Oliver took a breath, raised the chalk, and drew the Ember Rune on the slate.
"Good," Marla said. "Now change it. One small change only. Add, bend, or cut."
Oliver stared at the rune.
Oliver thought of the Focal Thread, the Cohesion Seal, the compound runes he had seen in artificer diagrams. Ideas floated up one after another.
He lifted the chalk again.
Instead of just bending a corner, he drew a short line inside the core of the rune and linked two inner angles together, turning the simple pattern into a tighter knot.
Marla's eyes narrowed slightly.
"Bold for a first try," she said. "Very well. Give it mana."
Oliver put his palm on the slate, touched the modified rune with his fingertips, and slowly pushed mana into it.
Mana flowed out, passed into the chalk lines, and sank into the pattern.
For a moment, nothing happened.
The rune glowed a faint red, and the air warmed a little.
Not satisfied, Oliver poured more mana into it.
The glow deepened at once, and the warmth turned hot.
"Stop," Marla said.
Oliver stopped, but it was already too late.
The rune kept growing hotter.
The lines on the slate flared, and the red light brightened to orange.
"Ah," Ethan thought. "This feels a bit wrong.
BOOM.
Heat burst from the slate like someone had slapped a furnace door open.
The front tables shook.
Liam lurched backward with his chair, arms flailing.
Celia's neatly combed hair lifted from the force of the air.
Ria's ponytail blew straight back as she burst out laughing.
Thin smoke rose from the slate.
A round black scorch mark appeared where the rune had been.
Oliver stood frozen with his hand still half-pressed forward, hair slightly lifted, face warm.
Inside the bag, Ethan laughed so hard he almost forgot to breathe. 'I knew it. You just had to blow something up.'
The classroom exploded into noise.
"My hair!" Liam shouted, clutching his head. "My beautiful hair! I can smell it burning!"
Ria let out a short laugh. "Don't worry. Being bald will only make you look manlier."
Celia calmly smoothed her hair back with her fingers.
Her smile did not change, but her gaze on Oliver carried a sharper interest now, like a researcher who had just found a rare specimen.
Marla clapped her hands.
The noise in the classroom died at once.
"Relax," she said.
She flicked her wrist.
A small glob of green slime shot out of her sleeve and landed on Liam's head with a wet splat.
It wriggled over his hair, putting out the faint singe and leaving it damp and sticky instead of burned.
Liam froze. "Teacher… it is in my ear."
"Good. That means it works," Marla said.
Another lump of green slime dropped from her sleeve, hopped to the floor, and swallowed the smoke near the slate like it was chewing food.
It slurped up the last of the soot on the desk for good measure.
The air cleared in moments.
Marla looked at Oliver and the burned spot.
"Oliver," she said. "Tell me what you did wrong."
Oliver opened his mouth, then hesitated.
"…Pushed too much mana?" he tried.
"Wrong," Marla said.
She pointed at the ruined rune outline.
"You did not only add a line. You changed the flow priority. You connected two structural angles that were never meant to touch.
You told mana to gather and spin in place while still acting like Ember.
So instead of spreading heat, you trapped it and squeezed it until the only thing it could do was explode."
She looked at the rest of the class.
"Remember this. Changing a rune is not just 'adding one more line.'
One extra stroke might be a new path, or it might be a rope around your own neck."
She tapped the slate again.
"Failure is normal when you experiment. If you are afraid of failure, you will never create anything new.
But that does not mean you can walk in blind.
First, you learn what is already known.
Then you test it step by step, and you prepare countermeasures before you touch anything."
She pointed at the ruined rune.
"From the world's point of view, you tried to force a basic Ember rune to act like a small core with compression but no proper release formula.
You had structure and concept, but not enough experience and understanding. So it did the only thing it could. It broke."
Marla turned her eyes to Oliver.
"It is good to try new things," she said.
"Artificers must dare to change lines. But next time, you prepare more.
You plan what you will do, what might go wrong, and how to stop it when it does."
Oliver's cheeks grew hot.
He remembered her words from earlier.
"If you do not understand that, you are just carving pretty lines and praying they work."
Marla looked away from the slate and faced the class.
"That's enough for now. Sit down, Oliver."
He walked back to his seat under three sets of eyes.
Liam with his hair half burned and still slimy leaned over and whispered, "You owe me a hair tonic."
Oliver pretended not to hear.
Marla pointed at the girl who had been idly spinning a small wrench between her fingers the whole time.
"You," she said. "With the wrench. Name."
The girl straightened, grin already on her face.
"Ria Stone, Instructor," she said. "Future crafter. I like things that explode, but in a controlled way."
Liam stared at her, then at the scorch mark, then back at her.
Marla's eyelid twitched.
"Ria," she said. "From now on you sit two rows farther back when we do live tests."
"Yes, Instructor," Ria replied happily.
She looked at Oliver and gave him a thumbs-up.
"That was a good one," she added.
Oliver was not sure if he should be proud or worried.
Marla's gaze slid over to Celia.
"You already gave your name earlier, Celia Cross," she said. "You plan to walk the alchemy and Rune researcher path, yes?"
Celia nodded politely.
"Yes, Instructor," she said. "I am interested in how different plant and animal could turn mana into different magic without using rune."
"Good," Marla said. "Then today's lesson should remind you what happens when a 'small change' goes wrong."
Celia's smile stayed gentle.
Her eyes, however, shone with even more interest as she glanced once at the scorched slate and once at Oliver.
Marla turned back to the class as a whole.
"Listen carefully," she said.
"Runes are man-made. Someone paid a price in time, blood, or mistakes to make them work.
When you modify them, you are challenging that price."
She drew a simple line on the slate.
"Structure is the path. Concept is the meaning. Authority is the weight behind it.
Most of you, for now, will use what has already been carved into the world.
That is fine. You are still learning to walk."
She glanced at the scorch mark beside Oliver's failed rune.
"But if you want to be a true crafters, artificers, or alchemists who create new things, you will need to go beyond copying.
You will test, fail, and sometimes blow something up. Just try not to explode yourselves."
The three students gave a small, uneasy laugh.
Ria looked even more excited.
Marla checked the crystal slate on her desk.
"That is enough live demonstration for the first day," she said.
"For the rest of this lesson, copy the basic three-rune fireball pattern and write one possible modification you want to test in the future.
Do not test it now. Bring it to me first next class."
Oliver sat down, took out his notes, and started copying the Ember, Focal Thread, and Cohesion runes with care.
His hand still felt a little numb from the earlier explosion.
Ethan commented, "Next time, tell me before you make another explosion. I am too handsome to die twice."
"Senior, you do not have a face," Oliver thought back. "And aren't you indestructible?"
Ethan replied. "That'ss different."
Time passed quietly as the class worked.
Marla walked between the tables, glancing at their rune diagrams, knocking a knuckle on a desk whenever she saw something especially foolish.
When the bell crystal chimed, she clapped again.
"Class dismissed," she said. "Do your homework. Bring your modification ideas next time, and make sure it properly thought of.
If anyone writes 'I want to add more mana and see what happens,' I will personally assign you to take care my exploding slime."
Ria looked strangely hopeful at that.
Chairs scraped.
Liam gathered his books and gave Oliver a look of frown before hurrying out.
Celia adjusted her sleeves, took one last thoughtful look at the slate, then left with quiet steps.
Ria slung her toolbox under one arm, spun her wrench once, and grinned at Oliver on her way out.
The classroom door closed behind them.
"Oliver Reed," Marla said.
Her voice cut through the silence.
"Stay behind. I have a few questions for you."
Oliver swallowed and turned back toward the front.