The airship, Altair, is a huge floating structure consisting of countless rooms. It is more than enough to house several thousand passengers, though Nobu didn't choose to do so since Miku's power is more than enough to do the maintenance of the ship.
Meaning, there are a lot of empty rooms within the ship. Even if the entire Chaldea comes over for a visit, it could house all of them.
There are a lot of other hidden features beneath the surface such as the ability to 'detach' into smaller airships in case of emergencies. The entire airship consisting of nanites has the capability to do just that without affecting the ship's aerial capabilities.
Nevertheless, every new passenger of this ship faced a common problem…
"It's still dizzying…"
Despite Jeanne "seeing" a direction pointed out to her, she couldn't help but be mentally exhausted by the ship's overall design. It is an endless labyrinth of silver metal.
Jeanne understood Nobu's explanations quite well, but experiencing things on her own is another matter altogether.
"If this is a fortress…"
{You have arrived at your destination.}
A synthetic voice rang all around her. Following that, the door to her room opened.
"This is…"
{Goshujin-sama decided to modify your [Room] according to your preferences.}
Instead of the usual metallic room, what greeted her eyes is an entire "house" placed upon a small flower field. A clear sky could be seen above.
In short, it doesn't seem like a "small room".
"Mister Galahad is a magician…"
Jeanne realized how he might've done it.
{Aside from the land and the house, a set of boundaries is present within this room. You will be warned once you come close to it.}
"I see."
*****
"You returned to our world and brought back a saint?"
"That should be it."
Using an earpiece, I connected a call to our King who is currently on a world trip. They should be currently in Malaysia.
"There's also another Mordred in that world."
"She didn't choose to come with you?"
"No."
"I see."
Our conversation revolved mostly on the findings of the other world as well as its current situation. Since I encouraged them to go on a vacation—knowing they wouldn't be able to once the world falls into chaos—I didn't want to take much of their time.
"That's right. How about you come with us tomorrow?"
"Tomorrow? Is it for the beach?"
Their travel itinerary was already completed by… Sir Lancelot before it started. Back then, he was responsible for foreign relations such as international trades. In a sense, he is the secretary of the group.
'Beach… It's been quite a long time.'
The last time I visited one was five years ago. After all, I was that frantic back then. I couldn't feel relaxed as much as now when I am becoming more certain of Twilight Syndrome's strength.
My final stop against it would be the [Realm Boundary] where [Lapis Exillis] is floating around. Then, replicate the [Lapis Philosophorum] through the grail's endless power and merge them all together. Coupled with the fact that I plan to enter the [Akashic Records], we should stand a chance.
It will become an unprecedented moment within all the possibilities present.
"Sure. I'll be dropping by tomorrow."
Just as the call ended, the cursed energy I repressed with my dreamland became a bit active.
For the second time, I utilized the cursed technique inherent to me.
Projections of the world appeared within my eyes one after another. It encapsulated all of the probabilities that remained dormant within the [Hillbert Spaces].
It didn't take long for me to determine the sole possibility that was unusual.
Hum-!
The moment that [Hillbert Space] was selected, a brooch with a huge red jewel appeared in my hand.
"..."
In that possibility, I saw an [Angel] throwing this object straight at me. Although…
"The Phoenix's blood…"
Unexpectedly, I received the [Lapis Exillis] with little effort.
*****
"Hey, Nobu."
"Mn..?"
"...Can I really do this?"
"Becoming a successful band? Well, it's only a matter of time."
Since Mashiro's dismissal is at 5 PM, Nobu always had an hour to go and hang out in Starry. It is one of his attempts to make up for his lost time with his childhood friend.
"You're already crazy good with the guitar. It was your composure that prevented you from performing with your full strength."
Nobu understands his friend's current dilemma. He saw Hitori studying the guitar since she was in middle school and was naturally gifted at it. If he didn't have any cheats, he might be the fan who cheers her on—or a talent manager that helps her with miscellaneous work.
"If you say so…"
Recently, doubts began stirring up in her heart. She didn't know when it started… no, she does have a small recollection as to when it began.
'That night…'
It was a dream.
She couldn't recall what it was, but that was when she started feeling uneasy. She attributed it to her career as a musician, resulting in this very moment.
'Nobu has already performed around the world. If I can't even overcome this..!'
As she began thinking about it, she started to enter her natural state. She became more and more focused with playing the guitar.
She was about to perform the chorus when her fingers froze.
"Huh..?"
Inadvertently, she finally remembered a certain scene in her dreams. It struck her with an overwhelming sense of familiarity—a deja vu of the most literal sense.
…
"If I could be a constellation with you..."
An unfamiliar yet familiar melody rang inside the room. The hands with several noticeable scars continued to play the unusual guitar. It was the same custom-made Gibson that a certain someone gave her, yet it felt slightly different—be it the scratches within the guitar itself or the visible damages done to it.
"Within the starry sky, that remains my…"
…
"Hm? Are you—?"
"Ah..?"
Nobu was surprised to see Hitori… crying. Even she was surprised to feel herself cry. She didn't know what happened. Only, a strange feeling swept through her, akin to losing something she holds dear.
Nobu lightly sighed as he handed her his handkerchief.
"It must've been the pressure."
Hitori took it from his hands. A small contact occurred between them.
"..!"
A special reaction occurred with Nobu's cursed technique. Instead of seeing the dormant "possibility" in the [Hilbert Spaces], what he saw is a [complete] parallel world—a possibility that became real.
Instead of [Hilbert Spaces], it is the [Many Worlds Theory] at work.
The next moment, he found himself in a similar yet different place. It was the same STARRY where he practiced with Hitori, yet its atmosphere was completely different.
It was as if it experienced the vicissitudes in life.
When Nobu saw a familiar pink-haired girl, he called out:
"Bocchi-chan?"
*****
A world after the end.
After the defeat of the [Twilight Syndrome], the entire world had changed drastically. Everyone now knows about the [supernatural] side of the world. Unlike the magecraft of another world, the magicians concealed the end purely because of the possibility of worldwide panic. It would strengthen the envoys of "End", and as such, they didn't want the world to know about it.
Unfortunately, everything changed after that day.
More than four hundred million casualties have been tallied down since the "Day of Advent". If not for the supernatural side's swift actions and preparations, the world would've lost nearly four billion—a hundred times more than today's casualty count.
At this time, many "talented" people stood out. Some of them are the "Ten Shadows" user Fushiguro Megumi, Defense Attorney "Higuruma Hiromi", Otherworld's Hero "Shana Reiji"...
However, the people who stood out the most were the ones already recognized by the supernatural side.
Undoubtedly, the "most dazzling" out of them all was "Sirius". Single-handedly building an entire planetary defense system, he was the main reason why casualties could be kept to the bare minimum. Coupled with the "World Cruiser — Altair", the situation was handled to the best humanity could ever do.
However, he perished during the "final battle".
"Bocchi-chan..?"
The faint familiar voice halted Hitori from performing her usual practice. When she looked around, she saw someone calling her name out.
"Am I hallucinating?"
That voice... It was supposed to be from someone she could not hear from anymore.
However, she was forced to believe it was true the next moment.
"It's really you… How come you dressed up as the hard metal fans you once said was cringe?"
"..."
"Hey..?"
"I turned schizophrenic..?" She could not help but mutter.
While she was doubting herself, she felt a faint touch in her hands. Once again, it felt extremely familiar to the point she recognized who it was.
"Calm down. I don't know how long I could maintain this connection but…" Nobu paused for a while before continuing, "What happened, Hitori?"
"..!"
The severity of this conversation was shown. Nobu no longer called her jokingly as 'Bocchi-chan', but by her first name.
Countless thoughts ran in her mind. The words she couldn't say to him were too many to count.
"...You're an idiot… We were already willing to sacrifice their lives! Four or even five more billion deaths wouldn't have mattered..! Why weren't you self-centered at that time..!"
"...In your world, I died?"
"It's just you… It's fucking unfair."
Hearing Hitori let out one curse after another, Nobu felt strange. Of course, the more important matter was the news about his death.
"From Yakagi-san… He told us that you merged the Philosopher's Stone fragments into one. You made some sort of one-time miracle and died with the 'End'."
One of the disadvantages received by Nobu is the loss of the holy grail whenever he "views" the future. It limits the number of things he could do within that iteration, forcing him to do some extremely dangerous decisions such as that.
Without the Holy Grail to act as a container, merging the Philosopher's Stone to its complete state became a suicidal act.
Nobu can imagine the implications it held… as well as the desperate situation he was forced into.
"Yakagi-san told us about the possibility of parallel worlds… You are from one of them?"
"Yes."
Facing his childhood friend who obviously suffered from his death, Nobu answered all of her questions honestly.
"..."
"..."
"I'm sorry." He said. "That was too selfish of myself. I chose what I thought to be the best without thinking of others…"
Nobu was jolted awake.
After he experienced "omniscience", his thoughts began to sway more towards "handling most of the things himself" rather than his original plans. What he failed to realize at that time is the possibility of this happening.
Back then, he consifered that those random deaths could be his loved ones, thus he chose not to gamble and limited the sacrifice to himself.
Unfortunately, a bad taste still remained in the two options he could choose.
"You really… Hic…"
Hitori's vision began turning blurry. All of the emotions she buried within her started exploding at this moment. Her shoulders slumped as their memories began storming her mind.
Without hesitation, Nobu activated the holy grail's function.
'Grant my wish.'
A familiar line of thought appeared in his mind.
'Miracle: To temporarily interact with another person in a parallel world'
'Purpose: Redemption'
'Confirm?'
'Confirm.'
With all of the energy he gathered from the greater grail in the Apocrypha world, Nobu's Holy Grail has enough energy to perform hundreds of 'small-scale miracles' such as this.
At this moment, Nobu started manifesting physically in this parallel world. His entire body was rebuilt by the greater grail, albeit only lasting temporarily.
It didn't take long for his shoulder to be filled with tears from Hitori.
*****
Another world…
No, it is more apt to call it a parallel world.
I didn't expect to be able to interact with them like this. Traveling through parallel worlds, in the case of this world, is more difficult compared to others. Instead, it could easily find new worlds (otherworlds), as opposed to some of the worlds I visited such as [Apocrypha].
Nevertheless…
'The outcome of my actions… Is this what I am facing?'
After losing the energy from the holy grail, I returned to Hitori's (introvert) side. We finished our usual training before bringing Mashiro home.
On the way, I realized a lot of important things. One of them was... how selfless yet selfish my decision was. I chose the path that would leave the least burden on my mind instead of bearing with the sacrifice of nearly the entire world.
There might be several more reasons why I made that choice, but the pain I left on others, not just Hitori, was more than evident.
'It shouldn't happen again.'
I clenched my fist as I became determined to steer away from that ending.
I blinked a few times before my mind returned to reality. Here, I faced Mashiro's golden pupils staring directly at me.
"What's wrong, Nobu?"
"I thought of something." I replied. "I'll have to meet some acquaintances tomorrow. Since it is the weekend, they decided to go to the beach."
"Can I come?"
"...Sure?"
After the encounter with the parallel version Hitori, I contemplated on whether to continue hiding the supernatural side or not. I am leaning more towards the latter… just because of Hitori's depressed look.
By withholding this information, I am keeping them "out" of the supernatural matters. However, everything would go crashing down three months later.
I admit, my thinking was too narrow back then.
"We might be joined by some other acquaintances, though."
"Who?"
"My childhood friend."
Mashiro's looks changed when she heard the mention of Bocchi-chan. She gave an "okay" gesture in front of me.
"Okay. I will talk to her."
'...Why do I have a feeling this won't work out?'
Two introverts…
'It's only their first meeting. It shouldn't be that bad…'
My own feelings suggested otherwise. I could already foresee how their meeting might go...