My lungs burned every time I took a breath. It was a deep, stabbing pain that reminded me I wasn't in a climate controlled office anymore. The air in the workshop was thick with the smell of wet leather and pine resin. I sat on a low stool, my hands covered in a sticky black film. I was trying to tighten the iron bands around the new pressure tank. Han was sitting across from me, her fingers moving with a speed I couldn't match. She was braiding the oak bark tanned leather strips into a reinforced sleeve for the main hose.
You are overthinking the seal, she said without looking up. She didn't call me Master anymore. She didn't call me Prince. She just spoke to me like a senior engineer talking to a junior intern who was about to mess up a concrete pour.
It has to hold forty pounds per square inch, I muttered. I didn't know the ancient equivalent for PSI, but the math was screaming in my head. If the seal fails, the nozzle becomes a projectile. It'll take my head off.
Then use more resin and less pride, Han replied. She tossed a finished section of the sleeve toward me. The river doesn't care about your numbers. It only cares about the gap.
I looked at the sleeve. It was perfect. The weave was tight, and the tension was uniform. This girl was a living miracle in a world of mud. She understood structural integrity better than the guys I used to work with who had six figure degrees.
Lao burst into the shed, his face pale under the layer of grime. He didn't say a word. He just grabbed his sword and pointed toward the southern road.
They are here, he said. Not the tax collector. These are the Governor's scouts. Twelve men. All on horseback. They are armed with heavy crossbows.
My heart did a slow, heavy roll in my chest. How far? I asked.
Crossing the lower bridge now, Lao said. They aren't in a hurry. They think they are coming to collect a toy from a bunch of peasants.
I stood up, my legs feeling like they were made of lead. Han, get the villagers into the granary. Lock the doors from the inside. If you hear a loud bang, don't come out.
She didn't argue. She just grabbed her shawl and ran. I looked at the pressure tank. It was connected to the water wheel by a long, vibrating drive shaft. The pump was already chugging, the leather valves clicking with every rotation. The pressure gauge I had built—a simple piston against a heavy spring—was already halfway up the scale.
Lao, get the nozzle, I said.
We dragged the hose toward the narrow stone bridge that served as the only entrance to the village. The mud was deep, making every step a battle. We hid the tank behind a stack of my fired bricks. The hose snaked through the dirt, looking like a dead python.
I crouched behind the wall, my fingers resting on the main brass valve. I could hear the horses now. The jingle of their harnesses and the wet thud of hooves in the muck. It was a confident sound.
The scouts rounded the bend. They were wearing red lacquered armor that looked far too clean for this province. The man in the lead was young, with a face that looked like it had never known a day of real work. He looked at the water wheel and laughed.
So this is the dragon the old man was crying about? he shouted to his men. It's just a pile of wood and some wet laundry.
He rode right up to the edge of the bridge. He didn't see the hose. He didn't see me. He only saw a quiet village that looked like it was ready to be bullied.
Where is the Prince? the leader yelled. Tell him to come out and hand over the keys to the machine. The Governor is tired of waiting.
I looked at Lao. He was white knuckled, his hand on his sword. I shook my head. We weren't going to use steel. If we killed the Governor's men with swords, it was a rebellion. If we used the river, it was an accident.
I waited until they were all bunched up on the narrow stone span. The weight of twelve horses on that old bridge was already pushing the structural limits.
Now, I whispered.
I cranked the valve open.
The hose didn't just move; it whipped around like a living thing as the pressure hit the nozzle. A jet of water blasted out with a roar that sounded like a building collapsing. It wasn't a spray. It was a solid, white pillar of concentrated force.
I pointed the nozzle at the lead scout. The water hit his horse square in the chest. The animal didn't even have time to scream. The force of the water pushed the horse backward, its legs sliding on the wet stone.
The leader was thrown from his saddle, hitting the bridge with a sickening thud. The water didn't stop. I swung the nozzle toward the rest of them. It was like hitting a house of cards with a sledgehammer.
Horses panicked, rearing up and throwing their riders into the mud. The scouts tried to raise their crossbows, but the force of the water was so intense they couldn't even stand. One man got hit in the face and was bowled over backward, sliding ten feet across the bridge before falling into the churning river below.
It's the dragon! someone screamed. The dragon is spitting!
The water wheel was screaming now, the gears whining as the pump worked at maximum capacity. I could feel the heat in the nozzle through my gloves. The recoil was trying to rip my arms out of their sockets. Lao had to get behind me, his massive arms wrapping around my waist to keep me from being blown backward.
Hold it! I yelled over the roar.
The bridge was a disaster zone. Men in red armor were rolling in the muck, trying to find their footing. The horses had bolted, disappearing into the fog. The leader was trying to crawl away, his face covered in mud and blood. I hit him with a short burst, pinning him against the stone railing.
Stop! Stop! he shrieked, his voice cracking. We surrender!
I closed the valve.
The silence that followed was deafening. The only sound was the steady thump of the water wheel and the heavy breathing of the men on the bridge. The white pillar of water vanished, leaving behind a dripping, broken mess of a scouting party.
I stepped out from behind the brick wall. I was covered in soot, my clothes were rags, and I probably looked like a madman. But I was the one holding the nozzle.
Go back to the Governor, I said. My voice wasn't loud, but in the quiet, it sounded like thunder. Tell him the river doesn't want visitors today.
The leader looked at me, his eyes full of a pure, primal terror. He didn't see a prince. He saw a man who had tamed a god. He scrambled to his feet, ignoring his fallen helmet, and started running down the road. His men followed him, slipping and falling in their haste to get away from the bridge.
Lao let out a long, shaky breath. He let go of my waist and sat down in the mud.
You actually did it, he whispered. You fought off an armed squad with a bucket of water.
It wasn't a bucket, Lao. It was physics, I said. But my hands were shaking so hard I had to hide them in my sleeves.
The villagers started coming out of the granary. They moved slowly, looking at the bridge and then at the water wheel. They didn't cheer. They looked at me with a new kind of fear. It wasn't the fear they had for a prince. It was the fear you have for a man who can change the rules of the world.
Han was the only one who walked right up to me. She looked at the hose, then at the nozzle.
The secondary seal held, she said. But the nozzle is warm. The friction is too high. We need to use a wider bore or the metal will warp.
I looked at her and started to laugh. I couldn't help it. It was a dry, hysterical sound that hurt my chest. Here we were, in the middle of a war, and she was doing a post-project analysis.
You're right, I said, wiping my eyes. We need a wider bore. And we need more tanks.
Lao stood up, wiping the mud from his pants. They'll be back, Lu. And next time they won't ride onto a bridge like idiots. They'll bring archers. They'll bring fire.
Then we build a better defense, I said.
I walked back toward the workshop. My body was screaming for sleep, but my mind was already moving. The water cannon was a good start, but it was a defensive weapon. It was reactive. If I wanted to protect this place, I needed to be proactive. I needed to move the village's economy from survival to production.
I needed to build a foundry that could produce more than just a few bars of iron. I needed standardized parts.
I found a piece of charcoal and walked to the wall of my shack. The silk was full, so I started drawing directly on the wood. I drew a plan for a steam vent. If I could use the heat from the furnace to create steam, I could increase the pressure in the tanks without needing the river's current. I could make the village independent of the flood.
Master Lu?
It was the village elder. He was standing in the doorway, looking at the drawings. He looked older than he had yesterday.
The men are saying you are a sorcerer, the elder said. They are afraid to touch the wheel now.
Tell them I'm just an architect, I said without turning around. Tell them the wheel is just wood and water. If they are afraid of it, they are afraid of their own hands.
The elder sighed. You are changing things, Lu. My grandfather lived in this house. His grandfather lived in this house. We have always lived with the river. We never tried to fight it.
You weren't fighting it, I said. You were drowning in it. There is a difference.
I turned to look at him. I wanted him to understand. I wanted someone here to see the world the way I saw it. The river isn't a god. It's an engine. The earth isn't a spirit. It's a resource. If you don't use it, someone else will. And the people who use it are the ones who make the laws.
The elder didn't look convinced. He just nodded and walked away.
I felt a sudden, sharp pang of loneliness. In 2025, I was surrounded by people who understood the world. Even if we disagreed on the design, we agreed on the facts. Here, I was a lone voice screaming in a cathedral of superstition.
Except for Han.
She walked into the shack and looked at the drawing on the wall. That's a closed system, she said, her finger tracing the line of the steam vent. If the pressure gets too high, the whole thing will explode.
I looked at her. Yeah. That's why we need a safety valve. A spring loaded cap that opens when the pressure hits a certain point.
She nodded slowly. Like the lid on a pot of boiling rice.
Exactly, I said.
She looked at me, her eyes bright. Teach me how to draw the math, she said. I can build the parts, but I don't know the numbers.
I handed her the charcoal.
We spent the rest of the night hunched over the wall. I taught her the basics of geometry and ratios. I taught her how to calculate the area of a circle and the volume of a cylinder. She soaked it up like a sponge. She didn't have the baggage of a modern education. She didn't think things were impossible because a textbook said so. She just saw the logic and followed it.
By the time the sun started to rise, we had the blueprints for a basic steam engine. It was crude, it was dangerous, and it was beautiful.
This is the heart of the new world, Han, I said, pointing to the drawing of the piston.
She looked at the wall, then out the window at the rising sun. I don't know if the world is ready for a new heart, she said.
Maybe not, I replied. But it's getting one anyway.
I walked outside and looked at the water wheel. It was still thumping away, a steady, mechanical sound that felt like the only real thing in the world. The river was still high, but the levee was holding. The village was still there.
I felt a weird sense of peace. I was tired, I was sick, and I was probably going to be executed for treason within the month. But as I watched the water turn the wheel, I knew I wouldn't change a thing.
I was an architect. And I finally had a project worth building.
I sat down on my stump and watched the first light of the day hit the water. The white foam of the wheel looked like diamonds in the sun. It was the most beautiful thing I had ever seen.
Lao walked out of his hut, rubbing his eyes. Is it over? he asked.
No, I said, picking up a piece of iron scrap. It's just the beginning.
I looked at the road where the scouts had vanished. They would be back with an army. And when they arrived, they wouldn't find a village of peasants. They would find a fortress of fire and water.
I gripped the iron and felt the cold, hard reality of it.
One valve, I whispered. One valve at a time.
I closed my eyes and let the sound of the wheel wash over me. I was home.