A Calculation of Yeast

Thjora

The copper grain chute rattles.

A shoe drops through the intake vent, followed by a shower of crushed barley hulls.

I do not raise the spanner to strike. The foot dangling from the sheet-metal pipe is too small for an enforcer, wrapped in frayed burlap and secured with split leather twine.

"Come down before you bend the copper," I say.

A muffled gasp echoes in the shaft.

A body slides out of the narrow duct, hitting the top of the roasted malt bin with a soft thump. Grain dust puffs into the cellar air, catching the orange light of the firebox.

Skirn scrambles out of the bin on her hands and knees.

She is sixteen, thin as a willow switch, her wool tunic dusted white with flour. Her dark eyes are huge in her gaunt face, ringed with dark purple circles from forty-eight hours without sleep. She has spent the entire morning hiding in the upper ductwork, watching the slaughter in the courtyard through the ventilation grates.

She lands on the stone floor, her knees wobbling under her weight.

"They threw the captain off the battlements," Skirn whispers. Her voice trembles so hard her teeth click together. "The new men... Vargun's men. They are dragging iron carts through the east block. They have chains, Mistress Thjora. Heavy ones."

"I know."

"Fjalar is hanging by his wrists from the gatehouse beam. I saw them strip his boots."

"Fjalar was an idiot who thought a broadsword could replace the grain supply," I tell her. I wipe the rim of the copper hydrometer with a clean rag. "Grab the broom. If Vargun's captains see loose grain on these flagstones, they will assume we have enough to waste."

Skirn does not move toward the broom.

She stares at the dark crimson stain near the central drainage trench—the spot where Torvald's neck snapped under Vargun's boot an hour ago.

"The blood," she rasps.

"It is washed," I answer. "Get the broom, Skirn. Fear does not scrub stone."

She swallows, her throat bobbing. She grabs the birch-twig broom from the corner and begins sweeping the spilled barley hulls into a neat pile beside the mash tun. Her hands are shaking, but she keeps her head down.

Good. An apprentice who freezes dies. An apprentice who sweeps survives.

Below our boots, the floor shudders.

It is not the rhythmic pounding from earlier. It is a sharp, chaotic clatter of tin plates and iron bars, accompanied by a chorus of raw, ragged screams echoing up through the drainage pipes.

Tier Four has crossed the threshold.

Without their noon dose, their adrenal systems have begun cannibalizing their blood sugar. The chemical delirium turns men into rabid wolves within ninety minutes.

"They are screaming," Skirn whispers, clutching the broom handle to her chest.

"They are starving," I correct her.

Footsteps pound down the spiral stairs.

Fast. Disorganized. Four or five men in iron-plated greaves, their boots clattering against the granite steps with desperate speed.

I step past the mash tun, resting my left hand on the four-pound spanner hooked to my belt. Beside the spanner, the four iron keys Vargun gave me clink against my hip. Deep inside my apron pocket, Hrokkr's brass master token rests cold and heavy against my thigh.

The distribution hatch at the far end of the brewhouse rattles violently.

It is a three-foot square opening set into a six-inch-thick oak partition, reinforced with crisscrossed iron strapwork. On the other side lies the main corridor to the lower holding wards.

An iron gauntlet smashes against the oak shutter.

"Open the hatch!" a man roars from the corridor.

"Identify yourself," I call out, walking toward the opening.

The sliding bolt on the exterior groans as someone throws it back. The heavy shutter swings outward, banging against the stone wall.

Five men stand in the dim torchlight of the hall.

They wear the boiled leather and steel pauldrons of the fortress guard, but none of them stand straight. The man in front is Captain Styr, a veteran who ran the east watch under Hrokkr for six years. His face is pale as tallow, slick with a film of cold sweat. His pupils are blown wide, his lower lip twitching in a rhythmic, involuntary tic.

Behind him, four soldiers lean against the damp granite walls, their hands trembling on the hafts of their short spears.

The smell of acetone and sour bile wafts through the hatch.

Metabolic crash.

"Give us the casks, Thjora," Styr rasps, gripping the iron bars of the inner grille. His knuckles are white, his fingernails split and bloody. "The whole tier is tearing the doors off the hinges. If we do not get the draught into them, they will breach the lower gates."

"The morning run is sealed," I answer, stopping two feet from the bars. "Twenty-four gallons. That is all there is."

"Give it to us!" a younger guard behind Styr shouts, his voice cracking with hysteria. His shoulders jerk with a violent tremor. "My hands... I cannot hold my spear. Give us the barrels!"

"Step back from the grate," I say.

"You do not give orders here, girl," Styr snarls. He reaches through the iron bars, his armored fingers grasping for the collar of my apron.

I do not flinch.

I take half a step backward, just out of his reach.

"Grab me, Styr, and I tip twenty-four gallons of fresh Maltar down the sewer drain," I tell him. My voice is flat. "You will be drinking bile off the floor while your kidneys turn to stone."

Styr freezes. His arm hangs through the bars, his fingers twitching in the empty air.

"We need the brew," he says, his tone shifting from rage to desperate pleading. "Just two kegs. For the watch. If the watch falls, Vargun's men will butcher the entire garrison."

"If you drink raw Maltar on an empty stomach right now, your heart will stop," I say.

"Bullshit," the young guard yells. "It is just strong ale!"

"It is an enzyme-bound metabolic regulator," I snap. "The wort is concentrated. If you drink it undiluted during acute withdrawal, the sudden glycogen spike triggers violent systemic shock. Your throat constricts. Your lungs fill with fluid. You drown in your own saliva in three minutes."

The guards exchange terrified, sweat-soaked glances.

None of them understand chemistry. To them, the brew is magic in a wooden cask—a bitter liquid that keeps the pain away and stops the madness from clawing out of their skulls.

"Prove it," Styr whispers, his chest heaving. "Give us a taste. If it works, we take the casks."

"Skirn," I call without looking back. "Bring the copper ladle and the small stoneware beaker from the balance shelf."

Skirn scuttles across the flagstones, her boots silent. She hands me the graduated copper cylinder and the long-handled ladle, her fingers shaking so hard the metal rings.

I turn to the first sealed oak cask beside the drain.

I pull the spigot plug. A stream of dark, viscous amber liquid pours into the copper cylinder. The rich, bittersweet scent of toasted rye, chicory, and concentrated valerian fills the air between the bars.

I measure exactly two ounces into the cylinder.

Then I reach down to the bottom sediment valve on vat four and draw half an ounce of raw, unfermented bitter-extract—heavy with raw lupulin resins and unbuffered mineral salts.

I step back to the hatch.

"Who wants the unmetered dose?" I ask.

The young guard shoves past Styr, his eyes wild with greed. "Give it here."

He thrusts his hand through the bars, snatching the stoneware beaker from my fingers before Styr can stop him. He tilts his head back and swallows the dark sludge in one greedy gulp.

"See?" the boy laughs, wiping his mouth with the back of his sleeve. "Nothing to it. It is just—"

He stops.

His eyes roll back until only the bloodshot whites show.

A sharp, wet gasp tears from his throat. His jaw snaps shut with a violent click, his teeth grinding together with enough force to crack enamel.

He hits the flagstones on his back.

His legs thrash against the stone wall, his arms locking rigid at his sides as his chest heaves in massive, silent convulsions. White foam bubbles at the corners of his lips, his skin turning a mottled, suffocating purple within ten seconds.

"What did you do to him?" Styr roars, drawing a rusted dirk from his belt and slashing at the iron bars. "You poisoned him!"

"I gave him what you asked for," I say coldly. "An unmetered dose of raw concentrate during metabolic crash. His liver cannot process the enzymes. His diaphragm has seized."

"Fix him!" Styr screams, slamming his shoulder against the oak frame. "Fix him or I burn this door down!"

"Drop the knife."

Styr hesitates for one heartbeat.

On the floor, the young guard's convulsions turn feeble, his fingernails scraping uselessly against the mortar.

Styr drops the dirk. The steel clatters against the stones.

"Step back," I order.

The guards drag the seizing boy closer to the hatch.

I lift the copper cylinder. In it, I have mixed two ounces of the finished, buffered Maltar with four ounces of cold valerian wash—a calculated titration designed to bind the unbuffered salts and flood his bloodstream with absorbable glycogen.

I reach through the bars, grip the boy's jaw with my left hand, and force his clenched teeth apart with the flat head of my spanner.

I pour the amber wash down his throat.

The liquid disappears into his gullet.

For five agonizing seconds, nothing happens. The boy lies limp, his chest still, the purple cast deepening around his eyes.

Then his rib cage heaves.

He draws a deep, ragged breath of cellar air, coughing violently as amber foam sprays across his tunic.

The tremor in his hands slows. The rigid tension drains from his neck. Within twenty seconds, his breathing settles into a steady, rhythmic rasp, his skin flushing back to a pale, normal tone.

He rolls onto his side, groaning softly, his eyes focusing on the granite ceiling.

The guards stare in stunned silence.

Styr slowly steps back from the hatch, his face drained of all color. He looks at the copper measure in my hand as if it were a loaded crossbow.

"You see?" I say, setting the cylinder on the wooden ledge. "Chemistry is not a sword, Styr. You cannot swing it harder to make it work faster. You measure it to the grain, or you die choking on your own tongue."

A slow, heavy clapping sound echoes from the stairwell behind the guards.