The evening settled over their hidden campsite like a damp blanket, thick with tension and the smell of damp earth and Borin's pungent cheese. They'd found a small clearing, ringed by thick ferns and sheltered by an overhang of rock, far enough from the main trail to avoid casual discovery. A small, smokeless fire of dry roots and moss glowed in the center, casting flickering shadows on their faces.
Borin had spread a waxed cloth and laid out his "excellent cheese," along with hard biscuits and dried apples. He ate with gusto, smacking his lips, seemingly oblivious to the strained silence around him. Tadao picked at a biscuit, his stomach too knotted to accept food. Every rustle in the undergrowth made him jump. He kept seeing the blue flash of the ward-runes, feeling that cold, ancient gaze.
"So," Borin said, wiping his fingers on his doublet. "The plan, once more for clarity. An hour past full dark—that's when the night watch changes at the abbey, bit of a lull. Rin, my dear, you and I will approach the south wall. You'll use that magnificent axe of yours to… encourage the postern gate. Not to smash it, mind you! Just to persuade the old lock. A bit of leverage."
Rin tore off a piece of cheese with her teeth, chewing slowly. "And if there's a monk on the other side?"
"Then we abort, melt back into the woods, and try another night. But according to your brother's scouting, that area's deserted at night. A calculated risk."
"Once inside," Etsuo picked up, her voice low and even, "Rin will create a diversion in the main courtyard. Something that draws attention but isn't overtly hostile. A fallen brazier, a loud argument with a shadow—something that makes the monks investigate the public areas."
"While that's happening," Fumiko said, pushing her glasses up her nose, "Tadao and I will already be inside the main building. We'll present ourselves at the scriptorium for 'late-night study,' a request Keeper Nilos might grant if we're persistent and scholarly enough. It gives us a legitimate reason to be near the restricted wing."
"And I," Borin said, tapping his chest, "will be a shadow in the corridors, making my way to our rendezvous at the warded door. Tadao, you'll meet me there with the device. We trigger it, go in, and have our ninety seconds. In and out, like mice."
"What's your target, exactly?" Tadao asked, unable to keep the suspicion from his voice. "What 'historical artifact' is so valuable you'd risk this?"
Borin's twinkling eyes met his. "A small thing. A scribe's seal, made of moonstone. Belonged to the abbey's founder. It's in a display case in the Hall of Founders, which is… conveniently adjacent to the restricted archives. While you're looking for your scrolls, I'll be two rooms over, picking a lock. We're not even in each other's way."
It sounded too neat. Tadao didn't believe him for a second. But he had no choice. The device was their only key.
As the last light faded, they made final preparations. Etsuo checked her spear and armor, her movements precise and unhurried. Rin oiled the hinge of her axe head, the repetitive motion calming. Fumiko sat cross-legged by the fire, her eyes closed, her staff across her knees. She was meditating, or trying to, but Tadao saw the faint tremor in her hands.
He walked to the edge of the clearing, staring up at the first stars piercing the deep blue. The air was cool on his skin. He heard soft footsteps behind him.
"Nervous?" Rin asked, coming to stand beside him. She wasn't looking at him; her gaze was on the dark shape of the abbey's silhouette against the horizon.
"Terrified," Tadao admitted quietly. "What if the device doesn't work? What if the ward screams and every monk in the place comes running? What if… what if what's behind that door makes things worse?"
Rin was silent for a long moment. Then she let out a short, harsh breath. "You know, back home, I used to get so pissed when you'd try to do everything yourself. Always rushing in, trying to prove something. It was annoying as hell." She glanced at him, a faint, wry smirk touching her lips. "But here… I get it now. That feeling of being stuck. Of having something inside you that you don't understand and can't control." Her hand went unconsciously to her stomach, a fleeting gesture. "At least you're trying to fix it. You're not just… waiting for it to happen again."
Her words were the closest thing to vulnerability he'd heard from her since they arrived in this world. "Rin… about Skill XXX. With Derrick. Did it… did it feel good?"
Her smirk vanished. She looked away, her jaw tightening. "That's the fucked up part, Tadao. Yeah. It did. Even when it hurt. Even when I wanted to punch his smug face. The skill… it twists everything. It makes the shame feel like a thrill. It makes you want the degradation." She shook her head, as if trying to dislodge the memory. "Afterwards, all I could think was, 'I hope Mama never finds out. I hope you never find out.' And then I'd feel that new power in my muscles, that broadsword affinity, and I'd think… 'was it worth it?'" She let out a bitter laugh. "What kind of person does that make me?"
"A person who's fighting," Tadao said softly. "We're going to find a way to control it. Or get rid of it. Tonight."
She didn't answer, just gave a short nod and turned back toward the fire. "Don't die, idiot. Mama would never forgive me."
*
Full dark brought a deep, velvety blackness to the forest. They doused the fire, shrouding themselves in gloom. Borin produced a small, hooded lantern with a shutter, casting a thin beam of light just enough to see their feet.
The trek to the south wall was tense and silent. Every snapped twig sounded like an alarm. They moved in single file: Borin, surprisingly light on his feet for his bulk, then Rin, then Tadao, with Etsuo and Fumiko bringing up the rear. The abbey walls loomed ahead, a darker black against the night sky.
Borin halted them twenty yards from the wall, in the deep shadow of a gnarled pine. He pointed. The postern gate was just as Tadao had described—a small, reinforced door set into the stone, half-overgrown with ivy. No light spilled from around its edges.
"Alright, my fierce friend," Borin whispered to Rin. "Your turn. The lock is old iron. The wood is stout. You need to break the bolt inside without making the sound of a full break. A sharp, focused impact. Can you do it?"
Rin hefted her axe, her eyes narrowing as she assessed the door. "Stand back." She crept forward, her form blending into the shadows. Tadao watched, holding his breath. Rin reached the door, ran her fingers along the frame, finding the seam. She positioned herself, not for a swinging chop, but for a precise, powerful thrust. She reversed her grip, holding the axe like a battering ram, the thick, metal-shod pommel aimed at the spot where the lock would be.
She took a deep breath, her shoulders bunching. Then she drove forward, her entire body behind the motion.
THUD.
The sound was a dull, deep punch, muffled by the wood and the surrounding stone. It wasn't loud, but in the silence, it felt monumental. Rin recoiled, listening. No cries of alarm. No footsteps.
She did it again. THUD-CRACK. A softer, splitting sound this time. She leaned her shoulder against the door and pushed. With a groan of protesting wood and a snap of broken metal, the door swung inward a few inches, revealing pitch darkness.
Borin grinned, clapping her softly on the shoulder. "Marvelous! A true artist." He squeezed through the gap, his satchel catching for a moment before he popped through. Rin followed, then Tadao, with Etsuo and Fumiko slipping in last.
They were in a narrow, walled garden, overgrown and neglected. The air smelled of damp soil and rotting leaves. A gravel path led toward the main buildings, visible as blocky shapes against the starry sky.
"Right," Borin whispered, his cheer gone, replaced by a cold efficiency. "The scriptorium wing is that way." He pointed north-east. "Lady Etsuo, Fumiko, Tadao—you make your approach from the main courtyard now. Use the front gate knocker, be seen. Rin, with me. We'll find a spot for our little distraction. Give us a count of five hundred, then make your move."
Etsuo nodded. She touched Tadao's arm, her grip firm. "Be careful. Trust your instincts." She looked at Fumiko. "Ready?"
Fumiko adjusted her glasses, her face pale but set. "Ready."
They split up, melting into different shadows. Tadao's heart was a frantic drum against his ribs as he followed his mother and sister back out of the garden, circling around to approach the abbey from the 'proper' direction. The walk to the front gate felt like a march to an execution. The massive doors were shut, the viewport dark.
Etsuo lifted the knocker and let it fall. The clang was impossibly loud in the nocturnal quiet.
Minutes passed. Tadao counted his breaths. Then, the viewport slid open. The same aged eyes, Brother Fenric, peered out. He looked weary.
"You return? At this hour?"
"Forgive our imposition, Brother," Etsuo said, her voice carrying a practiced mix of respect and urgency. "My daughter, the theorist, has had a breakthrough in her calculations. She believes she has identified a cross-reference in your general catalog that may be critical, but it requires viewing the original scroll tonight, while the astral alignment is still favorable for her divinatory magic. It is a matter of scholarly passion. We would not ask if it were not of the utmost importance to her research."
It was a gamble, appealing to a monk's potential understanding of obsessive scholarship. Fenric's eyes shifted to Fumiko, who had summoned a tiny, glowing orb of light at the tip of her finger—a simple light spell, but it made her look every inch the dedicated, slightly eccentric mage.
"The scriptorium is closed for the night," Fenric said, but his voice lacked finality.
"We would be silent as ghosts," Fumiko pleaded, her voice soft but intense. "We would disturb no one. Just the scroll, and my notes. An hour, no more. Please, Brother. Knowledge should not be bound by the sun's schedule."
Fenric sighed, a sound of profound tiredness. The viewport shut. For a horrible moment, Tadao thought he'd refused. But then, the familiar groan of the great door sounded, opening just a crack. Fenric stood there, a shawl now over his robes. "One hour. You will be accompanied. Do not touch anything not directly related to your query. Follow me."
They were in. The courtyard was deserted, lit only by a few shielded lanterns hung by doorways. The silence was even deeper at night, a living thing. Fenric led them toward the main building. As they approached the steps, Tadao heard a distant, muffled crash from the direction of the south gardens, followed by a raised voice—Rin's, shouting something about a "loose statue" and "almost brained me!"
Fenric stopped, his head tilting. "What was that?"
Etsuo immediately looked concerned. "It came from over there. It sounded like someone might be hurt."
Fenric hesitated, torn between his duty to escort them and the disturbance. "Wait here," he commanded, and hurried off toward the sound, his sandals slapping softly on the stones.
The moment he was out of sight, Etsuo's demeanor changed. "Go. Now. We'll keep watch here. You have your count."
Tadao and Fumiko didn't need telling twice. They sprinted up the steps and into the dark antechamber, then down the corridor toward the East Scriptorium. The hallway was lit by the same dim lanterns. They passed no one. The abbey felt like a sleeping beast.
They reached the scriptorium door. It was unlocked. Inside, the vast room was dark, the tables and shelves mere silhouettes. A single candle burned on the librarian's desk, but no one sat there.
"This way," Tadao whispered, leading Fumiko past the study tables to the far wall, to the small oak door. The hum was there, fainter but perceptible, a vibration in his teeth.
They waited, crouched in the shadows. Every second stretched. Come on, Borin.
A soft scuff of leather on stone. Borin appeared from the other direction, his round face slick with sweat, but his eyes bright with excitement. Rin was not with him.
"The distraction is working beautifully," he breathed. "Your sister is a virtuoso. She's got three monks arguing about structural integrity in the herb garden. Now, the device."
Tadao took the brass compass-like object from his pocket. It felt cold and heavy.
"Place it against the door, right on the center," Borin instructed, his voice a thread of sound. "Wind the key three full turns. No more, no less."
Tadao pressed the device against the rough oak. He fitted the small key into the stem and turned. Click… click… click.With each turn, the tiny internal gears whirred, and the dull crystal in the center began to glow with a sickly green light.
The moment he completed the third turn, the green light pulsed. A visible wave of energy, like heat haze, washed out from the device over the door's surface. The faint hum they felt cut off abruptly, as if severed. The blue runes that had flashed before did not appear.
"It's down," Borin hissed. "Ninety seconds. Go!"
Tadao grabbed the iron latch and pulled. The door swung open silently, revealing darkness. A wave of stale, cold air washed over them, carrying the scent of extreme age, dust, and something else—ozone, and a faint, coppery tang.
Borin slipped past him. "I go right. You go left. Good luck." He vanished into the blackness to the right, his lantern shutter opened a fraction, a tiny beacon quickly swallowed.
Fumiko summoned her light orb, holding it aloft. The room they entered was not a library. It was a circular chamber, perhaps twenty feet across. No shelves. No scroll cases. The walls were bare, seamless stone. In the center of the room stood a single, waist-high pedestal of black basalt. And on the pedestal lay one thing: a massive, leather-bound tome, easily a foot thick. Its cover was unmarked, but it seemed to drink the light from Fumiko's orb.
"This… this is it?" Tadao whispered, dread coiling in his stomach. "This is the Restricted Collection?"
"It must be," Fumiko said, stepping forward, her light illuminating the dust on the pedestal. There were no footprints. No one had been here in a very, very long time.
She reached for the tome.
"Wait!" Tadao grabbed her wrist. "What if it's trapped?"
"The ward was on the door. This is what it was protecting." Her voice was filled with a scholarly hunger that overrode caution. She gently opened the cover.
The pages were not parchment. They were a strange, metallic, silver-like material, thin and flexible. And they were blank. Completely, utterly blank.
"What…?" Fumiko flipped a page. Blank. Another. Blank. "Is this a joke?"
Tadao leaned closer. As Fumiko's light played over the metallic page, something shifted. Words began to flow onto the surface, not written, but appearing as if from within the material itself. They were in a language he didn't know, angular and harsh.
Then the words melted and reformed into Japanese.
The Catalogue of Aberrations. The Index of Broken Gifts.
Fumiko sucked in a sharp breath. Her finger trembled as she traced the title. "This… this is a record. Of Legacy Skills gone wrong."
She turned the page. More text flowed into being.
Entry #7: Skill XXX. Designation: The Corrupting Covenant. Manifestation: Post-coital acquisition. Primary Effect: Compels host to engage in sexual congress to acquire traits, abilities, or knowledge from the partner. Secondary Effect: Gradual erosion of host's pre-existing moral and social inhibitions related to the act. Tertiary Effect: Neurological reward reinforcement, linking acquired power to pleasure derived from the act. Corruption Level: High. Status: Active. Hosts: Multiple. Current Vector: Bloodline Koyanagi (Female Line).
Tadao's blood ran cold. "It knows our name. It knows us."
Fumiko was already turning pages, her eyes wide behind her glasses, scanning the flowing text. "There's more… it lists variants. 'Skill XXX-Alpha: The Dominant's Due'… 'Skill XXX-Beta: The Submissive's Surrender'… Mother's, and ours, they're… they're different strains. Tailored." Her voice broke. "It says the skill is designed to… to breed. Not children. To breed more of itself. It passes through intimate contact, but it can also… lay dormant, and activate in a new host under stress or strong desire."
"Like a magical STD," Tadao said, the crude analogy the only one his reeling mind could grasp.
"Look," Fumiko whispered, pointing. The text had changed again, showing a complex, branching diagram like a family tree. At the top was a symbol—a stylized, inverted goddess. Below, lines branched out to three names: Etsuo, Rin, Fumiko. And from them, lines extended further, to other names he didn't recognize—Kadyr, Derrick, Fynn. And from those names, dotted lines reached out into emptiness, labeled "Potential Vectors."
"It's mapping its own spread," Tadao realized with horror. "We're not just hosts. We're… patient zeroes. We're spreading it."
"There has to be a way to stop it," Fumiko said, frantically turning pages. "A cure. A countermeasure."
The text shifted, responding to her unspoken query.
Remediation: Incomplete data. Theoretical counters involve: 1. Celestial Purification (High-risk, may erase host personality). 2. Willful Abstinence & Aversion Therapy (Low success rate, high recidivism). 3. Master Host Subjugation (Untested).
"Master Host Subjugation?" Tadao read aloud. "What does that mean?"
The book's pages rippled. New text formed, not in the main body, but in the margin, in a different, more flowing script, as if someone had added a note.
The skill seeks a master. A central will to direct its hunger. Without one, it spreads chaotically, corrupting randomly. A designated Master Host could theoretically consolidate the corruption, control its expressions, and potentially direct its acquisitions… or begin the process of draining it back from the network.
"A master…" Fumiko breathed. "Someone to take all the corruption into themselves? To control it?"
"Or become the ultimate monster," Tadao finished. His skin crawled. The count in his head was screaming. They had to be past sixty seconds.
"We need to take this book," he said.
"We can't. It's too big. And it might be anchored."
"Then we memorize. What else? How does it start? Where did we get it?"
Fumiko flipped back to the beginning of the entry. The text scrolled.
Origin: Bestowed erroneously by the Transmigration Goddess Amara during the 'Isekai' event. Intended blessing 'Mighty Family Bond' corrupted by an extant, dormant psychic meme in the goddess's own divinity. The 'Corrupting Covenant' meme attached itself to the blessing, targeting the female recipients as optimal vectors for its reproductive strategy.
"It was a mistake," Tadao spat. "A fucking bug in the system. And we got infected."
"There's a footnote," Fumiko said, her voice dropping to a whisper. She read aloud, "The meme is believed to be a fragment of a defeated Lust Demon's essence, absorbed by Amara in a prior age. It hibernated within her, dormant, until a suitable vehicle for its expression—a family unit with strong emotional bonds and latent power—presented itself."
A demon. They were carrying a piece of a demon inside them. A piece that wanted to fuck its way into the whole world.
From the right-hand darkness, they heard a soft, satisfied chuckle. Borin emerged, holding a small, glittering object—a crescent moon carved from milky stone. The scribe's seal. He tucked it into his satchel. "Find what you needed?" he asked cheerfully.
Before they could answer, a change swept through the room. The green glow from the device on the door outside sputtered and died. The hum of the ward returned, not a gentle vibration, but a rising, angry drone. The blank metallic pages of the tome began to glow with a soft, purple light.
"The window's closed," Borin said, his cheer vanishing. "And I think we tripped a secondary alarm. Time to leave. Now."
They ran for the door. Tadao glanced back as they crossed the threshold. The giant tome was now glowing brightly, and the flowing text on its pages was shifting, coalescing into a single, repeated phrase that burned itself into his vision as he slammed the door shut.
THE NETWORK AWAKENS. THE MASTER IS NEAR.
The ward was back at full strength, the runes glowing a steady, angry blue. But they were on the right side of it. For now.
"Separate ways," Borin gasped. "I'll exit the way I came. You get back to the scriptorium, act normal. Go!"
He scuttled away into the dark corridor. Tadao and Fumiko sprinted back toward the East Scriptorium, their footsteps echoing. They burst into the dark room, skidding to a halt by one of the study tables. Fumiko extinguished her light orb. They stood there, panting, trying to look like they'd been studying in the dark.
Minutes later, Brother Fenric entered, holding a lantern. He looked frazzled. "A statue fell in the garden. No one was hurt, but it caused a mess. Your hour is almost up. Have you found your reference?"
Fumiko, with an incredible act of will, smoothed her expression into one of scholarly disappointment. "We… misremembered the catalog code. The scroll is not here. We apologize for wasting your time, Brother. The night air must have clouded my focus."
Fenric looked at them suspiciously, but nodded. "The night is for rest, not for study. Come. I will see you out."
They followed him, Tadao's mind screaming with the phrases from the book. Corrupting Covenant. Reproductive strategy. The Master is near.
They met Etsuo at the main door. She read their faces and said nothing. Fenric let them out into the cold night. The heavy door thudded shut behind them, sealing the abbey's secrets—and their own nightmare—inside once more.
They walked in silence until they were deep in the woods, then ran the rest of the way to the hidden campsite. Rin was already there, waiting, her axe across her knees. Borin arrived a few minutes later, beaming.
"A successful evening! I have my prize. And you? Any enlightenment?"
Etsuo looked at Tadao and Fumiko. "Tell us."
They did. In broken, horrified sentences, they described the metallic tome, the flowing text, the origins of Skill XXX as a demonic meme, its purpose to spread, and the terrifying concept of a "Master Host."
When they finished, the firelight painted their faces in stark relief, each etched with a new kind of fear.
"A demon…" Rin whispered. "We've got a fucking demon in our heads making us horny for power."
"And it wants a master," Etsuo said, her voice hollow. "Someone to… consolidate it. To become the center of its web."
"That could be a way to control it," Fumiko said, though she sounded like she was trying to convince herself. "If one person could direct it, stop it from making us… do things randomly…"
"Or that person becomes a puppet for the demon's will," Tadao countered. "A super-powered slut doing its bidding to infect everyone."
The crude word hung in the air. No one objected.
Borin, who had been listening with avid interest, cleared his throat. "Fascinating. Truly. A metaphysical parasite with a sexual transmission vector. That's a new one in my annals. Well, my part is done. I have what I came for." He stood, brushing off his trousers. "I wish you luck with your… infestation. If you ever need another mutually beneficial arrangement, you know where to find me." He tipped an imaginary hat and began to pack his satchel.
"You're leaving? Now?" Rin asked.
"The night is young, and I have a buyer in Oakhaven who keeps late hours. No sense lingering." He paused, looking at them. "A word of unsolicited advice? From a man who's seen many strange things? This 'Master Host' idea… be very, very careful who you choose for that role. Power like that… it changes people. Even with the best intentions." His eyes lingered on each of them, just a moment too long on Tadao, before he turned and disappeared into the forest.
His departure left them feeling more alone than ever.
"We need to think," Etsuo said finally. "We have information, but no solution. Only more dangerous possibilities."
"The book mentioned 'Celestial Purification,'" Fumiko said. "That must mean the goddess. Amara. We have to find a way to contact her. To make her fix her mistake."
"How?" Rin snorted. "Pray really loud?"
"There might be ways," Etsuo said thoughtfully. "Shrines. Rituals. If she bestowed the skills, there must be a channel back to her."
"And until then?" Tadao asked, the question they were all avoiding. "What do we do? Just… try not to have sex? What if the skill activates on its own again?"
No one had an answer. The fire crackled, the only sound in the heavy silence.
Tadao felt a strange warmth in his chest, not from the fire. A low, buzzing tension, different from his dash sickness. It was faint, but it was there. He looked at his sisters, at his mother. Did they feel it too? A new connection, a faint, pulsing thread linking them? The "network" awakening?
Fumiko suddenly shivered, wrapping her arms around herself. Rin shifted uncomfortably, her knuckles white where she gripped her axe. Etsuo's gaze became distant, her lips pressed into a thin line.
Something had changed in that chamber. They hadn't just read about the corruption.
They had alerted it.
And now, it was looking back.