The quarry was silent.
It was a vast, excavated pit of white marble, ten miles outside Rome. Birds circled lazily in the blue sky. The wind rustled the dry grass.
Marcus stood on the ridge, watching.
He wore a leather apron over his tunic. His face was smudged with soot. He held a pair of smoked glass lenses to his eyes.
"Ready?" he asked.
Galen stood beside him. The physician—now the Chief Engineer of the Empire—was trembling. He held a long fuse that snaked down into the pit.
"It's too much," Galen whispered. "We calculated for two pounds. You put in ten."
"Rome doesn't need a firecracker, Galen," Marcus said. "It needs a hammer."
He nodded to Narcissus.
The giant gladiator lit the fuse with a torch.
Hiss.
The spark raced down the line, vanishing into the pile of rocks at the bottom of the quarry.
One second. Two.
BOOM.
It wasn't a sound. It was a physical blow.
The air compressed, slamming into Marcus's chest like a fist. The ground jumped.
In the pit, the world ended.
A massive cloud of white dust and black smoke erupted upwards, blotting out the sun. Boulders the size of wagons were tossed into the air like pebbles. The shockwave ripped through the trees on the ridge, stripping the leaves from the branches.
Narcissus laughed. It was a manic, terrified sound.
Galen fell to his knees and vomited into the bushes.
Marcus lowered the smoked lenses. He watched the dust settle.
Where a solid wall of marble had stood a moment ago, there was now a crater.
EXPLOSIVE YIELD: 4.2 KG TNT EQUIVALENT.
SHOCKWAVE VELOCITY: MACH 3.
STATUS: SUCCESS.
"It works," Marcus whispered.
The Ghost of Commodus purred in the back of his mind. Beautiful. Imagine that under a city gate. Imagine that under a throne.
Marcus silenced the voice. He wasn't building this for assassination. He was building it for survival.
"Pack it up," Marcus ordered the stunned Praetorians. "We have the formula. Now we mass produce it."
He walked away from the destruction. He didn't look back.
The Colosseum had changed.
Six months ago, it was the site of the greatest duel in history. Now, it was a factory.
The arena floor was covered in wooden sheds. The underground tunnels—where lions used to prowl—were now storage bunkers for sulfur and charcoal.
The smell was acrid. It tasted like rotten eggs and burning wood.
Hundreds of workers swarmed the site. They weren't slaves. They were citizens, paid in silver to mix the black powder that would save their lives.
"Caesar!"
Sextus Pompey strode across the sands. The Pirate Admiral looked out of place on dry land. He wore a fine toga, but he still walked like the deck was moving.
"You are turning the city into a forge," Pompey spat, waving at the smoke rising from the vents. "The people are complaining. Their laundry smells like hell. They want games, Marcus. They want bread and circuses, not soot and chemistry."
Marcus stopped. He picked up a handful of black dust from a crate.
"The games kept them docile," Marcus said. "The soot will keep them free."
He let the dust slip through his fingers.
"The Parthians aren't bringing gladiators, Sextus. They are bringing an army that stretches from horizon to horizon. If we don't have this," he pointed to the powder, "Rome is just a very expensive graveyard."
Pompey grunted. "You push them too hard. Even a mule kicks if you load it too heavy."
"Let them kick," Marcus said cold. "As long as they shovel."
He walked past Pompey, descending into the dark tunnels of the munitions plant.
He needed to check the production quotas. He needed numbers. The machine in his head demanded data.
The Imperial Palace felt empty, even though it was full of people.
Marcia sat in the audience chamber. She wasn't wearing the silks of a concubine. She wore a simple, severe woolen dress. A dagger was strapped to her belt.
She looked tired.
A fat Senator stood before her, waving a ledger.
"Lady Marcia," the Senator whined. "The grain rationing is choking the nobility! My estates in Campania need workers, but the Emperor has conscripted them all for the sulfur mines! We cannot eat gunpowder!"
Marcia didn't look up from her maps.
"You can't eat Parthian arrows either, Senator," she said.
She slammed the ledger shut.
"We are exporting terror," she said, her voice hard. "That pays better than wheat. Your workers stay in the mines. If you complain again, I will send you to join them."
The Senator paled. He bowed and scurried away.
The door opened. Marcus walked in.
He was covered in quarry dust. He smelled of explosions.
He didn't go to her. He didn't kiss her.
He walked straight to the large map table in the center of the room.
"How much?" Marcus asked.
"Two hundred barrels produced this week," Marcia said, joining him at the table. "But we are running low on saltpeter. The caves in Spain are tapped out."
"We need more," Marcus said, staring at the map. "Find new caves. Or scrape it off the walls of the sewers. I don't care."
Marcia reached out. She touched his hand. Her fingers were warm against his cold, soot-stained skin.
"Marcus," she whispered. "You haven't slept in three days."
"The enemy isn't sleeping," Marcus said. He pulled his hand away. "They are marching."
He looked at her. For a second, the mask slipped. He looked exhausted. Scared.
"I can feel them, Marcia. They are a wave. And we are building a sandcastle."
"We are building a wall," she corrected. "Go wash. You smell like a bomb."
Marcus retreated to his private study.
It was the only room in the palace that was truly secure. No guards. No servants.
He sat at his desk and opened the leather satchel.
He pulled out the laptop.
It was dusty. Scratched. The sticker on the lid was peeling.
He opened it.
The screen flickered. It took longer to boot up than it used to.
SYSTEM ALERT.
BATTERY HEALTH: 74%.
CHARGING EFFICIENCY: DROPPING.
PROCESSOR TEMP: HIGH.
Marcus stared at the numbers.
The solar charger Galen had built was crude. It provided power, but the voltage was inconsistent. It was slowly frying the battery.
"You're dying," Marcus whispered to the machine.
JARVIS didn't respond. It was just code. But it felt like a friend on life support.
He ran the simulations.
SCENARIO: PARTHIAN INVASION.
ROMAN VICTORY PROBABILITY: 32%.
WITH GUNPOWDER: 48%.
It wasn't enough. It was a coin flip.
"I need more," Marcus muttered. "I need an edge."
The door burst open.
Galen rushed in. He was holding a large, rolled-up parchment. His eyes were wide with manic energy.
"I figured it out!" Galen shouted.
Marcus slammed the laptop shut. "Knock, Galen!"
"Forget the knock!" Galen spread the parchment on the desk. "The bomb. It's too static. It waits for the enemy to step on it. But what if we bring the explosion to them?"
He pointed to a drawing.
It was a thick iron tube, reinforced with metal bands. One end was closed. A ball was drawn inside.
"We put the powder here," Galen explained, tapping the breech. "We put a lead ball in front of it. We light the fire. The gas expands. It has nowhere to go but out."
He looked at Marcus.
"It throws the rock for us. Faster than a ballista. Harder than a catapult."
Marcus looked at the drawing.
It was crude. Dangerous. It would probably blow up and kill the crew half the time.
But it was the future.
"A cannon," Marcus whispered.
"A what?" Galen asked.
"Never mind," Marcus said. He traced the line of the barrel.
"Can you build it?"
"I need better iron," Galen said. "And a lot of it. We'll have to melt down statues. Gates. Maybe the cage bars in the Mamertine."
"Melt it all," Marcus said. "I want fifty of them by spring."
Galen grinned. "What do we call it?"
Marcus looked at the drawing. It looked like a throat ready to spit fire.
"Don't call it a cannon," Marcus said.
He looked at the map on the wall. At the red stain of the East.
"Call it a Dragon."