breaking it. It didn’t fear him. He had tended their nesting roof ledges for years, carrying up dry, bleached eelgrass to replace bedding washed away by water drops leaks, and clearing fallen stones that threatened the fragile speckled clutches.
With his free left hand, Qiao Ming drew a piece of willow charcoal and a thin slab of smoothed grey slate from his harness.
He was here to map Relief Panel IX—a section of the high nonstop frieze that spanned the upper stone upper wall of the sixth hall.
At floor level, the frieze appeared as nothing more than a band of textured shadow eighty arm-lengths overhead. Only from this precarious ledge, balanced between the cloud-track and the deep pit, could the deep incisions of the ancient sculptors be studied.
The relief depicted a nonstop historical set from the Era of the Great Flooding.
In the first section, beneath an arch of stylized thunderbolts, rose the likeness of three huge void-arches, their prows shaped like horned dragon-turtles, riding upon a curling wave of stone-hard liquid. Along the decks stood hundreds of tiny figures in flowing robes, their arms raised toward a sky sphere that was visibly fracturing into seven jagged shards.
Beside them, the second section showed the beginning of the turning to stone.
The sculptors had rendered the transformation with chilling care. The lower halves of the figures had merged seamlessly into square stone-built foundation blocks, their torsos becoming fluted pilasters, their heads forming the brackets that held up the soaring vaulted roof. They hadn’t built the hall around themselves. They had willingly surrendered their mobility. They allowed their marrow to crystallize into the bedrock of the universe so that the stonework might hold the dropping flood in check.
Qiao Ming traced the contour of an emperor’s stone mantle with the blunt tip of his charcoal, transferring the proportions to his slate tablet.
“You traded your lungs for limestone,” he whispered to the carving. “And in exchange, you gave the water a house that would never wash away.”
The tern upon his hand gave a sharp chirp and took flight, joining a dozen others circling the head of a huge stone king whose crown formed a resting platform ten paces ahead.
Qiao Ming tucked his charcoal into his horn tube and began to edge toward the king’s head. He didn’t look at his feet. His soles felt the stone for him, noting each hairline seam, each patch of slippery green micro-algae where water drops seeped from the mortarless joints. When he reached the king’s left ear, he stepped off the narrow top stone ledge and hauled himself onto the crown.
The platform atop the king’s head was three paces wide, carved with castle walls and stylized stars. In the sheltered depression between the front diadem and the stone hair-knot lay four tern nests, each woven from dried kelp-fibers and lined with down. Inside two of the nests rested pairs of olive-green eggs, heavily blotched with dark brown spots.
Qiao Ming knelt with infinite care, ensuring the stiff skirts of his oilskin coat did not brush the rim of the nests.
From his basket, he withdrew several strands of soft, dried sea-silk and laid them gently beside the nearest nest. The mother tern, who sat watching him from the tip of the king’s stone nose, hopped forward with an inquisitive flutter, seized a strand of silk in her beak, and right away began weaving it into the inner lining of her nursery.
“A warm cradle for the cold months,” Qiao Ming said to her.
He unclipped the Folded brass star-compass from his harness and placed it upon the flat stone surface of the king’s central diadem.
He unfolded the hypsometric arm—the upright bar tuned to measure height through air pressure and sightline angles against the floor datum. He brought his eye to the lower sight-vane, peering through the cross-hairs down at the tiny, distant box-shaped block of the central altar in the nave below.
The air pressure up here was thin and sweet, smelling faintly of ozone and cold fog. The star compass’s internal aneroid bellows—a wafer-thin chamber of beaten sea-silver that swelled or tightened with height—settled against the graduated brass arc.
Eighty-four arm-lengths. The height was stable. The foundation pillars of the sixth entry hall had settled by not so much as a grain of sand since his last sounding during the spring equinox.
Qiao Ming recorded the numbers on the margin of his slate tablet, wiped the brass face of the star compass with his woollen sleeve to clear the mist droplets, and packed the instrument away.
Below him, a distant sound echoed through the lower archways.
It wasn’t the wind, nor was it the high whistle of the fluted pillars. It was the first, underground boom of the Median Surge entering the lower drainage shafts of the southern vaults. The tide was beginning its climb into the middle tier, three miles away. Within three hours, the lower steps would be awash in two arm-lengths of green salt water.
A flock of fifty terns rose together from the neighboring stone beams, their pale bodies wheeling all at once against the dark slate ceiling before diving toward the high window row vents, eager to greet the rising waters that would flush fresh schools of shrimp into the outer rows of stone pillars.
Qiao Ming stood, breathing in the cold air of the upper vaults.
He felt a huge, quiet thanks for this place. The world below might drown in silence, and the sky above might be an artificial vault of painted slate and star-iron studs. But here, in the high spaces between the friezes and the clouds, life endured with unrushed dignity. The terns raised their broods in the hair of dead emperors, and the dead emperors held up the roof so the terns might fly.
“Rest safely, little mother,” he whispered to the bird on the nest. “I will bring more silk when the next tide falls.”
He turned back toward the top stone ledge. Stepping down with his bare toes, gripping the narrow margin of the marble, he began his descent along the flying stone support prop toward the floor of the Seventh Hall. There, the non-Euclidean folds of the Peristyle awaited his measuring cord.