Chapter 7: The Logic of Magic

The night air was sharp against my skin as we slipped into the shadows of Bellmare’s winding alleyways. My heart pounded, the stolen grimoire clutched tight against my chest. Ryn led the way, his steps near soundless despite the uneven cobblestone. Lena followed close behind, her keen eyes scanning every corner.

We needed to get out of town before the Crimson Fangs regrouped.

The heist had been successful—barely. The mercenaries had been on our heels the entire time, and the only reason we escaped was pure, dumb luck. But something about that felt off. The Crimson Fangs weren’t amateurs. They were ruthless and efficient. They should have had us cornered.

Which meant either they had been sloppy—or they wanted us to take this.

My grip tightened on the grimoire.

It was heavier than I expected, bound in dark leather with intricate silver inlays forming symbols I recognized all too well.

Because I had written them.

We ducked into a small abandoned storehouse on the outskirts of town. Lena barred the door behind us, and Ryn leaned against a wooden crate, breathing heavily.

“Well,” he said, running a hand through his dark hair. “That could’ve gone better.”

Lena shot him a glare. “We have the grimoire. That’s all that matters.”

“Yeah,” I muttered, lowering myself onto an overturned crate, “except we have no idea why they had it in the first place.”

This tale has been pilfered from Royal Road. If found on Amazon, kindly file a report.

Ryn stretched, his usual smirk returning. “That’s where you come in, mystery boy. You’re going to open it and tell us what’s inside.”

I hesitated. The symbols on the cover—it wasn’t just any magic book. It was one of mine.

More specifically, it was a grimoire that shouldn’t exist in the hands of low-level mercenaries.

I exhaled and flipped open the cover.

Immediately, I was met with a page full of mathematical equations and spell diagrams—the kind of structured spellwork I had designed to give magic a logical framework.

Mana wasn’t just some mystical force in this world. It obeyed rules, just like energy in physics. I had created formulas to explain how spells functioned—calculating mana flow, efficiency, and stability the same way an engineer would calculate structural integrity.

And this? This was my work.

Lena peered over my shoulder. “What the hell am I looking at?”

I traced a familiar equation with my finger, my mind racing. “A spell formula. A structured breakdown of how to cast a spell efficiently. The average mage learns magic through instinct, but grimoires like this make it possible to calculate magic.”

Ryn raised an eyebrow. “You’re saying spells can be… engineered?”

I nodded slowly. “That was my idea, yeah. Magic follows laws, just like physics. And I—” I stopped myself.

I couldn’t just blurt out I wrote this world.

Instead, I cleared my throat. “I studied these principles before. This book is written with the same logic I used.”

Lena frowned. “You’re saying you understand this?”

“I don’t just understand it,” I murmured. “I can rewrite it.”

The realization hit me like a punch to the gut. If this grimoire was based on my system, then I could adjust the equations. That meant I could modify spells in ways no one else in this world could.

And if someone else had written this… it meant I wasn’t the only one who understood my system.

I turned to the next page. Then the next. My pulse quickened.

“This spell,” I whispered. “It’s a mana compression equation.”

Lena folded her arms. “In common words?”

“It allows a spellcaster to store massive amounts of mana in a condensed form, increasing spell efficiency by nearly 300%,” I explained. “But—” I tapped the margin of the page. “This calculation is wrong. If someone actually tries to use this, it’ll cause a mana feedback loop—which means…”

Ryn’s eyes widened. “Which means they’d explode.”

I swallowed hard.

If the Crimson Fangs had been planning to sell this book, or worse—use it—whoever cast this spell would have died instantly.

This wasn’t just a magic book.

It was a trap.

And if I hadn’t checked the formulas first, one of us could have been the test subject.

Lena let out a slow breath. “So, we just stole a book of lethal spells.”

“Looks like it.”

Ryn grinned. “And I’m guessing our employer didn’t mention that part?”

“Definitely not,” I muttered.

I shut the grimoire, my thoughts racing. If someone out there was modifying my formulas—corrupting them, twisting them into something deadly—then I needed to find out who.

Because this wasn’t just a stolen book.

This was a message.

And whoever had written it… knew the same magic I did.