The next three days were a lesson in patience and tension.
For the Earth People, waiting was a form of agony. They were a people of action, of hunting and movement. Being anchored to a mound of smoking dirt that smelled like sour wood was unnatural.
Kael was the worst. He spent the hours sharpening his iron knife, casting murderous glances at the charcoal mound and then at Seiko. He muttered to the other warriors, talking about how the Cold Fire was deceiving them, making them work for nothing.
Iris let him be. She watched Kael, but mostly, she watched Seiko.
Seiko, to her frustration, seemed completely unaware of the tension he was causing. For him, the waiting time didn't exist; it was simply a processing period that freed up his time for another critical task.
On the morning of the first day, after cleaning Acies's wounds (who was now recovering quickly, his eyes almost free of swelling), Seiko headed to the ruins of his barricade.
"The work never stops," he had told Iris. Now he was going to prove it.
He took the broken spear from the Alpha Krookodile and began to trace a line on the ground, not straight, but a semicircular curve connecting the cave wall with the opposite cliff.
"What are you doing now?" asked Iris, approaching.
"A wall," said Seiko. "A real one. Wood can burn. Wood rots. Wood gives way."
"Stone?" she said, looking at the countless rocks scattered across the clearing. "You will stack rocks? An Excadrill will knock them down."
"Stacking rocks is what a child would do," said Seiko. "I won't stack, but rather use them as a base to create something."
He pointed to Tyla, the curious young warrior. "You. Come with me. You are strong and you ask questions. That makes you useful."
Iris was amused by the order. "Tyla. You are Seiko's apprentice. Watch."
Seiko ignored the mockery. He handed Tyla the makeshift shovel made of Krookodile hide. "Dig here," he ordered, pointing to the line he had traced. "A trench, as wide as your foot and as deep as your shin."
Tyla, although obedient to Iris, seemed confused. "A trench? What for?"
"For what we will do," said Seiko. "You can't build something heavy on soft ground. It sinks. It cracks. Dig the trench, fill it with small gravel from the stream, and then put the large stones on top. The weight is distributed. The wall holds."
It was the most basic engineering lesson, but for Tyla, it was a revelation. It was a reason for something she had never considered. She began to dig, her resentment replaced by curiosity.
While Tyla dug, Seiko took Rorin and Toma, the other two warriors, and set them to work moving the larger stones. Acies, now agile, scurried between them, acting like a miniature supervisor, letting out a sharp ching if anyone got too close to Seiko's tools.
They spent the first day digging the trench and filling it with gravel. Kael watched from afar, sneering. "The great Seiko! Making us dig in the dirt like a Sandshrew!"
Seiko did not respond.
On the second day, the smoke from the charcoal mound changed. The thick white gave way to a finer, bluish smoke. The Earth People grew nervous, but Seiko simply nodded, satisfied.
"It's working," he murmured.
That day, the next lesson began: mortar.
"Dry rocks fall," he explained to Tyla and Rorin. "They need glue."
He took them to the edge of the stream, where the water ran slower, and pulled out a handful of sticky gray clay. "This."
Then he went to a sandbank. "And this."
Finally, he gathered a bunch of tall, dry grass from the plain. "And this."
Back in the clearing, he had Rorin bring water. They mixed the clay, sand, and cut grass into a thick, muddy paste on one of the Krookodile hides.
"He plays with mud!" Kael mocked again.
"I make liquid bricks," Seiko corrected. He carried a pile of the mortar to the gravel trench. He placed the first large stone. Then, he packed the mortar into the gaps, pressing it down before placing the next stone.
It was slow, dirty, exhausting work. But by the end of the second day, they had a row of stones, 2 feet (0.6 meters) high, solidly fixed to the ground. It wasn't a pile of rocks. It was a wall.
Tyla touched the mortar joint, which was already starting to dry in the sun. It was hard. "It doesn't move," she said, amazed.
"That is the point," said Seiko.
On the morning of the third day, silence fell over the camp.
The charcoal mound had stopped smoking.
Kael was the first to notice. "All that work. All that smoke. For nothing. You've tricked us!"
Seiko, who was placing another stone on his wall, stopped. He set down his hammer. He wiped the mud from his hands.
"It's not dead," said Seiko. "It's ready to use."
He walked toward the dirt mound. Everyone followed. Iris, Kael, Tyla, Rorin, Toma. Even the other warriors stopped processing the Krookodile hides to look.
Seiko picked up one of the hide shovels. He approached the mound and, carefully, began to remove the dry, cracked earth from the top.
A dry heat radiated from it.
"Stand back," said Kael, impatient. He shoved Seiko aside and plunged his obsidian spear into the side of the mound, tearing open a large hole.
A cloud of gray ash puffed out, followed by... nothing. Just a dark void.
Kael reached in. "Ashes! I told you! Nothing but...!"
His voice cut off. He pulled his hand out. He was holding a piece of wood. Except it wasn't wood. It was black like obsidian, but incredibly light. It shone faintly in the sunlight.
Seiko reached in and pulled out a larger piece. It was brittle. He snapped it with his hands. The inside was pure black, porous.
"Cooked wood," whispered Tyla, astonished.
"Charcoal," said Seiko. "The blood of fire. The fuel of iron."
Kael looked at the piece in his hand. It was so light it felt like a scam. "This? This is what we waited three days for?"
Seiko didn't answer with words. He grabbed a handful of the new charcoal and took it to his forge, which only had a few embers of normal wood. He dropped the charcoal on top.
At first, nothing happened.
"Ha," Kael scoffed.
Seiko grabbed his bellows. He began to pump air.
There was no burst of orange flames like with wood. Instead, the charcoal embers began to glow. First red, then intense orange, and then, with a low, hissing roar, the fire turned a bluish-white.
The heat radiating from it was different. It was intense, dry, almost painful to look at. It was a heat the Earth People had never seen.
"By the Earth!" exclaimed Rorin, stepping back.
Seiko took his iron hammer and stuck the head into the white flame. In less than a minute, the iron began to glow bright orange, much faster than the ten minutes it used to take.
"This," said Seiko, his voice echoing over the roar of the forge, "Is the heat that iron respects. This is the fire that bends metal. This is the power I offered you."
Iris stepped closer, her face illuminated by the white light. She didn't look away from the fire. She saw the glowing iron. She saw the half-built stone wall. She saw the now-opened mound, full of the miraculous fuel.
"Seiko," she said, and for the first time, there was no mockery or suspicion in her voice. There was awe. "You have shown us the foundation. You have shown us the fuel."
She looked up at him, her dark eyes reflecting the white flame.
"Now, teach us to make the iron."