Chapter 130: Sinbound Engineering
Construction had already begun at the eastern edge of the industrial district by the time they rounded the final corner before the foundry complex.
Scaffolding climbed the near wall of the largest empty structure, workers were setting the first layer of the chimney base into place. Timber and cut stone waited along the street in organized stacks.
Mab slowed as they passed.
"Are they building something?" she tilted her head.
"More foundries," Beorn replied without slowing. "Right now we don’t have enough of those."
She looked back at the scaffolding while still walking, considering its size, then faced forward again and let the question go.
Walking with them, Mod hadn’t looked at the construction once. Her attention was where the streets met the foundries and on the faint shimmer of heat rising above the chimney even at this hour.
The main loading bays were open toward the street, wide doors pulled back to allow cart movement during pours.
Beorn led them past those entrances and toward the secondary access point, a narrower side door that opened into a passage before the main floor.
"You girls use this entrance," he informed, pushing the side door open.
"Because of the taboo?" Mab said.
Beorn held the door for them.
"Because of how the crew reacts to it, for now," he answered.
The wording was important enough.
The heat struck them first.
The passage was warm before the main floor even came into view. It had the tinge of iron, burning fuel, and something deeper beneath both, felt in the chest before it fully reached the nose.
Then the main floor appeared before them.
The furnace, the mold table and Aestrith at the far bench with Tam beside her.
Aestrith spared them one glance.
Then she returned to the part in her hands, a component from the boring machine that would be used in the new foundries. She didn’t pause.
Tam looked up from the schematics at the workbench. She saw Mod and Mab, and something in her expression eased.
"Welcome to the iron pit~!" Tam giggled.
She learned the term from the foundry workers break discussions.
Mab surveyed the room.
Mod watched the furnace.
Beorn was already walking toward it.
"Come here," he said.
He waited at the furnace opening until they joined him. From their position, they could see the entirety of the foundry and the furnace from a gallery, while the workers could not see them.
Heat rolled from the iron mouth in visible waves, bending the air above it.
He pointed to the bellows mounted along the side, a large double-chambered leather mechanism driven by a long lever arm. During pours, the crew worked it in constant rhythm, forcing air through a channel into the furnace base.
"Watch that for a minute," he said. "Don’t touch it. Just watch the flame."
The bellows were midway through a stroke.
A worker across the floor pulled the lever down and the chamber compressed. Air drove into the furnace base. The flame surged at the opening, brighter, hotter, its color edging toward white.
Then the arm released.
The chamber expanded. The bellows filled again.
In the pause before the next stroke, the flame dropped.
Visibly weaker, as the color shifted back toward orange an the heat lessened enough to notice.
The next stroke came.
The flame surged again.
Once you knew to listen, the sound became obvious.
Each compression produced a heavy whump through the mechanism. Between strokes came a distinct absence, the fire continuing with less breath, its roar dropping into something rougher and lower.
Mab frowned.
"Um... I see fire?"
"Indeed," Beorn nodded.
She glanced at the furnace again, confused of how the mechanism worked.
"Is that bad?"
He considered how to explain it to her. "Normally, whenever the heat falls off, the metal weakens in response. It’s not something you can spot by looking, even really hard."
He turned back toward the furnace.
"The bellows are the best solution anyone has found for moving this much air into a furnace."
He nodded toward the girls.
"They’re also the source of the problem."
Mod was still watching the flame.
She hadn’t shifted from where she’d stopped, slightly left of Beorn where nothing blocked her view.
She spoke to no one in particular.
"If there was always an empty place there, the air would keep running into it."
Beorn stopped.
He looked at her.
She wasn’t looking at him. She was watching the next bellows stroke drive the flame upward.
"Go on, elaborate on it."
"The air goes where the empty space is."
Mod said, still speaking toward the furnace. "The machine shoves it."
She watched the flame sink between strokes.
"And then it stops."
A small pause while she thought, "But if the emptiness was already there... and stayed there... the air wouldn’t have to wait. It would just keep going."
She watched the flame falter again.
Beorn looked at the furnace.
He had been thinking about the problem for days, and how to apply the girls abilities in some form that could be used for the foundries.
She had come to the conclusion on her own.
"That’s right," he nodded.
She finally checked his expression.
A brief confirmation.
Then she turned back to the furnace.
Mab blinked.
"So Mod solved it?"
"She identified the solution."
Beorn chuckled. "Now we determine whether she can actually do it, how long she can keep it up, and what it costs."
Mod accepted that immediately.
He led them further toward the Sinbound section of the plant.
Aestrith’s work area sat apart from the main casting zone, shielded by the secondary corridor wall and by distance. Far enough from normal crew sightlines that operations there could proceed without direct observation.
Tam looked up as they approached with an oddly territorial glint in her gaze.
"My lord."
She set down a caliper, then looked to Mod and Mab. "Okay, so this side is the precision work. Anything involving the furnace, you do from there."
"Aestrith and Tam manage the casting runs."
Beorn curiously watched their interaction. "You’d work alongside them for the near future."
Mod was already past both his and Tam’s words, looking over the components with interested eyes she struggled to hide.
Tam let her, but in a way a senior worker observes a newcomer, watching out for any mistakes before they started berating the inexperience.
He let that settle.
Mod received the information with her usual quiet indifference.
She was already thinking through something else.
Beorn glanced toward Tam, then toward Mab, who was examining a finished boring bar with exaggerated caution, convinced it might break if she touched it too strongly.
Mab was eleven, maybe a little older.
Mod was probably around eighteen.
He had considered this issue through his head a dozen times while thinking about Tam. Every path returned one answer.
He was not much better than a greedy factory owner hiring children to a foundry.
Even if the powers were real, the people possessing them were also real.
Despite how the world’s conditions were what they were.
The standard he kept was whether they were fine, not whether circumstances matched what they should have been doing at this age.
The conclusion still sat badly with him.
He set the thought aside and kept moving.
Mab carefully placed the boring bar back on the table and looked toward the furnace from here.
"When Mod does her thing," she asked, "will she need to stay right by the fire?"
"That," Beorn moved on, "is what we’re about to test."
He turned to Mod.
"This emptiness that you can create."
He pointed toward the opening at the furnace base. "If you maintain it at the opening point instead of inside the furnace chamber, air gets drawn through the channel continuously."
He glanced toward the flame.
"And the fire would receive air in a steady flow."
Then he looked back at her.
"How long can you hold a zone like that without tiring yourself?
Mod stopped to contemplate. Either her powers, the evolution in how she wielded them over the last week and the task at hand.
She stared at the fire.
"There’s only one way to find out."
"Good," Beorn said. "Then let us start."
