Chapter 235 - Proof of Non-Humanity
"In other words, you are claiming to be a human weapon? And one that surpasses even nuclear weapons, no less."
"Th-that's how it works, yeah."
"...No matter how I look at it, you appear to be nothing more than an ordinary man... well, you surely must possess something extraordinary regarding your vitality."
Professor Otsuki's gaze was fixed on Erin, who was clinging to me.
"Indeed, high reproductive capability could be considered the strongest weapon for a biological organism."
"No, it's not like that. ...Anyway, once we get out of the car, I'll show you various things. That should convince you."
While we were engaged in such trivial conversation, the car carrying us entered roads that looked increasingly familiar.
We proceeded down an unpopulated road, passed under a pedestrian bridge, and the brakes were applied just as a public restroom came into view.
It seemed we had returned to the vicinity of the university.
"Now then."
I urged Professor Otsuki, who was sitting next to me with his arms crossed, to get out of the car.
"Just trust me and go along with this. I won't let you lose anything."
"...Very well."
Since it was a request from the man who would become his son-in-law, the professor complied reluctantly.
The door opened slowly, and we exited the car in the order of the professor, myself, and then Erin.
It seemed Sugitani-san and the others intended to watch over us from inside the vehicle.
"Is around here okay? He... ya!"
After I sat Erin down on a bench, I leapt vertically right then and there. The distance traveled was roughly twenty meters, I'd say.
The sound of wind rushing, followed by a heavy thud upon landing.
It was a leap of such power, reminiscent of a wire-action movie, that anyone could see it was an abnormal occurrence.
"Your thoughts?"
Professor Otsuki had been standing with his mouth agape for a while, but after regaining his senses, he muttered, "A trick."
"You must have set something up in this park beforehand. Specifying this location was suspicious."
"Then I'll jump at a location of your choosing."
I crossed the pedestrian crossing with the professor and leapt once more in the shade of some trees a few hundred meters away.
The distance was, as expected, dozens of meters vertically.
"How about that?"
When I asked as I landed, Professor Otsuki was deep in thought with his hand on his chin.
"Are you still planning to doubt me? Should I try breaking a piece of playground equipment with a flick to the forehead next?"
"No, that's fine. I believe you are a superhuman. However..."
Is there still something bothering him?
The professor was incessantly muttering to himself.
"What exactly is on your mind? ...Anyway, as you can see, even without drones, most things can be settled if I'm around, so please rest eas—"
"You, do you ever hear a woman's voice?"
"—Huh?"
Just as I thought he had suddenly looked up, he asked something strange.
Moreover, because I had a suspicion regarding that, it was a topic I couldn't ignore.
"...Can I ask specifically what you mean by a woman's voice?"
"Does the voice of a spouse or lover ever play back inside your head, regardless of your own will?"
"...What if I say I do?"
"I see... then you really are a returnee from another world..."
I felt as though the way Professor Otsuki looked at me had become somewhat gentler.
What does this man know about me?
"Did Sugitani-san tell you about me?"
"To a certain extent. Only that there is a man who returned from a different world, not here."
"How did you figure that from that, that I'm in a state where I hear El... a woman's voice?"
"Is it alright if this takes a little while?"
I gave my consent, saying it was fine.
"You've heard that I am investigating the brains of those monstrous creatures called Goblins, haven't you? It was discovered through that, but it seems their circumstances are also worthy of sympathy in their own way."
"In what way?"
"A massive tumor was found inside every individual. When I grew suspicious and attempted to excise it, it turned out not to be a tumor, but a small brain. ...My first thought was a fetus in fetu. This occurs when beings that were supposed to be born as twin brothers fail to divide cells properly at the fertilized egg stage, causing the larger fetus to swallow the smaller one."
I felt like I had seen a character like that in a famous medical manga.
In that one, after being constructed in the form of a girl, she ended up loving the protagonist, who was her foster father.
Is that also a kind of father complex? While my thoughts drifted off into such tangents, I listened to the professor's words.
"However, while there are reported cases of teeth, hair, or fragments of brain tissue appearing, I have almost never heard of a complete, perfectly formed brain being found."
"So it's like a brother was living inside their head. That's a creepy story."
"In the case of the Goblins, it was not a brother's brain. The chromosomal structure of the larger brain and the excised brain were different. To put it simply, the two brains were of different sexes. A miniaturized female Goblin's brain had been embedded within the male Goblin's brain."
"...A twin younger sister?"
"They are likely not blood relatives. According to testimony obtained from a head that still possessed consciousness, it seems the Goblins were performing acts of combat being guided by the voices of dead lovers or wives. Isn't that the case?"
My heart began to pound like a drum.
The Goblins I killed were being guided by their deceased wives or lovers?
That means—
"There is an experiment. First, a male mouse is allowed to play with a female mouse to create happy memories. The parts of the brain that become active during that time are recorded. Next, that mouse is subjected to a kind of torture to put it into a state of depression. To the point where it cannot even drink its favorite sugar water. However, if the group of neurons that were active when playing with the female is artificially stimulated—he recovers from his depressive state. His motivation was restored by memories of the opposite sex."
"...That's a cruel experiment."
"I believe the treatment the Goblins received is similar in concept. In order to reinforce a fragile psyche, a mechanism to encourage them from within the head was implanted. ...Occasionally, demi-humans other than Goblins are sent to us, and they have undergone the same treatment. The Assassins sent from 'another world' have all had their minds remodeled for combat. If so, wouldn't it be natural to think the same of you, a returnee from another world?"
"You mean my head has been messed with too?"
"Shall we try a scan?"
Professor Otsuki pointed toward the university where he worked with his thumb.
"There is equipment there. ...Let's see. If I am allowed to examine your body, I could even suspend my research on the Goblins."
"Because you seem more interesting," the professor whispered with a pale face.