Over the next week, Leon became obsessed with glass. He tested five different formulas, adjusting the ratios of sand, soda ash, and limestone, but each batch ended the same way—exploding at the slightest impact.
His second attempt: natural cooling. He left the glass sheet in the workshop overnight, letting the air cool it slowly. The next morning, he held his breath and tapped it with a feather. It exploded.
Third attempt: insulated cooling. He wrapped the hot glass in thick wool, trapping heat to slow the process. Two days later, he unwrapped it—smooth, clear, and seemingly solid. He dropped a pebble on it. Boom.
Fourth attempt: rapid magic cooling. He blasted the hot glass with cold air, mimicking quenching. The glass cracked instantly, shattering in the furnace.
Fifth attempt: quenching in water. He dropped the glowing glass into a bucket of cold water, hoping to harden it like steel. It shattered into dust.
Leon collapsed onto a stool, exhausted. His mana was drained, his hands covered in tiny cuts from glass shards, and his patience was wearing thin. He'd followed the Earth formula perfectly—why wasn't it working? Even his gunpowder had been semi-functional (if smoky), but this glass was a disaster.
He stared at the shards, his mind racing. Back on Earth, glass didn't explode like this. What was different? Maybe the impurities in the sand? He'd picked the purest sand he could find. Or the temperature control? The furnace's runes kept the heat stable.
"Stupid glass," he muttered, kicking a pile of shards. He'd been working alone, too stubborn to ask for help, but now he had no choice. Im knew more about materials and magic—maybe he could solve the problem.
He swept up the shards, wrapping them in a thick cloth, and headed to Im's laboratory. The mage was hunched over a table, drawing rune circles on parchment, his eyes bloodshot from lack of sleep. He'd been obsessed with designing a charcoal-based purification rune circle—something that could filter liquids and air, building on their paper's success.
"Master," Leon said, tapping on the door.
Im looked up, rubbing his eyes. "What is it? I'm in the middle of something." He liked Leon—his curiosity and work ethic were rare—but he'd been neglecting his students to focus on the rune circle. A mage's legacy often rested on such innovations; most Gray Robes never created anything lasting.
Leon held out the cloth bundle. "I made something, but it keeps breaking. Can you look at it?" He unwrapped the cloth, revealing the sharp glass shards.
Im picked up a shard, holding it to the light. "Crystal? No—this is glass. I haven't seen glass like this in years."
Leon's heart skipped a beat. "You've seen it before?" He'd worried the otherworld didn't have usable glass, but Im's reaction suggested otherwise.
"Along the coast, in the Maritime Trade Federation," Im said. "Merchants there make it—colored pieces for church windows. They guard the process fiercely—glassmakers are locked on islands, never allowed to leave. It's a luxury, too fragile for practical use." He frowned. "Why did you make this? And why are all the pieces shattered?"
Leon explained his greenhouse idea, then described his failed attempts. "Every time I tap it, it explodes. I followed the formula—sand, soda ash, limestone. What's wrong?"
Im's eyes lit up. "Ah—stress. Internal stress."