"————"
Staring at the black cover of the Book of the Dead cradled in his arms,
Just moments before, his brain had been consumed by a Socratic loop of questions that led nowhere, a self-interrogation with no answer.
In truth, the thoughts occupying Subaru's mind were, more often than not, the kind of shallow musings one would normally dismiss as a waste of brainpower.
The sort of vague, childish doubts that anyone would sneer at.
—No matter who a person is, they hide a face different from the one they show the world.
That was a self-evident truth, something everyone learned growing from child to adult.
Behind the smile lurks a face twisted with hatred; behind the fury simmers the tear-streaked grief of sorrow. Concealing such true feelings while interacting with others as though nothing is amiss—that is what it means to be human.
No one can ever know another person's true heart, true feelings, true nature—not with one hundred percent certainty.
Siblings, parents and children, husbands and wives—even family cannot fully understand one another.
Friends, childhood companions, confidants, lovers—no matter how deep the bond, the heart remains a black box, impossible to pry open completely.
That someone loves you. That someone thinks fondly of you. That someone trusts you. That someone is willing to give themselves to you. All these ties of mind and body are an entirely separate matter from *knowing* a person.
Yes, he understood all that. But that didn't mean he could simply stop trying.
He wanted to know, wanted to understand, wanted to hear, wanted to tear it all open—a wish that was arrogant, yes, but desperately earnest. And when lives—his own and others'—hung in the balance, that urgency only deepened.
Even if the means to do so were impossible, nonexistent.
—No. It *had* been a nonexistent means.
Because it didn't exist, anyone would have scoffed at the very idea of searching for it.
But here, in the library of this wretched watchtower, Subaru had learned otherwise.
"————"
By deciphering the Book of the Dead, Subaru had vicariously lived through Meili's life, understanding what schemes drove her, what she had been thinking, and whom she had ultimately hated.
Of course, that fleeting secondhand experience did not encompass the entirety of the girl called Meili.
To absorb an entire lifetime into one's brain in a single instant—the sheer volume of time involved made that impossible. Even a young girl's half-life was far too vast to take in all at once.
He had nibbled at the highlights, chewed them up however he pleased, and now he thought he understood Meili.
He knew, with a pain that cut to the bone, that this was precisely how Natsuki Subaru felt in this moment.
But even so.
By confronting the fact that he had previously understood absolutely nothing about her, Subaru's comprehension of Meili had deepened to a degree that dwarfed everything before.
—That the girl known as "I" had once cherished someone precious. That when that person was taken from her, her rudderless heart had been wandering ever since. That by staying alongside those who had done it—Subaru and the others—she had agonized over her own uncertain standing. That she had sought out the Book of the Dead to understand her own true feelings, only to be discovered—and had despaired.
None of it was a Meili that Subaru had ever known.
And yet, having inadvertently glimpsed the feelings buried deep within her heart, Subaru realized something.
That *this*—the Book of the Dead—was perhaps the one true means of knowing another person's unvarnished, honest feelings without a shred of deception.
"————"
He had simply wished to *know*.
To know
Why did they believe in the "Natsuki Subaru" who had killed them?
How did they feel, now, toward the Subaru who was desperately playing the part of the "Natsuki Subaru" they should despise above all else?
Was their affection merely a performance, with hatred as the truth beneath? Were their anger and sorrow and joy nothing but fleeting facades, while hostility, malice, ill intent—those were their genuine feelings?
He didn't know. He wanted to know. He wanted to believe. But he couldn't.
Were Emilia and the others allies or enemies—the enemies who had killed Subaru, or allies who would let him live?
Could he love them, or could he not? Could he hate them, or could he not?
—Could the answer be found by reading *their* Books of the Dead?
"…Subaru, you really do look unwell. If staying here is making you uneasy, perhaps we should move somewhere more comfortable."
Beatrice touched the shoulder of the brooding Subaru and offered that suggestion.
Trapped by her distinctive blue eyes with their butterfly-like pattern, Subaru held his breath for just a moment. A glance confirmed it: the girl's tiny—far too tiny—palm rested on his shoulder.
What would happen if he took that hand, pressed her head down with all his strength, and drove it into the floor?
"Small… aren't you."
"Hmph… what kind of thing is that to say out of the blue? This compactness is precisely what makes Betty so adorable. You've said so yourself, Subaru."
Beatrice pouted as she spoke, and Subaru felt his cheeks nearly soften into a smile.
Indeed, the real Subaru would have said something like that without hesitation. The thought that this was a point of similarity between himself and "Natsuki Subaru" made the smile turn bitter almost immediately.
She was small. Truly, Beatrice was small—a child.
Her neck was slender, her bones soft. Her hand on his shoulder was small enough to be swallowed entirely by his palm; if he hugged her with even a fraction of real force, it felt as though her whole body might shatter.
If he mustered every ounce of strength and acted on it, he could probably kill her with ease.
—If he killed her, ended her life, would her book appear in the library?
*"Like what he did to me, y'know?"* "————"
Without warning, a voice that was not Subaru's own echoed through his mind.
It was sweet in a way that didn't match its owner's age, subtly alluring, yet disturbingly *familiar*—a voice he had grown so accustomed to within such a fleeting span that it felt like his own.
The dead girl's voice, internalized within him, mocked Natsuki Subaru's will.
"————"
But Subaru refused to engage with it, focusing his attention instead on the matter before him.
Namely: as a practical measure, was there a viable path to using the Book of the Dead?
If so, how would he make it a reality— "You look even paler. We really must move. Before that, though…"
"—Ah."
"Let me just put this back where it was. I can't afford to let myself grow hazy too, not now."
With that, Beatrice carefully pried the Book of the Dead from Subaru's stiffening hands. Holding it with deliberate care so it wouldn't open, she carried it back to the shelf where it had been lodged and slipped it into the empty gap.
"Position-wise, this should be easy to find and remember. However, books in this library have a tendency to shift on their own, so…"
"So we can't call it a safe bet. …Yeah, you're right."
"Taking it outside would be far too dangerous as well. Leaving it on the floor is no good either—
"Feels like a once-in-a-lifetime library," Subaru said in a dry tone, even as he kept talking.
In the world Subaru remembered, too, there was a saying that encountering a long-out-of-print book was a once-in-a-lifetime event. A dusty bookshop discovered by chance while traveling—miss the chance, and you might never come across that book again. Perhaps the same kind of fickle design governed this library.
Then again, he was probably overthinking it. It was safer to assume it was just there to be a nuisance.
Either way, while Beatrice stood with her back to him, painstakingly committing the positions of every book to memory with tireless vigilance, Subaru dove deeper into the ocean of his own thoughts.
Grimly, practically, he worked backward from the warmth he had touched and arrived at the girl's death, probing for the method of killing.
He wasn't only considering Beatrice. Everyone inside the tower—every member of the expedition—was a potential target for his Book of the Dead plan.
*"Can I really trust them, or should I be suspicious? 'I just wanna kill 'em so I can figure out which'—oh my, big brother, you're sooo messed up."* The girl's taunting voice made Subaru click his tongue internally.
He needed to make one thing clear from the outset: this was, above all else, a thought experiment forced upon him by necessity.
He was *not* a psychopath driven by murderous impulse, nor was he some deviant who derived pleasure from such acts.
It was simply that, when he pursued logic and rationality to their utmost conclusion, this was the first option his mind conjured.
*"Skip the excuses—what exactly are you planning to do, hm?"* —Beatrice's elimination would be simple.
Even now, the back she presented to Subaru radiated vulnerability, helplessness, a total lack of vigilance.
To put it bluntly, Beatrice's life was held together by nothing more than a wafer-thin strand of "Subaru's reason," balanced on an unsteady fulcrum. The moment rationality overrode that reason—by however slim a margin—Subaru would succeed in taking her life without the slightest difficulty.
When it came to Beatrice, there was really only a binary: do it or don't. The countless minor branches and contingencies that might exist before reaching that point could all be ignored entirely.
*"Then what about the half-elf, big brother?"* Emilia was even easier—a cakewalk.
There was already a precedent: when Subaru had first awakened, she had let him seize her slender neck without offering a single shred of resistance. If he had simply clenched his arms with everything he had in that moment, he could have snapped that fragile neck like a twig.
Yes, she possessed strength that would put professional wrestlers to shame, but strength meant nothing if it was never deployed. One instant—that was all it would take. Squeeze with everything he had.
*"Heh heh heh. That's your specialty, isn't it?"* —
He remembered the moment she had pressed her forehead against his with tears in her eyes, begging him to confirm or deny her memories. The arms she had used to cling to him had been thin, her grip weak. She had been, in that instant, just one solitary, ephemeral girl.
More suitable personnel had surely been available. The shortage of capable people must have been dire.
Which meant Subaru had room to exploit, but the final obstacle was another matter entirely.
"—Julius."
The only man who stood alongside Subaru—and one who carried a sword—blocked his path.
He alone could not be confronted head-on. —Though to be fair, challenging Emilia head-on would be equally suicidal, but that was a different story.
In any case, if Subaru intended to carry out the Book of the Dead plan, Julius would be the greatest wall he had to scale.
Put another way, that also meant Julius was the first one who needed to fall.
*"If you think about the time needed to find the right book, you'll never have enough, will you?"* As the girl said, Subaru's goal was not simply "kill and be done."
Rather, killing was a necessary waypoint—a toll to be paid—and the real prize lay beyond: the Book of the Dead, obtained in exchange for a life.
To ensure success, he needed to be certain.
Kill, fail, and it was over. His objective lay on the other side of that threshold.
"Subaru, the book is fine where it is for now. Let's leave this place… shall we go to the spirits' hall? It should be calmer there."
"The spirits' hall…"
Beatrice returned and tugged his hand; her light weight pulled him to his feet. The mention of a place with spirits brought his restart point flooding back to mind.
That place was the spirits' hall, and in that place— "
"…Again, that name of the earth dragon's. Honestly, you're a partner impossible to worry about properly. Betty is the one who's worried, and you go and zone out like that."
"…S-sorry. It's nothing, really. No ulterior motive or anything."
For an instant, the silhouette of the black earth dragon flashed through his mind, and Subaru's lips softened. Beatrice caught it immediately, and he scrambled to rein in his expression.
Even so, in this situation, the one being Subaru could place his absolute trust in was Patrasche.
In truth, it was Patrasche alone who had risked his life rushing to protect Subaru—and he would side with Natsuki Subaru regardless of any true feelings or hidden thoughts.
*"Really? If that child learned that big brother isn't actually 'Natsuki Subaru,' would he still do the same?"* "————"
*"In the end, there's no one on big brother's side, is there?"* The voice that echoed in his skull, a smile lurking within every syllable, mocked Natsuki Subaru.
The entity that had taken root inside him—a presence distinct from Natsuki Subaru—sought to shatter Subaru's optimism.
He should have laughed it off as a ridiculous observation. But in reality, Subaru had no such luxury. Half his heart was already in agreement with the girl's words.
Even Patrasche's boundless kindness—his willingness to throw everything away—had been directed at "Natsuki Subaru." The moment he realized that the current Subaru was an impostor, he would surely turn away without a second glance.
"Come, Subaru. Shall I help you with your hand?"
"A-ah…"
His mind in turmoil over the girl's voice, Subaru clenched his molars against the unbearable emotions surging within.
Because of this, his focus had drifted entirely from what was right in front of him. When Beatrice, obedient to his silent compliance, reached out to take his hand, her gaze suddenly snagged on something.
She was staring at his wrist—and he noticed.
"You have scratches. And so many of them…"
Beatrice rolled up the sleeve of Subaru's right arm and frowned at the ugly nail marks. She didn't seem to notice the deeper, gouged wound above them, but even the superficial ones were more than alarming.
"————"
In the strictest sense, Beatrice did not know the manner of Meili's death.
So she would not immediately connect these scratches to Meili. But even setting that aside, she would surely be troubled by what could have caused them.
If Meili's body were found on top of this, suspicion would be inescapable.
"————"
His unprepared heart began to hammer like a war drum.
Before him, Beatrice's gaze had settled on his hand, oblivious to the expression on his face. Right now—in this moment—he could restrain her with a single impulsive motion.
*"So? What'll it be? Are you finally gonna start?"* The voice goaded him, toying with his pride, pressing him toward a decision.
With every throb of his heart, blood surged and his temples pulsed with pain.
If Beatrice's next words went a certain way, he would— "—You've scratched your own arm again, it seems. My, what a bad habit."
"…Huh?"
"This position isn't good at all. If Emilia found it, there's no telling how worried she'd get. And even Betty can't just turn a blind eye if it's this bad."
As she traced the wound on Subaru's wrist with her finger, Beatrice's eyes clouded with sorrow.
Her words struck Subaru with an unexpected shock that left him rooted in place.
Beatrice was looking at the scratches on his arm with the air of someone who had seen them many times before.
That was a *completely* different scenario from the dreadful outcome he had anticipated—not "Meili" at all, but something far more mundane: self-inflicted wounds on his arm.
Even told he had been hiding them from Emilia, the realization hit him like a blow.
"If you go to that room with the spirits, perhaps they can be healed. Even so, I can't stand to look at them, so let me treat them a little, at least."
As she spoke, Beatrice enveloped the wound on Subaru's wrist in a pale, gentle light.
What washed over him was a warm, tingling sensation—the unmistakable feeling of a wound mending. Healing magic, displayed before his very eyes.
"————"
At the same time, within Subaru, the hostility toward Beatrice dissipated with startling speed.
Alongside that warmth, alongside the wound on his wrist, the humanity of Natsuki Subaru—fractured and splintering—seemed to receive a firm, quiet repair.
*"Boring."* The girl's voice drifted through his mind, flat with disappointment.
Hearing it resonate directly inside his skull, Subaru swallowed the grim reality of his situation.
Yes, it was an option. But it was *only* an option.
There was no need to let himself be led toward the Book of the Dead on his own initiative.
Especially not in a situation this half-baked, where nothing was in place.
"————"
Here, in this moment, harming Beatrice would serve no purpose.
His preparations were still incomplete. Even if the worst course of action eventually became necessary, it could only be carried out when he was fully ready.
For that reason, here and now— "Come, let's go, Subaru. I'll tell the others later."
"…Got it. Sorry for all the trouble, Beatrice."
"That's something of a standing promise, isn't it?"
And so, guided by the concern of the girl before him—whether it was genuine or not, he could not say, but he decided it was something he ought to follow nonetheless—Natsuki Subaru moved.
※※ ※ ※ ※ ※ ※ ※ ※ ※ ※ ※ ※ ※ A small aside: there is a saying.
—*Murder becomes a habit.* It is one of the words left behind by that legendary detective, Hercule Poirot.
—*Murder becomes a habit.* The meaning is not that a person who has killed will develop a taste for killing, nor that they will be driven to repeat the act to satisfy some twisted desire.
—*Murder becomes a habit.* It means that once a person has resolved a problem through murder, they will, when the next problem arises, naturally consider murder again as the solution.
—*Murder becomes a habit.* The very moment you begin to count murder among your options—a thing that need never be done—you have already misplaced something fundamental.
—*Murder becomes a habit.* Even if you have never actually killed of your own free will, even if you loathe the very idea, even if you have glimpsed the pain of those who have been victimized—the habit does not go away.
—*Murder becomes a habit.* The habit does not go away.
—*Murder becomes a habit.*