The entrance to the Deep Iron Mines looked like a wound in the mountain. It was a jagged tear in the grey rock, breathing out a cold, stagnant draft that smelled of sulfur and old death.
The regiment stopped fifty yards from the opening. I could see the fear in their posture. These were men who would charge a shield wall without flinching, but they were terrified of the "Invisible Killer."
"This is as far as we go, My Lord," Captain Hareth said, his hand resting nervously on his sword hilt. "The Bad Air usually starts here. If you walk past the marker stones, you just... fall asleep. And you never wake up."
I looked at the ground. There were indeed piles of bleached bones—mostly foxes and wolves that had wandered too close to the heavy gas pooling near the ground.
"It is not a ghost, Captain," I said, climbing down from the wagon. "It is chemistry."
I signaled to Giles. "Bring the equipment."
Giles hurried forward, carrying a strange contraption I had spent the morning assembling with the blacksmiths. It looked like a standard oil lamp, but the flame was completely enclosed inside a cylinder of fine copper wire mesh.
"A lamp?" Hareth frowned. "My Lord, if we take fire into the 'Black Blood' fumes, it will explode. We all know this."
"A normal lamp, yes," I agreed. "But this is a Davy Lamp."
I held it up.
"The wire mesh acts as a heat sink. The flame can burn inside, but the mesh absorbs the heat so fast that it cannot ignite the gas outside the cage. We can walk through explosive air, and this lamp will not kill us. Instead, the flame will turn blue to warn us."
Hareth looked skeptical. Magic concepts like "heat sinks" were foreign to him.
"And the second sensor?" Elara asked. She was standing beside me, wearing heavy leather workman's clothes that did nothing to hide her size, but she stood with the stillness of a statue.
I nodded to the covered cage Giles was holding. He pulled off the cloth.
Inside, a small yellow canary hopped nervously on a perch.
"A bird?" a soldier snickered nervously. "Are we going to sing the ghosts to sleep?"
"Canaries have a metabolic rate ten times higher than a human," I explained coldly. "They breathe faster. If there is carbon monoxide—the silent killer—in the air, this bird will stop singing and fall off its perch long before you even feel a headache."
I took the cage.
"I am going in," I announced. "If the bird falls, we run. If the flame turns blue, we run. Otherwise, we walk."
I stepped toward the dark cave mouth.
"My Lord!" Hareth shouted. "You cannot! It is suicide!"
The soldiers hesitated. They were brave, but fear of the supernatural held them rooted.
Then, heavy footsteps crunched on the gravel.
Elara walked past the Captain. She didn't say a word. She just walked up to me, took the heavy coil of canvas ventilation tubing from the wagon, threw it over her massive shoulder as if it weighed nothing, and nodded.
"Lead, Husband," she said.
Her agency broke the soldiers' paralysis. Their Princess—the woman they had mocked for her weight—was walking into the dark while they stood trembling in the sun.
"Damn it all!" Hareth cursed, drawing his sword. "Form up! Protect the Prince!"
The interior of the mine was vast. The ceiling vanished into darkness, supported by ancient, rotting timber beams.
We walked in silence. The only sound was the crunch of boots and the chirping of the canary.
I watched the bird like a hawk. Chirp. Chirp. Hop.Status: Oxygen levels nominal.
I watched the lamp. The flame burned bright yellow. Status: Methane levels negligible.
"It... it is just a cave," Hareth whispered, his voice echoing. "Where are the ghosts?"
"Physics is the only ghost here," I murmured, scanning the walls.
Then I saw it.
The rock walls were weeping. Thick, black sludge oozed from cracks in the stone, pooling in stagnant puddles on the floor. It shimmered with an oily rainbow sheen.
"The Black Blood," Hareth hissed, recoiling.
"Crude oil," I corrected, kneeling to inspect it. "Millions of years of compressed biomass. It's not a curse, Captain. It's fuel. It's plastic. It's fertilizer. It's the future."
Suddenly, the canary stopped singing.
I froze.
The bird swayed on its perch. Then, without a sound, it toppled backward, landing on the floor of the cage with a soft thump.
"HALT!" I screamed.
The column froze.
I looked at the lamp. The yellow flame was stretching, turning a ghostly, wavering blue.
"Gas pocket!" I shouted. "Back! Everyone back ten paces! Do not run! Do not create sparks!"
We retreated efficiently. I watched the cage. Once we reached the fresher air near the entrance, the bird twitched. Then it fluttered its wings and hopped back onto the perch, shaking its head.
"It lives?" Elara asked, staring at the bird.
"It fainted," I said, my heart hammering against my ribs. "The gas concentration ahead is lethal. We cannot go further."
"So the mine is closed?" Hareth asked, looking almost relieved.
"No," I said, turning to the canvas tubing Elara was carrying. "Now we install the lungs."
I pointed to the mine entrance, where the wind was blowing across the valley.
"The air inside is stagnant. We need to force it out."
I grabbed the canvas tube.
"We build a Wind Catcher outside—a large funnel facing into the wind. We connect it to this tube and run the tube all the way down to the workface."
I drew the airflow diagram in the air with my hands.
"The wind outside pushes fresh air down the tube. The fresh air blows the poison gas out of the tunnel. We flush the mine like a toilet."
I looked at Hareth.
"Captain, set up the intake. Elara, help me run the line. We are not leaving until I have a barrel of that oil."
An hour later, the canvas tube was pulsing like a giant artery as the valley wind pumped air into the deep shaft.
We stood at the oil pool again. The canary was singing loudly. The lamp burned a steady yellow. The draft from the tube was blowing the heavy fumes away.
"Safe," I declared.
"We conquered the curse," Giles whispered, looking around in awe. "With a bird and a bedsheet."
"We conquered it with Ventilation and Monitoring," I corrected. "Standard safety protocols."
I handed a bucket to Elara.
"Scoop it up," I said. "Tonight, the dungeon furnace eats well."
She took the bucket, dipping it into the black sludge. She looked at the viscous liquid, then at me.
"You see treasure in the mud," she said softly. "And you see a Queen in a..." She hesitated.
"In a what?" I asked, checking the lamp.
"In a mountain," she finished, a small smile touching her lips.
"A mountain is unmovable," I said, meeting her eyes. "A mountain is permanent. That is what a kingdom needs."
I checked the bird one last time.
"Fill the barrels. We have an industrial revolution to start."