Chapter 1: Vanished on a Rainy Kyoto Night

Rain in Kyoto was never a weather event. It was a cleansing, carefully orchestrated and executed with brutal precision.

The downpour lashed down, a grey curtain dropping from the heavens to seal off this city where the ancient tangled with the modern. Puddles surged past the laces of Xiaoxue Matsudaira's expensive sheepskin boots, muddy torrents dragging debris and sludge from beneath broken walls. The friction between mud and stone groaned, like the city itself was chewing on its own secrets.

She stood in the deep shadow of an old alley, rain dripping from the tips of her hair, soaking the shoulders of her black trench coat. Yet the chill didn't penetrate the cold, assessing glare in her eyes. Three minutes ago, her partner had vanished from an area the authorities had already labeled an "accident," leaving behind a splash of startling, dark red.

The blood wasn't splattered at random. It formed a诡异, linear pattern, as if someone had carved a guiding line through the mud, leading straight into the abyss.

Xiaoxue narrowed her eyes slightly. Her fingertips trembled—not from the cold, but because her professional instincts had just snapped fully awake. Beneath the surface calm of Kyoto, an invisible intelligence chain was being forcibly severed. And she was standing right on top of the frayed end.

The air around her was so heavy and damp it felt suffocating, thick with the scent of rust, old wood, and the metallic tang of wet earth. It was a smell that felt both familiar and a warning.

"The danger coefficient here is far beyond your imagination."

A low, raspy voice drifted from the shadow of the eaves, carrying the cold, hard texture of metal. Sōji Yūgise leaned against the wall, a black cloth umbrella in hand. The brim was tilted just enough to shield the alley entrance from the rain, but he stayed hidden in the shadows.

Water dripped from the hilt of the antique sword he held, tapping against the bluestone paving slabs. The sound was sharp, fragmented, and urgent; every tap felt like a needle pricking Xiaoxue’s frayed nerves. He was a traitor to the Blood Covenant, yet currently Xiaoxue’s only ally. A crushing guilt ate away at him from the inside out, fueling his drive to shelter her in this steel jungle.

Sōji’s gaze swept the surroundings. The watchers hidden in the rain veil were like dormant venomous insects, ready to devour any prey that crossed the line. He lowered his voice, his tone brooking no argument: "Drop the pursuit and leave this death zone. The moment you step across that warning line, the truth isn't waiting for you. Eternity is."

Xiaoxue didn't respond to his fear. She ignored the protests of the sword master and crouched down. Mud splashed onto her skirt; she didn't care. Her eyes, honed by countless rounds of high-stakes business maneuvering, locked onto the blood trail on the ground.

She reached out, the thin material of her glove brushing against the wet, still-warm blood. The resistance her finger felt was distinct. This wasn't the chaotic scuffle of a victim dragging themselves; that kind of mess belonged to panicked civilians. The trail here was smooth, precise. Every turn angle conformed to the most ergonomic principles of human movement.

Xiaoxue’s mind rapidly constructed a three-dimensional flow chart. She realized with clarity that this wasn't a victim’s final testament. It was a preset guidance path, breadcrumbs deliberately left by the mastermind behind the curtain, waiting to lure a specific cat out of the cage at a precise moment.

Rain hit the bridge of her nose. She pressed her lips tight, her thoughts sharpening as she ran through the logical deductions at breakneck speed.

Sōji frowned, leaning forward slightly, anxiety almost spilling from his eyes. His rebuttal came fast and heated: "You are gambling your sanity with your life! The blood trail leads directly into the strict cordon set up by the Machi-bugyō’s office. You should know better than anyone about Nobayoshi Kitamura’s ironclad impartiality.

Any ordinary person stepping in there doesn't need a formal charge. Just one count of 'suspicious inquiry' is enough to get you detained on the spot. There are no chances for defense down there, only cold chains and a long list of disappearances. Do you really want to be the next number erased from the archives?"

Xiaoxue stood up, brushing the sludge from her knees with a motion that was calm and decisive, as if she had just calibrated a precision instrument rather than inspected a muddy ground. She looked up at Sōji. There was no wavering in her gaze, only a coldness like the deep currents beneath ice.

She replied coldly: "If they planned this route that carefully, even leaving such obvious trail markers, it means they are desperate to make this lead vanish before a specific deadline. If we back down now, we just prove the calm and cruelty of the hand pulling the strings. We make them think we’re scared stiff.

Sōji, in business negotiations, retreating has never once beaten persistence."

Sōji fell silent for a moment. The sound of the rain suddenly seemed deafening, drowning out every other subtle noise in the alley. He stared into Xiaoxue’s ripple-free eyes, a look of determination that was both familiar and strange to him. Finally, he closed his umbrella and sheathed his sword. The crisp sound of metal sliding against metal rang out, piercingly loud in the quiet, rainy lane.

He agreed to walk with her, but the warning hung tight at his heels: "I can guarantee you an unscathed escape only if the enforcers block us. But I cannot fight an entire system, nor can I reverse the flow of time. Remember, my sword only shields you from disaster. It does not clear the path for you."

The two slipped into the depths of the alleys. The rain began to ease, and the cloying, choking scent of blood faded, replaced by the damp, musty smell of decay. The flagstones stretched out beneath their feet, walls on either side crawling with moss that glowed a ghostly green in the dim, overcast light.

At the base of a broken wall from an abandoned trading house, Xiaoxue found a copper coin half-buried in the mud. The metallic glint was glaringly bright in the dull light, like a watching eye, quietly staring back at her.

Xiaoxue crouched and picked up the coin, her finger tracing the rough, worn edge. The calculations in her head had already taken shape. If this was current Kyoto currency, its weight and purity were severely off from the standards published by the Chamber of Commerce. This deviation wasn't a casting error; it was deliberate impurity.

The coin itself was a signal. A commercial code that only a traveler with exceptional insight could decode. Distant thunder rumbled faintly, breaking the dead silence of the alley.

Suddenly, the rapid clack of leather boots echoed from the distance, shattering the reflections in the puddles. Nobayoshi Kitamura arrived at a sprint, flanked by two subordinates from the Machi-bugyō’s office. Rain had soaked through her collar, her black uniform gleaming with a cold sheen under the dim streetlamp. Her gaze was sharp, locking instantly onto the evidence in Xiaoxue’s hand. The air around them seemed to freeze in a single second.

"Surrender the coin."

Nobayoshi Kitamura’s voice wasn't loud, but it carried the authority and pressure of an iron fist. She extended her hand, palm up, her posture demanding and admitting no refusal. As the Machi-bugyō, she pursued members of the Blood Covenant with ruthless impartiality. Any unauthorized investigation was, in her eyes, a provocation of the law.

"This area has been designated a high-sensitivity zone. Your private investigation has violated state taboos. Hand it over immediately, and you can leave with your dignity intact."

Xiaoxue looked directly into the eyes of the iron-faced law enforcer. She didn't let go of the coin, but asked calmly, "Do the markings on this coin belong to state archives? If they do, why is the expulsion process here so high-profile and hostile? Machi-bugyō Kitamura, your moves look like you're trying to destroy evidence, not maintain order."

Nobayoshi Kitamura’s eyes chilled instantly, the air around them solidifying. She warned in a low voice: "Do not cross the line. You have no right to know the truth, Xiaoxue Matsudaira. If you insist on staying here, you face charges of illegal detention and commercial espionage. I’m giving you one last chance. Hand it over, or I’ll take it."

Xiaoxue didn't answer. She simply flipped the coin in her fingers. The miniature number on the back flickered in the weak light, a carving that did not belong to the current dynasty. It pointed to an archive that had long since vanished from history.

Nobayoshi Kitamura’s fingertips had already touched Xiaoxue’s wrist, the force precise enough to dislocate a joint in an instant. In that split second, a rapid, heavy thunder of hooves echoed from the distance, mixed with the clanging crash of iron, forcibly cutting through the tense standoff between the two women.

"Machi-bugyō-sama, alert from the Northern Border!" A cavalryman, soaked to the skin and his armor caked in mud, crawled forward, his voice cracking from heavy panting, "Unknown biological entity infiltration detected! Traces of the 'Zero' series have appeared! The target is suspected to be moving toward the site of the Amaterasu Zero Archive!"

Nobayoshi Kitamura’s brow furrowed, her gaze locked dead on the flickering copper coin in Xiaoxue’s fingers. Her pupils constricted. She slowly withdrew her hand. Her previously overwhelming presence suddenly became distant and translucent, as if the coin were the true master of this place, and she was merely a hound guarding the gate.

"Get out." She dropped the single word, her voice as cold as a ice cellar.

Xiaoxue did not retreat. She knew that stepping back now would mean a permanent parting. Using the chaos of the interruption, she quickly stuffed the copper coin into a special inner pocket of her sleeve, where she had also hidden the half-sentence of cipher she had eavesdropped on from her missing partner—the truth about the succession between the Old Dynasty and the New Order.

Rain dripped from the ends of her hair. She melted into the crowd being herded away, her figure quickly disappearing into the complex web of dark alleys in Kyoto.

The night grew deeper, the downpour intensifying. Xiaoxue hid under the eaves of an abandoned shrine, hands trembling as she pulled out the copper coin. She traced the unfamiliar miniature number on the back. The touch was cold and eerie, as if the metal carried the temperature of some living thing.

The number was a string of fine, variant Sanskrit characters. Combining this with the flow path of the blood trail she had just traced, a historical black hole covered up by the authorities snapped into focus in her mind—the "Amaterasu Zero Archive."

There were not only secrets from before the current dynasty's establishment stored in that place, but also the source of the last distress signal her partner had sent before vanishing. Just then, a very light sigh drifted from the depths of the shrine. It wasn't the wind; it was someone deliberately suppressing their breathing.

Xiaoxue held her breath and slowly turned around. In the darkness, she saw a pair of eyes burning with ghostly blue flames, quietly staring at the copper coin in her hand. There was no anger in that gaze, only a hunger that had spanned centuries, cold enough to make one tremble.