Morgan hadn't borrowed the guest register on a whim.
While chatting with Sakura and Caren about how many times she'd been here, she found herself oddly unsettled.
She couldn't remember exactly which visit this was.
The Shiomi Residence didn't come every year. Up to 2001, their trips had been fairly limited. In Morgan's memory, there should have been three or four hot spring getaways.
More importantly, there was a clear pattern.
She distinctly remembered 1995, 1997, 2001, and then 2003 afterward.
Basically, it was once every two years.
Which raised a question: if it was that regular, why didn't they come in 1999?
That year, Shiomi did take the family to the Clock Tower in London. He even met with Lord Valualeta, and through her mediation, became Reines's family Magecraft tutor.
But that was in September, and there hadn't been any major commitments before then.
No matter how she tried, Morgan couldn't recall anything that year that would have made the whole family cancel their Kumano hot spring trip.
Not that the trip itself was some absolute necessity.
Still, things didn't just get canceled for no reason, and Morgan couldn't remember even the slightest hint of one.
There was no chance this was the result of memories being erased by magecraft.
And with this place having become a Singularity in 2001, that left only one other possibility.
That 1999, too, had involved something connected to the Singularity.
After the Singularity was corrected, Morgan—who had merely been "retained" as a Servant, or rather, as the "top-tier familiar that existed at the time"—had her memories adjusted along with the Singularity's restoration, leaving her with nothing to remember.
Shiomi was the same.
"Leaving Morgan aside," Touko said, "it's been six thousand years. Do you really still remember?"
"...During my first century, I'd already put protections in place for my memories of Proper Human History," Shiomi said, tapping his temple. "As for those six thousand years, I kept the parts that mattered most. When I try to recall the rest now, all that remains is the rough shape of it."
Because he'd chosen what to keep, he hadn't lost what was truly important.
Those six thousand years in Fairy Kingdom hadn't been meaningless, but to Shiomi, the only parts that mattered were what involved Morgan and what involved his companions.
Everything else was unnecessary. It was enough that he hadn't forgotten it completely.
While Shiomi was being surrounded by his master and the others, pressed with questions, Aoko flipped through the lodging register and briefly wore a troubled expression.
But it disappeared just as quickly, replaced by sudden understanding.
"Looks like Aoko remembered something," Touko said.
"Don't stare at me like that, sis," Aoko said awkwardly, turning her face away. "You're making it look like we're really close or something…"
Ignoring Touko's strange smile, Aoko shifted her attention to the others from Chaldea and began to explain.
"This situation turned into a mess because the 'first Aoko' didn't explain things properly. Let's assume she was in a state where no one could trust her," Aoko said. "The details are fragmented, but thanks to the register, I was barely able to synchronize with the scene the 'first Aoko' witnessed."
She stood up and started pacing the room.
"In May 1999, a 'Star' appeared here. Its true nature was unknown, so it could only be called a Star. The moment it appeared, it blew away the entire Kumano area. After that, the mana wind it released flattened everything around it. Most likely, the Star's mana output was limitless. As long as humans existed, it would continue to stir up an eternal storm."
"Human existence…" Shiomi asked. "If human civilization vanished from the fabric on the planet's surface, would the storm stop?"
Shaking her head as she sorted through her thoughts, Aoko replied, "If that were the case, it would just be a civilization-destruction incident, which is outside my jurisdiction. What I deal with is 'human extinction'… though that's not exactly something anyone gets to decide."
She said something terrifyingly serious in a remarkably casual tone.
Much like how the Second Magician oversees parallel worlds, the Fifth Magician bears a similar responsibility.
"But the problem is, the 'Star' was replaced after that," Aoko continued. "At least, that's all the 'first Aoko' could observe. Not long after releasing the mana wind, the Star disappeared. In its place, a 'brand-new god' descended upon this land."
At last, Aoko's explanation overlapped with Shiomi's earlier speculation, startling everyone present.
Shiomi included.
"A 'brand-new god'… You phrase it that way because you realized the god that descended wasn't from the distant Age of Gods, but a new god born and established in this era," he said, his expression turning grave.
"Whoa, you're sharp," Aoko said in surprise. She hadn't expected Shiomi to pinpoint the core of it so precisely.
She quickly pulled herself together and went on.
"A 'brand-new god' descending. Setting aside what kind of impact that would have on a world long removed from the Age of Gods, at the very least, something was wrong with that god. From the moment it descended, it began rewriting the rules of the world. Realizing she couldn't solve it alone, the 'first Aoko' sent the problem two years into the future, to this very moment in 2001."
In other words, Aoko herself was the reason this Singularity came into being.
"I see. So the source of the Singularity is you, the Fifth Magician. No wonder there's no Holy Grail reaction or anything like that," Shiomi said. "And because of that, the 'first two versions of you' were wiped out so cleanly. The new god's power isn't complete, so in theory, a Magician should still be able to fight it—"
But because most of her mana was used to maintain the Singularity, she lacked the strength to fight. In front of a god, she was reduced to a complete mortal, with no room to resist.
"If the Singularity was sent from 1999 to 2001, then why has everything remained normal until now, without the situation Touko's sister described coming to pass?" Artoria said. "That means the event itself has been delayed. Compared to 1999, we're currently positioned before the new god's full descent."
As she spoke, she subtly turned her gaze toward Shiomi.
"Which means that before long, what happened in 1999 will happen again here," Scáthach said, as the pieces finally came together. "And Touko's sister appeared here to find the cause before it happens."
Just as they were about to trace the thread back to its origin, Morgan cut in.
"The cause doesn't matter," she said. "What matters now is dealing with the 'new god' back in 1999. That's the only way to keep 2001 from repeating the same disaster."
She rested one hand on her hip and quietly looked at Aoko Aozaki.
"Since your interests align with those of Chaldea, let's stop wasting time, Magician."