After leaving the Tohsaka house that night, Alvin headed out.
After activating the authority of "Watchman EX," he moved through the snowy night like a shadow, slipping silently into Mount Enzo.
After the last Holy Grail War ended, the Greater Grail of Fuyuki seemed to have been relocated, but its core was still buried within Mount Enzo.
The only question was where the Three Families had hidden it back then.
Alvin was just about to close his eyes and sense the presence of the Greater Grail, at that moment, he suddenly noticed a sneaky figure struggling up the back mountain steps.
Dressed in white mage robes and holding a staff, he looked nothing like a Grand Caster. Instead, he looked like a thief sneaking around.
Merlin!
The man glanced around as if he caught onto something.
"Come out. I know you're hiding here."
Alvin was startled inside.
'I already activated the highest level of Presence Concealment authority. How did this guy notice me?'
'Don't tell me my Assassin class is fake?'
Just as he was feeling annoyed and preparing to step out of the darkness, the sneaky white-haired mage pulled back his gaze in satisfaction and headed toward a spot near the mountaintop.
The look on Alvin's face quickly turned strange.
Clearly, Merlin had never noticed him at all. He had just been bluffing.
And Alvin had almost fallen for it.
'Compared to Artoria, this guy feels more like a scammer,' Alvin muttered inwardly.
Seeing Merlin walk farther away, Alvin maintained his Presence Concealment and followed behind him the entire time.
Thinking about it, the two of them really were natural enemies.
Merlin possessed Clairvoyance capable of observing the present, yet he alone could not see Alvin after he activated "Watchman EX."
Meanwhile, Alvin possessed absurd brute strength, but he had little way to deal with a mage like Merlin who specialized in illusions.
If he couldn't win, he would just escape with illusions... Catching this white-haired mage was not easy.
The mountaintop at night was filled with wind and snow, carrying biting cold.
But Servants did not feel cold.
The footprints left on the ground were quickly buried by the snowstorm.
Following behind Merlin, Alvin found things strange.
Logically speaking, they had both only recently been summoned for the Holy Grail War, so how did Merlin know the location of the Greater Grail so well?
And why was he secretly coming here behind Illya's back?
With questions in mind, the two unknowingly arrived at the cliff near the summit.
Merlin raised his staff and lightly tapped the ground.
Buzz!
At that instant, the entire Mount Enzo seemed to release a faint rumble.
Alvin had just stepped across the icy surface when he suddenly saw an insect with incredibly complex patterns fly past his eyes.
Its abdomen was semi-transparent, and inside it was the faint image of a Holy Grail.
"Crest Worms?"
Alvin's pupils shrank as shock filled him.
Because he soon witnessed something that made his skin crawl.
More and more Crest Worms poured out from cracks in the ice, weaving together in the air into an inverted Tower of Babylon.
At the center surrounded by the Crest Worms, there seemed to be a temple.
A temple standing within a snowy mountain.
'When did Mount Enzo get a temple like this?'
The thought had just crossed Alvin's mind when he saw Merlin turn around with a smile.
"These little things have already transformed the whole mountain into a Beast incubation ground..."
"What do you think, Alvin?"
The shadows twisted in the darkness.
A moment later, Alvin stepped out from them and looked over the white-haired mage.
"When did you notice me?"
"At first, I really didn't notice anyone following me. It was only after this thing appeared that I realized you were here."
Merlin smiled and pointed toward the snowy mountain temple ahead.
"There's a Beast sleeping inside. It absorbs other people's emotions and turns them into its own power. You probably didn't even notice it yourself, but your emotions were already sensed by it just now."
"Normally, a person's emotional fluctuations wouldn't be this strong. Looks like something happened at your Master's house earlier that stirred you up quite a bit."
"Did you come out in the middle of the night to clear your head?"
Merlin asked with a smile.
"Talking too much isn't always a good thing," Alvin replied in a flat tone.
"You already knew there was a monster hidden inside Mount Enzo?"
"On the first night after I accepted my Master's summoning, it already tried to devour my emotions," Merlin shrugged.
"But it failed. After all, I don't even have that kind of thing."
Nightmares did not understand human emotions.
Or rather, the opposite was true. Nightmares themselves were creatures that enjoyed feeding on "emotions."
"The reason you accepted Illya's Heroic Spirit summoning was because of this thing?"
Alvin raised his head and stared seriously at the temple in the snow mountain. He could sense a terrifying aura inside.
These Crest Worms were probably transporting "negative emotions" into Mount Enzo every night as nourishment for the Beast within the temple.
Merlin nodded without comment.
"If I'm not mistaken, this thing already existed during the previous Holy Grail War."
"It's absorbed ten years of negative emotions as nutrients. If the thing inside comes out one day, it'll be a major problem."
The fact that even Merlin called it "troublesome" was enough to show how wary he was of the creature inside.
"Speaking of which, did you find out where the Crest Worms came from?"
At that moment, Merlin suddenly changed the subject and asked with a smile, "You investigated it tonight, didn't you?"
When Rider's Master "escaped" earlier that night, she had left behind a Crest Worm wing, and Merlin had clearly noticed it back then.
Alvin's eyelid twitched slightly, "No leads."
"Is that so... What a shame," Merlin sighed theatrically.
"If this thing isn't dealt with, then when it awakens in the future, it'll definitely devour the girl controlling the Crest Worms behind the scenes."
"At that point, her consciousness probably won't belong to her anymore."
Alvin glanced at the man calmly, "Merlin, you really are just as rotten as ever."
"I genuinely want to save humanity," Merlin smiled helplessly.
"I was doing perfectly fine staying shut inside my tower. You think I wanted to come out and work, Alvin?"
"Do you have a solution?", Alvin asked directly.
"Even if it's still in its juvenile stage, if a Beast is left alone, the destruction it can cause isn't something humanity can withstand."
Merlin turned to look at the temple projection behind him.
"But there's only so much a Servant can do..."
'You mean you're planning to stop being human again?'
Alvin said in a low voice, "Stop dragging it out. Just say it."
"The Beast inside should be trying to use the Sea of Chaos, the black mud, and the negative emotions of the people in this city as a medium to fully manifest," Merlin smiled.
"But it probably never considered who the Sea of Chaos actually belongs to."
A trace of approval appeared on Alvin's face, "Looks like we have the same idea."
After all, in order to manifest the creature inside the Greater Grail, the Crest Worms had worked hard for nearly ten years. Nobody knew how much "black mud" had already accumulated inside the Greater Grail.
Ordinary people might have no way to deal with black mud.
'But if it is Tiamat...'
Alvin and Merlin exchanged a look.
The latter obediently walked off to the corner.
Alvin took a deep breath.
"Mom!"
Along with the low shout, the pitch-black night sky split open like a crimson crack.
Within the crack, an incomparably beautiful figure quietly descended.
Tiamat.
She drifted gently onto the ground. Her skirt lightly brushed across the snow, and wherever she passed, the "black mud" hidden within Mount Enzo boiled like joyful song.
In an instant, countless Crest Worm corpses fell from the sky like rain.
She was absorbing the black mud that was supposed to nourish the Beast of Desire.
———
[Late night, Matou Household]
The night was silent as snowflakes fell from the iron-gray sky.
Matou Sakura suddenly woke as if from a nightmare. The moment she opened her eyes, instead of changing clothes, she spoke in a low voice: "Rider!"
The door opened, and the purple-haired woman quietly arrived before the girl.
"What is it, Master?"
"Go to Mount Enzo... Someone is tampering with the thing inside."
Matou Sakura's tone was low.
The weak look she usually carried was gone. What remained was an extremely dark coldness.
Clearly, this was not Sakura Matou's own personality, but another consciousness within her body.
Beast III/L, the Beast of Desire known as "Kama."
Although she had made an agreement with the White Dragon from the beginning that she would not act against him no matter what, there was one major condition for that.
He had to obediently listen and submit beneath her feet.
Otherwise... that so-called White Dragon... would simply become food for her.
———
Before this, Alvin had never thought of using such a shameless trick.
Rider's Master, or rather, the "Beast" inside the Greater Grail, had spent all these years secretly absorbing human "emotions" in order to evolve from a juvenile beast into a complete Beast. It had even been damaging the barrier purifying the Greater Grail.
However... even it probably never imagined that the true owner capable of controlling the Sea of Chaos also existed in this world.
Or rather, Alvin could summon her out at any time.
Having Tiamat devour the "Sea of Chaos" inside the Greater Grail ahead of time could also be considered a form of "purification" in a sense.
"Aaaaa!"
As if she had eaten to her heart's content, Tiamat slightly opened her mouth and released a song.
A satisfied smile appeared on Merlin's face as he nodded.
"Very good. Keep it up and turn all the 'black mud' inside the Greater Grail into your own power, Mother Goddess of Creation!"
Bzzzt!
But right then, a sound like electrical static suddenly rang out nearby.
Merlin's gaze sharpened.
He suddenly saw that beside Tiamat, who had been floating in midair devouring the "Sea of Chaos," a crack was quietly opening.
An incomparably terrifying aura poured out from within it.
The sudden change caused Merlin's expression to shift slightly.
"This is bad! She has to stop first!"
Tiamat's true body had always remained asleep.
Now that the "spiritual body" summoned by Alvin had devoured the Sea of Chaos, that power was directly being transmitted to her true body within the Imaginary Number Space.
If she kept "eating" like this... the Beast in Fuyuki might not evolve into a complete Beast, but Tiamat in the Imaginary Number Space was about to awaken.