In the book 'Harry Potter,' there is a truth serum known as Veritaserum.
Beyond that, in many media outlets… especially those dealing with 'fantasy,' spells that force one to reveal the truth or their inner thoughts, or spells that detect the opponent's lies, are staples of the genre.
The Naraka Path is the same. It possesses the power to pull out the tongues and execute those who lie before its eyes.
The personification of Great King Enma, who governs the Hell of Tongue-Pulling within the Buddhist Hells… In that case, is that power absolute?
'…No, it is not.'
I know this fact all too well.
Even if the words uttered are not the objective truth, if the speaker believes them to be the 'truth,' the Enma of the Naraka Path will not punish them. Furthermore, the opponent is Sherlock Holmes… a consulting private detective with a mind comparable to the trio of Clairvoyance users.
If he were the mastermind, there exists a possibility that he could escape the power of the Naraka Path by using means to directly distort his own memories… However.
"How unexpected. You know quite a bit about me. And yet, you present this to me… Have you considered the possibility that I might distort my own memories or respond in a way that avoids telling a direct lie?"
"Of course that possibility exists. But it's out of the question for two reasons."
"And what might those be?"
"First, rummaging through a Heroic Spirit's memories is no simple task. At the very least, you'd need the Holy Grail or an equivalent resource, along with a precision magus capable of wielding it… Like the King of Demon Gods or the Grail itself, for example."
But Holmes had never come into contact with the King of Demon Gods since his summoning.
"Then is it not possible that I am a spy? Deducing from Chaldea's records… like a 'Reversed Body—Alternative'?"
"…What do you take me for? Your class is Caster, but you have the aptitude for the Ruler class as well."
Excluding those like Jeanne d'Arc [Alter], whose existence was literally forced into place, those in the Ruler class are beings for whom a reversed body cannot exist.
Of course, considering his essence—the Alien God—it might be worth suspecting, but if it came to that, it would actually be better for us. Even from the Alien God's perspective, the Incineration of the Human Order by Goetia is an act that must be stopped.
"Anyway, just answer the question. Are you an enemy of us, of the Human Order? YES or NO?"
"The answer is… No. I am on the side of the Human Order. And to add to that, I shall state clearly that I will assist you and never betray or cause you harm."
"…Good."
If he has gone this far, then it is the truth.
I hadn't ignored the possibility that he might act out, claiming 'The Human Order and Chaldea are separate!' but regardless, Sherlock Holmes underwent the trial of the Naraka Path while accounting even for that possibility.
"…By the way, those two over there… Andersen and Shakespeare. Do they not have to undergo this 'trial' as well?"
"No, I'm going to do it now."
"W-Wait a moment. We are currently in the middle of writing…!"
"Hush, hush. Get over here!"
*
After Paracelsus's house had been slightly disarrayed and the ideological verification of Paracelsus, Sherlock, and the two authors was complete, a transmission from Romani came through.
[This is Chaldea. Is the ideological verification over?]
"More or less. At least there seem to be no spies among them… although I'll still have to check Zolgen, Jekyll, and Nursery Rhyme."
"Hmm… Zolgen is a trustworthy friend. He was the one who drew me into this side to begin with."
"I know that. But it's trouble if you underestimate the King of Demon Gods… He's the kind of guy who can induce every action of his opponent according to his own intent to create the result he desires."
Angra Mainyu was transformed into a Beast of Humanity that way, and Leif Lainur Flauros—thanks to Mash surviving—didn't commit suicide but moved forward to become a Demon God Pillar.
It's almost at a point where I should say it's impressive how he uses goodwill to stubbornly advance toward his own twisted ideals… He really is a troublesome fellow.
"Alright, anyway, we've secured the Paracelsus faction and the Makiri faction among the P.M.B. All that's left is B—Big Ben…"
"As for the Big Ben faction, that is originally where I should have been. It's just that I decided to hide in Paracelsus's hideout for a while after having a skirmish with Nikola Tesla."
"Not bad. Where are the people from the Mages' Association?"
"They are in the northeastern region of London."
Holmes spoke while puffing vigorously on his pipe.
Paracelsus, seemingly uncomfortable with even the slightest mist in his house, even if it was just pipe smoke, summoned an elemental to scatter it. Holmes took a regretful final breath before continuing.
"There are seven remaining Brand-rank magi in total. Furthermore, the situation is that the Clock Tower headquarters is currently being held by traitors… those who were selected as 'Mafia,' those who were victims of them… or just plain madmen aiming for the Root."
[…That's a headache. Blowing up the Clock Tower entirely would be possible for you or the other Servants, but if you did that…]
"The history of the Clock Tower itself might be gouged out entirely. In the end, the most feasible thing to do is to end this damn Mafia Game."
The source of the Mafia Game is surely the Holy Grail.
Just as the Curse of the Tetragrammaton was, deploying a Magecraft circle of this scale is impossible without a massive resource like the Grail. Judging by past experiences, there must also be an administrator managing the game using this Holy Grail.
Like Gilles de Rais in France and Leif Lainur Flauros in Rome… Finding that 'someone' is the key strategy for this Singularity.
[It's a pain. It could be an ordinary magus, or even a normal human.]
"No, it's hard to believe this is the work of a normal human. At the very least, it's closer to being directly orchestrated by the King of Demon Gods."
[Why is that?]
"It's simple. The 'Mafia Game,' or 'Werewolf,' where an unspecified majority who don't know each other's identities find a minority of criminals through interrogation and discussion, was created in 1986. A psychology professor at Moscow University in the Soviet Union devised it. Even if there were oral stories or personal games passed down before then, do you think people of this time period could combine the words 'Mafia' and 'Game'?"
[…I see! Unless it's a Servant receiving backups from the Grail or a Servant with transcendent vision…]
"They could never use the keyword 'Mafia Game.'"
Of course, the King of Demon Gods probably couldn't hide the name, just as it was with the previous Curse of the Tetragrammaton.
A name carries great power, and if he tried to twist it somehow, there's no telling how the situation might bounce, just like the Tetragrammaton incident.
"When this night ends, I'll have to start with an investigation. I'll visit the Mages' Association's district and save the 'B-Magi' who are working hard to hold out."
"…Hmm, it seems the mansion will need some maintenance."
"Is the… house too small? I can lend you some puppets if necessary."
When I spoke cautiously, Paracelsus spoke while floating a giant mud doll and an elemental.
"Please rest easy; I can finish the expansion work on the basement in an hour."
"…Ah, right."
[I always get this feeling, but because the Caster class gets beaten by you every time, you seem to underestimate them a bit.]
"Shut up, Romani."
A King who is the pinnacle of the Caster class and yet got backstabbed by his own familiar certainly has a lot to say.