The blue lead-acid batteries were heavy enough to turn four strong scouts into staggering oxen, but by midnight, all six arrays sat lined up on the damp concrete floor of the postal basement.
Old Oakes was on his knees, scrubbing the oxidized terminal posts with a wire brush until the lead shone like raw dull silver. "Good cells," he muttered, spittle flying from his chin. "Silas might be a parasitic rat, but he knows how to grease his gear. These'll hold three thousand amp-hours easily."
"They'll have to," Danial said, sitting at the workbench. He was trying to recalculate the resonance harmonics for the Deep Sump, but his hand was so tired his pencil kept skittering across the paper.
In the corner, Maya was quiet. She had been quiet ever since they returned from Brimstone Alley. She sat on a wooden crate, binding a fresh layer of copper thread around a ceramic core, her eyes fixed on the door.
"You're thinking about Vane," Danial said softly, without looking up from his calculations.
"I'm thinking about the market," Maya replied, her voice flat. "I went up there ten minutes ago to get fresh water. Someone smashed the glass on the emergency temperature gauge near the bakery. They wrote 'DANIAL'S COLD' across the bricks in red coal grease."
Danial didn't answer. He couldn't. The pencil line cut deep into the paper, tearing a tiny hole in the margin of his father's journal.
Before Maya could say anything else, the floorboards beneath their feet vibrated with a sharp, sickening shudder.
WHIRRRR—CLACK.
It wasn't the deep, steady thrum of Node 1. It was a high-pitched, metallic screaming sound—like an iron flywheel being forced into reverse at top speed.
Across the room, the primary harmonic gauge on the basement wall—a long glass tube filled with glowing blue Selar fluid—spiked wildly toward the red line, the liquid bubbling furiously against the cork seal.
"Node 2!" Oakes yelled, dropping his wire brush, his spectacles flying off his ears as he scrambled to his feet. "Node 2's destabilizing! The busbars are melting!"
Danial was already moving. He grabbed his tool satchel, shoved his father's journal into his inner pocket, and bolted out the heavy oak door into the main corridor, with Maya and Oakes heavy on his heels.
Node 2 had been installed at Pillar 12—a massive, iron-reinforced support column sitting at the far western edge of Sector 4, right against the frozen outer wall.
When Danial burst into the western conduit, the air hit him like a physical blow.
It wasn't warm anymore. The ambient temperature had plunged twenty degrees in five minutes. White frost was already creeping across the iron floorboards in delicate, razor-sharp ferns. A thick cloud of choking, white ozone steam billowed out of the junction housing at the base of Pillar 12, smelling horribly of scorched Bakelite and melted copper.
"Get back!" Captain Vane's voice boomed through the steam.
She was standing twenty feet away, her face black with soot, using her heavy copper lance to keep back a dozen terrified refugees who had run out of their sleeping quarters in their nightclothes.
"Vane! What happened?!" Danial shouted, coughing violently as the ozone hit his lungs. He pulled his collar up over his nose and shoved his way through the crowd.
"It blew five minutes ago!" Vane called back, her eyes watering from the acrid smoke. "No warning! The thermal boundary just collapsed!"
Danial didn't wait for the steam to clear. He ducked under the high-voltage warning rail and threw himself down beside the junction box at the base of Pillar 12.
The main primary coil—a thick, beautiful spiral of braided copper that Maya had spent four hours winding—was completely ruined. It wasn't just burnt; it was warped into a blackened, slagged knot of metal, glowing a dull, angry cherry-red in the dark.
"Is it a harmonic spike?" Maya asked, dropping to her knees beside him, pulling a thick pair of oiled leather gloves onto her hands. "Did the Council increase the grid pressure from the upper gates?"
"No," Danial said, his voice dropping into a deadly, ice-cold register.
He pointed his wrench into the heart of the blackened junction box.
Nestled right between the primary crystal housing and the grounding rod was a twisted lump of iron. It wasn't part of the node. It was a crude, heavy iron shipping bolt—the kind used to lock freight crate lids—deliberately jammed straight through the insulator glass into the raw Selar matrix.
Oakes leaned over Danial's shoulder, staring into the ruined box. His jaw went slack. "That... that didn't vibrate loose, Danial. Someone shoved that in there with a pair of pliers."
"Short-circuited the feedback loop," Maya whispered, her face going deathly pale in the cherry-red glare of the slagged metal. "It forced the crystal to dump its entire stored charge straight into the grounding plate at once. If Danial hadn't built the emergency fuse at the postal basement... this whole pillar would have shattered."
Danial reached in with a pair of heavy insulated tongs, clamped down on the melted shipping bolt, and yanked it free. He dropped the glowing chunk of iron onto the frost-covered floor, where it hissed violently, sending up a tiny plume of black steam.
He turned the bolt over with his boot. Etched into the flat hex-head of the bolt was a small, scratched symbol: a crude cross inside an inverted triangle.
Captain Vane stepped over the rail, staring down at the mark. Her hand tightened on her lance until her knuckles creaked.
"The Frozen Hand," Vane growled, her voice shaking with a dangerous, quiet fury.
Danial looked up at her. "Who?"
"Cultists," Vane spat, her eyes scanning the dark shadows of the upper catwalks overlooking Pillar 12. "Extremists from the lowest coal tiers. They believe the big freeze isn't a natural disaster—they think it's a divine cleansing. They think anyone trying to warm the city with Selar technology is committing heresy against the frost."
"They aren't cultists, Vane," Maya said quietly, pointing to the edge of the ruined junction box. "Look at the cut on the main feed line. That wasn't done with a chisel. That was done with a high-density carbide shear. The kind of tool only council maintenance crews carry."
Silence fell over the small circle, heavier than the freezing air rushing through the conduit.
"Silas," Oakes muttered. "Or the Envoy left someone behind before the blast gates dropped."
"It doesn't matter who gave them the shears," Danial said, standing up. He looked at the ruined node, then out at the terrified faces of the refugees huddled in the frost at the end of the hall. "The point is... we aren't safe down here anymore. The Council doesn't need to break down the blast gates. They have people in this district who will break the grid for them."
Vane turned to her two best scouts. "Lock down the conduit. Nobody enters or leaves Pillar 12 without my personal pass. If you see anyone carrying heavy tools near the cable trunks... shoot first."
"We can't guard two miles of copper pipe, Vane," Danial said softly. "Not with twenty scouts. Every hour we stay up here trying to patch Node 2, we're just waiting for the next bolt to be jammed into Node 1."
He looked at Maya, then at Oakes.
"How long to bypass Pillar 12 and reroute the emergency feed to the basement?" Danial asked.
"Two hours," Oakes said grimly. "But it's a temporary patch, boy. Without Node 2, our thermal perimeter shrinks by forty percent. The outer residential blocks are going to drop back to freezing by morning."
"Then we don't have time to fix Node 2," Danial said. He reached into his pocket and pulled out his father's journal, turning past the pages of Node 1, past the battery schematics, straight to the heavy, ink-stained fold-out map at the back of the book.
The map showed the dark, uncharted depths beneath Sector 4—a labyrinth of forgotten Victorian drainage tunnels, flooded shafts, and ancient steam vaults labeled simply as "The Deep Sump."
At the very bottom of the drawing, marked in thick, red wax pencil, was a single, heavy circle: PUMPWORKS 0 — GEOTHERMAL VENT.
"We leave for the Deep Sump tonight," Danial said, his voice firm, echoing off the frosted iron walls of the conduit.
Maya looked at him, her eyes wide. "Danial... Node 2 is dead, the district is freezing, someone is sabotaging our wires, and you want to drag six heavy lead batteries down into three hundred feet of flooded, toxic tunnels?"
"Because if we build Node 4 at the geothermal vent, we aren't tapping into tiny Selar ore veins anymore," Danial said, his eyes burning with a desperate, sharp intensity. "We're tapping the planet's core. We build Node 4 down there, and the heat won't just hold Sector 4—it will blow back through the pipes, thaw Node 2 from the inside out, and make it impossible for anyone to short the grid ever again."
He looked at Captain Vane.
"Can you hold the perimeter for three days, Vane? Keep the cultists off Node 1 and keep the people from tearing each other apart?"
Vane looked at the scorched, ruined junction box, then down at the small boy holding a dead man's notebook. She slowly raised her copper lance, resting the iron butt against the frosted deck.
"I'll hold the perimeter, Danial," Vane said, her voice hard as steel. "Even if I have to stand on Node 1 myself with a loaded steam gun. But you better bring back that heat, boy... because if you fail down there, there won't be a Sector 4 left to come home to."