The limestone blocks from the quarry were rough-hewn, massive chunks of ancient grey sea-bed that still held the faint, spiral impressions of prehistoric shells. They sat in the mud by the stable wall, their wet surfaces glistening like the skin of landed whales under the cold dawn light. The carters had left them where they fell, a chaotic heap of stone that blocked the path to the granary and forced the milk-girls to skirt the edge of the drainage ditch.
Thomas stood at the vertex of the new line, a long ash measuring rod in his right hand. He had driven three iron stakes into the yellow clay of the southern slope, connecting them with a heavy, multi-stranded twine he had twisted himself from the hemp cords of the old wool sacks. It wasn't the silk-smooth line a surveyor in his own century would use, but it was straight enough to expose the uneven ground.
"The rise is four inches over ten paces, my lord," Elias said, adjusting his iron compasses over a fresh sheet of hide. He had set up a small folding stool on a dry patch of shale, his ink-pot secured in a hollowed-out block of pine so the wind wouldn't capsize it. "If the masons lay the first course flat without digging down to the shelf, the weight of the mortar will push the outer face toward the river by winter."
"Then they dig," Thomas said, his voice flat from a night spent in the cellar. He had scarcely slept two hours, his ribs aching from the hard firkin and his eyes still filled with the green ghost-images of his apartment screen. "We don't build on the loam. We clear the dirt until the iron spikes strike the grey stone beneath. I want the foundation three feet thick at the base, tapering to two at the breast-work."
He reached into his pocket, his fingers passing over the cold copper wire before finding the smooth glass of the device. He pulled it out, keeping his body between the screen and the mapmaker.
Battery: 81%
System Download: 61%... 62%...
The red line was crawling again, a minute fraction of a percentage with every turn of the water wheel down the valley. The 300-second timeout had passed, but the live feed of his room didn't return. The interface remained stuck in a grey diagnostic loop, a series of local pings that returned nothing but asterisks and latency errors. The remote desktop script was still running on his PC in Denver, but the connection was losing its grip on the temporal grain.
Victoria arrived from the kiln yard, followed by two boys dragging a low wooden sledge loaded with square brick tiles. Her kirtle was tucked up into her belt, her wool stockings caked with grey lime-dust from the mixing pits. "The master mason says he needs six bushels of slaked lime before noon, Thomas. He says the mortar we mixed yesterday has gone thin from the rain, and it won't hold the weight of the corner stones."
"The lime is in the third shed," Thomas said, his thumb scrolling through a cached dictionary of medieval construction techniques. "Tell him to use the double-burned batch—the stuff we pulled from the kiln after the second coal run. It has more silica in it. It will set underwater if we have to flood the ditch."
Victoria stopped by the ash rod, her dark eyes looking down at the red line on his screen before shifting to his face. She could see the grey shadow of the coal smoke under his jaw and the dry, white crust of salt on his lips. "You look like a man who has spent the night in the guard-house, Thomas. The line is straight enough. Go up to the solar and eat the bread."
"The bread can wait," Thomas said, locking the device. "The server update won't."
He walked down the line of twine to the spot where the master mason, a gnarled old craftsman named Hamo whose knuckles were twice the size of Thomas's, was leaning on his heavy iron mallet. Hamo had a leather apron full of wooden wedges and a square piece of lead sheet he used to check the level of the courses.
"It's too close to the ditch, my lord," Hamo said, spitting a mouthful of dark tobacco-leaf into the clay. He didn't look at Thomas; he looked at the iron stakes. "If the river rises in the autumn, the water will eat the lime out of the joints before the mortar has time to turn to stone. We usually build twenty paces back from the willow fringe."
"We don't have twenty paces, Hamo," Thomas said, his boot tapping the iron stake at the corner vertex. "If we move the wall back, we lose the line of sight from the watchtower on the bluff. De Born's riders could clear the turn of the gorge before the lookout could strike the first note on the bell. The wall stays here."
"It's your stone," Hamo grunted, swinging his mallet down onto a wedge to split a limestone block. The sound was a sharp, ringing clink that echoed off the stable wall. "But if she slides into the silt when the frost breaks, don't tell the Archbishop's proctor that Hamo laid the line."
"If she slides, Hamo," Thomas said, "we'll all be too busy running from the Baron's pikemen to care about the masonry."
He turned back toward the Great Hall of Wheels, his cloak catching on a wild briar at the edge of the track. The factory was loud today—a high, rhythmic shriek that meant Cerdic had increased the tension on the main drive belts to finish the second shipment for the Oakhaven market. The sound was a comfort, a mechanical pulse that proved the system was still executing its loop despite the shadow of the Sunday deadline.
As he reached the forge yard, Wat was waiting by the cooling trough, a long bar of square-section steel clutched in his iron tongs. The metal had been quenched in oil instead of water, giving it a dull, iridescent black skin that looked like a beetle's wing.
"We cracked the third mold, Thomas," the smith said, holding the bar up to the light. It was a gear-blank, six inches across, with twelve square teeth cast into the rim with an accuracy that would have been impossible with a hammer and anvil. "The steel is clean. No cold-shuts in the sand, and the teeth are sharp enough to cut leather. But the axle-hole is too small. The drill bit we made from the old ploughshare won't bite into this stuff—it just dulls the tip after three turns."
Thomas took the gear from the tongs, the metal still warm enough to make the grease on his fingers smoke. He looked at the precise geometry of the teeth. This was the first true mechanical component produced by the valley's new chemistry—a gear that could withstand the high torque of a high-pressure engine without stripping its face.
"We don't use the ploughshare," Thomas said, his mind shifting back to the files he had downloaded during his first week in the cellar. "We need to make a tungsten-alloy bit, or at least a case-hardened tool steel with a high manganese content. I've got the extraction drawings for the bog-iron deposits in the northern marsh. There's manganese in the black mud there."
He pulled out the phone to check the local map data he'd cached, but as the screen woke up, the grey diagnostic loop vanished.
A new notification banner dropped down from the top of the black glass, its white text stark and terrifying against the blue background.
System Warning: Registry synchronization failed. High latency detected on gateway 192.168.1.105. Temporal drift exceeded maximum tolerance (+0.0042s/hr). The connection will be downgraded to read-only text transmission within sixty minutes.
Thomas felt his breath hitch in his throat. The progress bar for the system download was stuck at 64%. The "read-only" state meant the binary file transfer would terminate; he would still get the text messages from his mother and Sarah, but the rich data—the technical drawings, the chemistry tables, the blueprints for the turbines—would remain locked on a server eight hundred years away.
"Wat," Thomas said, his voice dropping into a register that made the blacksmith look up from his trough with his good eye wide. "Get the boys. Leave the gear-blanks in the sand."
"My lord?" Wat asked.
"We're out of time," Thomas said, turning toward the stairs of the keep. "We need every scrap of coal we have left brought down to the cellar furnace. I want the temperature in that vault high enough to melt lead before the sun hits the ridge."