The Manufacturing Zone, Northumbrian Coast
Fed by the wagonloads of sulfurous "Sea Coal" from the north, the blast furnace roared with a terrifying sound. Black smoke billowed into the sky, creating a permanent smudge that probably confused the local seagulls.
Inside the perimeter, Director Leif was screaming.
"Hotter! The slag is too thick! Feed it!"
"Toke, run faster or I will put a crab in your breeches!"
Toke, sweating buckets inside the giant hamster wheel that powered the bellows, groaned but picked up the pace. The air blast intensified. The internal temperature of the furnace climbed past 1200 degrees Celsius a temperature that shouldn't exist in 865 AD.
Leif wiped his face with a rag that was dirtier than his face. He looked like a demon, his beard singed and his skin glowing red from the radiant heat. But he was happy. He was the master of the flow.
"Director!" a worker shouted. "The Master Builder approaches!"
Leif straightened his soot-stained tunic. He grabbed a hammer, not because he needed it, but because it made him look busy.
Ragnar walked into the foundry. He looked like a health and safety inspector who had lost his clipboard. He was squinting at the black smoke.
"Long live the Builder!" Leif shouted, saluting with the hammer.
"At ease, Director," Ragnar said, waving a hand at the furnace. "She sounds hungry today."
"She is a beast," Leif beamed, patting the hot brickwork (carefully). "The black rocks... the Sea Coal... it is magic. We are tapping the slag every hour."
Ragnar walked closer. The heat hit him like a physical wall. "And the output?"
"We are filling four sand-pits a day," Leif reported proudly. "That's five hundred ingots. Or two thousand arrowheads. We have so much iron we are running out of places to put it."
Ragnar nodded, satisfied. In this era, a good smith might produce a few pounds of iron a day. They were producing tons. It was an industrial miracle.
"Show me the ammunition," Ragnar ordered. "The siege starts tomorrow. I need to know the Torsion Spikes and the Ballistas have food."
Leif puffed out his chest. "We have cast a thousand bolts, Lord. They are piled over there."
He led Ragnar to a covered wagon. Inside, stacked like firewood, were hundreds of iron bolts—short, heavy projectiles designed to be fired from the smaller siege engines and the handheld Torsion Spikes.
Ragnar reached in and grabbed two bolts.
He held them up to the light. He frowned.
He placed them side by side. His frown deepened.
One bolt was thick, with a jagged fin. The other was slender and smooth.
"Leif," Ragnar said slowly. "Why is this bolt fat?"
Leif squinted. "Ah. That one was cast by Toke's cousin, Snorri. Snorri has... heavy hands. He likes things big."
"And this one?" Ragnar held up the thin one.
"That was cast by Little Arne. He likes to save metal."
Ragnar felt a familiar headache forming behind his eyes. It was the engineer's curse: Variance.
"Leif," Ragnar said, his voice dangerously calm. "If I put Snorri's fat bolt into a Torsion Spike designed for Arne's thin bolt, do you know what happens?"
Leif scratched his beard. "It... sticks?"
"It jams," Ragnar corrected. "The weapon explodes. The Princess loses an arm. We lose the war."
"And if I put Arne's thin bolt into a wide barrel?" Ragnar continued.
"It... rattles?"
"It falls out," Ragnar sighed. "Or it fires with zero pressure and hits the ground three feet away. We look like idiots."
Ragnar looked at the pile of a thousand bolts. They were all slightly different shapes. In a hand-to-hand fight, it didn't matter. But they were building machines. Machines hated individuality. Machines demanded uniformity.
"Stop the casting," Ragnar ordered.
Leif looked horrified. "Stop? But the metal is flowing!"
"Pour it into ingots. Make bricks. But do not make another weapon until I say so."
Ragnar turned and walked toward the "Academy of the Stick." He needed to invent Quality Control.
An hour later, Ragnar sat at a table with Leif, Bjorn, and Gyda.
"The carpenters have the Stick," Ragnar explained, holding up his 'Ragnar Unit' ruler. "So the trebuchets are square. That is good. But the smiths... the smiths are artists. And artists are terrible for mass production."
"They are proud of their work," Leif defended his men. "Each bolt is unique."
"I don't want unique!" Ragnar slammed his hand on the table. "I want boring! I want identical! I want a bolt that fits every machine, every time!"
Gyda looked up from her ledger. "So you need a law for metal."
"I need a Judge," Ragnar corrected.
He pulled out a piece of flat steel he had forged himself. He had drilled a hole in it—a perfectly circular hole, exactly 20 millimeters in diameter.
"This," Ragnar held up the metal plate, "is the Hole of Truth."
Bjorn blinked. "It's a washer."
"It is a Go/No-Go Gauge," Ragnar said. "Leif, take this. Go back to the foundry. Every bolt that comes out of the mold must pass through this hole."
Ragnar demonstrated with a prototype bolt. He pushed it through. It slid perfectly.
"If it passes," Ragnar said, "it is a Good Bolt. If it gets stuck... it is scrap. Melt it down."
"And if it is too small?" Leif asked.
Ragnar pulled out a second plate with a slightly smaller hole.
"If it falls through the small hole too easily, it is also scrap. It must pass the big hole, but not be loose in the small hole. That is the Tolerance."
"Tolerance," Leif whispered the word like a prayer. "The metal must be disciplined."
"Exactly," Ragnar nodded. "And the same goes for the weights."
He turned to Gyda.
"We are selling iron to the Mercians. If we sell them a 'pound' of iron, it must be a pound. If we cheat them, they stop buying. If we give them too much, we lose money."
Ragnar pulled out a stone he had carefully ground down to weigh exactly one kilogram (or as close as he could get by estimating the weight of a liter of water).
"This is the King's Stone," Ragnar announced. "Make ten copies in iron. Give them to the Weasel. Every transaction must be weighed against this stone."
"The King's Stone," Gyda took the rock, feeling its weight. "Simple. Absolute. No arguing with a rock."
"Exactly," Ragnar said. "Arguments waste time. Standards save empires."
He looked at Leif. "Go. Sort the pile. I want every fat bolt melted down before sunset. Tomorrow, we load the machines. I want 100% reliability."
Leif saluted, grabbing the "Hole of Truth" as if it were a holy relic. "I will make them pass, Lord. Or I will melt their hammers."
The Foundry - Evening
Leif stood at the end of the casting line. He held the metal plate.
A young smith brought a freshly cooled bolt.
"Test!" Leif barked.
The smith pushed the bolt into the hole.
"FAILURE!" Leif roared, tossing the bolt into the 'Scrap' bucket. "Do you want the Princess to die? Try again!"
The next bolt. Slide. Perfect fit.
"PASS!" Leif shouted. "Mark it!"
The smiths were sweating, not just from the heat, but from the pressure. But strangely, the quality shot up. They started paying attention to the molds. They filed down the edges. They became obsessed with the "click" of a perfect fit.
Ragnar watched from the doorway. He saw the pile of "Good Bolts" growing—slowly, but surely.
"It works," Bjorn said, standing beside him, eating a roasted turnip. "They are scared of the hole."
"Fear is a good motivator," Ragnar noted. "But pride is better. Look at them when it fits. They smile."
"Brother," Bjorn asked, chewing loudly. "Does this mean we can fix the boots too? My left boot is tighter than my right."
Ragnar sighed. "One industry at a time, Bjorn. Let's conquer England first, then we'll revolutionize the shoe industry."
The camp was quiet. The fires burned low.
Ragnar sat in his tent, looking at a map of York. The city was surrounded by Roman walls. It was garrisoned by Northumbrians who knew the Vikings were coming.
But the Northumbrians were expecting a horde. They were expecting wild men who charged in a disorganized mass.
They weren't expecting standardized artillery. They weren't expecting 20mm Torsion Spikes. They weren't expecting an army that had played Rugby to learn formation discipline.
"We are ready," Ragnar whispered.
Gyda entered the tent. She was wearing her armor a custom-fitted leather cuirass Ragnar had designed. On her arm was the Valkyrie's Sting.
"The Weasel sent a bird," Gyda said, sitting across from him. "The Mercians bought the first shipment of skillets. We have silver."
"Good," Ragnar said. "We'll need it to rebuild the walls after we knock them down."
She placed a small pouch on the table.
"My father is impressed," she said. "He says you turned a beach into a kingdom in two weeks."
"Not a kingdom," Ragnar corrected. "A machine."
Gyda smiled.