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Chapter Text

The sea always smelled like blood when it was about to rain. 

Dazai Osamu stood at the edge of the quarterdeck, boot heels pressed to the slick wood, watching the water churn like something alive. The sky bled out in bruised hues — grey, purple, and hints of red that whispered danger in the clouds. Her long black hair stuck to her face, damp from sea spray, and she didn’t bother to tie it back. The bandages on her arms had soaked through hours ago, stained from the ongoing rain.

“Storm’s rolling in,” Hirotsu said behind her.

“No shit,” she murmured, eyes locked on the horizon. She didn’t turn around. “You think we’ll find her this time?”

He didn’t answer. She didn’t expect him to.

The wind howled. The Leviathan’s Eye groaned as the waves slammed against its hull, but the crew didn’t slow. The Leviathan’s pirates never did. You couldn’t. Not when Mori was watching. 

Not when you were hunting monsters.

The lookout shouted something unintelligible from the crow’s nest, and Dazai’s head tilted just slightly. She raised a hand, lazy, like a conductor calling the sea to hush.

“Say that again!” she called back.

“There’s something in the water!”

The crew scrambled to the rails, their quick movements too precise to be panic. They were trained for worse. They had seen worse. Akutagawa emerged from below deck, coat billowing from the wind and the storm-shadow magic curled inside his blade. Higuchi trailed close behind, hand on her flintlock as she scanned the horizon.

“Whales?” Kouyou asked, arms folded.

“No.” Gin had moved to Dazai’s side without a sound, eyes narrowed. “It’s singing.”

Everything stilled. Even the wind faltered, like the sea had drawn breath. Dazai’s gaze sharpened, a slow smile curling at her lips.

“Well,” she said. “We found her.”

The water was as dark and slick as oil. Beneath the surface, light pulsed — not sunlight, not lightning, but something internal. Something alive.

“Drop anchor,” Dazai commanded, “and get me a line.”

Akutagawa scowled, shedding his coat. “You’re not going in there yourself.”

“Of course not!” she said sweetly, manic glint in her eye as she slid a dagger into her belt. “You are.”

Akutagawa’s eye twitched, but he didn’t argue. He never did, not when his mentor smiled like that.

A thick rope was lowered, and the crew moved with unsettling efficiency. The Eye had done this before. They had pulled sirens and sea-wraiths from the deep, things too far gone to be called human anymore. But this one was different. This one was still fighting.

Higuchi leaned over the edge, jaw tight. “You sure it’s her?”

“No one else sings like that,” Kouyou said quietly.

And then they saw her.

The waves parted just enough to glimpse a silhouette curled in on itself, pale limbs drifting like seaweed with hair fanned out around her like fire trapped underwater. Rusted chains looped around her ankles, old magic still clinging to them like barnacles. 

Akutagawa dove before anyone could stop him.

⋆⋆⋆

He returned gasping, sodden, bloodied — and not alone.

They had to hoist her up in netting threaded with salt-sigils, careful not to touch bare skin. The closer she came to the deck, the colder the air grew. Dazai watched the pouring rain transform into ice and siren frost form on the railings, the delicate fractal veins of red and black ice spreading all throughout the ship.

The siren looked fragile. Too fragile. She was small, soaked, unconscious, and wrapped in seaweed and curse-marks, her long hair tangling around her like kelp and silk.

“She’s human,” Tachihara muttered, unnerved.

“No,” Verlaine said, “she only looks it.”

Dazai stepped forward, crouched low beside the figure now sprawled in the center of the deck.

The siren didn’t stir. Her chest barely rose. There was a shimmer to her skin under the lamplight. Not glittering, but wrong, like blood diluted in water. Her lashes were long and dark, and her lips were cracked blue.

Her body was riddled with signs of tampering: scars around her throat where runes had been carved, sigils burned into her collarbones, branding from chains too old to break. Her wrists were scraped raw, and even in unconsciousness, her fingers still twitched, like they were searching for something to reach for.

“She’s perfect,” Dazai murmured.

Kouyou glanced at her. “You sound like Captain.”

Dazai’s smile didn’t change, but her visible eye darkened at the comparison to Mori. “I sound like someone who knows a weapon when she sees one.”

Akutagawa wiped sea-brine from his face and said nothing, though his hands were still hovering around his sword, ready to draw.

“What do you want to do with her?” Kaji asked, quiet. The question was for protocol, not clarity. They all knew what Mori would want.

Dazai stood. Her boots left wet prints on the deck as she walked around the siren’s still body in a slow circle.

“We don’t cage her. Not yet,” she said. “We clean her up. Bind the voice until I say otherwise. And move.”

“To Captain?” Higuchi asked.

“No.” Dazai turned. Her eye glinted. “To the wreckfields.”

“You’re detouring,” Hirotsu warned.

“I’m protecting the investment,” Dazai countered. “He sent me to find a siren. I’m not handing him over a half-dead relic before I know what she can do.”

A beat of silence.

Then Gin said, “You’re keeping her.”

It wasn’t a question.

Dazai looked down at the girl again — no, not a girl, something deeper, darker, older. The ends of her long ginger hair had begun to dry, and it tangled in strange shapes, like glyphs from some underwater god.

“Someone already tried to hollow her out,” Dazai said softly. “I’d like to see what’s left.”

Kouyou didn’t like it. Akutagawa didn’t trust it. Hirotsu said nothing, but his gaze lingered. Higuchi muttered a prayer under her breath. But none of them moved. No one ever stopped the Black Wraith, not when she spoke as if the sea had given her orders itself.

A bucket of seawater sloshed across the deck, too close to the siren’s body. Black and red scales bloomed wherever the water touched, and the sigils etched into her skin smoked. She didn’t wake, but her fingers tensed, now sharp and clawed.

“She’s reacting,” Gin observed.

“To what?” Higuchi asked.

“To the deck. The ship. Us,” Verlaine murmured.

But Dazai was kneeling again, hand hovering just above the siren’s throat. Not touching, never touching, but close enough to feel the hum beneath her skin. There was power there. Ancient and raw.

“How do we know she won’t tear us apart the second she wakes up?” Akutagawa asked.

“We don’t,” Dazai said. “That’s the fun part.”

Hirotsu muttered something about madness. Kouyou scoffed under her breath. Kaji took a silent step back. And still, the crew waited.

Chains clinked as the siren stirred. A sharp inhale. Then, slowly, the girl’s eyes opened. One was rich, ember brown — too warm, too human. The other was as blue and cold as the trench, glowing faintly in the stormlight. The air seemed to hold its breath.

Then, she screamed.

It wasn’t a scream in the normal sense. It was music, twisted and fractured — a sound that scraped along bone, that made Higuchi clutch her ears and Akutagawa stagger back, eyes wide.

Dazai didn’t flinch.

“Bind it,” she snapped.

Kouyou threw the cloth embroidered in runes with practiced speed. The gag looped around the siren’s mouth in a practiced knot. Her voice was smothered, the sound muffled beneath the cloth like thunder under skin.

She thrashed wildly, and it was clear her fangs were bared beneath the temporary muzzle. Her eyes glowed, and the magic beneath her skin spread like veins of black coral, fracturing outward.

“She’s going to crack the hull,” Hirotsu warned.

“She’ll kill us!”  Kouyou hissed.

Dazai’s gaze didn’t move from the girl, who was still writhing, still caged in blood and salt. She gave a silent nod of approval and watched as they forced sedative mist through a rusted old censer, passed down from whatever beast Mori killed last. It filled the air with bitter herbs and deathroot. Slowly, the siren slumped, thrashing body now still. The frost on the rails melted, but no one paid it any mind.

Dazai stood, drawing her coat tighter. Her expression was unreadable now, except for the barest flicker in her eye. She watched the girl, the treasure they had been hunting for weeks, and smiled.

“Welcome aboard, siren.”

Chapter Text

The wreckfields reeked of rot and old curses. Shattered hulls jutted from the sea like broken teeth, sails torn, masts splintered, figureheads half-drowned and humming with the ghosts of storms long passed.

Dazai sat on the railing, legs swinging, arms crossed over her chest as she watched the fog roll over the water. Every so often, the waves would part just enough to show some sunken figurehead, some anchor still trailing chain, some shadow of a war long lost. The Leviathan’s Eye creaked beneath her, uneasy.

She didn’t blame it.

They were carrying a siren in their hold.

Below deck, a crash rang out — metal shrieking, chains drawn tight, then the dull, brutal sound of a body hitting wood, muffled curses following suit. 

“Should I check on her?” Akutagawa asked behind her, voice like steel.

Dazai smiled faintly. “She’ll scream herself hoarse eventually. Let her.”

Another thud.

“She sounds angry.”

Dazai stood, dusting salt from her dress. “Good. Let’s see if she bites.”

⋆⋆⋆

The brig stank of salt, blood, and sedative smoke. It coiled like incense through the iron-barred chamber where the siren was bound, arms behind her back, chains looped in sigils of binding and muffling runes. The gag had been replaced by a small shell necklace laced with deathroot, enough to let her speak, not sing.

Her eyes still burned. They locked on Dazai with such venom it was a wonder the walls didn’t blister.

“You,” the siren spat. Her voice was cracked and raw but still sharp enough to cut. “You’re the one who dragged me out.”

“Technically, Akutagawa did the dragging. I just gave the order.”

The girl lunged. The chains snapped taut. The air dropped ten degrees in an instant, and frost slithered along the iron bars.

“Careful,” Dazai cooed, stepping just out of range. “You’ll make the crew think you don’t like me.”

“You gagged me.”

“You screamed.”

“I’ll do worse next time.”

Dazai leaned down, eye gleaming. “I’m counting on it.”

The siren bared her teeth — not human, not quite. Her lips peeled back to reveal points like obsidian, her mouth a storm of coral thorns. Dazai didn’t flinch. She was used to monsters.

She’d been raised by one.

“Where are my sisters?” the siren demanded, her voice as brittle as driftwood. “The others you stole.”

Dazai tilted her head. “You assume I’d waste time capturing more than one.”

“You lie,” the siren hissed. The frost on the bars spread like veins. “Your ship reeks of it.”

Dazai’s smile widened. “I prefer compliments, but I’ll take what I can get.”

The siren lunged again, harder this time. The chains caught, groaning with the strain, and the floorboards beneath her feet crackled with ice.

Behind Dazai, the brig door creaked open.

“She’s pretty,” came a sing-song voice. “Can I keep her when you’re done?”

Dazai didn’t turn. She didn’t have to. The temperature dropped once more, but it wasn’t from the siren this time.

Q stepped into view barefoot, humming tunelessly. They wore a long coat far too big for their frame, stitched with old bone charms and Mori’s insignia sewn crookedly across the collar. Their smile was sweet and wide — a child’s face with a god’s appetite behind the eyes.

The siren recoiled instinctively. She didn’t know what the child was. Only that she didn’t want to.

“Q,” Dazai said flatly. “Did Captain send you to monitor me?”

“Captain said you were playing with your food again.” Q twirled a lock of hair around one finger, then pointed to the siren. “She’s cracked already. He won’t like that.”

“She’s not cracked,” Dazai said. “She’s adapting.”

Q giggled and padded closer to the bars. “Can I touch her?”

“No.”

“She’s twitchy. Like a rat.”

“She’s a siren, dimwit.”

The siren’s gaze sharpened, and for a moment, the ship groaned like it had a soul. Dazai felt it under her feet, the wood shivering at her growing temper. But Q just pressed closer, nose nearly against the cage.

“You’re not what I expected,” they said softly, “but you’ll do.”

The siren hissed low — a sound that belonged to something far older than her.

“I said,” Dazai cut in, “leave her.”

Q gave a pout, wide-eyed and sugar-coated. “You’re boring when you get protective.”

“And you’re expendable when you don’t follow orders.”

The silence that followed was the kind that made their ears ring. The siren stilled, staring between them, a creature of storm and salt caught between two devils with knives for tongues.

Finally, Q shrugged. “Fine. But Captain wants reports. He says the next time you keep a cursed relic from him, you’d better make it worth the risk.”

Then they turned to the siren and grinned, all teeth. “Have fun with the Wraith~”

They vanished back up the stairs like mist, their giggles trailing behind like wind through a graveyard. 

⋆⋆⋆

The brig felt quieter which Q gone, but not calmer.

Dazai leaned against the bars and watched the siren breathe like she was counting the beats between drowning and surfacing. There was a tightness to her frame, like she was always bracing for impact.

“You didn’t answer me,” the siren said at last.

“About your sisters?”

The siren nodded once — curt, untrusting.

Dazai sighed, pushing off the wall. “We don’t have them. You’re the only one we found. The rest are either dead or smart enough to keep swimming.”

“You expect me to believe that?”

“I expect you to believe whatever lets you sleep tonight.”

“I don’t sleep.”

“Figures.”

A pause. The siren shifted slightly, and a chain rattled.

“What do you want from me?” she asked.

“Everything,” Dazai said simply. “But we’ll start small. How about a name? I can’t keep calling you ‘siren’ forever, you know..”

The siren hesitated. Her glare didn’t fade, but something in it faltered. 

“…Chuuya.”

“Well Chuuya, we’re in the wreckfields,” Dazai continued. “You’re going to show me what you can do.”

“You ripped me from my sea, gagged me, chained me like some freak — and now you want me to perform?”

Dazai met her gaze. “No. I want you to survive.”

The rage in her face cracked, just slightly— and something older slipped through. Not weakness. Something deeper. Grief, maybe. Or guilt.

“Why?” she whispered. “Why are you keeping me?”

Dazai’s smile was slow and cruel and strange.

“Because monsters like us don’t last long alone. Even the clever ones.”

Chapter Text

The sea had no god, only graveyards. In the end, it would either bury them or bless them.

“Sing,” Dazai said, voice light but razor-edged. She stood by the mast, black dress ruffling in the wind. Chuuya stood chained at her side, bound by the wrists, the ankles, and the throat. Not silenced, not yet.

“If you don’t, we’ll be dead by sundown.”

“I’d rather drown you,” Chuuya spat, salt drying on her lips.

“You will,” Dazai murmured. “Eventually.”

A tremor rocked the ship. The crew staggered as the fog curled tight, the tension making breath a luxury they couldn’t afford. Above, the sails shivered like they were afraid.

“We can’t keep drifting like this,” Kouyou called from the helm, steady hands flexing on the wheel. “The compass is spinning blind. We’ve circled the same wreck three times.”

“I told you,” Higuchi muttered, fiddling with a charm stitched into her coat sleeve, “this place is stitched shut. You either get out by miracle or music.”

“Well, we’ve got a miracle,” came Akutagawa's voice, cold and silken as ever, perched lazily on a coil of rope nearby. “Or at least she used to be one.”

“She still is,” Tachihara added, popping his head out from the crow’s nest above. “Bit rough around the edges, though.”

Dazai didn’t look away from Chuuya. “Then let’s smooth her out.”

The siren’s chains glinted like oil in the twilight. She bared her teeth. “You want a song? Fine.”

Chuuya took a breath. For a moment, nothing. Then—

A note, low and trembling, spilled from her lips. Not a melody. Not yet. Just a sound, thick with salt and centuries, torn from the pit of her chest like something dying.

The air shifted.

A gull shrieked, then dropped mid-flight, spiraling like a ragdoll into the water.

The fog recoiled.

Then came the song.

It wasn’t in any human tongue. No language carved by gods. It was older than those things. The kind of song the sea might croon to the moon, or the moon to its monsters. It rolled over the deck like smoke, seeping into wood and marrow, pulling at the bones of the ship itself.

Dazai stood still, her eyes locked on the siren’s face.

Chuuya’s chains began to glow. Not white, not gold, but a deep, pulsing red, as though corruption itself had veins. Her hair blew wild in the wind, copper tangling in her face. Her eyes glowed—one the color of clear skies, the other like earth cracked dry.

And then the wrecks began to move.

The shattered ships that haunted the reef shuddered as if breathing. Some groaned, others cracked apart entirely, their skeletons sinking into the depths to clear a path. The Leviathan’s Eye lurched forward like it had been caught on a current too strong for even death to resist.

“…It’s working,” Gin whispered.

“We’re through the seal,” Kaji called from above, wonder curling through his voice.

“And she didn’t kill us,” Verlaine said, sighing. “A true miracle.”

Chuuya’s knees buckled as the final note fell from her lips. The silence that followed was too clean, too sharp. It was the kind of silence that came only after violence. She collapsed forward, but the chains caught her like a noose. Dazai stepped closer. Not to help—just to watch. Her gaze trailed over the siren’s trembling form.

Chuuya coughed as she weakly glared at Dazai, her voice wrecked. “You got what you wanted.”

“For now.”

“Is that it?” Chuuya rasped. “You’ll chain me up until you need another trick?”

Dazai tilted her head. “Until I trust you.”

“I swear, one day I’ll pull you down and make the ocean keep you.”

Dazai’s smile was slow. “Make it a good song when you do.”

The crew shifted. None of them dared to speak. 

Even as the cursed fog slipped behind them, even as the water cleared, even as the sea opened like a secret—they all watched her. The sea ahead was still. Behind them, the wreckfields hissed and folded in on themselves like a wound finally closing.

The Leviathan’s Eye creaked in relief.

Chuuya didn’t speak again. She didn’t have to. The silence she left behind was enough to weigh down every deck plank.

Akutagawa sighed under his breath but said nothing. Gin didn’t look away from Chuuya, gaze unreadable. Kouyou’s fingers flexed subtly on the wheel, like she was biting down words. Even Higuchi looked shaken. Not by the siren’s power, but the aftertaste it left in the air.

Dazai turned from her — not coldly, but with the finality of a blade being sheathed — and disappeared below deck.

⋆⋆⋆

Her cabin was dark. It always was.

A single lantern hung from the beam, burning with silverfire instead of oil. Sigils crawled across the walls in slow, glimmering loops. The air smelled of parchment, rust, and crushed nightshade.

Dazai knelt by the mirror, a tall, tarnished thing half-sunken into the floor like it had grown there. She sliced her thumb open with a ringed dagger, letting three drops of blood hit the glass.

It shimmered.

Mori appeared a moment later, leaned back in his own opulent throne aboard the Leviathan’s main vessel, The Black Tempest. His smile was waxy. Measured. Surgical.

“You’ve cleared the wreckfields,” he said without greeting.

“She sang,” Dazai replied, tone flat.

Mori steepled his fingers. “She survived?”

“Barely.”

“And your crew?”

“Whole. For now.”

Mori leaned forward. “I expected you to bind her tighter.”

“She was already bleeding.”

“Good.” His voice thinned. “Pain keeps monsters honest.”

Dazai didn’t blink. But her visible eye twitched—just once. The mirror caught it. The mirror caught everything. 

“You never used to flinch like that,” Mori observed. “Am I losing you?”

“You never had me.”

A beat of silence. The mirror hissed, as if it disagreed.

Mori’s smile widened. It didn’t reach his eyes. “Of course not. Not when you came to me broken already.”

Dazai’s hands curled tightly at her sides. “Is there a point to this? Or are you just bored?”

A pause. The mirror crackled again. Like even it wanted to shrink away from the silence.

“You’re not the only one hunting sirens,” he said smoothly. “The Celestial Fortune was seen near Tottori. Fitzgerald’s hoarding sirens like relics. He thinks the sea will owe him.”

“He’s a fool.”

“And yet he plays the game better than most.” Mori tilted his head. “Fyodor, too. That vermin began his purging. The Saint’s Corpse has already sent their jester.”

Dazai didn’t react. But her jaw tightened just slightly.

“You’re the only one hesitating,” Mori added, voice dipped in silk and venom. “Why is that?”

“Because I think before I bite.”

“Ah.” Mori’s smile thinned. “Still so clever. Just like when you were little.”

Dazai didn’t move. The lanternlight flickered, casting shadow across her face.

“You always had such a sharp tongue,” Mori murmured. “But back then, you knew when to hold it.”

“Back then,” she said, voice dry, “you had a dagger to my throat.”

“And you were so grateful, weren’t you?” He leaned back. “Look how beautifully you turned out.”

The room felt colder.

Mori sat back into his throne once more. “You have a week. Show me what she’s worth or drown her. There’s no middle ground in war, Osamu. There’s victory or death.”

A beat.

“You do remember the last one you got attached to, correct?”

Dazai said nothing.

Mori’s smile lingered, slow and thin. “Good. Neither do they.”

The mirror went dark.

⋆⋆⋆

Dazai stood in the dark, crimson still dripping from her hand. Outside, the sea was calm. But something in the wind still stung. Like a warning. She didn’t go back to Chuuya’s cell that night.

She didn’t sleep, either.

Chapter Text

The air shifted the moment they crossed into the drift market at dawn.

The sea went still. The fog pressed low. Even the waves seemed to hold their breath. Dazai stood at the helm, hair swept back by brine-laced wind, watching the massive ribcage of some long-dead leviathan rise from the shallows like a port built by bones. Lanterns hung from the ivory ribs, glowing faintly green, casting the whole place in the color of rot and old sickness.

The drift market wasn’t marked on any map. It moved with the tide and only appeared to those who could pay the toll—either in blood or secrets.

“Dock us in the mouth,” she ordered.

Behind her, Akutagawa narrowed his eyes. “You’re actually going down there?”

“You’re welcome to come.”

“I’ll guard the ship.”

“Hmph. Coward.”

Gin tossed her a blade. “Don’t take anything that breathes.”

Dazai caught it neatly. “You know me.”

“I do,” Gin said. “That’s why I said it.”

⋆⋆⋆

The market reeked of ghost salt, wet paper, and dried kelp. It wasn’t built so much as grown—nestled into the vertebrae of sea monsters long gone, half-sunk ships converted into stalls, bloodstained flags marking each vendor’s allegiance.

Dazai walked through with her coat trailing like a shadow, passing bone carvers and salt-witches, relic-peddlers and scavengers hawking siren teeth in velvet pouches. The Leviathan’s Eye had docked here before, but not often. Even pirates knew this place soured the soul.

And at its center, pacing like a man already haunted, was Mushitarou Oguri.

He wore a dark velvet coat fraying at the edges, buttons all mismatched, ink stains on his fingers and something twitchy in his expression. His boots were polished. His mind was not.

“Dazai,” he greeted, not looking up. “You’re late.”

“You’re always early,” she replied.

“I prepare,” he muttered, gesturing towards his crooked tent. “Come in before the relics start watching.”

⋆⋆⋆

Inside, the walls were lined with bookcases tilted at odd angles, like they were drunk on magic. Jars of preserved sea creatures floated on the shelves, most of them twitching slightly, as if not quite dead. A siren’s scale glowed faintly in a dish beside a bottle of something labeled voice sediment.

“You look like hell,” Mushitarou said, not unkindly.

“I need a relic,” Dazai replied. “Voice-binding. Stronger than last time.”

His expression twisted. “The last one nearly shattered when you tested it. Don’t tell me your new pet’s gotten stronger.”

“She cracked the wreckfields open with a note.”

He froze. “Gods below. You’re serious.”

“Unfortunately.”

Mushitarou rifled through a locked cabinet, muttering. “You know, people like you are why this ocean is cursed. Always taking things you don’t understand, turning miracles into weapons—”

Dazai smirked. “You sound like you’re part of the Guiding Star. Always trying to rescue sirens and stop the sea’s true rulers.”

He shot her a sidelong glance. “Don’t get too cocky. The Imperial Hound is sniffing closer every day, hunting anyone with magic or cursed blood. They’d kill us all if they could.”

“Would you like to be paid or gutted like a fish, Mushitarou?”

He sighed, fishing out a velvet-wrapped bundle. “Both, probably.”

He unwrapped the cloth to reveal a necklace strung with jagged black shell fragments, each one inscribed with trench-runes. The cord shimmered faintly with deathroot resin, and the shells pulsed faintly with muffling wards.

“Tuned to suppress resonance. The outer layer catches the first octave of a siren’s voice. If she tries a full melody, the resin sears the throat. One note might slip through, but she won’t sing twice.”

“Lovely.”

“She’ll hate you.”

“She already does.”

Mushitarou hesitated. “She’s the one, isn’t she?”

Dazai tilted her head. “What do you mean?”

“I’ve heard things,” he said, suddenly quieter. “About what’s coming. About a siren with the blood of the trench and a voice that can bring back gods. And now you show up with a dangerous one under your belt…”

“What, you think I’m harboring a prophecy?” Dazai asked, almost amused. “You’re not usually one for poetry.”

Mushitarou sighed. “I’m not. What I mean is—words getting out. I had a buyer last week who tried to bribe me with a relic soaked in a priest’s blood. Said he was a collector for the Celestial Fortune.”

“Fitzgerald?”

“One of his little lackeys. He wants to control the tide routes. Make the sea run where it suits him. He thinks enough sirens can bend the ocean.”

Dazai’s expression sharpened.

“And then there’s the others,” Mushitarou muttered. “A courier came through yesterday. Said the Saint’s Corpse is marking trench ruins with resurrection sigils. Fyodor’s calling something back. Something old.”

“The Deep One,” Dazai said quietly.

Mushitarou paled. “You know what that is?”

“I know it shouldn’t be spoken aloud.”

He handed her the relic with trembling hands. “You’re playing in waters we were never meant to survive.”

“Good,” Dazai said, tucking the relic into her coat. “I’ve never planned on living long enough to see how deep they go.”

⋆⋆⋆

When Dazai returned to the ship, the sky had darkened. Chuuya was still in the brig, slumped against the chains, eyes dim but not dead.

“You left,” Chuuya rasped, voice hoarse.

“Missed me?” Dazai knelt and held the new necklace between two fingers. “Don’t worry, I brought you a souvenir."

Chuuya scoffed. “What is it, a leash?”

“Close!” Dazai grinned, more threat than charm. “Think of it as a very fashionable muzzle.”

Chuuya’s expression didn’t shift. “You could kill me with your bare hands, you know.”

“Tempting, but that’s just brute force. I prefer artistry.”

Chuuya’s eyes flicked to the relic. “What is it?”

“Call it… insurance. I like knowing you won’t turn me to dust the second I unleash your voice.”

She paused. Her gaze darkened. “There are others hunting you.”

Chuuya stilled.

“You’ve made yourself too loud,” Dazai murmured. “This sea is full of creatures that want to use you to rewrite the rules.”

Chuuya looked away.

“Awww, don’t get shy on me now! Did I touch a nerve?”

“Shut up.”

“That’s all you have to say?” Dazai drawled. “Come on, siren. I’ve heard dying fish with more bite.”

Chuuya bared her teeth. “You will if you keep talking.”

Dazai stepped closer, voice low. “Alright, little devil. Tell me the truth. Do you want to be sold, silenced, or saved?”

Chuuya’s voice was barely a whisper. “I just want to be left alone.”

Dazai tucked away the relic with a flick of her fingers. “Then stop screaming like you want the whole ocean to find you.”

She stood.

Above them, the wind howled. Not like a storm, but as if something ancient had turned its head. As if something in the deep had heard. 

Chapter Text

The dawn came rust-red, the color of a wound that refused to close. It bled first along the horizon, a slow bruise swelling at the rim of the world, before spilling down into the waves themselves. The water swelled sluggishly under the Leviathan’s Eye, thick with the stench of rot. The sails hung heavy in the damp, and the deck creaked like it had been keeping bad secrets all night.

Dazai leaned against the starboard rail, hair unbound, brine-wet strands dragged across her cheek by a wind that tasted faintly of rust and bone dust. She watched the red seep deeper into the swells, each crest gleaming like the slit of an opened throat.

“Looks like the ocean’s bleeding out,” she murmured.

Kouyou didn’t smile. Her lacquered nails tapped once against the rail, catching the light like fresh blood. “That’s no tide. That’s a warning spill. Someone’s claimed this stretch with spellwork. They want the rest of us to choke on the hint.”

“And yet,” Dazai said, tilting her head toward the horizon, “here we are.”

Behind them, the crew’s rhythm shifted — smaller, sharper movements, like prey when it’s caught the scent of a hunter. Akutagawa’s cursed blade whispered in its scabbard like it wanted out. Tachihara’s rifle strap creaked under restless fingers. Hirotsu’s calm, clipped orders moved through the air like invisible rigging, keeping panic from spilling.

Near the aft rail, Q sat cross-legged, twisting the porcelain head from their doll with deliberate, unblinking care. Their eyes tracked Dazai every time she passed, but it wasn’t a guard’s watch. It was study, like a child studying an insect before pulling off its wings.

Somewhere far below the hull, something in the dark let out a slow, considering, breath.

⋆⋆⋆

Below deck, the air thickened — part iron, part salt, part something that belonged far below sunlight.

Chuuya was still chained to the brig wall, her wrists raw where steel met skin. Around her throat, the voice-binding relic glimmered faintly: jagged black shells threaded on deathroot cord, trench-runes carved into each shard. The resin pulsed once every few breaths, waiting, patient as a heartbeat.

Dazai stepped inside. “On your feet, belladonna.”

Chuuya didn’t move. “What now?”

“Calibration.” Dazai crouched, close enough for the siren’s breath to ghost her cheek. “Sing me an A.”

Her lip curled. “Go to hell.”

“Already here.” The smile was bright, but her eyes didn’t warm. “Sing.”

Chuuya gave her one note. Pure, sharp, clean enough to split glass. For a heartbeat, it rang untouched. Then the relic came alive.

The shells lit with dull red fire, the resin seared, and heat bit deep into Chuuya’s throat. The burn was meant to end the sound immediately, but she leaned into it instead, letting the note swell, forcing it higher. The brig walls rattled. Chains quivered.

The relic shuddered. Smoke curled from the cord. And still the note climbed. The steel underfoot groaned. A hairline crack whispered its way across one of the shell fragments.

Dazai saw it, and something alien in her chest caught. Not just a calculation, not just the pulse of risk, but an uninvited beat of awe, hot and sharp. Her heart skipped a beat as she watched a creature born to be free spit in the teeth of its cage and burn herself from the inside, just to prove she could. For the space of a breath, Dazai’s mouth forgot its curve.

Then she smoothed it back into place. Lazy. Careless. 

“Well,” she said, voice light, “looks like we’ll need a sturdier collar.”

Above deck, a shout tore through the boards: “Sails to starboard!”

⋆⋆⋆

By the time Dazai emerged, the horizon was breaking open with black-and-gold canvas. The insignia of the Celestial Fortune cracked in the wind — not Fitzgerald’s monstrous flagship, but a cutter built for speed, prow tipped with sirenbane steel that gleamed like fresh ice.

“Persistent little maggots,” she said, low.

At the cutter’s helm stood Louisa May Alcott, coat snapping in the spray, her hair bound in a sailor’s knot that didn’t shift even in the wind. Beside her, Margaret Mitchell raised a spyglass, the sunlight flashing once across its rim like an executioner’s blade. Her eyes were narrowed, and her mouth was drawn in the tight curve of someone already plotting how to gut their prey.

The first harpoon punched into the water a meter off their hull, sirenbane sizzling on contact. The second slammed into the rail, wood screaming under the impact. Ropes hissed across the deck like striking snakes, desperate to tether the Leviathan’s Eye in place.

Akutagawa moved first, his blade howling once as it tore through the anchoring lines, wind, and waves alike, sparks flying where steel met steel. Higuchi’s flintlock cracked over his shoulder, each shot snapping a rope before it could coil tight.

Tachihara dropped to one knee by the port gunwale, his rifle speaking in sharp, percussive bursts that chewed into the Fortune’s rigging. Gin flickered between shadows, knives flashing silver as she cut lines before they could knot.

Verlaine moved like a ghost along the starboard side, every step a whisper. Where Gin struck fast, he struck silent. A cut to a throat, or a shove to send a man overboard without a sound. Hirotsu stayed at the wheel with Kouyou, voice steady as he called adjustments that kept the Eye’s path slippery.

Kaji yanked the wheel from Kouyou, spinning them hard into the swell. The Eye heeled, spray exploding over the deck, the cutter swerving wide to keep from snapping its mast.

Q hummed to their doll, soft and tuneless. It carried under the noise, seeping into the Fortune’s deck like smoke into fabric until one of their gunners spasmed. His harpoon clattered from his grip, and he dropped like a marionette with its strings cut, head hanging loose.

⋆⋆⋆

The noise reached the brig in jagged bursts — the shriek of steel, the ocean’s roar, the shudder of bodies hitting the deck.

Chuuya listened. When the ship lurched hard under her, she grit her teeth against the burn of the relic and sang. Not loud, but just enough to slip between the chains and sink into the hull’s bones. 

Agony tore through her throat like a hooked wire being dragged upward. Her knees hit steel. Heat ripped up her windpipe until breath turned to iron in her mouth. The note faltered and cracked, but the water outside heard her.

The sea shivered. The cutter’s hull bucked, its deck canting dangerously. A mast split with a wet crack, splinters spiraling into sunlight before crashing down. 

Up above, Dazai’s gaze snapped toward the brig hatch. That stutter in her chest came again, uninvited. A slow, sharp smile that didn’t quite reach her eyes curled across her face. 

“Oh, darling,” she murmured, “you really don’t know how to be quiet.”

⋆⋆⋆

The cutter didn’t fall back easily. Louisa’s voice carried over the water, cutting through the wind with the precision of a thrown knife. Margaret’s spyglass followed the Eye’s every shift, each order from her helm keeping their bow aimed like a spear at the pirate ship’s ribs.

“Take us into the bloom,” Dazai ordered.

Kaji didn’t argue. The Leviathan’s Eye plunged into the rust-colored stretch. The swell thickened, choked with fish turned belly-up. The stench clung to the sails, to skin, to teeth. Blood filmed the water, glinting like scales. 

The cutter hesitated at the bloom’s edge. Its crew balked at the poisoned swells, their harpoons lowering by instinct. Louisa’s jaw clenched, Margaret’s orders went unheard, and slowly, almost reluctantly, the Fortune turned away, her black-and-gold sails shrinking into the distance.

When the Eye broke free into clean water again, only the slap of waves and the groan of blood-heavy canvas filled the air. They had escaped.

Kouyou’s gaze lingered on Dazai. “You’re pushing too far, too fast.”

“That’s the point.” Dazai’s tone was almost cheerful. “They’re more dangerous when they think they’re winning.”

Hirotsu’s voice was quiet. “Or when they’re desperate.”

Akutagawa wiped his blade clean, scowl imminent on his face. “Let them be desperate. We’re the kings of the sea.”

Q clicked their porcelain doll’s head back into place with a hollow snap. “Things scream better when they know they’re about to break.”

The wind dipped. For a moment, the world went strangely still.

Then the hull shuddered. Not from wave nor wind, but from something vast brushing its length, slow and deliberate. The wood moaned, deep and low, like the sound of a door opening in the dark. It was gone in seconds, leaving only the vast silence of deep water.

Chapter Text

Dazai moved quietly through the ship, the deck slick beneath her boots with seawater and something fouler she didn’t care to name. The moon hung low, a pale witness to the ship’s slow sway, tugging at her chest like a heartbeat she could almost reach out and clutch. 

The lanterns in the brig cast flickering shadows along the walls, making the chains look like they writhed of their own accord.

Chuuya sat on the cold stone floor, shoulders hunched, one hand wrapped loosely around her side. Her chest rose and fell with a shallow rhythm, and Dazai’s eye lingered on the slight tremor that ran through her.

“You’re… tense,” Dazai said as she walked in, her voice soft but edged with something she didn’t bother to name. She crouched beside her, careful not to startle her, and her fingers hovered over the bruise blooming along her ribs. “Let me—”

“Don’t,” Chuuya snapped, her voice sharp enough to sting despite her wince. “I can manage.”

Dazai paused, noting the way her jaw clenched, the way her gaze refused to meet hers. She could almost feel the electricity of her resistance, a taut wire strung between them. She leaned closer anyway, ignoring the sharp intake of breath she tried to hide. 

“It’ll hurt less if I do it carefully, I promise.”

Chuuya opened her mouth to answer only to close it once more. The siren’s wince was subtle, but it made something twist in Dazai’s chest. She hated admitting it, hated how seeing Chuuya, fierce and battered, dug under her skin in ways she wasn’t supposed to notice. Why did it feel different this time? 

The siren hissed in pain again, biting the edge of her lip. Dazai’s hands hovered just above her skin before she finally pressed gently, massaging the tense muscle near her ribs. She flinched, a small, almost imperceptible wince, but allowed her to continue.

“Fuck,” she muttered under her breath, half in pain, half in protest.

“You need to stop pretending pain doesn’t exist,” Dazai muttered.

Chuuya’s eyes narrowed. “And you need to stop pretending you give a damn.”

Dazai’s throat tightened. She didn’t answer, just worked carefully and stayed silent. The skin beneath her fingers was warm and alive, and it made her heart thump in a way she wouldn’t acknowledge. She looked away, adjusting the bandage covering her eye to hide the tremor in her hands.

“You’re too stubborn,” Dazai said lightly, though the edge in her voice was sharper than usual. “One of these days, it’ll kill you faster than anyone else.”

Chuuya scoffed, tugging at her chains despite the pain. “I’m already dead in a way that counts.”

Dazai’s pulse skipped. That phrasing… it rang a bell she tried to ignore. A shadow of someone else, someone she’d let herself care for before, flickered in her mind. Vague, incomplete, dangerous. She forced a smile and leaned back.

“Don’t be melodramatic. You’re very much alive.”

Chuuya studied her for a long moment, her mismatched eyes flicking with suspicion—or maybe something softer that made Dazai want to hide behind her coat. “Alive, huh? You make it sound like a blessing.”

“Depends on your perspective,” Dazai murmured. She thought she saw Chuuya’s lips twitch, a small, dangerous smile threatening to emerge.

For a long moment, only the sound of her shallow breathing and the soft scrape of her fingers against her skin filled the brig. Dazai’s eye traced the curve of her shoulder, the small shift in her posture when her hands pressed a little too firmly. She swallowed hard, forcing her thoughts away from the dangerous, magnetic pull she felt toward her. The last thing she needed was to get attached again.

A flash of someone popped into her mind, blurred and fragmented. A warm smile, a hand reaching for her own, a laugh she couldn’t place. She shook it off quickly. She couldn’t let herself think about that, especially with Chuuya sitting there, vulnerable and alive in a way that seemed impossible for someone chained like this.

“Better?” she asked, testing her reaction.

Chuuya let out a dry laugh that didn’t reach her eyes. “Barely.” She turned her head, avoiding her again, though there was no heat in her scowl, only a faint tension that made Dazai’s chest tighten in response. She had to fight the urge to lean closer, to touch her face, to see if she was breathing properly. Instead, she stood, brushing invisible dust from her dress. 

“Fine,” she said. “I’m going to get something for you. Food, water, maybe a blanket if I can find one.”

The siren’s eyes flicked to her, something unspoken passing between them, a mixture of suspicion and something else she wouldn’t admit. 

“Don’t take too long,” she muttered, but her tone lacked the bite it usually carried.

Dazai inclined her head. “I’ll be back soon.”

⋆⋆⋆

Up in her cabin, Dazai leaned against the edge of the desk, fingers tapping idly against the wood. Her reflection in the mirror caught her attention, and for a moment, the surface rippled with Mori’s voice, low and serpentine.

“I didn’t think I’d have to remind you twice in the span of a couple days, Osamu. You do recall the last one who wormed their way into your chest, don’t you?” Mori’s words slithered across the room, echoing in Dazai’s mind with a familiarity that made her stomach tighten.

Dazai froze. She knew who Mori was trying to hint at. Of course she knew. She could never forget the taste of their salty lips, the smell of gunpowder, the screams that still haunted her dreams. She could never forget the weight of their hand in hers and the feeling of it going slack.

Her hand tightened on the edge of the desk as she tried to control her breathing. She blinked, trying to shove it away, to focus on the present.

Chuuya waited down in the brig, and whatever that feeling was—it wasn’t something she could afford. Not with Mori watching, not with the rest of the world ready to exploit her voice like a weapon.

Still, she couldn’t deny the slow, creeping warmth that had begun in her chest whenever she was near since that same day, whenever she flinched and winced and still didn’t push her away.

Shaking off the thoughts, she gathered a small tray, filled it with some bread, salted meat, and water in a chipped cup before she moved back towards the brig. The flickering lanterns threw her shadow long and thin across the corridor, stretching toward the chains that bound her.

⋆⋆⋆

Chuuya looked up when she entered, eyes narrowing, but she didn’t move away. The faint light caught her hair, burning copper in the glow, and for a heartbeat, Dazai almost forgot what she was to do. Almost.

“Here,” she said, setting the tray down. “Eat.”

Chuuya didn’t reach for it immediately, studying her with a careful gaze that made Dazai’s pulse stutter. There was distrust, but also something more fragile, something that felt dangerously like hope.

“You planning to poison me now, or…?” she asked, voice edged with sarcasm.

Dazai smirked, leaning against the wall casually, though her heart refused to follow the pretense. Calm down.

“I’m feeling generous today. Who knows? Maybe tomorrow I’ll be a bitch again.”

Chuuya’s lips twitched in something that almost resembled a smile, but she remained seated, picking at the bread with delicate fingers. Dazai stayed silent, letting her eat, letting her reclaim some semblance of normalcy in the cruel, unnatural hell they called their world.

It was quiet for a while, only the soft scrape of bread against the tray and the occasional distant groan of the ship’s timbers. Dazai’s mind, however, refused to rest. She kept catching herself glancing at her, memorizing the way her eyes narrowed when she concentrated, the slight curve of her mouth when she thought no one was looking. Dangerous, she told herself. Dangerous in the way that currents are, pulling you in slowly until you realize you’re in too deep.

She cursed under her breath. Not now, she told herself. Not her. Not yet.

Chuuya’s hand grazed her ribs as she chewed, and Dazai’s fingers twitched. She wanted to reach out again, to make it less painful, to touch her so she knew she could trust her—even if she wasn’t sure she could trust herself.

Dazai watched, aware with a prickling unease that she had started to care. Not just for the survival of the siren she needed, but for the person beneath the chains.

“You’re quiet,” Chuuya said finally, voice softer, almost teasing. “Thinking about something?”

Dazai’s eyes flicked to hers but kept her face neutral. “Maybe,” she said, letting the word hang. “I’m very good at keeping thoughts to myself.”

Chuuya’s gaze lingered, sharp and assessing. “Hmm. I’ll believe it when I see it.”

The words hung between them. More than loyalty, more than duty, something unnameable wrapped around them like the dark waves outside the hull. Dazai wanted to speak it, to confess the pull she felt whenever she looked at her just so, but the words lodged in her throat. 

Dazai wanted to tell her she already had, in ways she could barely admit to herself. Instead, she shifted slightly, loosening the ankle chains just a fraction. Chuuya’s shoulder brushed hers, electric and maddening. This time, she didn’t flinch—testing whether Dazai would hesitate.

Dazai straightened, brushing her coat back into place. 

“I’ll get you some more water,” she said finally, hiding the thrum of something dangerous and insistent in her chest. “And maybe I’ll see if I can scrounge a blanket this time. Try not to eat all of it before I return.”

Chuuya looked up, and for a fraction of a second, Dazai thought she saw her soften, but the moment passed as quickly as it came. She returned to her bread, and she turned, retreating from the brig.

⋆⋆⋆

Back in her cabin, the mirror waited. Its surface shimmered, and Dazai felt the pull of Mori’s gaze through it again, probing, calculating.

“You’re fond of her, is that it?” Mori hissed, low, teasing, full of dangerous knowledge. “She’s not the first, Dazai. You’ve always been… captivated, haven’t you?”

The shards of the past pressed against her again—warmth, laughter, danger, loss—and she gritted her teeth, refusing to name the feeling.

“I’m not,” she said, the lie so convincing even she believed it. “Not like that.”

Mori smiled, lingering a moment longer before receding into the mirror’s haze. His grin seemed to linger behind her eyelids.

The mirror was silent for now, but Dazai knew better. Mori always waited. And so did Chuuya, down in the brig, unaware of the storm slowly curling in the Black Wraith’s chest—a storm she could neither control nor ignore. She took a deep breath, steeling herself. 

“Right,” she muttered, more to herself than to anyone else. “Food, water, blanket… and keep your head clear, Osamu. Don’t get attached.”

The current was dangerous. But like all dangerous currents, it pulled with a force that was impossible to resist.

Chapter Text

The sea stretched endlessly under a sky bruised with late afternoon clouds, the wind tugging at the sails of the Eye. On deck, Dazai lounged casually near the railing, one hand gripping a rope while the other toyed with a loose knot. The ship creaked under the strain of waves, but the larger tension came not from the sea—it came from the approaching shadow on the horizon.

A smaller vessel, white with sharp edges and gleaming with polished wood, cut through the waves toward them. Its banner bore the emblem of the Guiding Star, the fabled ‘heroes of the ocean’. Dazai straightened, tilting her head, a lazy smile forming even as her eye sharpened.

“Guests,” she murmured, as though tasting the word. “Or perhaps a warning.”

Akutagawa emerged from the deck’s shadows, cloak whipping in the wind, eyes narrowing. “Don’t get distracted, Dazai. They won’t be courteous.”

“Akutagawa, my dear gloom-bringer,” Dazai replied, voice teasing, “when have they ever been?”

The Guiding Star closed distance swiftly, and a small boat was lowered into the water, cutting through the waves with uncanny precision. Standing tall in it was a figure clad in white, with sleeves billowing in the wind, a presence that demanded attention even from a ship as fearsome as the Eye.

Atsushi.

Beside him stood Kunikida, his coat pressed sharp despite the spray of saltwater, a notebook strapped at his side like a weapon. His posture radiated rigid discipline, jaw set as though every word he carried had already been written down, measured, and prepared.

Behind them lounged Ranpo, their navigator, chewing idly on a strip of dried fruit as if this was all a game. His sharp eyes, however, were far from idle; they flicked constantly to the horizon, to the clouds, to the way the waves curled unnaturally at the ship’s wake. He squinted once at the Eye, as though the vessel itself whispered secrets to him.

Dazai’s smirk widened. “Ah. The little saint of the sea himself. Come to lecture me about a certain songbird, I assume?”

Atsushi’s expression didn’t waver, though his eyes glimmered with barely contained fury. “I’m here for the siren you’ve captured,” he said firmly. “You know exactly who I mean.”

Akutagawa snorted softly, stepping closer to Dazai while she inclined her head lazily, folding her arms.

“Fragile? Perhaps. Or maybe just… principled. I admire that about you, little saint. You would’ve been a great pirate under my command.”

“Cut the games,” Atsushi shot back. “You’re keeping her against her will. She’s not a weapon for your crew. I won’t let you—”

“Oh, please,” Dazai interrupted, tone light but with a knife’s edge hidden beneath. “I assure you, she’s not for amusement. She’s… complicated. Difficult. Dangerous. Just like the rest of us, really.”

At that, Kunikida stepped forward, voice ringing with clipped authority. “You speak of her as if she were cargo. The Guiding Star doesn’t permit the enslavement of sea-born creatures. Release her immediately, or you’ll answer to us.”

Akutagawa’s lip curled. “You sound like you’ve rehearsed that.”

“I plan for contingencies,” Kunikida shot back sharply. “Unlike pirates who think chaos is a strategy.”

Dazai tilted her head, mock-sweet. “Order, chaos… isn’t the sea a little of both?”

Ranpo chuckled quietly from the boat, leaning back with his hands behind his head. “She’s stalling. She always stalls when she’s hiding something. Cute trick, but the sea doesn’t lie like you do.” 

His eyes narrowed faintly on the water trailing the Eye. “Something’s off here. Has been since you dragged that siren aboard. The current doesn’t move right.”

Dazai’s grin tightened for just a second, then relaxed. “Oh? And what does your ocean whisperer’s gut tell you, navigator?”

Ranpo smiled lazily. “That something’s following you. Big. Patient. The kind of thing that doesn’t move until it’s ready to swallow the whole ship.”

The deck of the Leviathan’s Eye grew colder at those words. Even Akutagawa shifted, his jaw tightening as if he wanted to argue but couldn’t.

Atsushi, unshaken, pressed on. “You think I don’t know what you’re doing down there? You’re keeping her alive, sure—but for what? For your Captain? For yourself? For power?”

Dazai tilted her head, letting the wind tug at her hair. “Plans are mutable. Survival is… mutual. Amusement? That’s too cruel a word for what I do with her.” Her gaze flicked toward Akutagawa, then back at Atsushi. “You care too much for the creatures of the deep, don’t you? Admirable… but exhausting.”

Atsushi’s lips pressed into a thin line. “I care enough not to let them be exploited. That’s more than you’ve ever done for anything that matters.”

Dazai chuckled softly, a sound that carried across the waves. “Ah, Atsushi, you really do spoil the poetry of the moment.”

Akutagawa shifted, stepping closer to Dazai, eyes trained on the white-haired boy the entire time. “You do realize they’ll try to storm us if we don’t comply?” His voice was calm, but lethal, a silent threat hovering in the air.

Dazai’s grin didn’t falter. “I wouldn’t dream of compliance. Where’s the fun in that?”

Atsushi’s eyes met Akutagawa’s, silent disdain flickering through his face. “And you… what’s your job? Standing there? Who even are you?”

“I follow orders,” Akutagawa said flatly, then added angrily under his breath, “and watch fools get themselves tangled in nets they cannot get out of.”

The tension stretched, taut as the sails above them. Dazai leaned on the railing, pretending nonchalance, but her eyes scanned the horizon for any sign that Chuuya had reacted to their commotion. The faintest pang struck her at the thought of the siren, chained and unaware of what storms were brewing above.

Atsushi’s eyes sharpened. “This isn’t a game, Dazai. I don’t care how clever or poetic you think you are. Let her go, or we’ll—”

“Or you’ll what?” Dazai interrupted, tone suddenly cold, cutting. “Board us? Fight us? Perhaps. But I assure you, my dear golden boy, every action has consequences. Every current has its pull. And you… you have no idea what you’re wading into.”

The wind whipped at their coats, carrying the tension across the deck. Akutagawa’s fingers twitched near his blade, silent but menacing. Dazai’s smile returned, calm, teasing. Atsushi’s gaze softened, almost imperceptibly, as he looked out toward the brig below. 

“I don’t care about consequences,” he said quietly. “Not when she’s involved.”

Dazai’s chest tightened in a way she didn’t like. She forced her grin wider, covering the small flutter of guilt—or something closer to dread. 

“Oh, Atsushi,” she taunted, letting the word roll lazily off her tongue, “you’re so dramatic. I really do hope you don’t choke on your own righteous fury. That would be a bit of a problem, wouldn’t it?”

Atsushi didn’t respond. He simply held her gaze a moment longer before turning back, stepping back into the boat. Kunikida shot Dazai a final warning glare. 

“The tide won’t forgive you, Black Wraith. Neither will we.”

Ranpo, before settling into his seat, lifted a hand toward the Eye without even looking at her. “You should listen. Something’s already chosen to follow you. It’s patient now. It won’t be forever.”

The Guiding Star began to pull back, but their presence lingered on the deck like a shadow, a silent threat and reminder all at once.

Akutagawa let out a low whistle. “You’ve really managed to rile up the golden boy this time, haven’t you, Dazai?”

Dazai’s smile was tight, almost imperceptibly strained. “What can I say? I have… excellent taste in tension.”

The Star’s vessel shrank into the distance, but its shadow remained, clinging to the Eye like sea rot. Dazai turned toward the stairwell that led below, toward Chuuya, toward the place her thoughts insisted on drifting—but stopped short at the deck’s edge, eyes narrowing.

Above her, the sails creaked, and the horizon was empty once more, but the echoes of the Guiding Star lingered like the bite of winter water against skin. Somewhere in the distance, the sound of a bell from the departing vessel tolled faintly, a reminder that the currents of the world were already shifting—and that the next collision was only a matter of time.

Ranpo’s parting words had left a splinter in her mind.

The sails groaned, the waves lapped, and for a fleeting instant the horizon seemed too still. Too heavy. Something was following. Not a storm. Not a ship. Something older. Something vast. The faintest ripple broke the water far behind them, gone as soon as it appeared.

Dazai’s smile faltered. Her fingers tightened on the railing. She exhaled, hiding the tug in her chest, the warning pulse of a feeling she refused to name. She turned away from the deck’s edge, straightening her coat, and smoothing her hair against the wind. 

The brig awaited, and unknowing to her, so did the deep.

Chapter Text

The sea had no stars that night—only a white wall of fog, thick as bone dust, swallowing horizon and sky alike. The Leviathan’s Eye drifted blind, sails sagging in air too heavy to stir. Compasses spun in frantic circles, as though even iron had lost its faith in direction. Every rope creaked like a throat on the verge of breaking, and the crew moved with brittle caution, sailors haunted by waters that no longer seemed real. 

Gin and Verlaine dragged Chuuya up from the brig, shackles biting iron against her wrists, scraping each step with a hiss that set the crew’s teeth on edge. She stumbled as they shoved her onto the deck, nearly falling to her knees. Her hair clung in damp strands, plastered with sweat and seawater, curling wild against her pale face. A tremor ran through her limbs. Not from fear, but of exhaustion sharpened into defiance.

For a heartbeat, only a heartbeat, she lifted her gaze to the prow. Hope, faint and foolish, flickered there. The kind of hope no one could kill lived in her eyes, even while in chains: that maybe Dazai would look at her the way she had the night before in the brig, gentle and human. 

But Dazai’s eye was steel, and command was the only softness she allowed. Cloak brushing damp wood, the mist curled reverent around her silhouette as though the fog itself bent to her. Her voice carried like silk drawn across a blade.

“Sing for us, little siren. Lead us out.”

Chuuya’s face dropped, hope collapsing into ash. Her voice rasped low, hoarse with exhaustion, venom sharp enough to hide the wound beneath.

“Last time I sang, the sea didn’t part because of me—it was your orders that tore it open.”

The hush that followed was colder than the fog. Gin’s hand hovered over her blade. Verlaine sneered, lip curled, muttering about devils in human skin. Q giggled until Higuchi silenced them with a sharp look. Even Tachihara, lounging at the mast, stiffened as though the words had teeth. 

Dazai’s smile curved thin and cruel. “Then rip it open again. Unless you’d rather rot with us in this coffin of fog.” 

Chuuya’s glare flared, exhaustion dragging at the edges, but her lungs betrayed her. A siren’s voice could not rot in silence forever—it clawed its way out, whether she willed it or not.

Tachihara muttered under his breath, picking at his nails, “We’re gambling with a fucking curse.”

Gin’s blade hissed free, the whisper of steel a promise. 

“Shut it,” she murmured. He did.

The first note left Chuuya’s lips like smoke, faint and trembling. Then it swelled, resonant, threading into the marrow of sea and ship alike. It wasn’t the coaxing hymn she’d sung before. It was raw and jagged; a hymn scraped out of blood and bone. Half-scream, half-prayer.

The Leviathan’s Eye lurched forward, gripped by currents that curled around its hull like skeletal hands. The fog quivered, bowing back as if forced by an unseen hand. Shadows writhed in the mist, parting with each note.

For a fragile breath, the crew believed.

Then the ocean boiled.

The vibration began beneath the keel, a groan of deep water splitting apart. Whitecaps frothed, splitting into whirlpools that clawed at the hull. From below rose the bones of ships—barnacled ribs, broken masts, sails chewed to lace, their corpses crawling with crabs and rot. They rose like marionettes, pulled upright by the strings of Chuuya’s voice.

And deeper still, something older stirred.

Chuuya’s song fractured, shattering into registers no ear should bear. The relic at her throat blazed fever-hot, cracks fissuring across its surface like lightning across stone. Her body seized, blood slicking her nose, mouth, and eyes. Her voice twisted into a scream laced with a language older than salt, older than drowning, every note blackened by corruption even the devil cowered away from.

The world answered.

Visions burst from the fog itself, carved into the sea spray as though the ocean painted memory in salt and shadow. A pod of five sirens trapped in iron mesh, their cries rising through blood-red waters as soldiers drove spears through them until the sea boiled scarlet. A younger Chuuya, dragged in chains, nails raking splinters from the wood of a slaver’s deck. The sea aflame with her grief as a fleet broke under the weight of her voice, men clawing their ears until they fell into silence forever. At the end, only she remained—the siren adrift among corpses, throat raw, eyes wide with horror at her own survival.

The crew staggered, undone. Kaji collapsed, hands clamped over his ears, spitting curses. Verlaine stumbled back, muttering frantic prayers. Kouyou clutched Q tight to her chest, though her own face was paper-white. Higuchi gripped her flintlock but trembled too much to fire it. Hirotsu’s jaw was iron, but his knuckles whitened on his cane. Akutagawa stood rigid, pale, breath shallow—his loyalty keeping him still when every instinct screamed to run. Gin did not move, eyes locked on the girl in chains, as if staring could keep her tethered.

Dazai moved.

Her boots struck the deck like gunfire. She dodged the growing spikes of siren frost and crossed to Chuuya in three strides, the relic’s glow burning her palms as she seized Chuuya’s jaw. Blood slicked her fingers, but she pressed harder, forcing silence. Chuuya writhed, chains rattling, voice cutting her own throat raw. Dazai slammed her down, pinning her body with her own, one hand crushing her mouth shut.

The song died into muffled sobs, sound swallowed by flesh and palm.

For a moment, Dazai felt it—the tremor of a throat that was never meant for silence, the shudder of blood against her hand. Beneath all of it, not a weapon, not a curse, but a girl carved open by cruelty.

Dazai’s chest ached, ugly and raw. She despised it.

“Enough,” she hissed into the damp tangles of Chuuya’s hair, as though command alone could close the wound of her song.

And the ocean stilled.

The wrecks sank back into the dark. The fog thinned, drifting away as though ashamed. The sea steadied under the hull, though the silence left behind was heavier than mist.

Dazai lifted her hand slowly. Chuuya’s mouth was red, teeth glinting sharp in blood. Her eyes burned—not tired, not broken, but furious. The kind of fury that only betrayal could sharpen. The kind that spat in the face of whatever softness Dazai had once shown her.

Across the deck, the crew steadied themselves. Gin sheathed her blade in silence. Higuchi finally breathed, shoulders loosening. Hirotsu cleared his throat, masking his fear with dignity. Kouyou whispered something soft to Q. Verlaine leaned on the rail, muttering curses. Kaji vomited saltwater.

Tachihara spat onto the deck, pale but alive. When his eyes caught Gin’s across the chaos, something unspoken flickered there—an anchor in the storm. His shoulders squared, less bravado, more survival.

Akutagawa was the first to move. He crossed the deck, kneeling low beside Dazai, coat brushing the blood-streaked boards. His face was unreadable, but his voice was quieter than the sea.

“Dazai… you shouldn’t put yourself in her reach again. She’ll tear you apart one day.”

Not accusation. Only worry. His eyes flicked to Chuuya, then back, as though trying to grasp what kind of power had nearly swallowed them whole.

Dazai’s smile twitched into something knife-thin. “Then I’ll have to make sure she sings for me, not against me, won’t I?”

Akutagawa bowed his head. He did not argue.

Chuuya coughed, blood splattering the deck. Her voice rasped raw, but venom laced every syllable. Her chest heaved, chains clinking with each ragged breath. Her gaze seared, eyes wild and unbroken, a living testament to fury and survival.

“You think I’ll keep doing this for you? You think I’ll let you bleed me dry so you can play god? Fuck you, Dazai. I’ll never forgive you.”

Dazai leaned down, shadow falling across her face. Her voice was silk drawn across steel.

“Forgive me? Darling, I never asked for your forgiveness.”

Chuuya spat crimson at her feet.

The relic at her throat lay cracked, hairline fractures glowing faintly as though embers still smoldered inside. Too fragile now to hold her, too volatile to destroy. It pulsed like a second heartbeat, a reminder that chains could not bind the sea forever.

The fog had vanished, the sea stretched open once more—but the ship floated in a silence more oppressive than the mist and storm before. The crew, hollow-eyed and trembling, understood something primal: their treasure’s voice was no longer a tool. It was a reckoning, a promise written in blood and salt. And somewhere beneath the waves, something remembered.  Something patient. Something older than storms, older than fear.

And it would wait.