The cellar beneath Sister Merrow’s kitchen had remained undisturbed since the great flood fourteen years ago. The walls were built of heavy, rough-dressed limestone blocks crusted with thick coatings of wet stonework lime. Meanwhile, the floor consisted of packed river gravel that stayed permanently cool even during the humid dog days of summer.
Along the lower baseboards, patches of copper green rust coated the old bronze foundation tie-rods, proof of decades of exposure to river slow leak. The heavy, damp air was tinged with the familiar silt stench that rose from the tidal mudflats whenever the water gate gates were adjusted.
Eren Tal set down a wooden crate containing twelve unglazed clay pot bread-crocks and garden pots. He wiped his brow with his leather apron. The pots were dark brown, rough-textured, and smelled of cellar earth and old river clay. Beside him, Imran Bell was on his knees, testing the gravel floor with his heat probe.
‘Sixteen point two degrees,’ Imran reported, reading the dial with visible satisfaction. ‘This floor is seated directly on the deep river shale. The rock acts as an infinite heat sink. Long as the hot steam from Sorell’s drain tube is contained in the eastern channels. Then, this cellar will stay cold.’
Eren picked up one of the flowerpots, running his calloused thumb over the porous rim. ‘These came from the old greenhouse behind the brewery. They’re thirty years old if they’re a day. Master Orv was going to smash them up for drainage rubble.’
‘Don’t let him touch them,’ Imran said, taking the pot and turning it upside down. ‘Unglazed clay pot is the most efficient passive cooling system ever invented. It’s what people in the Indus Valley used four thousand years ago to keep drinking water cold in fifty-degree heat.’
He reached into a wet canvas sack Tavi had dragged up from the riverbank. He pulled out a handful of fresh, spongy green river moss. ‘Watch how this works, Eren. The clay is porous. When we wet the outside of the pot, water wicks through the baked-clay wall via tiny blood vessel action. As the dry cellar draft passes over the damp outside, the moisture evaporates, pulling latent heat out of the inside chamber.’
Eren leaned closer, his carpenter’s eye assessing the physical logic of the arrangement. ‘It’s an evaporative radiator. Like hanging wet canvas over the meat larder in August.’
‘Exactly,’ Imran said. ‘Except an insect doesn’t need fans or ice. It just needs a balance heat between sixteen and twenty degrees and a moisture in the air around eighty percent. If we pack the inside with damp moss, the larvae won’t desiccate, and the nurse workers won’t have to carry them anymore.’
Pella came down the cellar steps carrying two buckets of clean river water and a wooden scoop. Behind her, the brass arch in the upper washroom continued its low, ringing hum, shaking through the ceiling timbers like a distant church bell. ‘The heat in the larder just crossed forty-four degrees, Imran. The beetles are moving faster. They’ve reached the bottom of the cellar stairs.’
‘Then we build the matrix right now,’ Imran said.
Working together in the dim lantern light, Imran and Eren built four tiered rows of baked-clay pots along the northern limestone wall. Eren used scrap cedar battens to build three-inch risers, ensuring that air could circulate freely beneath the drainage holes at the base of each crock. Imran packed the inside of each vessel with two inches of damp river moss. That created soft, humid nesting cups that smelled of sweet river sedge and clean silt.
Eren knelt on the gravel, driving cedar wedges beneath the timber stringers to level the frame. ‘A three-tier rack has to sit level, or when the clay gets soaked, the front pots will tilt and slide into the walkway. In a boatyard, if your shores aren’t wedged plumb, the hull twists before the planking dries.’
Imran approved the solid cedar framing with a brief nod. ‘Good joinery. If these pots shake or vibrate when the heavy cart wagons roll down Fish Street, the nurse beetles will take fright and drag the brood back into the cracks. Balance is everything.’
To establish a heat runway, Imran took a handful of crushed pipe lime from Eren’s mortar box and laid down two parallel guide lines from the base of the cellar stairs directly to the rims of the lower pots. ‘Insects hate crossing dry lime dust because it clogs their ankle pads. These two lines will funnel the column straight into the nursery matrix without letting them wander into the coal store.’
Pella unrolled a scrap of heavy drawing paper. She took out her bottle of dark oak-ink to map the placement of every baked-clay vessel. ‘If we number the pots from one to forty-eight, Tavi can track the occupancy rates every morning without disturbing the beds.’
Imran checked the outside humidity with his hygrometer. The reading hovered at seventy-eight percent, creating an ideal evaporative slope against the porous terracotta walls. In the dim amber glow of the lantern, the damp moss shone with vibrant emerald green fronds. He smelled clean and cool.
Upstairs in the washroom, the tracking data slate gave a low, musical chime. Pella glanced at the ceiling. The numbers on the Courtesy Bridge slate were registering the quiet steadying of the ground, the deep ring index ticking upward as the displaced colony found safe harbor without conflict or chemical violence.
Tavi came down the stone steps carrying his first cardboard box of rescued nurse workers. His face was covered in white flour dust, but his hands were steady. ‘Where do I put them, Master Bell?’
‘Don’t dump them,’ Imran instructed softly. ‘Set the box on its side against the bottom rim of the first pot. Let the lead nurse smell the moss.’
Tavi knelt carefully, tilting the pasteboard container until the open flap rested against the damp terracotta lip. Inside, sixty adult beetles were huddled together around their pearl-white cargo. Their antennae shook in the cool cellar air.
The lead worker—a massive female with a scarred back shell and antennae twice the length of her body—crawled to the edge of the cardboard. She extended her front legs, touched the cool, moist rim of the clay pot, and paused.
For three heartbeats, the cellar seemed to hold its breath. Even Eren Tal stood motionless, his mallet resting quietly against his thigh.
The beetle moved. She climbed smoothly onto the terracotta, walked through the drainage notch. Then she dropped into the green bed of damp river moss. Two inches down, in the cool, eighteen-degree gloom of the inside, she gently released the brood capsule from her jaws. She pressed it firmly into a natural crevice between two moss fronds.
She turned, tapped the moss with her palps to verify its moisture. Then backed away two inches, leftover on guard beside the egg.
A second beetle followed. Then a fifth. Within two minutes, the entire contents of Tavi’s box were marching into the pot in an orderly, silent procession. From the stairs above, the faint clicking of thousands of approaching feet echoed off the wet stonework.
The vanguard of the main swarm had reached the cellar threshold. Guided by the cool draft and the chemical scent marks left by the first nurses, the endless black ribbon of beetles turned away from the hot larder floor and began dropping the stone steps, heading straight for the baked-clay nursery.
Eren wiped his brow. He stared in disbelief at the orderly file of thousands of glistening back shells dropping the whitewashed wall. ‘I’ve lived in Lowbank thirty years, and I never saw river bugs behave like people clocking in at the drayyard.’
‘Because nobody ever treated them like tradesmen before,’ Imran remarked quietly. That made another notation in his field book. ‘Treat a living creature according to its physical needs. It will surprise you with its sense of order.’
‘Look at them,’ Eren whispered, his eyes wide in the lantern light. ‘They aren’t fighting. They aren’t chewing anything. They’re just filing in like dockworkers reporting for the dawn shift.’
‘Because they know they’re safe,’ Imran said quietly, checking his pocket watch. ‘An insect doesn’t fight an environment that makes sense. When you give them the right heat, they do exactly what their biology built them to do.’
Pella looked at the rows of clay pot pots, each one filling with neat. It spiraled clusters of semi-clear white eggs and calm, resting nurse workers. ‘How many pots will we need?’
‘All forty-eight,’ Imran replied, picking up his water scoop to moisten the next tier. ‘By nightfall, we’ll have thirty thousand beetles sleeping in this room, cool as cucumbers. And not a single grain of Sister Merrow’s flour will have a drop of poison on it.’