"There!"
Holmes whispered, slipping into the chapel first, moving quickly toward the back of the altar while keeping to the shadows of the cold stone pillars, with Wright close behind.
As they approached the tapestry, the stench of damp earth mixed with rust suddenly became thick and pungent, laced with a faint, sweet, rotting odor that even the incense could not mask.
Holmes held his breath and carefully examined the edge of the tapestry; hidden deep within the shadowy folds near the floor were a few smaller symbols:
[HMHD]
Below it was another, smaller line of text, almost covered by dust, acting as a hint:
[The debt all mortals bear]
"What is this...?" Wright also noticed the symbols.
"A Playfair cipher," Holmes identified instantly. "The debt all mortals bear—the answer is death."
His brain raced, recalling the construction rules for this cipher: a 5x5 matrix, filling in the remaining letters in alphabetical order after entering the keyword, with I and J treated as the same letter.
Entering the keyword: DEATH, he constructed the matrix:
D E A T H
B C F G I
K L M N O
P Q R S U
V W X Y Z
Plaintext [HMHD], grouped as [HM], [HD].
[HM]: According to the decoding rules, since the two letters are not in the same row or column, the corresponding cipher letters are those at the other two corners of the rectangle formed by [HM], which are [AO].
[HD]: According to the decoding rules, since the two letters are in the same row, the corresponding cipher letters are those immediately to their left, with the last column wrapping to the first, which are [TH].
Combining them yields the password [OATH].
Without hesitation, Holmes reached out and pressed his fingertips precisely onto the runes corresponding to the password.
"Click... click-click... creak..."
A dull mechanical grinding sound echoed, and the entire massive "Good Shepherd" tapestry, along with the hard stone wall behind it, slowly rotated inward and sank, revealing a dark opening only wide enough for one person to pass through.
A foul gust of wind, dozens of times stronger than the air outside and mixed with the thick stench of incense, old blood, chemical reagents, and deep, decaying earth, burst forth from the opening, causing Wright to stagger back, his stomach churning violently.
Inside the opening were steep stone steps leading downward into an unfathomable depth; only the few steps near the entrance were barely illuminated by candlelight, while beyond them lay a thick, all-consuming darkness.
Holmes did not hesitate for a second; he pulled the high-intensity flashlight he had "borrowed" from the police station out of his trench coat pocket and switched it on. A beam of stark white light pierced the darkness, illuminating the slippery stone steps and the moss- and water-stained rock walls on either side.
"Follow closely."
Holmes's voice echoed in the opening as he stepped onto the stairs leading into the abyss, his figure quickly swallowed by the darkness.
Wright looked at the deep, dark entrance, his heart pounding so hard it felt like it might burst.
He thought of Joseph, who had resurrected in the morgue, and the Byakhee from the starry sky on the mountain road; extreme terror nearly froze him in place.
But Holmes's figure had already vanished, and his steady footsteps could be heard descending into the cave.
Wright bit down hard on the tip of his tongue; the sharp pain awakened him from his terror, driving him to move his leaden legs and stumble inside after him.
The stone steps were steep and slippery, extending deep downward. Holmes's beam of light acted like a sharp blade, cutting through the thick darkness and illuminating the limited area ahead.
The mixed odor in the air grew increasingly intense, the sweet, rotting stench almost solidifying and clinging to their noses and mouths.
The rock walls on either side were no longer rough stone; gradually, man-made masonry appeared, covered in dark stains that looked like dried blood and graffiti of unknown meaning.
In some places, rusted iron rings were embedded, seemingly used in the past to hang torches or... shackles.
After descending about two stories' height, the stairs came to an end.
Ahead lay a relatively wide stone archway, from which flickered a dim, reddish light, accompanied by a low, monotonous, and wickedly rhythmic chanting.
Holmes signaled for Wright to be silent and turned off the flashlight. The two pressed themselves against the cold wall of the archway and carefully peered inside.
Before them lay a shockingly large underground space, its scale far exceeding that of the nave above.
The floor was paved with huge, roughly polished stone slabs, upon which a vastly complex, enormous magic circle was drawn in dark red, almost black, pigment.
The magic circle consisted of nested rings, twisted runes, and blasphemous star charts; the central area was particularly intricate and emitted a heart-palpitating energy fluctuation.
The walls surrounding the space were ingeniously carved into a circle of rooms with archways, above which the signs of the Zodiac—Aries, Taurus, Gemini... all the way to Pisces—were clearly carved. Twelve archways surrounded the central hall.
At the core of the magic circle in the center of the hall, a figure draped in a deep red hooded robe paced slowly, hands making complex and eerie gestures, while a low, continuous chant emanated from their mouth.
It was Claire Corinna; the blood-drop pendant on her chest shimmered with an eerie, bloody light under the dim red firelight.
Holmes's gaze swept rapidly across the entire hall; so, the clue Joseph left behind pointed here.
In the Aries room, faintly visible within the archway on the altar were a glass bottle filled with clear water, a bottle of deep red wine, a silver bowl containing blood, a lit white candle, a uniquely shaped flame-bladed dagger, and a neatly folded red mask.
In the Virgo room, four items were prominently displayed on the altar: a shimmering cruciform-hilted longsword, a heavy, ancient-looking gold coin, a silver crown inlaid with dull gemstones, and a golden goblet inlaid with rubies.
In the Libra room, there was only a tray on the altar containing two small crystal vials: one filled with a pale yellow powder, likely sulfur, and the other with a bright silver liquid, likely mercury.
The Leo, Capricorn, and Scorpio rooms were those for which Joseph had given danger warnings.
Holmes's gaze swept over the wall between the Scorpio and Sagittarius archways. There appeared to be no door, but the masonry of the wall had extremely subtle differences from the rest, and a fissure hidden by shadows was faintly visible.
Above the archway, an Ophiuchus symbol, drawn in paint the same color as the wall, was almost indiscernible; the key'Sco-Oph-Sgr' in Joseph's clue pointed here!
"Wright, you hide here. Monitor Claire's every move and, at the same time, meet up with Watson."
"Huh? And what about you?"
"I'm going to see what Joseph left for us with his life. Or would you rather go?"
"Uh... I think I'll stick to meeting up with Watson."
Holmes retreated into the shadows and carefully crept toward the Ophiuchus room.
Passing the Scorpio room, he faintly heard heavy breathing inside.
Arriving at the wall between the Scorpio and Sagittarius archways, he found no complex mechanism; a dark fissure, only wide enough for one person to squeeze through, was perfectly hidden in the shadows.
Without hesitation, Holmes slipped inside. It was a small, nearly square secret chamber with bare walls; only a simple stone pedestal stood against the wall directly opposite the entrance.
On the pedestal lay a simple, ancient book that radiated an aura that made the soul tremble.