The heat in Sub-Basement Annex 4 began swinging like a broken swinging weight on the third morning after Arthur treated the boiler stoker’s ox.
At sixth bell, the stonework walls were weeping frost. Toby sat on an upturned oats barrel with an army greatcoat pulled over his shoulders. His breath condensing in was pale plumes as his shivering fingers inked receipts into the red ledger. Two hours later, without warning, the cold vanished. A dry, baking heat bled through the southern bedrock, thick with the smell of scorched iron and heated lime. He drove the room heat past forty degrees.
Toby stripped off his coat, groaning as he wiped sweat from his glasses with the hem of his tunic.
“First we freeze, now we’re being roasted like cellar sausages,” Toby complained, fanning himself with a stack of parchment vouchers. “Arthur, is the fire wall supposed to hum like a tuning fork? My teeth have been shaking since breakfast.”
Arthur stood by the backup workbench, cleaning a set of razor-sharp tweezers in a bath of pure alcohol. He didn’t mind the heat. His body had long adjusted to the brutal heat fluctuations of field trauma tents. But he noted the change in the room’s air currents. The draft pulling through the low air-flow grates had reversed. Instead of drawing cool underground air down from the northern gardens, the vents were pushing back a dry, acrid breeze that tasted of brimstone and crushed coal.
Beside the zinc table, Grimm was not sleeping.
The jet-black hound stood rigid on all four paws, his notched left ear cocked toward the southern wall. His black coat, dense with jet-black bone marrow deep ring, absorbed the surrounding heat without distress. But his nostrils were working overtime. He sniffed the seam where the granite blocks met the massive cast-iron housing of Exhaust Chimney pipe 07.
A low, questioning whine rumbled in the back of Grimm’s throat.
“What’s it, boy?” Arthur asked, setting the tweezers down on a clean lint cloth.
Before Grimm could respond, the heavy hall door rattled wildly. Three wild, thunderous blows shook the timber planks, followed by the muffled shouting of men choking on smoke.
Arthur unlatched the heavy iron bolt and pulled the door open.
A billow of yellow-gray soot rolled into Annex 4. It carried with it Head Stoker Garek and two junior fire mechanics. The three men were coughing wildly, their faces blackened with greasy carbon, wet rags tied across their mouths and noses. Garek was clutching a brass Bourdon-tube pressure gauge whose needle trembled dangerously in the red graduation zone.
“Cadet Vance!” Garek gasped, leaning against the doorframe to catch his breath. “Close the door! For the love of iron, slam it shut!”
Arthur shoved the heavy timber door closed, dropping the latch pin. The yellow smoke in the room began slowly drifting toward the ceiling vents.
“What happened in the boiler room?” Arthur demanded, his cold and exact voice cutting through the panic.
“Bio-Fire 07,” Garek wheezed, tearing the rag from his mouth and spitting a glob of black thick spit into the drainage gutter. “The main exhaust channel. It’s choked. The draft died twenty minutes ago, and the fire-box is back-drafting into the main service tunnels. If we can’t clear the stack, four hundred pounds of burning aetheric sludge will detonate the backup gas pipe hub!”
Toby leaped to his feet, knocking his inkpot over. “Detonate? As in explode? As in collapse the ceiling on our heads?”
“As in blowing a hole through the foundations all the way up to the Dean’s rose gardens!” one of the mechanics yelled, eyes white with terror against his soot-smeared skin. “The main stack runs right behind this wall! The bypass damper is jammed shut!”
Arthur walked to the southern wall. He placed a bare palm against the dark stone blocks. The stone was uncomfortably hot to the touch, shaking with an irregular, choked thrumming. It was like an animal suffering from a massive tracheal blocked path.
“Where is the main damper access?” Arthur asked.
“There’s an upkeep check port fifty paces down the service crawlway, right beside your annex wall,” Garek said. He waved his hands wildly. “A four-foot upright riser. But nobody can get near it! We brought the infrared heat gauge to the crawlway hatch two minutes ago. The air around the check plate is running three hundred and ninety degrees! The cast-iron damper plate has warped in the guide rails! If you open that hatch, the blasting heat will cook a man’s lungs in three breaths!”
“Did you try to engage the clockwork balance weight lever?”
“The balance weight chain snapped!” Garek shouted. “The plate dropped straight into the seat and wedged itself diagonally across the duct! It’s jammed against the exhaust throat! Standard fire-suits melt at two hundred and fifty degrees. We can’t get close enough to put a pry bar on it! The chief engineer wants to flood the shaft with liquid wet-melted rock waste from the upper hoppers to choke the fire!”
“If you dump wet melted rock waste into a four-hundred-degree exhaust pipe, the steam explosion will crack the bedrock seals,” Arthur said coldly. “And whatever is stuck in that duct will be boiled away.”
Garek blinked through the soot. “Stuck in the duct? Nothing’s stuck in the duct, cadet! It’s soot! Fifty years of uncleaned fire scale that collapsed off the chimney pipe lining!”
Grimm stepped between them.
The black hound didn’t look at Garek or the mechanics. He walked directly to the heavy iron check panel bolted into the base of the bedrock pillar. He pressed his broad black nose against the seam of the sealing seal ring. Then he drew in a deep, burning breath.
A sharp, electric pulse traveled along the Soul-Link into Arthur’s mind.
It wasn’t a warning of load-bearing collapse. It was sense tracking data.
Through Grimm’s hyper-acute smell nerves, Arthur caught a scent fully distinct from the burning hard coal and sulfur. It was the smell of organic protein undergoing rapid heat degradation. Specifically, the sharp, oily reek of scorched avian plumage.
And behind that scent came a sound signed name.
Grimm tilted his head, pressing his notched ear flat against the shaking iron duct.
Arthur tapped into the sense tap. Through the metal housing, drowned beneath the roaring rush of trapped burning gases, an impossibly faint, rhythmic fluttering reached Arthur’s brain.
Thump-thump.
It was a heartbeat. But it wasn’t the slow, heavy beat of a dying draft beast or the wild pace of a rodent. It was a micro-heart pulse, fluttering at an astonishing three hundred and eighty beats per minute.
Something was alive inside that inferno.
Something smaller than a man’s hand, trapped behind the warped damper plate, bathed in four hundred degrees of white-hot burning exhaust, still fighting for air.
Arthur didn’t hesitate. He swung his Zeiss monocle magnifying glass down over his right eye.
“Stand back,” Arthur commanded.
The mechanics scrambled away as Arthur stepped up to the backup check port. A thick, eight-inch disk of heat-resistant quartz set into the iron pipe rim of the duct casing. The glass was coated in oily black soot on the inside. But Arthur rotated the outer brass bezel of his magnifying glass, engaging the triple quartz prisms.
The sight array filtered out the visible haze, shifting his vision into heat-infrared and aetheric wavelengths.
Through the soot-streaked glass, the inside of Flue Duct 07 was an ocean of blinding orange and white fire. White-hot burning gases swirled in a violent vortex, starved of oxygen by the jammed damper plate above. The cast-iron damper—a slab of dark metal two inches thick—hung at an awkward thirty-degree angle, wedged tight into the hard dark metal guide rails.
And there, wedged directly beneath the lower lip of the jammed plate, caught between the glowing iron edge and the heavy melted rock waste grate, was a tiny, huddled dark shape.
It was an avian form, no larger than a fist. Its plumage was fully burned up, reduced to glowing, blackened stubs that hissed against the metal. Yet beneath the charred skin, Arthur’s magnifying glass detected something impossible.
A brilliant, thread-like network of blazing bright golden light pulsed through the creature’s tiny chest cavity. It wasn’t burning from the outside in. Its tiny, fragile core was actively absorbing the surrounding heat, channeling the four-hundred-degree heat inferno into its dormant chest bone in a desperate, gut bid to keep its tiny heart beating.
A test slate condensed with startling clarity across Arthur’s vision:
Arthur stepped back from the check glass. His eyes were cold, his pulse steady, his mind already shifting into the focused clarity of an emergency trauma surgeon facing a ticking clock.
“Garek,” Arthur said, his voice ringing with total guard post power.
The head stoker straightened instinctively. “Sir?”
“Don’t touch the melted rock waste hoppers. If a single drop of water or wet melted rock waste enters this channel, the pressure wave will destroy the sample.”
“Sample?” Garek’s jaw dropped. “Cadet, there’s nothing alive in a four-hundred-degree chimney pipe! It’s impossible! Flesh melts at half that heat!”
“Tissue never lies, Garek,” Arthur quoted Heseltine with razor conviction. “There’s a living sample trapped under the lip of Damper 04. Its heart is beating at three hundred and eighty beats per minute. And we have less than six minutes before the backing-up pressure blows the check seal ring.”
Arthur stripped off his wool uniform tunic, tossing it to Toby. He grabbed his heavy leather field apron—stiff, double-layered hide treated with alum and oil—and pulled it over his head.
“Toby!” Arthur barked. “Bring the bucket of salt water from the sink! Soak two canvas blankets until they’re dripping! Find the heavy four-foot hard dark metal pry bar from the tool chest!”
“A-right away!” Toby shouted, scrambling across the floor, abandoning his precious ledger to haul the heavy iron crowbar from the bottom crate.
Arthur turned to Grimm. The black hound met his gaze, his amber eye burning with intelligent focus. The dog understood. There was prey—or a friend—trapped in the fire.
“Grimm,” Arthur murmured, resting his hand on the hound’s thick neck. “You’re my balance weight. When that iron yields, we pull together.”
Grimm gave a single, deep diesel chuff, his heavy claws digging into the stone floor, his muscles knotting beneath his carbon-hardened skin.
Arthur grabbed the heavy brass high-pressure valve head Grimm had scavenged from the necropsy tiered arena the last morning. Its thick, solid hard dark metal-bronze bulk was impervious to heat.
“Garek, clear your men from the hall,” Arthur ordered, stepping toward the crawlway hatch. “We’re breaking the damper open.”