"Brother, what are you doing?"

The silver-haired girl took the little hand of the black-haired girl and ran over with a cheerful voice.

"Ah, Illya, have you already returned?"

"Hmm. 」

"Uh, I'm sorry, brother...... Brother, I'm worried about you. 」

In contrast to Illya, Miyu bowed her head with a little blush. Hearing this, the young man named Emiya Shirou wondered.

"Uh, there's no need to apologize, just play more if you like, it's rare to be in the suburbs. 」

At this time, Shirou and the others were not somewhere in Fuyuki City, but on the outskirts of it. That is, close to the castle of Einzberen. Although it is the castle where Illya once lived, it seems that Illya in front of her has not been to this castle, but she is not aware of its existence at all, so she has a strong curiosity about this castle under the name of Einzberen.

"But brother, what are you looking at?"

Illya, who poked her little head out curiously, looked at the newspaper in Shirou's hand, and when she heard this, Shirou replied.

"Recently, there has been a series of disappearances of children in Fuyuki City......

"Alas, alas!!"

Before Shirou finished speaking, Illya instantly screamed, and directly entangled Meiyou beside him and trembled.

"Missing?Is it abduction?Isn't it dangerous for me and Meiyou!!

"It's impossible. 」

You're all wearing high-end magic costumes.

Shirou said in his heart.

"I guess this is the Servant's doing. 」

What comes to mind is the murder and the so-called gas leak that occurred during the Fifth Holy Grail War. Could it be Caster?

"Anyway, uh......"

Illya, who squinted, said with a cheek.

"That...... Holy Grail War...... What the hell is it?"

"Well, I haven't explained it to Illya and Miyu yet, too, you were drawn into the battle when you first arrived. 」

As he spoke, Shirou thought for a moment and said.

"Anyway, the Holy Grail War is just a ridiculous ritual of killing each other by seven magicians summoning seven Heroic Spirits to compete for the almighty Wishing Machine. 」

"Ah, the Heroic Spirit!?, is it to summon heroes from the legends and myths of the past?"

"Well, that's true. 」

Shirou said, who was taken aback by Illya's overly excited attitude.

"Wow! However, does the Almighty Wishing Machine, that is, the Holy Grail, have the ability to grant any wish?"

"That's true. 」

"But if you summon the Heroic Spirit to serve them, aren't you afraid of their betrayal?"

Regarding Miyu's question, Shirou said with a smile.

"That's why I have the Spell. 」

"Spells?"

"It's stigmata, something like a tattoo, and that's proof of being a Master. Each Master has a three-stroke spell, and the spell is something that can forcibly command the Servant. However, this is not the only way to use the Command Charm, for example, in an emergency, you can use the Command Charm to mobilize the magic of yourself and the Servant to achieve the miracle of teleportation. Ah, Illya, are you listening?"

"It feels like it's chaotic. 」

Looking at Illya, whose mind was in a mess, Shirou chuckled and stroked Illya's head.

"Well, Illya, you don't need to know these things. After saying that, Shirou turned his head and smiled at Miyu.

"It's the same with Miyu. 」

—————— Dividing Line——————

It is about 30 kilometers west from the busy streets of Fuyuki City.

There is an east-west national highway that crosses the mountains far from the village. The highway is lined with dense forests, and the forest area seems to have been forgotten by the surging land development boom.

The land may be state-owned, but it appears from the land register to be privately owned by a foreign-owned company, and it is uncertain whether the foreign-owned enterprise actually exists. If you have to investigate this land, the first thing that makes people puzzled is this magical urban legend.

Legend has it that in the deepest part of this dense forest, there is a mythical city.

Of course, this legend is just a boring oddity. Although the forest has not yet been developed, it is less than an hour's drive from Fuyuki City. If there really is such a strange castle, everyone will know about it. In fact, there have been several land surveys in this primeval forest in the past, but no traces of artificial structures have been found.

But every few years, someone recalls the legend.

A group of children walked into the forest with a half-play, half-adventure mood. There is also a lost hiker. Out of the fog they saw an ancient city suddenly appear, a magnificent castle made of rock. The castle was uninhabited, like an abandoned city. However, the castle is well-equipped and everything is in order, which makes people feel as if someone lives here. It is said to be an unusually bizarre ancient city.

Of course, no one will believe this legend. At best, it's a one-page story told in a summer weird story in a third-rate magazine with no news material.

Only a handful of magicians know that this castle is real.

The castle only welcomes its owner who enters the castle to participate in the war once every sixty years, and it is a castle of demons.

The castle is shrouded in multiple layers of illusion and magic enchantments, which are never revealed except by the most occasional circumstances. It's a bizarre space. People who know about the existence of this castle call this dense forest the Einsbelen Forest.

At that time, the Holy Grail War was being fought in Fuyuki City, and the patriarch of the Einzberen family, Yubstakuhayd, felt that it was inappropriate to set up a stronghold in the direct territory of the Tosaka family, the arch-enemy. Therefore, he made full use of his family's financial resources to buy out the spiritual vein land closest to Fuyuki City and used it as the base of the Ainz Belen family. It was the eve of the Third Holy Grail War, which coincided with the period of tension just before the outbreak of World War II.

This vast primeval forest is shrouded in enchantments and completely isolated from the outside world, and the Einzberen family has transferred all their original castle to this forest. This shows that the Einzbelen family's huge wealth and dedication to chasing the Holy Grail are extraordinary. At that time, the Tosaka family negotiated for the purchase of land in Fuyuki and toiled for covert work in the area, which was only a laughable move compared to the Einzberen family.

……