As Watson spoke, he casually picked up a book from the top of a teetering pile of volumes that Holmes had just set down.
The gilded letters on the cover shimmered in the dim light: Star Chart Epoch.
He flipped through two pages; inside, it was filled with dense astronomical knowledge.
A nearly absurd, strange expression appeared on Watson's face, and he looked up at the figure immersed in the sea of books.
"The sun must be rising from the west."
Watson brandished the book in his hand, his tone full of disbelief.
"Sherlock Holmes, you are actually reading about astronomy? And you're so engrossed in it?"
"I distinctly remember you saying yourself, 'Astronomical knowledge is useless for solving mysteries on Earth; it is the most useless reserve of knowledge. Even if I knew these things, I would do my best to forget them.'"
He mimicked that caustic and precise tone Holmes was accustomed to using.
Holmes did not pause in his page-turning, nor did he lift his head; his voice was low: "That was before, Watson."
"The last incident, in Boston, beneath the Clavius Seminary... we witnessed the collapse of order with our own eyes."
He paused, as if savoring the memory of that annihilated magic circle, the writhing black slime, and the loathsome form of the Byakhee from between the stars.
"I realized that the great book of the universe is far more vast and... dangerous than I had imagined."
"Those things I once discarded like worn-out shoes—astronomy, ancient mythology, even certain philosophies dismissed as heresy—they are not entirely without value. They may be the footnotes to interpreting those dark chapters, the keys to understanding the 'abnormal'."
His long, slender fingers traced the complex star charts on the page.
"Therefore."
He emphasized his tone and finally glanced up at Watson, the flames of a thirst for knowledge burning deep within his gray pupils.
"I am not just 'reading', Watson; I am 'catching up'. I am seizing every minute and every second to fill in those gaps."
"Knowledge, no matter how distant or useless it may seem, in certain special situations, can be a lifeline, or... a weapon to fight the abyss."
His gaze swept over the deep purple cover of the book of eibon, which was vaguely visible deep within the pile of books.
Watson sighed, returned Star Chart Epoch to its place, walked to the fireplace, and used the tongs to poke at the dying coals, trying to make the room warmer.
"I understand your thirst for knowledge, Sherlock, but people are not machines. Even you, this 'precision instrument', need maintenance and rest!"
"Shutting yourself in this book grave for half a month, without seeing the sun, breathing in dust and the smell of old paper... it is a huge drain on both your body and your spirit!"
He turned around, his expression turning serious, and pointed to the book of eibon.
"Furthermore, this book itself... what about the curse it carries? In Boston, merely touching it caused that Insectoid to instantly collapse, its brain exposed."
"Now that you are studying it for such long periods at such high intensity, who can guarantee it won't have an irreversible effect on your mind? Haven't you experienced that maddening whisper yourself?"
Watson did not continue, but the concern in his eyes was clearly visible.
Holmes put down the book, leaned back into the chair, and habitually pressed his fingertips together, resting them against his chin.
"Regarding the curse... there is an interesting discovery."
Holmes spoke slowly, his voice returning to its usual calm.
"Since that time underground, after I was forced to use it as a 'weapon' against the Insectoid, the maddening whispers and sense of distortion that the book of eibon emitted, which acted directly on the mind... seem to have significantly weakened, or perhaps even vanished."
"Not completely vanished, but more like a... depletion of energy? Or perhaps the 'carrier' of the curse was consumed during that contact? The collapse of the Insectoid may have absorbed the most active, most aggressive part of the 'pollution' on the pages."
"As it is now," he pointed to the deep purple spine, "it is more like a tome that purely records... forbidden knowledge."
"Of course, it is the kind that is extremely profound and obscure, requiring the mobilization of one's entire intellect to interpret. It requires a massive amount of auxiliary material for cross-verification, which is why I need these..."
He gestured to the mountains of books piled around him.
"Astronomy, history, theology, alchemy, even paleontology... every fragment of knowledge that can provide clues."
Watson looked at the focus in Holmes's eyes and knew that his persuasion regarding rest had once again hit an impenetrable wall of will.
He shook his head helplessly, walked over to the relatively "cleaner" armchair opposite Holmes, and sat down, giving up on the plan to drag him out immediately.
"Fine, have it your way, you stubborn fellow."
Watson rubbed his brow. The blood, the stench of rot, and the soul-trembling roars from the underground hall of the Theological Seminary seemed to linger in his nose and ears again, making him feel a wave of exhaustion.
"So, after half a month of 'catching up' and 'breaking through', great Mr. Holmes, surely there must be some results to show? What shocking secrets are hidden in that terrible Book of Eibon, besides making people go insane?"
A gleam flashed in Holmes's gray eyes—the specific excitement that came with solving a puzzle or discovering a new clue.
He leaned forward slightly and carefully pulled the book of eibon from deep within the pile of books nearby.
The deep purple cover seemed to wriggle slightly in the dim light as if it had a life of its own. The touch of the human-skin material was cold and greasy. He did not open it, but merely stroked the edge of the cover with his fingers.
"Results... there are some, but more of them are confusion and even greater mysteries."
Holmes's tone carried a hint of caution.
"First, this book itself... it does not seem to be the complete original."
"Many chapters have obvious gaps; details of key rituals or summoning spells have been deliberately erased or replaced with unintelligible gibberish, like a forbidden manuscript that has been copied, tampered with, or even intentionally destroyed many times."
He paused, seemingly weighing his words.
"However, it is not without gains. There are still some relatively 'complete' fragments of knowledge that have been preserved, for example..."
His voice lowered, carrying a tone of speaking of forbidden things.
"For example, that... creature we encountered on the mountain road."
"Byakhee?"
Watson blurted it out almost instinctively. The name made the back of his neck feel cold instantly, and his temples began to throb with faint pain.
It was as if he were back in that touring car, shrouded by a huge shadow, with its roof torn open. A foul, fishy wind poured into the carriage, mixed with glass shards and Wright's terrified gasps.
"Exactly."
Holmes confirmed, his eyes becoming sharp.
"the book of eibon does indeed record the summoning ritual for the'steed of the stars', the Byakhee."
"Although incomplete and missing some details, the basic rune array, the specific medium required for summoning, and the requirements are all mentioned."
"The book mentions that if the summoner does not use binding spells, the Byakhee will prioritize its own safety and may break free from the summoner's control at any time; furthermore, it may even attack the summoner instead."
"This is likely the reason why the one we encountered last time was 'easily' banished by you."
He noticed Watson's instantly pale complexion and the subconscious action of rubbing his temples.
"Of course," Holmes added immediately, his tone soothing, "I am not showing you this with the intention of trying to summon that thing."
"I just want to illustrate that the knowledge in the book, no matter how disturbing, is real. They form part of the rules of that hidden world. Understanding them, even if it's just the tip of the iceberg, is for the sake of... better defense."
"Defense?"
Watson gave a bitter smile, picked up the coffee on the table that had long since gone cold, and took a sip, trying to suppress the chill and nausea rising in his heart.
"I would rather never see that damn thing again in my life! The last experience is enough to give me a headache for half a year."
Holmes nodded and continued to explain.
"Exactly, defense, or rather, countermeasures. Actually, I have been thinking about why Claire's magic circle would have the corresponding counter-items placed nearby."
"It wasn't until I studied the book of eibon that I discovered that the usage conditions for some magic circles are just like that; the items that break the magic circle also constitute a part of the circle itself."
"I wonder if it was a contingency left by the author of the book of eibon."
Watson put down his cup, deciding to change the subject, which was making him uncomfortable. He needed something to prove that life was still on its normal track.
"Let's talk about something else."
Watson tried to make his voice sound lighter.
"I went out tonight, not just to wander around, but to see an opera, a new production at the opera house."
"To be honest, the effect was quite good. The music was grand, the sets were exquisite, and the actors' singing was first-class. After being tense for so long, listening to music and watching the performance really relaxed my mind quite a bit."
"I highly recommend you find some time to go see it too, to clear your head, Sherlock. Spending all day looking at these..."
He pointed to the piles of books around them and that disturbing purple book.
"You need some normal comfort."
Holmes seemed uninterested in this suggestion, his gaze having already fallen back to the book on his lap. He twiddled the pages with his fingers and replied perfunctorily: "Hmm, perhaps. I'll consider it when I have time."
Watson picked up some of the scattered books and documents lying around to flip through.
"What... is this?"
He frowned, his fingers tapping lightly on the armrest of the chair.
"...A Carnival invitation?"