"...I'm sorry, Shirou."
After watching Waver leave, Shirou got in touch with Assassin and learned everything that had happened.
The Einzbern castle was probably already crawling with the enemy's eyes and ears. The moment they returned, they would be attacked. So Shirou and Hassan of the Hundred Faces met up at the inn they were using as a temporary base.
"You warned me yourself that even with the Holy Grail War nearing its end, I still had to stay on guard..."
Assassin looked apologetic.
"If I had been more careful, maybe none of this would have happened."
Shirou shook his head.
"No, this is not your fault, Assassin. No one could have seen this coming.
You made it back alive, and you saved Irisviel. That alone is enough... How is she doing now?"
Assassin replied, "I got a room for her. She is resting next door right now.
She must have taken quite a blow.
The Grail was corrupted because of Einzbern's cheating in the past, and on top of that, we lost Saber.
Then there is the burden of containing the soul of the fourth Heroic Spirit. With all of that hitting her at once, she does not seem to be in a very good state of mind.
Shirou, do you want to go see her?"
"Yeah, I'll go in a bit. First, tell me about the enemy."
The red-haired boy asked, "Do we know who the mastermind is?"
Assassin said, "According to Irisviel, the Avenger summoned in the Third Holy Grail War was supposed to be a divine spirit named Cernunnos.
That was how it should have been. But the one who actually answered the summoning was an extremely weak young girl, and she was defeated cleanly in the opening stage of the Holy Grail War."
Cernunnos...!?
Shirou's face filled with shock.
"...You know that name?"
Assassin tilted her head.
As the leader of a monotheistic sect, Hassan of the Hundred Faces knew nothing about polytheistic gods.
Shirou's lips trembled slightly.
"Are you sure? The one summoned in the Third Holy Grail War was Cernunnos?"
Assassin gave a light nod.
Shirou fell into thought, his expression turning grave.
Cernunnos. An ancient god from Celtic mythology.
The first deity created by the Earth Mother, Danu, he was a god of animals, plants, fertility, and life.
He was also a god of the hunt and the king of all beasts. Because he had taken part in the creation of the first humans, the Celts revered him as the Beast God, an ancestral deity.
As an eight-year-old Japanese grade schooler, Shirou normally would have known little beyond figures like Zeus, Odin, or Amaterasu. The reason he knew of such an obscure god was naturally tied to his experiences in Fairy Kingdom Britannia.
Those were the final days of Shirou's previous life.
Before the overwhelming power of the Nameless King, the conflict that had continued on that island for more than ten thousand years had finally come to an end.
One day, at the invitation of Aesc the Savior, Shirou went with her to investigate the great cavern at the center of Britannia.
Also traveling with them were the Black Knight Ector and the Fairy Knight Totorot.
Unfortunately, the sage Grímr had disappeared during a battle and had remained missing ever since. Otherwise, it would have been a reunion of the original hero party.
"Now that I think about it, Shirou really does live a ridiculously long time. If you count it up, we have known each other for over two thousand years."
The girl from the Wing Clan sat on top of Shirou's head as she said that.
"Even if you hibernate with Morgan every time... do humans from other worlds all live this long?"
"Ugh...!"
Aesc the Savior's expression turned awkward.
Totorot's careless remark stabbed right into her chest. She alone knew that Shirou's lifespan was almost gone.
Even though she had done everything she could to prolong Shirou's life, Magecraft had its limits in the end.
More importantly, Shirou no longer had the same iron resolve to keep living no matter the cost, even if it meant staining his own soul.
[Just like the fairy tales you love, Morgan.]
[As long as it is a story, one day it will reach its ending.]
[The evil dragon is defeated, the prince and princess are wed, the villains are punished, and so on. That is how a story ends.]
[No one wants to watch the hero return to a quiet daily life, or the prince and princess living out their married life.]
[For me, the founding of the Fairy Kingdom is the ending of the story.]
[So... isn't this enough?]
[For me, this has been the best life.]
[Thank you, Morgan.]
[You have to become a great king.]
For the first time, Morgan could not agree with the knight she loved.
So under the pretense of an investigation, she gathered Shirou and their old companions together.
She hoped that another adventure might reignite the passion Shirou had already lost.
The group arrived at the great cavern in the center of Britannia.
Just as its name suggested, it was a bottomless black abyss, and they were about to descend into its deepest depths.
Totorot nervously said, "Aesc, are we really going down there!? I am against this! This place is seriously creepy!"
"But there is no danger."
Aesc stole glances at Shirou as she spoke.
"Mors do not appear near the great cavern.
The fairies do not come near this place either, so we will not be attacked by the Anti-Fairy Round Table Organization.
The only things we need to watch out for are Totorot lowering the line, me protecting the line with Magecraft, and Shirou holding onto the line as he goes down. Just do not let go."
"Huh? Me?"
Shirou frowned. Seeing how enthusiastic Morgan was, he had assumed she meant to go down herself.
Morgan folded her arms and nodded.
"Of course. You are the strongest one here... right?"
In truth, Shirou was no longer at his peak by then. He still looked young on the outside, but inwardly he had already grown old.
Shirou could tell Morgan was up to something, but since there was no way she would harm him, he let out a helpless sigh.
"Got it. I really can't say no to you."
Once she got his permission, Morgan happily wrapped Totorot's line around Shirou's waist.
"My Enchant can extend Totorot's line to eight thousand meters, but there is no real need to go all the way to the bottom.
How deep is the great cavern, and what exactly is at the bottom?
Once you descend far enough to see anything, use voice Magecraft to report back to us.
All right, Shirou. This is only a reconnaissance mission, so remember that."
The old man of the Earth Clan standing nearby frowned.
"What do you mean, only.
You are the only one already thinking about what comes after the reconnaissance. I cannot agree with attacking the moment something is judged dangerous."
Totorot chimed in, "The Black Knight is right! Aesc is always reckless! She is totally cold-blooded and ruthless to her enemies too!"
"Huh? I am just setting priorities. Shirou, where are you going... ah!?"
While everyone was chatting, Shirou simply jumped straight off the edge of the great cavern.
"Wait... what happened to the safety rope under your feet!? Weren't we supposed to lower you down little by little!? Why did you just jump while wearing the safety line!? Shirou, that was way too reckless!!!"
Morgan threw herself onto the ground and roared.
Totorot covered her mouth and giggled.
"Speaking of reckless behavior, Shirou is not exactly one to talk either... You two really are a perfect match."
Shirou shoved his hands into his pockets and lejoined into free fall.
When he reached a depth of seven thousand meters, the rope around his waist gave a tug, and Morgan's complaining voice came through.
After being thoroughly scolded, Shirou obediently reported the situation back to those above.
"The size of the cavern has not changed. No signs of life.
The air is filled with ash... drifting up from even deeper below.
Looks like all that unexplained dust in Britannia's atmosphere is coming from here."
Morgan frowned.
"Hmm... I really did not expect it to be this deep...
Shirou, still cannot see the bottom?
And it must be completely dark by now, right? Is it cold?"
Shirou stayed alert as he answered.
"Yeah, there is no sunlight anymore.
But instead of getting colder, it is actually warmer than on the surface, and... the air feels unusually heavy."
He continued descending.
Between seven thousand and seventy-five hundred meters, a crimson glow appeared below.
Shirou poured magical energy into his eyes and finally made out the darkness at the bottom of the great cavern.
It was fire.
A gigantic corpse, wrapped in magical energy denser than any physical substance, burning fiercely amid curses.
It was clearly a corpse, and yet it was still alive.
Lurking in the deepest depths of Britannia for twelve thousand years, it had now accumulated a curse vast enough to cover the entire planet.
The moment Shirou's gaze met it by accident, he instantly lost consciousness.
In his haze, he heard Morgan's frantic voice.
"Cernunnos...! Why would an ancient Celtic god die in a place like this...? Shirou! Get a hold of yourself!"
That was how Shirou first encountered the ancient deity called Cernunnos.
As a side note, that single glimpse into the cavern directly shaved at least three years off Shirou's already meager remaining lifespan, and he died half a year later.
In other words... that bastard was the reason I never got to properly enjoy my retirement like I had planned!
Shirou ground his teeth in frustration.
In the end, I never even got to properly propose to Morgan. I just died like that, all of a sudden.
During those final six months, Morgan blamed herself for what had happened to Shirou and spent every day miserable and depressed.
Cernunnos! I will never forgive you!
That said, that was still Cernunnos, the Cursed God of Fairy Kingdom Britannia.
He should have nothing to do with the Beast God Cernunnos from Proper Human History... right?
But then why...
The girl who manifested under the name of Cernunnos kept bothering Shirou for some reason.
...
...
At the western side of Fuyuki City, atop Mount Enzou, stood Ryuudou Temple.
A blond young man in a biker leather jacket climbed the stone steps with his hands in his pockets.
At the top of the long staircase, the one waiting for Archer was the girl who had already taken over Ryuudou Temple as her base. Avenger.
"You are back, Archer."
The red-haired fairy girl smiled.
"Good work with Rider. There is nothing else for you to do, so you can leave now.
You are an eyesore, so turn into spirit form. I will call you when I feel like it."
"..."
The King of Heroes stared at Avenger expressionlessly, as though he were looking at a talking corpse.
"You insolent little brat who dared use a Command Spell on this king. Any last words?"
"Pfft, hahahahahahahahaha! Hahahahahaha!"
The red-haired girl laughed so hard she bent over and shook all over.
"What happened to the oldest Heroic King of mankind? So after all that, you are just an idiot!
Do you even understand the situation, Archer?
Surely you do not think that just because your Master only has one Command Spell left, and the only way I can control you is through that one Command Spell, that means I cannot do anything to you.
I control the terminal of the Holy Grail, you know? And a mere Servant thinks he can defy me, the will of the Holy Grail itself.
Looks like I need to teach you a lesson so you understand the difference in rank between us."
That condescending gaze from the Golden King is really annoying. I will cut off both his ankles and make him kneel before me.
Thinking that, Avenger raised a finger with a smile.
What shot from her fingertip was neither a cursed magic bullet nor one of those threads that could sever a body.
It was a rule.
As the will of the Holy Grail, she could kill a Servant with a single glance, because Servants only manifested in the first place through the Holy Grail's magical energy and rules.
"!"
And yet the ridiculous scene of Archer losing both feet and collapsing to the ground never happened.
"Fool. Who would get hit by something that obvious?"
The defensive Noble Phantasm the King of Heroes had deployed in advance blocked the rule-based attack.
At the same time, the Noble Phantasms launched by Gilgamesh flew toward Avenger as well.
Which was stronger. The will of the Holy Grail, with the authority to erase Servants at will, or the King of Heroes?
In Fate Heaven's Feel, it looked as though Dark Sakura devoured Gilgamesh, but that was really just the king's arrogance.
In truth, a fight between the two was simply a matter of who landed the first blow, because both possessed enough firepower to kill the other instantly.
Under normal circumstances, Gilgamesh probably would have been crushed because of his carelessness, but right now he was in an especially foul mood.
When the King of Heroes truly meant to kill someone, even a being above the level of a Servant could not escape death.
"...Ugh!"
Avenger's shoulder and calf were pierced by the [Gate of Babylon], and she crashed to the ground in an ugly heap.
Gilgamesh walked over to the red-haired girl and raised his right hand, pulling a sword from the void.
"I will ask you one more time, mongrel... any last words?"
"You dare...!"
Avenger ground her teeth and glared furiously at Gilgamesh.
"I will kill you!"
"What foolish last words."
Archer swung his sword down at the girl without a trace of expression, but at that moment...
"!!!"
A pitch-black beam of light tore through the silent temple grounds and the night itself.
"What?"
Gilgamesh narrowly dodged the blast at the last instant, leaping backward as he frowned.
"You are..."
A small figure emerged from the night fog.
Black armor, platinum-blond hair, skin pale enough to look sickly, and golden eyes.
Saber Alter stood in front of Avenger, holding the corrupted Holy Sword.
Watching the black Saber, the King of Heroes narrowed his eyes and revealed a dangerous, alluring smile.
"I see... so the number of Fakers has increased."