The road from the residential district curved east, and the workshop district appeared when the first buildings came into view.

The tanning operations hit first. Treated hide carried a sharp acidic smell that lingered no matter how the wind shifted. Coal smoke sat beneath it in heavier layers, and under both was the mineral scent of heated metal, harsher than ordinary craft ironwork. That smell came from the weapons section farther east.

The street widened as they entered the district. It had to. Loaded carts moved in both directions here, and the road was broad enough that neither driver needed to pull aside.

The oldest buildings stood nearest the entrance to the district. Tanneries occupied the west side of the road, ironworkers the east, and both showed the signs of age.

Outside one leather workshop, a craftsman stood at a heavy timber table inspecting a saddle. He flipped the piece face-down and ran his thumb along the stitching, testing the tension for weak points.

Satisfied, he turned it over again, found the right corner, and pressed a guild stamp into the leather with both hands behind the tool. He checked the impression, added the saddle to the finished stack, and picked up the next piece without wasting motion.

Across the street, a discussion was underway inside the open front of an ironworking shop. Two men stood over a metal bracket on a bench. One held it with the back face upward so the other could inspect the weld.

"That weld line shows on the back face," the inspector said. "The mark requires clean surfaces."

The Rus metalworker answered in rough Mongolian. He spoke with heavy bluntness, clearly someone who had learned the language on workshop floors and loading yards.

"This side goes to wood after mounting. Nobody’s seeing it. Rule was made for pretty pieces."

"The standard applies to the finished piece. Every surface."

The metalworker snorted and looked back down at the bracket. "You’re using decoration rules on a damned support bracket. Weld’s solid. I’d stamp my own name on it."

"Grind it smooth and bring it back."

The metalworker stared at the piece another moment, expression tight now, putting wasted labor against the time it’d take to redo the finish.

Then he muttered something short and sharp in Rus, clearly not meant for the inspector, grabbed his tools, and went back to his bench.

Batu glanced toward Suuqai. "Can you tell the real argument?"

Suuqai kept his eyes ahead as they walked. "He’s trying to determine where his own tradition stops and the city’s standards begin." A brief pause. "Today the conflict happened to appear in a weld."

They continued into the newer section of the district, where the Bulgar craftsmen worked beside the Rus metalworkers.

These buildings were lighter and newer, their workshop fronts open toward the street to improve airflow and movement.

At the near end of the Bulgar section, a Rus metalworker stood watching a bronze casting. The Bulgar craftsman poured molten metal into a sand mold with steady control, keeping the flow smooth as the crucible tipped in his hands.

When the pour finished, he set the crucible aside and finally noticed the Rus man observing him.

The Rus worker pointed toward the mold. His Mongolian slowed while he searched for the right words.

"You always leave cast sitting in sand like that?"

The Bulgar craftsman answered in equally broken Mongolian, Bulgar words slipping through where his vocabulary failed.

"Sand keeps heat even." He spread his hands.

"Cool too fast, metal goes bad here." He tapped two fingers against the casting. "Cracks."

The Rus worker frowned toward the finished piece cooling nearby.

"And after? Makes it harder?" He pointed again. "Or softer than water cooling?"

The Bulgar craftsman picked up the cooled casting instead of answering. He dragged his thumbnail slowly across the surface, then held it out.

"See?"

The Rus metalworker leaned closer. He studied the finish in silence for a few seconds, then grunted once in understanding.

"Hnh."

He kept looking another moment, fixing the lesson in memory, before turning and heading back toward his own workshop.

Batu watched him go. "You see a difference between these men and the workers in the gers this morning?"

"Their tools are sitting on the table," Suuqai said. "They’ve stopped keeping them within reach."

It was a subtle difference. Workers who expected violence kept tools close enough to become weapons. Men who set them down expected tomorrow to arrive normally.

The dry channel marked boundary of the district. A timber bridge crossed it, built wide enough to support loaded carts moving in either direction.

Beyond the crossing the smell changed again. Sulfur pushed to the front while tanning chemicals and coal smoke faded into the background.

The ground between the channel and the weapons compound had been cleared of anything unrelated to production. Batu could see the refinement facility through the northern fence, low buildings, separate ventilation structures, three workers moving inside the open ground. Farther beyond stood the foundry section and the sand beds.

Wei stood beside the cannon.

The barrel sat buried in packed sand, compacted evenly around the casting to regulate the cooling speed. Only the upper curve of the cannon remained exposed above the sand bed, pale gray iron releasing heat into the air. The sealed rear end protruded near the edge of the pit.

Wei had both palms pressed against the exposed surface. He wasn’t simply touching the metal, but reading temperature changes through the iron and packed sand, tracking the cooling rate by feel.

Nearby, the Kashgar engineer worked over a scale model of the carry frame. The miniature version used lighter timber but preserved the full structure. Batu could see the sled conversion immediately, runners extended beneath the original wheel positions, and the balance problem revealed itself clearly even at reduced size.

At the far end of the compound, one of the Rus metalworkers adjusted a component fitting.

Wei spoke without lifting his eyes from the cannon. "Add two finger-widths to the runner mount. The balance shifts on slopes once the frame starts moving."

The metalworker checked the measurement against his hand.

"Yeah. Saw it too."

Wei still did not look up. The work was more important than conversation.

Batu stopped near the compound and watched in silence.

Suuqai stood beside him. After a time he spoke without prompting. "For three years I’ve been focused on the next knife coming for you." He looked toward the cannon buried in sand. "That was how I understood this place."

His gaze stayed on the weapons compound.

"I didn’t realize the city itself was becoming the thing that keeps you alive."

Batu turned toward him. "And what do you think of it?"

He wasn’t asking about administration or production records. He meant the city itself. The thing growing here beside the Volga from what had once been nothing more than a banner planted in flood-marked earth.

Suuqai understood the weight of the question. He took his time before answering.

"It works."

He watched the workshops behind them for a moment. "Some people came because they wanted to. Others stayed because leaving became harder every season. Eventually the reason stops mattering. They are part of the city either way."

Suuqai paused again.

His attention shifted back toward the weapons compound. "The city will grow over time. What concerns me is that someone will eventually understand what’s being created here before it’s ready."

He let the thought hang for a moment. "And once they understand it, they’ll act."

Batu absorbed the warning without replying.

Wei still stood with his hands against the cooling iron. The Kashgar engineer had rotated the scale model again, checking the runner alignment from another side to test how the load would shift in motion.

After a moment Batu turned back toward the bridge crossing.

"That’s enough for today."