Mab did not ease into it.

She planted her feet the way Aestrith had taught her, how people stood when they were about to do real work, took one steadying breath, and reached toward the fuel bed at the furnace base.

She approached it carefully at first, but with full concentration, knowing hesitation could matter just as much as force. She still did not know exactly how much pressure the task required, so she chose the safer mistake and pushed hard enough to guarantee a result.

The fire reacted immediately.

They expanded.

Orange shifted through yellow almost instantly, then turned white at the center within seconds. The brightness at the furnace mouth increased so sharply that the entire foundry dimmed around it.

Beorn recognized the effect from the courtyard demonstration with the iron fittings. The energy concentration altered the surrounding light as it gathered into a single active source.

Then the heat hit.

Not ordinary furnace heat. Not the broad warmth of a foundry floor.

This came off in a focused wave, sharp and physical, the kind of heat that made even metalworkers complain it is too hot.

A second problem followed immediately.

Smoke began pushing back out of the furnace.

The draft channel had been designed for normal combustion. It could not process this output, and exhaust that should have flowed upward through the vent instead rolled outward at the mouth in thick grey waves.

Tam lifted a hand to shield her eyes.

Mod two wide steps sideways, moving clear of the direct blast from the furnace mouth.

Mab blinked at the sudden change.

"Oh. That’s a lot."

"Less," Beorn exhaled and said once.

He was already watching the smoke instead of the flame itself. The exhaust failure was more important than brightness.

"About half of what you’re doing now. The vent can’t keep up."

Mab reduced the pressure immediately.

The white core retreated first, fading back toward orange-gold.

A moment later the smoke thinned, then resumed drawing properly upward through the vent. The foundry’s lighting normalized as the glare weakened.

Ten seconds after that, the heat at Beorn’s face dropped from dangerous to merely uncomfortable.

"A bit more," he instructed after watching another moment.

He kept his eyes on the furnace while he spoke.

"Do it carefully, one step at the time."

She adjusted again, slower this time.

The furnace stabilized at a point beyond normal bellows output but still inside the exhaust venting capability.

The fire stopped into a deep orange-gold burn. Its brightness was steady instead of pulsing with the bellows rhythm, even though the bellows were still working beneath the furnace. The flame simply ignored the interruptions.

Beorn watched carefully.

The fire remained consistent. No surge. No drop. No ordinary combustion fluctuation.

The fuel was burning completely instead of partially, releasing far more energy than the standard process extracted.

The outline of a theory about Mab’s domain formed in his head while he observed it.

It wasn’t finished yet, but just enough to see the direction.

Matter stored energy. Ordinary combustion released only part of that reserve while the rest remained trapped in the carbon structure.

Mab was not creating heat from nothing. She was interfering with whatever process normally restricted the energy release. The excess light likely came from energy escaping faster than the furnace could fully turn it into heat or Mab herself control.

The concept itself remained unclear.

Chemical bonds? Thermal state manipulation? Something between both? He lacked enough retained technical knowledge to identify the exact interaction.

Still, the observation itself was solid even if the explanation remained incomplete.

He wrote release rate in the ledger margin and left the unresolved question in blank.

"How long can you maintain that?" he asked.

Mab kept her eyes on the flame while she answered.

"It’s harder than the stone. The stone is obedient, but this guy is like a naughty child."

"Because it doesn’t stop moving...?" Beorn blinked, unsure he followed her logic right.

He continued watching the furnace for another half minute, checking for instability.

The fire was constant.

"That’s enough," he decided. "Release it."

Mab let go.

Immediately the furnace dropped back into the normal bellows cycle. Surge. Dip. Surge again.

After the previous steadiness, the inconsistency became obvious enough that Mab noticed it audibly before she realized it visually.

"Did I do it right?" she asked.

"It worked," Beorn nodded.

He added another note to the ledger, then closed it.

"At this stage, that’s what it looks like."

Mab exhaled slowly.

Only then did she seem to realize how tense she had been holding herself. She rolled her shoulders once, loosening the strain, then glanced toward Mod.

Mod had already returned to her position beside the workbench. Her expression carried only detached focus.

Beorn turned toward Aestrith.

She stood with her arms crossed, her resting posture, watching the entire test without reaction.

"Well?" Beorn asked.

"Barely acceptable," Aestrith replied.

She looked directly at him rather than at Mab or Mod. "With my supervision present, both can work in the foundry without accidents."

Her eyes shifted briefly toward the furnace.

"And in the case there’s any, I can intervene and minimize damage."

She shifted her weight slightly before continuing.

"They’ll start slow and pick up the pace as they become more used to the task."

"Understood," Beorn said.

That was enough for her. Capability identified, constraints identified, limit identified. Analysis completed.

Aestrith returned to the workbench without comment.

Beorn looked between Mod and Mab.

He started to explain calmly, "The schedule will be the same as Tam. You arrive during the foundry workers break. When they leave the foundry, you girls enter through the secondary corridor, complete the work, then leave when the shift alarm sounds."

He tapped the ledger lightly against his palm.

"Everything outside that stays the same. Classes, exercises, personal time."

Mab answered immediately.

"Can we start tomorrow?"

Beorn simply nodded.

She very carefully avoided looking too pleased by focusing intently on a completely unimportant part of floor near the furnace base.

Mod, meanwhile, had somehow repositioned herself beside the workbench without anyone realizing she moved there.

"The work period fits between classes?" she asked. "Not before them, I assume."

"Before the afternoon class," Beorn confirmed.

Mod fell silent.

Beorn recognized the pause. She was comparing the proposed schedule against whatever obligation currently ranked highest in her mind and deciding whether it justified resistance.

"The teacher assigns homework in the morning," she said finally with some impatience.

Beorn stiffened a chuckle. "You can do those during the evening."

Another brief pause followed.

"Fine," Mod said to no one in particular.

That was sufficient.

Then the steam whistle sounded from the pipe device at the far edge of the industrial district.

The release was short and clean, pressure venting through the pipe with a sharp metallic note that carried easily through the foundry walls.

The sound hit them in an instant.

Beorn knew the system intimately because he had designed it himself during the district planning phase. One secondary engine pressure fed the valve mechanism, timed specifically for shift transitions.

Workers in nearby buildings would hear the signal and know their break was ending.

Tam crossed the foundry immediately without waiting for instruction. She already had the apron half removed and her book tucked beneath one arm.

When she reached Mab and Mod, her posture had an easy confidence, ready to introduce the routine to newcomers.

"So, for lunch break, there’s a food cart nearby," she nodded. "An old married couple runs it."

Tam paused briefly with a tilt of her head.

"They are there every shift change and somehow knows most of the workers by name."

Tam adjusted the book under her arm. "The bread’s baked fresh in the morning, but the stew depends on what’s good for the week."

Then she looked directly at Mab.

"It’s better than the citadel kitchen."

Mab frowned slightly.

"That seems impossible."

She sounded genuinely uncertain whether Tam was exaggerating.

"It isn’t," Tam nodded seriously. "Trust me. The bread is so fluffy it tastes like a dream."

Mab was already heading for the secondary corridor before the conversation fully ended.

Mod followed a step ahead of where it would appear intentional, one hand straightening her coat as she walked.

"I reserve judgment," she informed the corridor entrance.

Tam went after them.

A moment later the door shut behind all three girls.

The furnace returned to its normal rhythm.

Beorn and Aestrith remained where they were and exchanged glances.

One rolled their eyes, the other chuckled lightly.