Marrow's people had found the main furnace of Cinder Row in the dark, the way you find a sleeping animal you are afraid of waking.
It stood at the center of the district, a brick-and-iron beast four stories high, its mouth wide enough to drive an ore cart through. The old furnace, the one that had burned, was gone. What Dessik had built to replace it was a blackened shell, half its roof fallen in, the iron plating warped and split. Whatever had burned here had burned hot enough to make steel run like wax.
"Witch-fire," I said quietly, running my thumb along a seam of fused slag. It was glassy, white at the core, with a crust exactly like the one Vell had described on the burned skin. "She was right."
"Who was right?" Marrow asked.
"Doesn't matter yet." I wiped my hand on my cloak. "How many of your people have worked a forge?"
"Everyone. This was a foundry district. Before the fire, we made rails, boilers, and ore carts for the Wardens." She counted on her scarred fingers. "Forty-three who can pour. Maybe twenty who can read a heat. Nine who can actually build a furnace."
"Nine is enough."
"Enough for what? We have no iron, no coal, and the Tallyman owns the building."
"Greaves owns the debt on the building," I said. "He doesn't own what's inside it, and he doesn't own what we do with it before the Sitting. A man who forecloses on a working furnace gets a working furnace. A man who forecloses on a ruin gets a ruin. That changes what the Council thinks he's worth."
Marrow looked at me for a long moment. "You want to make the Row look valuable."
"I want to make the Row look like it's about to be valuable. That's cheaper, and it works better."
Kaelen, who had been walking the perimeter of the shell with his hand resting on his sword, came back and stopped beside us. Lyra trailed him, wrapped in her borrowed cloak, staring up at the blackened bulk with an expression I couldn't read.
"It can't be repaired in two days," Kaelen said flatly. "I've seen siege forges. This needs a new roof, new plating, a new flue. Weeks of work."
"I'm not repairing all of it."
"Then what?"
I walked to the mouth of the furnace and looked inside. The firebox was intact, the one part Dessik had built right. It was a deep brick chamber, scorched but sound, with a ring of cast-iron tuyères around the base for the air blast.
"The roof doesn't matter if we don't need to melt iron," I said. "We only need to light one fire. A real one, with real heat, that every territory in the Undercity can see and smell from here. A signal."
"A signal for what?"
"That Cinder Row is still alive," Marrow said slowly. She had understood before Kaelen did. "That we're not hiding anymore."
"Exactly."
"That's a stupid idea," she said. "Every raid we've ever had came after someone lit a fire."
"I know."
"The last three leaders died for it."
"I know that too." I turned to face her. "But you stopped lighting furnaces because you were afraid of who would come. Now they're coming anyway. The Council has already called a Sitting about us. Greaves has already scheduled the foreclosure. The only choice left is whether they find a dark, silent district waiting to be eaten, or a lit one that looks like it might bite."
Marrow didn't answer. Behind her, a few of her people had drifted close enough to listen, gaunt faces half hidden in the gloom. A girl of about twelve stood at the front, holding a bucket she had clearly forgotten she was carrying.
"Coal," I said, raising my voice just enough to carry. "We need coal. Not much. Enough to burn for one night. And somebody who knows how to light a firebox that hasn't been fired in fourteen months without cracking the brick."
Nobody moved.
Then the girl set down her bucket. "My da taught me," she said. "Before he went in the fire."
The silence that followed was a different kind. Heavy, but not hostile.
"What's your name?" I asked.
"Wren."
"Wren, can you teach me?"
She looked at Marrow. Marrow, after a long moment, gave the smallest nod.
"You have to start with kindling," Wren said, folding her arms like someone who had been waiting a long time to say this. "Dry stuff first, then splits, then coal. You can't rush it or the brick shocks. It has to warm up slow."
"Slow," I said. "I can do slow."
Behind me, Kaelen let out a breath that was almost a laugh.
◆
It took the whole day.
By the time the first thin thread of smoke rose from the firebox, my hands were black to the wrists, my back ached from hauling scrap timber, and I had learned more about brickwork from a twelve-year-old than I had in a semester at the Academy.
Wren supervised with the ruthless authority of a foreman. She corrected my kindling twice, my splits three times, and when I tried to add coal too early she smacked my hand with a stick. Kaelen, to my private delight, fared worse. He tried to lift a beam the way he'd lift a sword and was told, in front of thirty people, that he held things like a nobleman.
"I am a nobleman," he said, with great dignity.
"Not in here," said Wren.
Lyra didn't haul or build. She sat on an overturned crate near the firebox, hands folded in her lap, watching the small flame take hold. I'd asked her not to use her gift unless it was needed, and she had agreed without argument. But I saw her fingers twitch every time the fire guttered, as if she could feel it through the stone.
By evening, the flame had grown from a flicker to a steady bed of orange coals. The brick glowed a deep cherry red. The air shimmered. And for the first time in fourteen months, the heart of Cinder Row was warm.
People came. Not many at first. A man with a limp. A woman carrying a sleeping child. Then more, drifting out of the dark halls and cold rooms where they had been hiding, drawn to the glow like moths. They stood in a wide half-circle around the furnace, saying nothing, faces lit orange, holding out their hands.
Marrow stood at the front. She didn't speak. She was watching the fire the way you watch something you had stopped believing in.
"It's only coals," I said quietly, stepping up beside her. "It won't melt iron. It won't feed anyone. It's just a fire."
"I know what it is," Marrow said.
"Then why are you crying?"
She wiped her good eye roughly with the back of her hand. "I'm not."
"Okay."
"Don't tell anyone."
"I won't."
◆
Three hundred yards away, on the rooftop of a collapsed warehouse in Territory One, a man in a leather apron lowered a brass spyglass and wiped soot from his face.
He was big, even sitting down, with forearms like anvils and a beard singed ragged at the edges. The last light of the dying day caught the burn scars that covered the left side of his neck. He had been watching the glow in the dark for the better part of an hour.
"Well?" said the boy beside him, a lean youth with a smith's calluses and nervous eyes.
"Somebody lit the Row," said Hask.
"Dessik's people? I thought they were done."
"Dessik's dead. Marrow wouldn't be fool enough." Hask rubbed his scarred neck, an old habit, and looked again at the thin column of smoke rising against the red haze. "The Broker's boy, then. The one who claims the empty seat. I heard he was at the Hospice. I heard he went to Greaves and walked out standing up."
"Is that good?"
"It's interesting." Hask's mouth twisted, and what showed in the shadows of his beard was almost a smile. "Nobody lights a furnace in the open unless they want to be seen. Which means either he's a fool, or he wants every voice on the Council looking at the Row on the day of the Sitting."
"Which is it?"
"I don't know yet," said Hask. "That's what makes it interesting."
He folded the spyglass and tucked it into his apron. Below them, in the dark streets of the Forges, a hundred hammers were falling in slow, steady rhythm, the heartbeat of the only trade in the Undercity that never slept.
"Tell the foremen to keep the Row's order," Hask said. "The one for brackets and braces. Don't fill it yet."
"But the boy hasn't paid—"
"He hasn't asked, either. Wait. Let's see what he does with a lit fire."
◆
By midnight, most of the crowd had drifted away. Wren had fallen asleep against the firebox with her bucket in her lap. Marrow carried her to a cot and came back, and we sat together on the cold steps, watching the coals.
Kaelen and Lyra had gone to rest. The yard was quiet. Somewhere in the dark, someone was humming a tune I didn't know, low and tuneless, the sound of a district remembering how.
"You didn't tell me why," Marrow said after a while.
"Why what?"
"Why a furnace. Why not coin, or men, or one of your tricks." She was watching the glow. "You could've gone to the Pit with a better story than this. Something clever. Something that would've made them afraid."
"I tried that," I said. "Three times, upstairs. It worked every time. It cost me every time." I turned a lump of dead slag over in my hand. "I thought about it for a long while after Vell. She said she was afraid of becoming Greaves. Holding something over people so long that you forget why you started."
"And you're afraid of that too."
"I'm afraid of becoming someone who only knows how to be afraid at people." I set the slag down. "I'd rather the Council see a fire and wonder what it means than see a boy with a clever story and wonder what he's hiding."
Marrow was quiet for a long time.
"They'll still wonder what you're hiding," she said finally.
"I know."
"Because you are."
I didn't answer. In my pocket, against my thigh, I could feel the edge of a black metal card with silver runes I had not looked at in days. In my head, a dull ache pulsed behind my left eye, a tab running quietly in the background.
"Yes," I said. "I am."
"Good," said Marrow. "I'd be worried if you weren't." She stood, brushing coal dust from her knees. "Sitting's tomorrow. You should sleep."
"I will."
"You won't."
"No," I admitted. "But I'll sit very still and look like it."
She almost smiled. Then she walked away into the dark, and I was left alone with the coals, a hundred small orange eyes blinking in the dying firelight.
I watched them for a long time. Somewhere above me, through six hundred feet of rock and a city that wanted me dead, an engine I had built was still beating in the dark. Somewhere ahead of me, in a Pit I hadn't seen yet, six voices were deciding what I was worth.
The furnace ticked and settled.
It would have to be enough.