Beyond the massive door lay a void of pure white. A large black sphere hung in the sky like a substitute for the sun, but otherwise, the world was a uniform, blinding ivory. At the far end of this space stood a lone girl.
She stood roughly one hundred and fifty centimeters tall, her long, rust-colored hair possessing a stubborn wave. She wore a white one-piece dress embroidered with geometric patterns resembling gears, draped in an oversized, dark brown cardigan.
The girl possessed distinctive iridescent eyes and a single mechanical wing crafted from iron and gears, which sprouted only from the right side of her back. She turned toward Alice and offered a soft, gentle smile.
"Should I say 'welcome'? Or would 'it has been a while' be more appropriate?"
"What a nostalgic sight. Aside from the eyes and that mechanical wing, you look exactly like the Machina I once knew."
"Hehe."
As Alice murmured with narrowed eyes, caught in a wave of reminiscence, the girl—Machina—laughed merrily. For a moment, she was not the God of a world, but simply Machina, rejoicing in a reunion with her best friend.
"Did your little inquiry session conclude successfully?"
"Actually, much to my disappointment, it seems Information Level IV isn't quite enough to satisfy Alice-chan's intellectual curiosity."
"Oh my, that is a problem. I suppose I'll be the one bombarded with questions instead."
Exchanging casual banter, the two walked toward one another, coming to a stop at a natural distance as if by mutual agreement.
"So... am I right to assume you are indeed the Machina I know?"
"Hmm, you could say that is true, but you could also say it isn't. The consciousness operating this body is undoubtedly the Machina you know, but the body itself is a program—Mother Brain, code-named 'Deus Ex Machina.' It is essentially a main device that I am constantly connected to."
"I see. So Machina is the pilot, and the vessel is Mother Brain Machina. That explains why Paradise (Eden) used different names for you."
"Exactly. Though this body is ultimately a copy of my own form. By the way, my truly original body... is right up there."
Machina pointed toward the black sphere floating in the white sky—her core, and her heart.
"I’ll tell you this as a special favor since it’s you, Alice. The body inside that sphere is my core and my heart. If that body is killed, I—the God known as Machina—will meet with annihilation. It is quite literally my life."
"Then that sphere is your weakness?"
"Not quite. Even if you can see it right there, it is fundamentally impossible to interfere with or reach that sphere unless you completely defeat me as the Mother Brain. That holds true even for me, despite being omniscient and omnipotent. Yet, the Mother Brain is immortal so long as the core exists. That absolute contradiction is the source of my immortality."
"That’s a headache-inducing theory. It’s like the chicken or the egg."
Indeed, to defeat Machina, one had to destroy the core, but the core could not be reached unless Machina was already defeated.
"Excluding absolute outliers like the Epilogue (The End of the Story), no one exists who can defeat me... save for one person."
"Me?"
"Yes. Alice, you are the sole exception. If you use the Key Only You Can Use that I entrusted to you in the past, you can reach the core that even I cannot. In that sense, you could say Alice is the only existence that can defeat me through conventional means."
"Well, I don't have any plans to use it for now."
"I would prefer it if the opportunity never arose..."
Caught by Alice’s wry smile, Machina let out a small laugh of her own. They shared a moment of quiet amusement before Alice spoke up to change the subject.
"By the way, I received quite the explanation on the way here. It seems you’re holding onto a lot of rather dangerous iron spheres. Planning to start a war?"
"You mean Tartarus? No, it’s not for starting a war... I’m just recycling the leftovers."
"The leftovers?"
"This was back before I created my own world. After we parted ways, I traveled through various worlds to study, increasing my power as a God as I went. I wasn't always treated cordially in every world I visited. Sometimes, I ended up in battle with the local creator. I was quite powerful, so most opponents weren't a problem, but there was one time I encountered an outrageously strong enemy."
Machina scratched her cheek lightly, her smile turning a bit weary as she recalled the battle.
"It’s the one I used as an example when I explained Shallow Vernal’s power to you before."
"The existence that possesses infinite identical existences across an infinite multidimensional universe... the one whose power sits above omniscience and omnipotence?"
"Yes, that one. It was the strongest thing I’ve ever fought, by a wide margin. To counter its infinite identical existences, I created my Infinite Omnipotent Soldiers to do battle... but in the end, we couldn't reach a conclusion."
"A battle of infinity versus infinity. That is a different dimension of conflict entirely."
"Neither of us had a decisive move. No matter how many I defeated, the enemy would keep reviving infinitely. No matter how many were destroyed, my Tartarus army would keep being produced infinitely. Neither of us could land a winning blow, so we ended up fighting for about a hundred million years. At that point, whoever suggested a ceasefire first would be at a disadvantage in negotiations, so it became a test of endurance."
"And did you win that test of endurance?"
"Don't be mean. You already know the answer."
"So... the opponent met their end?"
The conclusion of that war was exactly as Alice suspected. The enemy Machina had been fighting met its end along with its entire world due to the phenomenon known as Shallow Vernal. In that sense, Machina was the winner simply by virtue of survival.
"That was the moment I first learned of Shallow Vernal. When my omniscience revealed her... I was stunned. I was terrified. My opponent, who was my equal, met its end easily, without a hint of resistance. When I think about what would have happened if Shallow Vernal had targeted me instead, I still tremble. From that day on, just like the creators of other worlds, I came to fear Shallow Vernal from the bottom of my heart."
"Well, her power is certainly absurd. Since seeing it at Kaito-san's party, I've run countless simulations to find a countermeasure... but the fact that the only conclusion I can reach is 'never make an enemy of Shallow Vernal-sama' is just ridiculous."
"Even if you check with omniscience, the only answer you'll get is 'there is no countermeasure.' But to return to the subject—after the battle ended, I erased any Tartarus units that were even slightly damaged and just kept the ones that were unscathed. Most of them are stored in a dimension I created specifically for them. If you want one, I could give it to you. They're set to automatically retaliate against hostility, so they make excellent watchdogs. Although, they will blow away the entire world if you don't adjust them properly..."
"I don't need a dangerous iron sphere like that."
Alice retorted lightly, shaking her head to clear the mood before speaking again.
"Well, there are other things I want to ask, but it'll never end if I don't stop somewhere. Let's call it a day for the questions."
"Right. We've strayed quite a bit from our original purpose. Well then, let's pull ourselves together and start trai—"
"Let's have a meal!"
"Huh?"
"Man, hearing and thinking about all that stuff made me hungry. So, please give me some delicious food!"
"O-Okay."
Just when Machina thought the training was about to begin, Alice demanded food. Machina wore an exasperated expression, but she nodded, realizing it was useless to argue.
"Oh, and this scenery doesn't exactly whet the appetite. Change it to something that feels a bit more appropriate."
"You're so demanding."
At Alice’s request, Machina moved her hand as if stroking the air. The stark white void smoothly dissolved and shifted.
The scenery became a metropolis of skyscrapers beneath a leaden sky. They now stood on the rooftop of an exceptionally massive skyscraper overlooking the city. Despite the height, there was no wind, and the city below was silent, as if it were merely a hollow projection.
"It's cloudy. I can't say it's a very good view."
"That day was cloudy too."
"Was it?"
"It was. Here."
After their brief exchange, Machina produced a paper bag and handed it to Alice. Alice looked a bit dubious, but she sat down on the edge of the rooftop and checked the contents of the bag. A faint, genuine smile appeared on her face.
"A God prepared a meal, and it’s a hamburger? Talk about a commoner-like God."
"I can't help it. I don't know any food more delicious than that."
"Oh? Weren't you supposed to be omniscient?"
"It is because I am omniscient that I say it. To me, the most delicious food in the world is that hamburger."
In response to Alice’s teasing, Machina smiled softly, produced a paper bag for herself, and sat down beside her. The two of them took out their hamburgers and took a bite.
"What a nostalgic taste."
"Yeah. The taste, the scenery... it’s all nostalgic."
"Life is full of surprises. That sheltered, island-exiled young lady is now the God of a world."
"There you go with the island thing. Alice, you're the only one who says that."
A warm atmosphere flowed between them as they ate and laughed together.
"Hey, Alice... do you still remember our promise from back then?"
"I remembered. That’s why I said those things earlier... about you saving me."
"I suppose you did."
"What is it? Shall we tell old stories?"
"That sounds nice. I'm feeling very nostalgic right now..."
Gazing up at the sky covered by thick clouds, the two girls let their memories blossom—the story of the meeting and the promise between the Girl Called a Hero and the Girl Who Wished to Become a God.