Adrin left the mansion chuckling evilly. It would've been perfect with a cat on his lap. The family had unwittingly handed him the jackpot, and he had only realized after he had absorbed it.

The old butler had handed him a few things which also included the [Book of Runes], the spellbooks for [Torch], and [Fireball]. He was forced to absorb them right in front of the butler’s eyes just to be sure he would sell it or something.

The old man was alternating in between relief and regret after it was done. The books must have cost a fortune, but they were worried about the totally wrong thing.

They should be worried about what he could do with this knowledge.

“Don’t disappoint the Matriarch,” the butler warned as he closed the door to the carriage.

Who was this old man? He was acting like a passive-aggressive father who had suddenly found out his little girl had a boyfriend. The problem was he doubted the old man was her father and she wasn't a little girl anymore. She wasn't even close.

Adrin had just nodded to the old man, but he didn’t need a warning or something. He wanted to crack the code of the blue flame for his own use.

And he would say, he already had it, but he had to be sure. The spell glyph had to be solid. He didn’t want to embarrass himself in front of the leader of the family. The lady would spit on him and kick him out without even blinking an eye. She only had one thing in her mind, the blue flame.

It made him wonder, what a patriarchal noble family would look like.

Finally able to relax, Adrin laid down on the carriage’s seat. He stared at the roof while looking back at the encounter with the Matriarch. The lady had way more baggage than Hana.

He was able to keep it cool only because he was awakened and the experience that came with it. It was even worse than facing multiple managers in an interview or something. An average young man would have pissed his pants in front of such a lady.

Hana’s [Fireball] had scared the shit out of him, but that was nothing compared to the Matriarch. The bombshell of a lady didn’t need to cast any spell but the 'flame' coming out of her was already suffocating. It must have been an [Aura] or something or he would already be toasted alive.

However, it had been worth it when the key was given to him. The Book of Runes had everything he was looking for and more.

Adrin had spent one whole night tinkering with the [Candle] spell. He had tested every rune and connection in its spell glyph by using what he called the mana version of a multimeter. It wasn’t as simple as buying the thing and poking around, but he had made it work.

He found a rune that functioned like a resistor when the mana capacity or flow reduced after moving through it. A capacitor rune would absorb the mana until it reached its limit, it would discharge it when the mana was needed.

There was also a collection of logic runes that set the conditions but it was obviously not binary. The logic gates were impossible to figure out. He only learned their names from the book and further confirmed with the knowledge he had just absorbed.

More complex runes like [Ignia] let out a spark when tested on their own, or [Aero] which turned mana into gas. The last major rune [Nif] turned mana into fuel and mixed in [Oaru].

The key rune was the one that oscillated the mana. The [Essa] rune differs in output based on how it was written. He was looking for this particular knowledge because no matter how or what he had tried, he couldn’t change the strength of output.

He got off the carriage when he got back and found the house empty, except for Lily, of course.

“Where’s everybody,” he asked as the girl helped with his shoes. Trying to stop her would be a fruitless endeavor, better just get used to it.

“Miss Emi and Miss Nerina went shopping with young master Brian,” Lily said as she kept his shoes. “I thought you already talked about this.”

“Ah yes, I forgot, thank you, Lily,” he said as he slipped past her. Adrin took a seat on the couch breathing in relief.

“How- how does it go?” the girl asked.

“You mean the meeting with the Matriarch? It is fine, everything is cool.”

“Cool?” she looked confused for a moment, “you mean it’s confirmed?”

“Yes, it should be, she claimed that she is my Matriarch,” Adrin shrugged. “And I got this black tag with something carved on it.”

Lily placed her hand on her chest and breathed in relief, “That’s the family’s emblem, can this one greet you now, young master?”

“Yes, I supposed,” Adrin replied.

Lily kneeled on the couch and kissed him on the lips. It was so sudden until Adrin just sat there like a fool while the girl stood back up.

It was just a quick kiss but the girl's face was all red.

He just stared at the girl for a few seconds too long.

“Young master, is everything alright?” The girl asked, concerned.

“Is that how-”

“Yes, every morning and before bed,” she answered like a script.

“Every young master is like this?”

“Yes, if the family has allowed him to have a maidservant, but he has more than one maidservant, we will take turns,” she helpfully answered. “Would you like a drink?”

He was willing to bet the spoiled young masters would beg their mothers for one. They might even throw a tantrum like a child denied his toy, but that did raise another question.

“Yes, please, but what about, you know, a female young master or something?”

“She can choose to have a servant, but most would rather preserve their chastity until they find the one worth it. I’ll go and make your drink now.”

Lily bowed and hurried her way to the kitchen. Her steps were springy like she was having the time of her life. The girl really loved to serve, but he couldn’t help it to feel bad for her. It felt like she had been brainwashed.

But as a slave, maybe that was her only light at the end of the tunnel. He wanted her to be like others, free to make her own choice, but who was he to decide her fate? She was happy doing what she was doing, wasn’t that enough?

Adrin sighed and placed the issue at the back of his mind. It wasn’t his business to do anything about her life. If she needed help, she would ask him and then he would think of a way to help.

He molded the [Candle] spell glyph again and began to make changes. Backed by the vast collection of knowledge in the ancient runic words, he began to make changes to the [Aero] portion of the glyph.

His first complete glyph failed as he had expected.

Adrin said his thanks when Lily returned with his drink. The girl then sat not far from him, marveling at the melded glyph floating in the air.

Just like programming or designing an electric circuit, the first few tries would fail to produce anything. He wasn't a genius or anything. He noticed the extra connection to the other runes which might be a feedback loop and timing mechanism.

Adrin molded two more fire-based spell glyphs and compared all three of them. The [Torch] had a few more control runes that control the range and intensity of the flame. Based on what he saw, the spell should work like a flamethrower.

He enlarged one part of the runes and he noticed something very puzzling.

‘Is that a math equation?’ he said inside his head.

It looked like the triangle formula, but of course, in this world’s unique language. Because the written language was based on the ancient runic words, it looked like random symbols included in the glyph at a glance. He had just wanted to make a blue flame, but this finding was much more interesting at the moment.

‘Spell glyph accepting math equation?’ Adrin mused. ‘Then how advanced is math in this world? Is anything like trigonometry already discovered? How about other shapes or polygons?’

Adrin dispersed the [Fireball] spell glyph and formed the [Shell] glyph. He searched for anything that looked like a math formula, but he couldn’t find anything. It was not what he had expected. After checking every nook and cranny of the glyph, he found a curious similarity.

It looked similar to the [Torch] part which contained the triangle formula but empty. He dispersed everything and rested on his back, astounded by his latest finding.

Spell glyphs used math to set something? But what was it used for? Has anyone else noticed this crucial fact?

Adrin wanted to ask someone but what if advanced math had never been developed? Would he surprise someone if he had even asked the question?

The main reason math became as advanced in the old world was because it had no magic. It was needed to build things, and math was crucial to any technological advancement.

Sure, you could build a two-story house without any math, but it became exceptionally more difficult with each floor. There were a lot of things needed to calculate to ensure the building wouldn’t crumble under its own weight or simply not be built straight.

Adrin looked around the house. The chairs and the cupboards. Every little thing might be hand-built, no, hand-shaped by using skill, just like his [Metallurgy] or [Crystal Meld]. The glasswork, the clothes he wore, the kitchen utensil Lily used in the kitchen.

“Necessity is the mother of invention,” he mumbled.

In fact, because of their religious needs, Muslim mathematicians had studied and improved trigonometry into the modern form everyone use. It was the complete opposite in this world. Who would need for complicated calculation when one could point and shoot a [Fireball].

No gunpowder, or trains, let alone airplanes. He certainly had seen anything like it speeding through the skies. Who would invent such things if people could [Teleport]?

Math might only have developed in trading if that was the case. It might be worth it to join the Merchant's Guild to find out. He had always enjoyed role-playing a merchant even if there was no class for it in the old world. Unlike merchants, a blacksmith might have just used their experience to measure anything they made. Even modern blacksmiths didn’t accurately measure their material or complete work.

But if math didn’t exist but in its very basic form, then it made sense why this world was stuck in the modern medieval era. No advanced math means no computer, no engine, no electric motor, or any other advanced technology.

Mathematics might be a headache-inducing subject, but it was the key to almost everything. It was the queen of all subjects.

Adrin sat up and recreated all the spell glyphs he knew, and began to check everything while he mused on the subject. He cast the [Shell] spell, and as he had suspected, a wobbly, flimsy shell came into reality around him.

The [Shell] protective barrier looked fine in one glance, but the surface was like a calm water surface, and not even close to a solid object as it should be. One or two [Fireball] would destroy it easily.

It only became dependable when he used his [Crystal] affinity to turn a part of the [Shell] into [Stone Shell] as the knowledge from the spellbook had instructed. At a whim, he changed another part into [Diamond Shell] and Lily gasped as she saw it.

The door swung open as he was moving the circular [Diamond Shell] around.

Brian was at the door and he had become a statue at the sight. Nerina and Emi stepped inside and they too were surprised to see the shiny floating shield.

‘That’s not good,’ Adrin thought.