Working by the yellow light of a single animal fat candle in a horn lantern, Eren Tal and Tavi moved through the brick crawlway like two badgers reinforcing a winter sett. Above their heads, fifteen inches of oak floor beams, hemlock floorboards, and Sister Merrow’s deal tables muffled every sound from the kitchen, while seventy feet away, the town guards sat on the street cobbles in the autumn drizzle.
Eren had rigged a four-wheel rolling dolly using four-inch boxwood pulley wheels and an ash timber tray. On this flat trolley, he loaded four squared ash wooden props balks, twelve thirty-pound canvas bags of washed river sand, two heavy screw jacks, and three rolls of oiled reed canvas sewn by Dima Fen. With Tavi pulling the hemp drag-rope from the washroom end and Eren pushing with his thick leather work boots, the trolley rolled silently along two hemlock runner boards laid over the gravel.
“Watch your knuckles against that brick ledge-stone, Tavi,” Eren whispered, his deep voice barely louder than the scuff of his leather apron against the stonework. “If you take a chunk out of that mortar, it drops onto the runners and makes the wheels squeal. Silence isn’t luck, boy. It’s clean timber and well-greased boxwood.”
Pella knelt at the washroom end of the under-road drain, receiving each timber balk and stacking it neatly against the damp wet stonework of the western foundation wall. Her muscles ached from the climb up the thousand steps. But the physical rhythm of the work drove away the lingering chill of Sorell’s council chamber.
As she reached up to guide the third ash prop off the dolly, Tavi suddenly halted. His candle beam pointed toward the ceiling arch five feet ahead. ‘Pella... Look at the mortar seams.’
Pella leaned closer, holding her lantern high. Clustered along the curved brick vault, tightly packed into the tiny recesses where the lime mortar had begun to soften from moisture, were hundreds of small, glossy black beetles, each about an inch long. Their hard-shelled shells shone like polished jet under the candle flame.
They weren’t scattering in panic from the light, nor were they crawling over the floor toward the food stores. They sat in dense, orderly rows, their long, delicate antennae twitching all at once toward the south. Every few seconds, the semi-clear belly segment of a beetle would pulse with a faint, rhythmic amber glow. A cool, organic soft glow that mirrored the standby hum of the Courtesy Arch.
“Lantern beetles,” Pella said softly, reaching out to gently touch the brick beside the cluster. The stone was distinctly warm to the touch—not boiling like the sub-larder pipe, but streaming a steady, feverish heat of nearly thirty degrees.
“They’re fleeing the lower channels,” Eren said. He knelt on the gravel runner boards and inspecting the insects with a craftsman’s curiosity. “My old grandfather used to say that when the river spirits got angry, the beetles would climb into your chimney bricks. But they aren’t angry. They’re cold-blooded creatures looking for an even heat. The heat from Sorell’s bypass is cooking them out of the mudflats.”
Tavi picked up a piece of grease pencils from his apron pocket, marking the outer edge of the beetle cluster on the brick with a clean white circle. ‘They’ve got pale egg sacs under their bellies, Eren. Look at that one on the edge. She’s carrying six little pearl eggs in her front legs. If they lay their eggs in this warm mortar, the larvae won’t hatch until spring.’
“Unless the stone gets hotter,” Pella noted, her brow furrowing. She pulled her pocket heat gauge from her pocket, touching the copper probe to the mortar seam beside the cluster. The needle climbed rapidly, settling at thirty-one degrees. “Hal’s baseline surveys say this under-road drain has run at fourteen degrees for forty years. Sorell’s second pipe hub isn’t even fully connected yet. The heat footprint is already spreading through thirty feet of residential foundation.”
She picked up Hal’s brass measuring tongs, measuring the width of the beetle cluster. Eighteen inches long, four inches wide, containing an estimated four hundred individuals. She recorded the count and the heat on her tally slate with a small stick of chalk.
She examined the brickwork above the beetle colony. Thin crusts of green copper green rust had formed along the edges of an abandoned lead drain pipe that crossed the ceiling, reacting with the acidic sulfur steam leaking through the subsoil. The underground environment was deteriorating faster than her models had predicted.
Tavi leaned over, watching the insects gently with his bare hands clasped behind his back. ‘Imran said they eat the white fungus that grows on wet timber. If we keep the under-road drain cool, they’ll eat the rot off Eren’s runners and keep the air sweet.’
“We don’t crush them, Tavi,” Pella instructed, seeing the boy reach for an empty canvas sandbag. “Imran told us on the audio bridge last week that if you kill the detritivores, the river mold takes over the mortar and rots the lime twice as fast. They’re doing our surveying for us. Wherever those beetles cluster, that’s where the underground heat is migrating.”
Eren wiped a smear of pipe lime from his temple with the back of his calloused hand. ‘Aye, but if Karas’s men see four thousand beetles crawling through the pantry floorboards tomorrow, they’ll call in the academy cleansing wardens with their brimstone pots. And brimstone will kill Sister Merrow’s sourdough yeast before it kills a single bug.’
“Then we call Imran Bell,” Pella said. She looked toward the dark brass oval of the Courtesy Arch. “His scheduled fifteen-minute test shift is booked for nine tonight during his supper break. He said he had a non-chemical method for relocating insect colonies using unglazed clay pots and river moss.”
Sister Merrow crawled down the entrance tunnel carrying a covered tin pail of hot boiled tea and three wedges of sourdough crust spread with cold mutton dripping. She set the pail on a timber balk, breathing hard in the cramped brick space. ‘You boys drink this tea while it’s steaming. If we’re going to live like moles under Karas’s boots, we might as well eat like Christians.’
They sat on the hemlock runner boards in the dim yellow light. They passed the tin mug in silence as they listened to the muffled rumble of the river above. The physical labor had welded them into a unit that had no need for titles or academy degrees.
Eren picked up a cedar mallet and four oak wedges, securing the base of the timber hoist. ‘When Ada comes back on Tuesday, we’ll have sixty feet of runner boards laid right up to the restrictor saddle. She won’t have to crawl on her knees through the sulfur puddles. She can roll her tool chests on the dolly like a lady in a carriage.’
Pella touched the cool brick arch beside the beetle cluster, feeling the subtle, rhythmic pulse of the insects’ abdomens glowing in the dark. It was a fragile, living tracking data line, warning them of the pressure gathering in the deep stone.
Pella struck Hal’s brass tone check fork against the brick arch, holding the shaking stem against the stonework. The chime died away with a dull, chattering flutter, with a low, eighty-eight hertz rattle. ‘The bedrock is shaking in sympathetic deep ring with the High Sluice pipe hub,’ she observed, logging the pitch on her slate with grease pencils. ‘The stone is taking eighty-eight cycles a second. If that hum climbs past one hundred, the mortar between these bricks will turn to dry sand.’
Eren picked up an auger and began boring two air-flow holes through the header timber into his sawpit above. ‘Then we don’t let it climb. We get Ada down here on Tuesday, we drop the Nine Lanterns flap valve, and we bleed fifty barrels of head into the gravel before Sorell realizes the pressure has dropped. In timber framing, when a joint starts screaming, you don’t pray. You drive a relieving wedge. And we’re about to drive the biggest wedge Lowbank has ever seen.’
They finished unloading the sandbags, stacking them three-high against the quarantined washroom door to create a sound baffle that would muffle the sound of their underground work. Eren wiped down the boxwood pulleys with an oily rag, checking his pocket watch by the candle flame.
“Six o’clock,” Eren said, stretching his broad back until the spine bones popped like dry kindling. “The wagon drivers have finished their stew, the street guards are shivering under their oilskins. Our underground supply line is fully working. Let’s get that audio link open to Yorkshire. It’s time to find out what Mrs. Saye thinks of academy legal contracts.”