Contract with an Outer God (1)

The Outer Deities in Outer God Slayer possess the characteristics of the Constellations that appear in constellation stories. They form contracts with humans, lend their power, and assign quests. Clear the quest and they even grant rewards. Looking at it that way, they seem no different from ordinary Constellations—or even benevolent gods. The truth is something else entirely.

First, the contract. Outer Deities force contracts on humans ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠who catch their interest. Exactly like right now.

Once the contract takes hold, the Outer Deity settles onto the contractee’s cerebral cortex. This is called “erosion.” Like a host infected by a virus, humans bound to an Outer Deity gradually lose their minds. When erosion finishes, the human either becomes a wreck, mutates into a monster, or simply dies.

There are two main ways to block the contract. One is to wrap the universe’s fifth fundamental force—Ether—around your body like a vaccine. The other is to already possess a madness equal to the Outer Deities themselves. In the latter case, the deity decides erosion is already complete and leaves in search of different prey.

I had no desire to become a lunatic just to avoid contracting with an Outer Deity. That would be like burning the house down to catch a flea. So I planned to enter the academy and learn how to wield Ether.

But then—

It was already too late. I had drawn an Outer Deity’s attention before I could even do anything. My luck was absolute garbage.

A sickening laugh drifted through the air. It felt as if my cortex were being gnawed away. The world itself seemed to fracture. I clenched my teeth. I refused to lose my sense of self.

Wait, what?

“Urk!”

The Outer Deity’s sudden shriek made my head spin. Every cell in my body screamed as though it would burst. Just as the lore described—merely hearing an Outer Deity’s voice plunges humans into agony and buries them in madness. I was no exception; my vision flooded crimson.

Yet the headache passed quickly. The blood pressure that had spiked returned to normal. The mind that felt ready to tear apart settled back into place.

“……?”

What? Why am I not going mad?

I took slow, steady breaths and pieced together what had happened. I didn’t know the reason, but somehow everything had worked out. I clenched and unclenched my fist, calming my pounding heart.

A clear chime rang out. At the same time, a translucent window that had been drifting inside my mind floated before my eyes.

This was the so-called status window—the primary tool Outer Deities used to communicate with humans. Talking through it supposedly drove people insane a little less. Their version of consideration, I suppose.

No, never mind. Consideration my ass.

What kind of consideration is a forced contract? Her desire to toy with me was practically dripping from the window. A sigh escaped as I scanned it. Cold sweat poured down my head, neck, and spine like rain. Damn it. I had just taken a shower.

“Young master, are you all right?”

Sonia brought a dry towel and pressed it to my forehead. Her expression looked genuinely concerned. I rose with her assistance.

“That bizarre object… where did it go?” Sonia asked, glancing around the box.

“It must have vanished…”

“Vanished? You mean it warped without any device?”

“…Ha.”

“Exactly what did you purchase, sir?”

Ordinary androids like Sonia had no ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠knowledge of trapezohedrons. Their very existence was classified.

“I didn’t order anything.”

“Then…”

“Looks like the delivery company sent it to the wrong address.”

I told her it seemed to have returned automatically. It was a relief this was an era with warp technology; otherwise I would have had no idea how to explain it.

Anyway.

I examined the status window updating in real time.

The Outer Deity of Wisdom—Cartesia. Just as the window described, she brimmed with curiosity. Other Outer Deities viewed humans as less than insects. Cartesia was different. She observed people with genuine interest, even allowed them to struggle. And if they pleased her, she offered help.

Why Cartesia felt favorable toward humans was never explained, even until the ending. A kind of MacGuffin. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Of course, if you failed to satisfy her she would mercilessly ruin you, exactly like the others.

“Haa…”

I had been prepared for something like this. Still, it was faster than expected. Extremely so. Forming a forced contract with an Outer Deity from the prologue made the road ahead feel pitch black.

She had probably already learned about my plan to research the graviton bomb. I had no idea what to do…

…Wait a minute.

“……?”

What was this now? No matter how special an entity she was considered, an Outer Deity was protecting a human who sought to oppose her kind? Was this some kind of challenge—try it if you dare?

“……”

Better not to understand. Trying to understand an Outer Deity only turns you into a madman. Just accept it. Accepting it and minding my own business would be better for my mental health.

“Hoo.”

I organized my thoughts. In one sense, this could be seen as good. No—it was definitely good. Wasn’t there a saying about turning crisis into opportunity? Cartesia held a high rank among the Outer Deities; if I played my cards right, I might avoid interference from the others.

Of course, that was a problem for future me to solve.

Clink!

Right on cue, a clear metallic sound rang out and a quest appeared before my eyes.

“Ah, damn it.”

“Why are you like that again, sir?”

“It’s nothing…”

I ground my teeth. This was only the beginning. Sudden quests like this would keep popping up constantly. If I couldn’t clear every single one, my life was finished. In the original story, Idel failed every quest and died insane.

But me? I would never end up like that. I would save myself, this world, and the entire universe. Whether I returned to my original world or lived happily here, I would reach a happy ending in some form. That was my goal, if it could be called one.

So it began.

Without hesitation I opened the first problem book within reach. Mathematics. I was confident.

“Are you sure you can solve it without any proper study?”

“Yeah.”

“Young master, weren’t you worst at mathematics?”

“What are you…”

I sighed.

“…Sorry, but could you step out for a while, Sonia?”

“What do you mean so suddenly?”

“I need to concentrate.”

Sonia shook her head.

“Observing the young master is the mission the family head entrusted to me. I cannot leave your side even for a moment.”

Yes, that made sense. Given everything Idel had done until now, it was reasonable. Father probably believed that without Sonia watching, who knew what trouble he would cause next.

The only unfair part was that I wasn’t that Idel.

Studying was something that should be done alone in a quiet place…

“If you truly intend to study, I will remain silent and not disturb you.”

Sonia spoke softly and moved to the corner where the android charging station stood.

“Huaa…”

Sonia sat at the station, let out a relaxed sigh, and closed her eyes. After that she didn’t move a single inch.

Well… that much was acceptable. I would simply pretend I had come to a reading room. Forty decibels of ambient noise was something I could ignore and still concentrate through.

Flip.

With that thought I turned the first page.

“……”

The very first problem ran over ten lines. It felt closer to an essay exam than the CSAT, or perhaps Japan’s entrance examinations. And it was even in essay format.

“Tsk.”

Difficult. I spent a full thirty minutes on the first page. The concepts were middle-school level yet extremely advanced. As expected of problems from Stellarium, the greatest academy in the universe.

It took several errors before I found the solution. Because it had been so long, concentration did not come easily. Still, once I passed the first ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠page my pace improved. After that I solved them smoothly.

How much time had passed?

“Whew…”

O Outer Deity. I had finally finished one volume. After solving question 150 I closed the book.

“That was a hard fight.”

“……”

When I glanced back, Sonia was staring at me. Her gaze was locked on the problem book I had just completed.

“You solved all of that…?”

Her expression and tone both said she could not believe it. Sonia narrowed her eyes and approached.

“May I check it?”

Her eyes sparkled with clear curiosity. She seemed genuinely intrigued.

“Go ahead.”

I willingly handed her the book.

It was then.

The messages meant Cartesia had checked every solution, down to whether each answer was correct. It wasn’t strange. She was known to love mathematics and science. There was no way she would have missed me solving the problems.

“Let’s see… everything appears correct.”

Sonia flipped through the pages at high speed, finished her computation, and looked up. The bewilderment on her face was unmistakable.

“How… how on earth did you solve something this difficult?”

“What?”

She scanned every inch around me.

“Do you know the answer to 40−32/2?”

“Four.”

“Ah, as expected…”

“Factorial.”

Sonia’s eyes grew even wider. As if she had seen the unbelievable. As if she had heard the impossible.

“You thought I was an idiot who couldn’t even do basic arithmetic?”

“You definitely could not.”

“At sixteen years old?”

“You could not.”

I slapped my forehead with a loud smack.

“Really?”

He had been that bad at studying? The thought that he might have been even worse than the novel described sent a chill down my spine.

I sighed and looked at Sonia.

“……”

Faintly, I could sense it. The contempt that had clearly resided in her pure white eyes had vanished. In its place was a small measure of respect and surprise.

“…How curious. To think a human could change this much simply by hitting their head.”

It seemed Sonia had decided everything changed after I was struck in the head by the gambling den security guard. If that was what she believed, it was actually convenient. After all, I would continue living this way from now on.

There was no time to waste. I quickly opened the next problem book.

“Hey, what are you doing?”

But this time my concentration was inevitably broken. The voice was one I had never heard, yet somehow familiar. I reflexively turned around.

There stood a girl with golden eyes identical to my current ones.

“You blew two thousand trillion in family assets, right? You gambling-addict bastard.”

The girl who appeared without warning and immediately hurled abuse. I knew exactly who she was.

“…Seti.”

Seti von Rheinland. My half-sister had appeared.