After that, Irisviel told Ye Sizhen her true identity.
Like Shirou, she had been a Master who participated in the Fourth Holy Grail War.
Silver hair and red eyes were the most famous physical traits of the Einzbern family. They were so well known that alchemists would immediately think of Homunculi the moment they saw someone with silver hair and red eyes.
However, Ye Sizhen was not a Western Magus, so she had not realized Irisviel's identity at first glance.
Ye Sizhen listened as Irisviel told her about the hidden history that had unfolded in Fuyuki eight years ago.
She spoke of what had happened at the end of the ritual, how Shirou's encouragement had helped her resolve to betray the Einzbern family and join him in ending the Holy Grail War.
Ye Sizhen found it almost unbelievable.
Shirou had already saved the world once when he was only eight years old.
"...Shirou really is amazing."
Ye Sizhen had fallen in love for the first time in her life with the boy who had saved her.
And to think that somewhere beyond her knowledge, Shirou had lived through such a dramatic life and fought such extraordinary battles...
For Ye Sizhen, a Thought Magus who dreamed of one day leaving her own footprints across the entire world, this discovery was like a rare and precious treasure.
"Right? Shirou is the best, hehehe♡"
"Mm."
Ye Sizhen nodded in heartfelt agreement with Irisviel.
The silver-haired woman before her spoke of those memories with sparkling eyes, looking so happy that she did not seem like an artificial lifeform at all.
Ye Sizhen could not help thinking that this, too, must have been thanks to Shirou.
Just as Shirou had made Ye Sizhen realize that she was not a heartless machine (Magus)...
It was also Shirou's appearance in her life that had allowed an artificial lifeform to gain a true "heart."
That child was far more extraordinary than she had imagined.
Ye Sizhen felt happy, and at the same time, endlessly lonely.
Of course, that was not because "Shirou Amamiya" was the "target" she had been searching for. Rather...
She had suddenly realized that she was not worthy of Shirou at all.
Normally, Ye Sizhen would never think that way.
As a well-known top student of Spiral Manor, she had always lived by the principle of giving everything her full effort.
If she fell in love with someone of the opposite sex, she would pursue them no matter what obstacles stood between them.
Age, seniority... even if the other person already had a family, Ye Sizhen would not care in the slightest.
But right now, she did not feel that way.
It was not because Shirou had a noble character, nor because he had secretly saved the world.
It was not because he was a better Magus than she was, or because he was a stronger warrior than she was.
Ye Sizhen had simply realized one thing.
Shirou was already living the life he considered happiest.
No matter how hard she tried to enter his world, there was no way she could make him happier than he already was.
Shirou was Ye Sizhen's savior, and he was also her first love.
So the only way Ye Sizhen could repay him was to let Shirou keep things as they were and continue living peacefully.
"I think it's about time I took my leave."
"Ah, please wait a moment. Shirou should be back soon."
Irisviel tried to stop her. "Sizhen-san, you just said you came to Japan to find Shirou.
Could you explain the situation? What exactly happened?"
Irisviel seemed to think there was some kind of misunderstanding between Ye Sizhen and Shirou, and she was eager to clear it up between them.
But... that wasn't it, Ye Sizhen thought.
Shirou had done nothing wrong.
What was wrong was this world, which refused to let Shirou live in peace.
Ye Sizhen swallowed the faint ache in her chest and gave a gentle smile.
"There's no need, Lady Irisviel. The misunderstanding has already been cleared up."
"Huh? It has? When?"
Ye Sizhen did not answer directly. Instead, she said:
"I'll leave Japan right away. My time here has come to an end.
Please don't worry. I won't approach Shirou again."
Once she had accepted that, the heaviness in Ye Sizhen's chest faded, and she even felt a little cheerful.
Just imagining the frustrated look Shirou would make when he came home and found that she had already left Fuyuki made the corners of her mouth lift.
"But... no, please wait. You should at least wait until Shirou comes back before..."
"I'll leave a letter for Shirou. Please give it to him for me.
I'll explain everything clearly in the letter. That should be all right, shouldn't it?"
With that, Irisviel had no reason left to ask Ye Sizhen to stay.
By the time Shirou finally returned home, it was almost noon.
There was no helping it. He and Aoko had kept going until almost five in the morning before finally falling asleep.
Aoko was still sleeping soundly in the bed at the love hotel. The fact that Shirou had managed to fight off his drowsiness and come back at all was already impressive.
Of course, Ye Sizhen had left the Amamiya residence several hours earlier.
"I would very much like to call a family meeting right now and have a serious discussion about you hiding an unfamiliar woman in your room, Shirou...
But you should read this first."
Irisviel said that with a grave expression, handing him a letter with "To: Shirou Amamiya" written on the front.
It was a very unusual envelope. Not because it was old, but because the surface of it gave the strange impression of being steeped in the weight of history.
Shirou returned to his room without a word and only then opened the envelope.
...
...
"Dear Shirou Amamiya,"
"By the time you read this letter, I imagine I'll have already left Japan.
Hehe. I've wanted to try saying something like that for ages. It really does put me in the mood."
"You must be terribly confused by my leaving without saying goodbye, but I firmly believe this is the right thing to do."
"If I could, I wouldn't have left any message at all...
But that noble lady didn't seem likely to let me go unless I left something behind, so here we are."
"From Lady Irisviel, I heard about the life you've lived until now, Shirou."
"I was truly moved... You are an even more remarkable man than I imagined, Shirou...
Well, you would be perfect if you fixed that bad habit of always lying to girls."
"This is more or less my last chance, so in exchange, let me tell you about myself."
"You see, I've actually always had a dream... I want to establish my own manor."
"A place where even a Magus of ordinary talent like me could be trained properly... That is my dream."
"Oh, and I've never told anyone this before, you know?"
"I'm only telling you because I thought you wouldn't laugh at me, Shirou♡"
"But establishing my own manor won't be easy. Spiral Manor has very few branches outside the continent."
"Since ancient times, Magi have fought one another over powerful Spiritual Lands."
"Good Spiritual Lands are limited, after all. On top of that, Western Magecraft organizations would never allow excellent Spiritual Lands to become the territory of Eastern Magecraft organizations."
"In the world of Magecraft, money alone will not get you anywhere... If you want to reach your goal, you have no choice but to rely on power."
"In truth, not long ago, I obtained a new power."
"Through an unexpected meeting and a string of coincidences, I gained Thought Magecraft from the Age of Gods, something different from modern methods."
"My life as a Magus, spent studying desperately for more than ten years..."
"The pride and confidence I had from being recognized as a talented woman by Spiral Manor..."
"All of that past seemed to lose its meaning the instant I learned Age of Gods Magecraft."
"The Thought Key is powerful enough to make a person doubt themselves."
"And so, I felt both dejected and happy... That joy was something nothing else could replace."
"I felt that I had come very close to my dream."
"Do you have something you want to do too, Shirou? If it's you, I'm sure it must be a truly remarkable ambition."
"Of course, there is no such thing as a free lunch."
"You're clever, so I'm sure you've already guessed..."
"That's right. As the condition for obtaining the Privilege of Age of Gods Magecraft, I accepted a certain commission."
"The Magus who granted me the Privilege of the Thought Key ordered me to go to Japan and capture a boy named Shirou Amamiya."
"Before that, I didn't know any Shirou Amamiya. In fact, I only learned about the ritual called the Holy Grail War while doing my preliminary investigation."
"What kind of person was Shirou? Was he good or evil? What had he been through?
None of those details mattered to me."
"As long as I captured him, I would be able to keep the Privilege of the Thought Key forever."
"Trading the life of a complete stranger for my own dream... There could hardly be a better bargain."
"Shirou, I'm sure you're very disappointed."
"That is the kind of selfish woman I am... the typical Magus you hate most, not someone worth saving at all."
"Then again, even a heartless, cold-blooded woman like me would not stoop so low as to harm the person who saved her life."
"So, let's forget this whole matter."
"I've decided to let you go, Shirou."
"Please treat our meeting as though it never happened."
"From now on, please be more careful. Cherish that precious life you worked so hard to keep, and don't let yourself be deceived by suspicious women again."
"Sincerely, Ye Sizhen"
"Ah... right, one more thing. About Miss Tohsaka, the girl you're looking for.
She's currently locked up in the workshop I set up in an abandoned factory on the outskirts of town. Please give her my regards."
Inside the envelope, along with the letter Ye Sizhen had left behind, there was a simple map of Fuyuki. Naturally, it had also been drawn by her own hand.
An abandoned factory on the outskirts of Fuyuki was circled on the map. It was both Ye Sizhen's temporary workshop and the place where she had kept Rin Tohsaka after defeating her.
From the Amamiya residence, it would take about an hour to get there.
By that calculation, even if Shirou rushed there as quickly as possible, the place would probably already be deserted.
The only one waiting for Shirou there would be Tohsaka-san, who had been sealed inside a Barrier for four or five days and was still perfectly lively.
She really... had no intention of leaving me any way to contact her.
"She really is a heartless woman."
Shirou looked at the crumbs of Chinese pastries on the plate and thought resentfully, I probably won't ever see Sizhen again.
"...You promised you'd let me taste your cooking."
At the same time, the contents of the letter caught his attention.
They lined up perfectly with the information Byakuya Matou and the others had extracted from Atrum during last night's interrogation.
Someone was targeting Shirou Amamiya and carrying out some unspeakable secret plan.
Only...
Shirou noticed a problem.
The one who had taught Ye Sizhen Age of Gods Magecraft, and the one who had ordered Atrum to capture Shirou, did not seem to be the same person.
Just how many people are targeting me?
Forget it. There was something far more urgent to deal with right now.
Shirou explained the situation to Irisviel, then immediately left to rescue Rin Tohsaka, who had been trapped for days.
...
...
Ye Sizhen arrived at the appointed location, a seaside manor.
This was still Japan, but it was no longer within the borders of Fuyuki City.
When she left the Amamiya residence, she had played a small trick.
Ye Sizhen had told Irisviel that she intended to leave Japan immediately.
That way, Shirou would naturally assume Ye Sizhen had already gone abroad and give up on searching for her whereabouts.
But Ye Sizhen had not actually left Japan.
Of course she could not leave. After all...
The Magus who had ordered her to capture Shirou Amamiya was currently in Japan.
"Master."
The man who appeared before her had wolf-gray hair.
Ziz, a Magus of the "Wandering Sea."
Although Ye Sizhen called him Master, he was not her mentor from Spiral Manor.
This beautiful man from the "Wandering Sea" had used some unknown power to grant her the Privilege of the Thought Key.
There was only one thing Ye Sizhen knew for certain.
Though he had a youthful appearance, he had existed since before the Mystery on the surface of the world began to thin.
A true monster who had lived for more than two thousand years.
"You're here."
Ziz spoke. "Sizhen, have you captured Shirou Amamiya?"
"Yes," Ye Sizhen replied expressionlessly.
"Where is he?"
Ziz looked behind his disciple in confusion, but there was no one there except her.
Ye Sizhen said calmly, "More importantly, Master... did you invite your allies here as well?"
"Ah, yes. You did say that in the communication Magecraft."
Ziz stroked his chin and murmured to himself, "You hoped my allies could witness the result of your capture of the 'Heroic Spirit Killer' with their own eyes."
"...Please."
Ye Sizhen nodded silently, sweat beading on her forehead.
Ziz knew that Ye Sizhen's wish was to establish a manor of her own.
To accomplish something like that, she would need powerful connections, so she had used this opportunity to ask her master to introduce her to powerful Magi.
"They... are already here."
The moment he finished speaking, two new figures appeared.
Both were women.
One looked even younger than Sizhen, no older than around twenty-five.
Because of her beauty, with those tightly closed lips, Ye Sizhen could not help being reminded of the Homunculus she had seen that very morning.
She felt even more inorganic and artificial than the Einzbern Homunculi.
She wore a futuristic-style Mystic Code from a Western alchemy academy, and her calm blue wavy hair swayed lightly.
The other gave the exact opposite impression. She was like a pure white flame set ablaze.
Across that gleaming skin were pale patterns that looked neither like pigmentation nor tattoos, adorning the woman with extraordinary beauty and making her seem like a flame in human form.
Rough shackles and chains hung from both her wrists, and a beautiful golden bell dangled from her right ear.
Merely having that beautiful woman appear there made Ye Sizhen's body tremble, leaving her unable to move.
She realized a terrifying truth.
The woman before her was the supreme peak all Thought Magi longed for but could never reach.
One of the great beings known as Immortals, who had created the "Pseudo-Root: Thought Disk" in the Age of Myths.
"Your disciple really is willful, Ziz. To think she would dare drag me all the way to a place like this..."
Wuzhiqi, the Immortal of the "Summit Court," looked at Ye Sizhen with a ferocious smile.
"You little girl from Spiral Manor, I asked you a question. Where is that boy Shirou Amamiya?"
"..."
Ye Sizhen lowered her long lashes, suppressing the fear in her chest as much as she could.
A noble of the "Atlas Institute."
An Age of Gods Magus from the "Wandering Sea."
And an Immortal of the "Summit Court."
These were the three people who had set their sights on Shirou...
I won't let you do as you please anymore.
I won't let you lay a finger on that child.
She closed her pitch-black eyes, making her final farewell to the person she had once been.
I will protect Shirou.
Ye Sizhen was prepared to take them all down with her.