Reclamation (Detective Shirou)

Deep in the German Alps, on the grounds of the Einzbern Castle, stood the Einzbern family's main stronghold—the "Winter Castle."

Inside the Winter Castle, a little girl with white hair lay sprawled against a window, gazing outward.

She was waiting for someone—someone very important to her. Ilyasviel still remembered the words her father had spoken to her a year ago:

"Ilya, your mother and I have to go do something very important. We'll be back in about a month. Once we return, we can stay together forever."

That month had long since passed. Ilya had waited a whole year, but she still hadn't seen that tall figure walk through the walnut grove where they once counted the new buds together.

"Kiritsugu... liar! He promised he'd be back in a month! Kiritsugu's a liar!"

Even as she said it, her body stubbornly remained pressed against the window. She was still waiting—afraid that if she turned away, she'd miss the figure she dreamed of day and night.

At that very moment, outside the walnut grove beyond the Einzbern Castle, a man was checking his equipment. He loaded Origin Bullets one by one into his most trusted magical tool—the Contender, a handgun with rifle performance.

Those bullets were made from powder ground from his own ribs. True to his name, Kiritsugu—meaning "cut" and "succeed"—his actions were about severing and binding. But this binding wasn't restoration. For example, when a thread is cut and then tied back together, the knot changes in thickness.

In other words, the act of "cutting and succeeding" caused irreversible "alteration" in its target.

This was Kiritsugu's second time here. The last time, the head of the Einzbern family—his wife's "grandfather," Jubstacheit von Einzbern—had refused to open the barrier for a failure who hadn't brought back the Holy Grail.

But as a father, Emiya Kiritsugu still couldn't let go of his beloved daughter. This time, he decided on a different approach: force his way into the Einzbern Castle!

Now, Kiritsugu truly had the ability. In other timelines, he had been tainted by the Black Mud after destroying the Holy Grail, and to save Shirou, he had transferred Avalon into Shirou's body, suffering further corruption from the mud. His body had grown weaker, the Magus Killer's strength had faded, and he had died without ever seeing Ilya again.

But this time, not only was Avalon still inside him, but his skills hadn't diminished either. His goal was clear: break into the Winter Castle and take back his daughter.

"Alright, I'll infiltrate like this." After one final check to confirm his gear was ready, Emiya Kiritsugu stepped forward, preparing to enter the walnut grove where he had once played with Ilya.

But then, an unexpected voice called out to him—

"Hold up, old man!"

Only one person used that title for Emiya Kiritsugu: his adopted son, Emiya Shirou—whose strength and mind were utterly mismatched with his youthful appearance.

"Hm? Shirou? What are you doing here? Didn't I tell you to—"

"Watch the house, right? I just happened to be out for a walk and ran into you, old man. No need to be so surprised!" Shirou interrupted calmly.

That was quite a walk—all the way from Japan to Germany!

Even though he thought it, Kiritsugu didn't say it—he had no right to.

When he was just a bit older than Shirou, he had shot his own father, then flown around the world with his surrogate mother, Natalia, taking contracts and killing people without hesitation.

Compared to that, Shirou flying from Japan to Germany on his own was nothing—at least he hadn't shot his own father.

As for whether Shirou might be discovered by some scheming magus, Kiritsugu wasn't worried at all.

Shirou's power was immense. If measured by a Servant's parameters, aside from Luck being unquantifiable and Noble Phantasm indescribable, his other four stats could all reach A-rank.

Servants were beyond the reach of ordinary magi—even just having similar power was enough. Kiritsugu knew this firsthand from his experience in the Holy Grail War.

As long as Shirou didn't provoke some ancient, immortal magical family, there was nothing to worry about.

"You're here, so what about the house?"

"Don't worry! Fujimura-sensei's there, isn't she? I asked her to watch the place for us." Shirou casually brought up Fujimura Taiga. "She seemed pretty happy to help!"

"No, if you put it that way, I'm even more worried." At that, a cold sweat dripped down Kiritsugu's face.

"Huh? Is it really okay for you to talk about Fujimura-sensei like that, old man?" Shirou blinked.

"It's fine. Taiga's just that kind of person." Kiritsugu said flatly.

At the same time, far away in Fuyuki, Fujimura Taiga suddenly sneezed. "Ah-choo! Huh? Is someone talking about me?"

"Geez, Fujimura-sensei's really unlucky to know you! By the way, old man, you have another daughter, don't you?"

"Brat, you're already taking her side."

"Don't try to change the subject, old man. I've got proof!" With that, Shirou pulled a photo from his pocket—a family portrait of Kiritsugu, Irisviel, and Ilya!

"I found this in a castle on a mountain not far from Fuyuki. The man in it is you, right, old man?"

"How... how did you find this?" Seeing the photo, Kiritsugu lost his composure. He remembered that photo had been lost during the Fourth Holy Grail War.

"The adult woman in this photo looks a lot like this girl, who's about my age. Based on age, they're probably mother and daughter. But since you look younger in the photo too, this girl should be around my age.

And then there's the way you look at this girl, old man—it's the same way you look at me. So she must be my sister. That's right, isn't it, old man?"

Given Shirou's age and that deduction, if he put on a pair of glasses with the right background music, it would be pure Conan vibes.

"Your deduction's spot on, Shirou. Planning to be a detective when you grow up?"

"Who'd want to be something like that?" Shirou turned away dismissively, but with his childish face, it only came off as adorable.

"But the real point is this—" Shirou pointed at the background of the photo: a walnut grove, identical to this one. "They're both here, aren't they?"

"If I could, I really wouldn't want you to know about this, Shirou." Since he couldn't hide it anymore, Kiritsugu came clean. "The adult woman in the photo is Irisviel von Einzbern, my wife. You should have called her mother, but she's dead.

As for the little girl, you should call her sister. Her full name is Ilyasviel von Einzbern... What's with that look, Shirou?"

At that, the way Shirou looked at Kiritsugu made his hair stand on end.

"With a last name that ridiculous, you're a live-in son-in-law, old man. Married into the family. That's just pathetic!"

"S-shut up!"

"Ohhh! Tsundere, but a guy being tsundere isn't cute at all!"

"..."

"So, what happened next?"

"Nothing!"

"Aw, come on! There's gotta be a good story in there!" Shirou's eyes were practically burning with gossip.

"I said there's nothing!"

Stare~~

"...Fine. Right now, Illya's been held captive by Irisviel's grandfather. I'm planning to infiltrate this place and rescue her." Unable to bear Shirou's dead, lifeless stare, Kiritsugu finally relented.

"Interesting. Then count me in. I'm pretty strong, you know, old man." Shirou raised a small fist above his head and flashed a bright smile.

"I knew you'd say that!" Kiritsugu pressed a hand to his forehead, looking pained.