Archive of Our Own ^beta

Chapter Text

"Let’s stick together until we understand the phenomena of this island." 

That was the last thing Heizou told her before the detective was nowhere to be found, leaving Sayu alone on this creepy island. 

Wasn't disappearing supposed to be her thing? 

Initially, Sayu didn't mind too much. There were only two of them and the detective had enough voracity for mystery for three. Weird ley line phenomena, ancient bird-rocks, and some rumor about a missing scholar who might not even exist—if Shikanoin was so eager to chase ghosts or inspect grass or whatever, he could do that alone. It’ll be a start on atonement for his past tattle-tale tendencies. 

So Sayu scaled a nice, tall tree and toyed with a strange little triangle thing she’d found in her pocket. This was a fine excuse to rest and it wasn't even Sayu’s fault this time. She relishes opportunities where the logical course of action is inaction and while she’s a (despite her efforts) highly trained member of the Shuumatsuban and not a lost child, she should just remain where she is and let Heizou find her when he’s done, right? Yes. He’s the detective.

However, the mechanical triangle thing—some toy or piece of a ruin machine, maybe—only makes little clicks, thus quickly losing its intrigue, rendering it useless as a distraction. Sayu shoves it back in her pocket. 

As she rests high in the branches, eerie whispers drift through the thick fog, punctuated by the howling of wolves to a moon which can’t be seen. Those indescribable whistles from the phantoms’ Maushiro resonate like some kind of demonic bird flock, sending shivers down her spine. 

Sayu is a master of avoiding unpleasant things. She could ignore the rising tide of fear if she tried, but the effort itself is draining and it’s not as if she could actually get real sleep here anyway! Everything on this stupid island is an unsettling illusion or creepy mystery and Sayu doesn’t share someone’s enthusiasm about it.

She’s going to kill him. Shikanoin just disappeared? Left her here without a word? So he’ll snitch on her to the shrine maiden when there's nothing important on Narukami, but he'll pull a disappearing act now? He’s so stupid!

Sayu’s perch is uncomfortable. The foliage resembles feathers but the leaves are not soft at all. The fog becomes a suffocating blanket, amplifying her anxiety. She ignores her instincts, telling her to remain unseen and silent, and whistles into mist—a different pitch than those ancient wooden instruments and not incredibly loud but loud enough that Shikanoin could probably hear if he’s nearby—which he better be. 

Every rustle of scratchy leaves and every creak of branches or call from creatures beyond the dense nothingness sends her heart racing. Moments pass and she doesn’t hear her signal returned. 

This is so dumb! Maybe it would be better to head back towards the dock and wait there. 

No, she should move—look for clues; anything to get off this island sooner. 

And what if Heizou is actually in trouble? Sayu can’t just sit by if he’s really in danger. Ugh, idiot. She needs to go find Kano Nana’s stupid cousin. How long has it been since he ran off? Time is so hard to tell here…

A whistle cuts clear through the fog; the signal—the short, distinct sequence she and Heizou had agreed upon. Sayu jolts up and scrambles down the tree, heading towards the source of the sound. 

“You’re so annoying!” Sayu declares with a scowl, emerging into the clearing. “Don't tell me what to do and then not do it. Where did you even go?” 

But it's not Heizou standing amidst the feathery flora and ancient bird-stone carvings. Instead, Sayu finds herself facing a boy, younger—and shorter—than her, clad in blue and sporting a woven kasa hat. 

There’s something vaguely familiar about him. He looks so tired—way more tired than Sayu feels despite this mission’s incursion on her valuable resting time because some fox lady’s writer found an excuse to get Tri-Commission agents involved!

An unused Maushiro hangs at the boy’s side. Sayu narrows her eyes, suspicion replacing her anger. “Who are you?"

The boy smiles but it’s overshadowed by weariness. “Hi, I’m Ruu. We should get someplace safer; out of the fog.”

The boy isn’t one of this island's translucent apparitions but Sayu’s not in the mood to heed anyone’s directions—he’s shorter than her. She recalls the rumors about an immortal scholar Tsurumi native or something who met adventurers but she hadn’t been expecting a kid.

Unease flickers in Ruu’s face when Sayu doesn’t immediately follow, "you're looking for your friends, right?" 

From his satchel—strangely out of place, like something she’d sooner expect to find at a shop selling foreign merchandise in Ritou—he produces a gold-framed gemstone. 

Sayu’s breath catches. The Anemo Vision glows a faint teal in Ruu’s palm.

Chapter Text

Tsurumi Island is a treasure trove of historical wisdom, ancient puzzles, and oh-so-many untouched mysteries. For Faruzan—an expert in ancient ruins and exploration in harsh environments—it is the perfect site to unearth relics from a long-buried civilization, and texts in the rare Isshin language of the tribe that followed.

Upon arrival, she’d had the fortune of encountering two Inazuman youths investigating something on behalf of a Narukami Commission—was it the Yashiro Commission? Tenryou? Faruzan hadn’t paid attention to the bureaucratic detail. Irrelevant.

The detective boy was a bundle of frenetic energy and boyish flippancy that began to grate at Faruzan’s patience, but his intellect and relentless curiosity made him a decent, unofficial student. The girl he’d brought along—his cousin?—was not nearly as interested as she ought to be about the academic riches Faruzan offered. Until Faruzan began discussing her work on Deshret-imitative cloaking technology—techniques that could render a person completely invisible. That captured the little ninja’s attention right away.

If only that stubborn Vahumana student had accepted her earlier offer to collaborate on Inazuman history, she might’ve had a full research team by now…

Then again, keeping track of just these two was already a challenge. And that student would only have worsened the current situation.

Anemo Visions…

The initial blast had been the result of a miscalculation—faulty communication. 

Faruzan will shoulder most of the blame. Her polyhedron matrix amplifies Anemo through resonance with the elemental energy in the ley lines. In a confined space with strong elemental flow and three Anemo Vision wielders… Well. The young detective had brazen confidence in his intellect, but his humble claims in combat capability caused Faruzan to severely underestimate his martial prowess. As it happens, he had the ability to unleash a highly concentrated burst of Anemo energy. 

She had not accounted for that.

A deafening ringing filled Faruzan’s ears. The world tilted precariously. One powerful move from Heizou short-circuited the elemental cores of every ancient ruin machine in the vicinity. Faruzan had no time to register how impressive it was because the shockwave nearly knocked all three of them unconscious.

Unfortunately, the abyssal beasts were not as easily disrupted as the machines. 

Damned hounds! As if those ruin machines weren’t trouble enough. Has the whole Abyss and all its dogs chosen here to congregate? 

Faruzan grit her teeth, forcing one eye open to focus on the crack in an exposed mechanism, peeking out from an illusory barrier. With a surge of adrenaline, she drew back the bowstring, her muscles straining with the effort. Just a little closer…

She released the arrow. The device embedded in the arrowhead detonated on impact and the mechanism erupted in a blinding flash.

…

"Hey, easy now," Faruzan scolds, voice laced with concern, as Heizou stumbles on the uneven ground.

A wave of dizziness crashes over her—her head still pounds from the shockwave—but she steadies them both, guiding him carefully to the floor. Blood, dark and thick, seeps from the gash in his leg, mingling with the sickly black ichor of the Abyss.

Abyssal corruption gnaws relentlessly at its victim—a creeping poison that devours flesh and spirit alike. It's a small miracle the corrosion around Heizou’s wound seems to have stopped spreading. But that in itself is troubling. The possible implications leave another bone-chilling recognition to fester. 

No. She pushes the dread aside. She has to stay calm. Rational. Heizou is alive—and she refuses to let this boy die under her care.

Despite the pain, Heizou looks up at her with furrowed brows and murmurs, “how did you do that? The explosion, it—”

"That's what's on your mind right now?" Faruzan huffs, stressed. The ringing in her ears persists. "Ask me again later. I'll explain everything in detail.”

The second blast—that little trick to overload the elemental sensor—had been an act of pure desperation. She might call it luck, but it wasn't. She knew those symbols. Recognized that language, the energies which contrast the Abyss, and the remnants of another fallen civilization struck with ineffable power from the Heavens. 

Another Celestial Pillar is rumored to be in Inazuma. No traces had been unearthed by modern scholars, so it remained a mystery—until now, perhaps. Without the imminent threat of monsters, Faruzan can’t shake the feeling that these ancient shadows mock her.

There’s no room for error. Time will never stop for me again. 

“Hold still,” she says firmly, giving him no room to protest.

Heizou hisses through his teeth as she cleans the wound. How he’d even managed to move—let alone fight—in this condition was beyond her. Adrenaline, surely. And perhaps his Vision, offering his body just enough resilience to slow the spread of corruption.

He endures the pain with clenched teeth, but Faruzan can see it’s draining him quickly. She curses her lack of preparation. No first-aid kit, no antiseptic, she’d left everything behind at their last camp. Not that it would have been much help in terms of treating abyssal corrosion but—at least she’d have given him painkillers, something.

“Sayu got away, right?” Heizou asks, not looking at his leg.

“I believe so. She evaded the brunt of the elemental discharge. Most of the monsters were deactivated or stunned. She had the clearest route to escape.”

Faruzan knows what he’s thinking. She’s wondering the same thing. Their survival had depended on her split-second gamble—a deliberate error in the puzzle. Archons, she only just met these kids three days ago, fresh off the shores of Tsurumi. How had things gone so wrong, so fast?

“Sayu’s smart,” Heizou says, quietly. “She wouldn’t be reckless. She’s dependable when it counts.”

“She’ll come looking for us,” Faruzan summises, though unease prickles in her chest. The little ninja girl may be talented, but those beasts of the Abyss are no idle threat. Sayu could very easily get in over her head. 

Faruzan stands. “Stay put. I’m going to look around.”

The ruin’s interior is dim, suffocating. Not as intricate as the winding labyrinths beneath the desert. They’re sealed off in a closed loop of three adjacent chambers, each worn smooth by time. No obvious exits. The air is stale, as if even the shadows are holding their breath.

She moves slowly, fingers brushing along the stone walls, tracing faded carvings and fractured paint. Echoes of stories lost to time.

A sun above. An island in the sky. Celestia. A civilization of prosperity, now reduced to ruin and whispers beneath the ground. 

Prophecy and history often blur. But the more she observes, the more her memory claws at her: this structure reflects Dahri design—but the power here is that of Deshret’s civilization. That power which can warp time itself.

A chill runs down her spine. She cannot do this again. Time will not stop for her again. And yet, everything feels familiar.

Researchers are bound to make mistakes. Take calculated risks. Embellishing the stories of the past or present situation is futile. Back then, in those desert ruins, her error had led to a century of imprisonment. As much as the experience still plagues her mind, she can now call it merely the result of an “experimental error,” nothing more. Horrific as it had been, she survived, she learned, she endured, and she moved forward.

But if… But this— this is different.

This time, it’s not just her life on the line. It’s not just her absence. 

Failing to save someone else can never be written off as a mere “experimental error.”

Faruzan returns to Heizou, notebook in hand, scribbling frantically. Her handwriting has shrunk. She's being more conservative from the start. This time, she won’t be so careless with blank space. She knows its value.

Before she can speak, Heizou murmurs, “The abyssal creatures haven’t followed us. It’s the mechanism you triggered, isn’t it? Some sort of ward?”

“Astute…” Faruzan pauses. The dim teal glow of her Vision still flickers faintly—but only hers. Her eyes snap to Heizou. “Where’s your Vision?”

“Ah. So you didn’t find it,” he replies, far too casually. “Must’ve been lost during the fight. Ironic, isn’t it? Convenient, even.”

Faruzan’s pulse jumps. “Was that sarcasm?”

Heizou shakes his head. “No. As a detective, it’s convenient to leave a trace. I don’t need my Vision to fight, and there are no enemies here. It’s more useful outside—where we have an ally.”

“Visions protect against abyssal corrosion, Heizou!” Faruzan snaps, kneeling beside him. Her voice trembles. “Can you still feel its presence? Your Anemo—can you summon it?”

He grimaces. “No. But the spread has stopped. I think... it’s this place. The mechanism you activated. The ley line flow is strong but… There’s something else here—ancient, powerful.”

Faruzan stares at him, then slowly nods, retrieving her notes. Her pulse hammers against her ribs.

Heizou leans back with a quiet chuckle.

Faruzan shoots him a scowl. “What?”

“Heh. The irony,” he mutters, a faint grin playing on his lips. “First step off Narukami Island, and I lose my Vision.”

Faruzan had almost forgotten the Vision Hunt Decree had only recently been abolished. Without the Sakuko Decree gone, she never could have come here at all.

“You never had to give yours up?”

Heizou shakes his head. “Doushin of the Tenryou Commission. We were granted temporary exemptions. I would’ve turned it over if I had to.”

Faruzan says nothing. There’s nothing to say. She turns another page in her notebook and begins to write. She absolutely has to figure this out. She must get all three of them out of this alive—and in this century, this time.

Chapter Text

Sometime during the Vision Hunt Decree, Sayu had hidden herself in the Kamisato estate’s garden for a nap—tucked away in a place so obvious that even Kano Nana wouldn’t bother checking Tattletale Central. She was half-asleep in the bushes when she overheard a conversation between Kamisato Ayaka and her tall housekeeper.

At the time, Sayu hadn’t cared. She’d been busy fighting off a yawn and counting how many minutes she could steal away from her greedy training routines. But something the housekeeper murmured about the Shogun’s statue stuck in her head.

“Visions are bound to mortal ambition, and ambitions are bound to our lives. The statue shines now, but in a few decades? Its wings will be heavy with dead Visions after we’ve all died our mortal deaths. Surely the Almighty Shogun has foreseen the eventuality—it must be the blink of an eye for Her. So is that the symbol of Eternity She wants? The monochrome rot of our faded dreams?”

The Almighty Shogun stole Visions because she feared humans were too fragile, too fleeting—and too dangerous for her Eternity. But if she really cared about their lives, why display the stolen Visions like trophies? Like—Sayu could understand tossing them all into some fancy room in Tenshukaku that no one ever went into but why keep them in the open where they’d be seen as they changed from alive to dark? 

“Where are you going?” Ruu whispered, barely keeping pace a few steps behind her. He kept glancing over his shoulder every few seconds, checking for something unseen. It made Sayu more tense.

Right—clue one: the boy’s name was Ruu and he claimed to be a resident of this island—which was suspicious, because Sayu had been told they’re all supposed to be long, long dead. “Time is funny here,” Ruu had said when she pressed him, offering her that forced little smile that she knew meant he wasn’t telling her everything but he only explained more when he led them to a strange break in the fog—a hollow, rocky cavern cradling one of those feathery trees in its center. “You don’t remember me. That happens here. Things go back to how they were every three days for the ceremony. But you and Heizou helped me when you got here and I showed you the north shore where Madam Faruzan was studying. Then, the day before yesterday, I had to finish preparations, and the three of you went to explore the ruins by Chirai Shrine.”

Then apparently Ruu’s ceremony happened, they didn’t show up like they’d promised, and ultimately only Sayu ever came back from the ruins—though she didn’t remember any of that. The last thing she recalled was half-listening to Heizou musing about how the ancient people here must have adapted to navigate without sight—perception something, learned familiarity with the environment, other senses like hearing or smell or intuition blah blah. He’d gone on about whistles, signals, patterns, floral growth for navigation—yes, Sayu had listened to the useful tidbits. So if sight was unreliable why did Ruu keep glancing around like he could see something through this suffocating fog? It was stressing her out more than she already was.

Sayu ignored it—ignored the itch under her skin. She trudged on with purpose, picking her way across rough ground littered with thorny shrubs that snagged at her clothes. The path was swallowed by mist, lit only by the faint ghostly light of blue mushrooms clinging to tree roots and rocky ledges. They reminded her of Sea Ganoderma—and the stories the shrine maidens told about child sacrifices to the waves now trapped forever in slimy ocean things didn’t help. Every rustle made her flinch.

Heizou’s Vision glowed a faint teal in her palm—fainter than her own. The breeze within it felt stifled. Ruu claimed he’d found it near the ruins when he went back to look for them. He said they're in trouble. The Vision felt cold in Sayu’s hand. Dull without its master. Like it was waiting to die.

Sayu hated this.

Rationally, the Vision was a lead. It should be reassuring. But irrationally—honestly—she didn’t want it. She hated carrying this stupid gem while Heizou was who knows where in who knows what condition but presumably in trouble. She tucked it into her belt, hidden from sight, trying not to think about what it meant and how anything she could do would be useless to protect it from just going out. It was bad not knowing if Heizou or that scholar lady Sayu didn’t remember were alive. But this in-between state, this half-knowing with no context, was worse still. It was like a broken clock ticking with unmoving hands, a glass hourglass with invisible sand—no way to mark when the light would simply gutter out. Just— poof! Someone’s dead ‘cause Sayu failed to save them.

Heizou was alive now—the Vision still held power, it hadn’t gone dark like a dead person’s gem. But that could change in a single heartbeat. She wasn’t ready to glance down and feel her heart drop, the stab of horror as hope dissolved and her brain scrambled to comprehend that Heizou—who she’d just seen making some dumb joke to himself about the bird rocks—was dead. She wasn’t prepared to comprehend how badly she’d failed to protect someone.

“Sayu, where—? Wait.” Ruu called in a hushed voice, breathless, trying to match her quick steps and her silence—yeah, both stealth and speed at once was hard without training, Sayu knew, but she wasn’t trying and wasn’t bothered by his crunching footsteps now. Ruu stumbled a step. Sayu slowed down just a bit, and Ruu composed himself and asked anxiously, “shouldn’t we go back to the perch to wait first?”

The “perch” meant that feathery tree in the hollow mountain Ruu showed her—somehow related to Ruu’s bird ceremony. Right—birds. These people worshipped birds. Another fact about this place that Heizou had seemed to think was important for some reason, though Sayu didn’t see how that was relevant to her. He worked for the Tengu General and had like infinite energy for irrelevant things, but Sayu wasn't a youkai expert or a bird enthusiast and she was still too short to store enough strength or energy. However, Sayu had accumulated enough unsolicited knowledge about important trees and ceremonial tree rituals to not fully dismiss the bird trees as irrelevant, but they weren’t the point and she couldn’t think about trees now.

The trees made ominous shapes though the fog, large looming silhouettes with leaves flapping in the wind. She didn’t want to be here. Even the worst training was preferable. She hadn’t wanted this mission—this whole mess was taller than her. 

Sayu wasn’t stupid—she knew there was more than just some Yae Publishing mystery book; they were scouts. The Guuji Yae and the Yashiro Commissioner had talked about Tsurumi Island months ago. The evacuation of Seirai way back some time ago, the storms isolating the archipelago during the Sakoku Decree. Kano Nana had rambled about Thunder Sakura on Kannazuka during the war—stuff Sayu hadn’t bothered to think too hard about because it wasn’t her job. Then Heizou recounted all this stuff and more on the way here, explaining how it tied together, and Sayu didn’t have his genius intuition or whatever so she just languidly collected whatever pebbles of disconnected information she caught. She was unprepared.

They should have sent someone else. Anyone else but her. Someone taller, someone braver. Sayu hated that she was the one walking through this fog—hated the thought that she might be the only one to come back out of it. 

“Sayu, slow down—”

It was so stupid. She hardly knew Heizou. He was the distant cousin of the bane of her existence and he could be an annoying disturbance in his own right. Weaponized incompetence and not showing up for work were the only things they shared. 

… Well, that Vision she kept hidden matched hers exactly. So long as its glow was sustained, or she didn't look at it.

Visions, Visions, always about Visions. She’d never given hers up, only because the Shogunate never knew she had one. The Guuji Yae’s people didn’t tattle to them. The Shuumatsuban weren’t on any exemption lists because they didn’t exist. They were shadows. Not even lightning could strike what it couldn’t see. 

Sayu reached the island’s edge. The waves lapped close to her shoes, and the fog gained the ocean’s saltiness. She’d promised herself she’d check the Vision here—that was the point.

She looked out over the ocean. The fog thinned at the rocky shore, like the island’s creepy infested blanket pulled back just enough to show the glistening blue of Sea Ganoderma just under the water’s surface—slick and bright and not the souls of drowned kids.

The Vision weighed down her pocket like a stone. She hardly knew Heizou. If the Vision was dull now it meant he was gone. Simple. Kano Nana would mourn her cousin probably—definitely. They were close. But did Heizou have anyone else? He probably had other family, right? He bragged about being unliked by his co-workers, but they would probably be unhappy if he was gone. Did Heizou have friends that would mourn? There was the Arataki Gang if that counted. Then that one guy from the Bantan Sango Detective Agency who spoke to Heizou in Ritou. And that quiet ronin—one of the few people to have Sayu’s full approval because despite all the drama he apparently caused the Shogunate, she mostly only ever saw him napping in trees or on rocks.

So at least three people back home would be hurt if Sayu failed to find Shikanoin in time. Then some more probably just because he was famous for catching criminals and doing half the Tenryou Commission’s work. But if he didn’t have many people close to him, there were less people who’d really grieve if he died, right? In any case, it didn’t matter because if he already died then he was already dead and then Sayu would have to re-evaluate her goal here.

Sayu pulled out the Vision.

Relief slammed through her at the sight of that faint turquoise glow. Dimmer than before. Brighter would have been better, but dim was still good, she told herself. Did that mean she was right—that it glowed brighter the closer it was to its master? Yes: evidence to support her theory. Theory that would help her find them. She would find them.

Sayu turned. Ruu was perched on a rock behind her, swaying like a songbird on a windy day, watching her with wide, worried eyes.

“Let’s go back,” Sayu decided. “Show me exactly where you found this.”

“Did you learn something? Do you know how to find them?” Ruu asked, hope creeping into his voice.

Oh. Sayu silently added Ruu’s name to the crude mental list of people who would be hurt if she failed to save Heizou and the scholar lady. But that list didn’t matter because Heizou wasn’t allowed to die, and now Sayu was doing his stupid job for him. She held up the Vision for Ruu to see. “It’s dimmer here. We’re farther away.” 

Ruu hopped off his rock and asked, “the gem glows brighter the closer you are to Heizou?”

“Yes.” Sayu tucked the Vision back out of sight before she could lose her nerve. “When the omnipresent god statue was being filled with Visions, the ones from people who left to join the Watatsumi resistance were always dimmer.”

She never saw the statue up close, but she’d heard. She really hoped the faintness was related to distance and not… life force or something.

“We’ll find them,” Sayu said, forcing the words to be solid. She would find them. She wasn’t useless—not when she really tried—and if Heizou was alive, he'd be working just as hard. 

“What if they find us first?” Ruu said quietly, and it sounded kinda like a joke, but Sayu groaned, entirely serious when she said,

“Then I might forgive him eventually if he also solved everything so we can get off this creepy island and go home.”

Ruu nodded silently. He dragged his feet, scattering pebbles along the shore.