Tavi knew every cellar grating, coal chute, and dry sewer bypass in Lowbank before he was ten years old. But he had never explored them with a wooden ruler and a stick of white chalk. He sat on an upturned nail keg in the alley behind Sister Merrow’s kitchen, five younger boys squatting in the mud in front of him like dock apprentices waiting for the morning tally.
The boys were shivering in their patched wool rags, their bare toes red from the river slush. But their eyes were fixed on the warm tin kettle Merrow had set on the bench. The steam smelled richly of split peas, salted pork rind, and boiled cabbage. In their small, dirt-caked fists, each boy held two copper bits—real coin, paid in advance from Pella’s workshop reserve fund.
‘Listen sharp, or you don’t get the second bowl of soup at dusk,’ Tavi said. He tapped his ash stick against a square of heavy butcher’s parchment pinned to a pine shingle. He had ruled the parchment into six numbered grids with Eren’s dark oak-ink and a dry reed pen. ‘This isn’t bird-nesting and it isn’t snatching apples from the High Terrace carts. Mr. Bell wants counts, not stories.’
‘What counts, Tavi?’ asked Pip, a nine-year-old chimney climber with soot permanently etched into the lines of his knuckles. ‘If there’s rats down there, I’m not sticking my arm in the dark for two coppers.’
‘No rats,’ Tavi said. ‘Lantern beetles. The bronze ones with the fat tails that buzz in the sedge grass. You know the ones that came up into Merrow’s flour bin yesterday?’
The boys nodded quickly. Every child in Lowbank knew lantern beetles. On summer nights they caught them in punched holes in willow baskets to read chapbooks under their blankets.
‘You go to the six cellars marked on this board,’ Tavi ordered. He pointed his stick at each grid. ‘Pip, you take Old Mother Vane’s coal cellar on Cooper Lane. Bram, you take the cooperage dry store. Sim, you take the cellar beneath the Red Anchor tavern. Kester, the tannery lime vault. Jory, the flour cellar at the bakery on Fish Street. And I’m taking Master Orv’s boarding house at the Nine Lanterns.’
He showed them how to knot their hemp twine into precise squares. ‘A square foot is twelve inches of string tied in a loop. Lay it flat on the stone where the wall meets the dirt. If you just guess, your numbers are useless. Mr. Bell said a watching without a defined boundary is just gossip, and gossip doesn’t fix pipes.’
He reached into an iron nail box and handed each boy a four-inch piece of white chalk and a length of knotted hemp twine. ‘You don’t guess. You find the darkest corner of the cellar. There, the foundation wall hits the dirt floor. You lay this twine down in a square—one foot on each side. Then you count every beetle crawling inside that square while you count sixty heartbeats. You write the number on the wall with your chalk, then you run back here and give me the tally.’
‘What if the householder takes a broom to us?’ Bram asked, rubbing his nose on his sleeve.
‘They won’t,’ Tavi said firmly. ‘Every landlord on Fish Street has water backing into his coal bins. They’re scared their foundations are rotting. If they ask what you’re doing, you say you’re running a civic damp survey for the Courtesy Bridge Workshop, and if they interfere, their cellar won’t be on the drainage check list tomorrow. Say it with your chin up, like you’ve got a court guard standing behind you.’
The boys grinned through their soot and grease, pocketed their chalk sticks. Then they scattered into the freezing alleys like sparrows flushed from a barn floor. Tavi tucked his parchment under his arm, picked up his horn lantern and a brass check rule Pella had lent him from her kit. Then he set off toward the Nine Lanterns.
The Nine Lanterns was a sprawling, ramshackle tenement house three hundred yards upstream from the ferry boat ramp, its upper timber overhangs sagging over the narrow street like rotten teeth. As Tavi slipped through the rotting basement hatch on the alley side, the smell hit him right away. Dense, choking humidity, heavy with copper green rust, pipe lime, and the rotten-egg stench of baked sulfur shale.
The cellar floor was six inches deep in warm, brown sludge. The boarding house tenants had stacked their winter potatoes and firewood on wooden pallets. But the pallets were already floating. Tavi balanced along a row of loose river bricks, his lantern beam cutting through the thick underground vapor.
He reached the northern foundation wall. There, the ancient stone blocks met the bedrock shelf. When he raised his lantern, his breath caught in his throat.
The entire wall was moving. It looked as though someone had draped a thick, shimmering carpet of polished copper over the stonework. Thousands of lantern beetles were crawling upward in dense, wild columns. It climbed over each other in their hurry to reach the floor beams above. The sound was like dry autumn leaves scraping across flat stone slabs in a gale.
Tavi knelt on a wet timber balk. He laid his knotted string square against a relatively clear patch of stonework. Then he began counting. ‘One, two, three... Ten... Twenty... Forty... Sixty-eight... Eighty-five... Ninety-two.’ In a single square foot, ninety-two adult beetles were packed together. It shook their wings to shed excess body heat.
He touched the mortar joint with his bare knuckle. It was warm to the touch—not the tepid chill of cellar stone, but the feverish heat of a horse’s flank after a steep pull. Water dripped from the ceiling beams, warm and bitter-salt, stinging his eyes.
Tavi pulled out his chalk, wrote 92 - N. WALL on the dry side of an oak post, and scrambled back up the cellar steps into the cold drizzle of the street.
Along Cooper Lane, he passed Bram running out of the cooperage with his horn lantern swinging wildly. The cooper’s apprentice had been scared by the hum of beetles inside the empty barrel staves. There, the warm air had packed like an oven. Even in the cooper’s dry store, usually the coldest room in Lowbank, the beetles had blanketed the floor in a crawling bronze crust. The sound of their shaking wing cases echoed inside the oak barrels like dry rain falling on autumn leaves.
Tavi checked his own pocket watch against the bells of the High Sluice tower. The runners were moving with remarkable discipline. The promise of Merrow’s hot pea soup and real copper coin had turned five alley urchins into careful survey agents. In every cellar, the chalk squares had been drawn squarely against the damp foundation stone.
He returned to Merrow’s kitchen yard thirty minutes later. Then, the other five runners were already huddled around the soup kettle, slurping split-pea broth from wooden trenchers. Their faces were flushed, their eyes wide with excitement and unease.
‘Old Mother Vane’s coal bin has them three layers deep!’ Pip shouted, spitting soup in his eagerness. ‘I counted seventy-four before they crawled over my boot, Tavi! The coal was so warm you could dry socks on it!’
‘The cooperage is full of them,’ Bram chimed in, holding up his chalk-stained fingers. ‘Eighty-one in my square! The cooper thought it was witches until I showed him the chalk marks!’
‘The bakery cellar had sixty-six,’ Jory added quietly. ‘The baker’s wife was crying because they were crawling up into the empty flour barrels. She gave me a sourdough crust to tell her if the house was going to fall down.’
Tavi took his reed pen and carefully entered the numbers into the six grid squares on his parchment. He stared at the completed tally. His stomach tightened with a cold, hollow dread that had nothing to do with the winter wind.
Every single cellar had returned counts between sixty and ninety-five beetles per square foot. There were no blank zones. There were no safe pockets. Across a circle two hundred yards wide, centered squarely on the alley behind the kitchen, the underground soil was so hot and high-pressure that every living insect was fleeing for its life.
Pella came out onto the back porch, wiping her hands on a clean linen towel. She saw the children huddled around the board and walked down the steps. Her gaze dropped to Tavi’s parchment.
‘What did you find, Tavi?’ she asked softly.
Tavi looked up at her, handing over the shingle with its inked numbers. ‘It’s not just our kitchen, Pella. It’s the whole ward. From the bakery all the way to the Nine Lanterns, the ground is cooking them out. Every single basement within two hundred yards is infested with fleeing colonies.’
Pella looked down at the parchment grid, her mouth setting into a thin, grim line. ‘Come inside, boys. Merrow has another pot of broth on the fire. Tavi, bring that parchment to the slate. Eren needs to see this before sundown.’