The question hung in the smoke.
Li Dao Xuan had only asked one thing—
Why is there so much black smoke?
And suddenly, no one on the rooftop dared breathe too loudly.
Every face was gray. Every robe smelled like regret.
The steam engine stood there innocently, as if it hadn't just tried to suffocate an entire school.
Bai Gongzi cleared his throat.
"Tianzun… the machine itself isn't the problem," he said carefully. "The problem is that we ran out of proper fuel."
Li Dao Xuan raised an eyebrow.
"Explain."
Song Yingxing stepped forward, already resigned to fate.
"At first, we used the spirit alcohol you bestowed. It burned clean, stable, powerful. Then it ran out."
He paused.
"So we began… improvising."
Improvising, it turned out, meant burning everything that could vaguely be persuaded to catch fire.
Wood scraps. Damp coal. Half-dry straw. Something that might once have been a chair.
The steam engine, noble creature that it was, accepted all sacrifices equally—and converted them into force, smoke, and moral lessons.
Li Dao Xuan listened in silence.
Then he laughed.
A real laugh, not divine thunder—more like someone watching bright students accidentally reinvent industrial pollution.
"No fire, no casualties, no school burned down," he said. "That already puts you ahead of most pioneers."
The tension snapped.
Song Yingxing's eyes lit up again, instantly forgiven.
"Tianzun, this machine is astonishing. With nothing but heated water, it can lift stone that would normally require dozens of men. Gears change direction. Pulleys multiply force. It doesn't get tired. It doesn't complain."
Li Dao Xuan nodded.
"And what would you use it for?"
Song Yingxing answered without hesitation.
"Wells. Mills. Smelters. Weaving frames. Anywhere people break their bodies just to repeat motion."
A pause.
Then Li Dao Xuan turned to the other side.
"Bai Gongzi. What do you see?"
Bai Gongzi had been staring—not at the engine, but past it, toward the little rail car resting below.
He smiled, a young man's smile. Dangerous in its optimism.
"Tianzun," he said, "you once showed us a vehicle that moved without horses. You called it a 'fire cart,' even though there was no visible flame."
He gestured at the steam engine.
"Now I understand the hint."
Song Yingxing froze.
"…You're thinking—"
"Put this inside a moving carriage," Bai Gongzi said, voice rising. "Let fire turn water. Let water turn force. Let force pull weight. The name was never metaphorical. It was a direction."
Li Dao Xuan said nothing.
Because Bai Gongzi had just done the most frightening thing a young mind could do.
He had connected dots without permission.
"In other words," Bai Gongzi continued, warming to the idea, "we may not command divine power—but this machine gives ordinary people a borrowed version of it."
Li Dao Xuan finally spoke.
"Good."
One word. Heavy as a stamp on history.
"Then refine it," he said. "Shrink it. Make it obedient. If it fits in a cart, you'll know you're close."
Bai Gongzi bowed, practically vibrating.
Behind him, his mother appeared from nowhere, instantly emotional.
"Did you hear that?" she grabbed the nearest bystander. "Tianzun praised my son's imagination."
That sentence would be repeated for decades.
Eventually, Bai Gongzi's excitement cooled just enough for reality to catch up.
"But Tianzun," he admitted, "there is one problem we cannot avoid."
Li Dao Xuan waited.
"Fuel," Bai Gongzi said. "A lot of it. Wood burns poorly. Alcohol is precious. Coal is ideal… but scarce around Gao Village."
Li Dao Xuan smiled.
"Then it's settled."
He turned.
"Yiye."
Gao Yiye, still faintly smudged with soot, stepped forward.
"Yes, Tianzun."
"Prepare to depart," he said. "You, Shansier, and an escort. Destination: Heyang County."
Her eyes widened.
"Coal?"
"We're not discussing coal," Li Dao Xuan said lightly.
"We're discussing the future being dug out of the ground."
Behind her, the attendants whispered urgently.
"Saintess, your face—"
Gao Yiye looked at Bai Gongzi.
At Song Yingxing.
At everyone equally dirty.
"…Later," she said, and ran.
Moments later, she emerged clean, composed, dignified—no longer a girl from a village, but a woman who could walk into a county and change it.
The escort assembled. Horses stamped. Armor shifted.
The steam engine exhaled behind them, satisfied.
Li Dao Xuan watched them go.
Fire had been mastered long ago.
Now, it was time to feed it properly.
Chapter Trivia:
Coal Before Industry
Coal wasn't rare because it was unknown—it was ignored. Without machines hungry enough to demand it, coal stayed a local convenience instead of a strategic resource. Once engines appear, the ground itself becomes negotiable.
Why Smoke Comes First
Every new power announces itself badly: noise before order, smoke before control. Clean systems only appear after people survive the messy stage.
Fuel Changes Society Quietly
Tools reshape labor. Fuel reshapes everything else. Once energy becomes transportable, predictable, and scalable, people stop arguing about strength—and start arguing about ownership.