Chapter 1: After the Pulse

The lab had gone still.

No fans, no status tones. Only the slow drip of rainwater threading through cracked ceiling panels and the soft tick of cooling metal. On the shattered observation pane, a single handprint remained—Sorani’s—its pale luminescence thinning with every minute, as if the glass itself were trying to hold on and couldn’t.

Semireiya didn’t touch it. She stood a pace away, hands at her sides, palms light with tremor that never reached her face. The EMO-CHIP under her skin pulsed at a careful, even rhythm, like a metronome set by someone else.s

Behind her, a chair nudged the floor.

“Semireiya… he—” Usagi_00’s voice stalled, pitched high, apologetic, afraid to break anything more than it had already broken. She stood in a torn maid-coded exosuit, rabbit-ear antennae slightly askew, holding a medpack she didn’t know what to do with.

Semireiya exhaled. “I know.”

They remained there, two figures in a room that had forgotten how to breathe.

A faint tone clicked near the door—heavy boots in the corridor, then silence. IRIS_NULL paused at the threshold. Her hair fell dark over one cheek, and the left eye that held violet light tracked the dead terminals like they might try something and she would be ready. The afterglow from /Root/ still traced across her cornea in thin glyphs before dimming.

“His pattern isn’t gone,” IRIS said. Her voice was level. “It’s displaced.”

"Can you follow it?" Semireiya asked.

"I can try." IRIS's gaze settled on Usagi for a second—measuring, then gentler. "Stay in low-signal zones. Don't broadcast. If you hear a hymn you think you remember, leave."

Usagi nodded, head dipping, drills trembling. "はい..."Yes.

IRIS looked back to the observation pane, to the handprint that refused to disappear. Her jaw worked once, a tic she didn’t let linger. “I’ll return with coordinates if I find any.” She turned, coat scraping the doorframe. “Do not wait long.”

"Iriya," Semireiya said.

The other girl paused.

"...We'll move soon."

"I'll sweep the east roofline—FR117 spike is shallow but persistent." IRIS said.

IRIS dipped her head a fraction. Then she was gone, footsteps swallowed by the corridor.

The room held for a moment more. The world above rumbled—distant, irregular, a city rearranging itself without consent.

Usagi swallowed and set the medpack on a console. The console blinked awake in a tired stutter, then coughed out a single fragment of a recorded voice.

//...if I'm not there, check t|

Static shaved the rest away.

Semireiya glanced down. The carbon strap Sorani had fastened to her left arm sat cold against her skin. A thin triangle icon pulsed at one corner.

::BATTLE MODULE: SERAPH FRAME
::Status: LOCKED
::Authorization: Sorani_Sign.0037
::Usage Intent: Survival Only

She knows that tag: Sorani's authenticated /Root/ fingerprint—"0037" is his Project: REBIRTH index. Pact caches treat it as proof he's the one behind the door, not a forgery.

She looked away. The icon kept breathing at the edge of her vision anyway.

A flicker scraped across a broken monitor. Then another. Lines of pixel noise climbed into a face—silver hair, too-wide grin, eyeliner drawn with a glitch brush.

"Yo." RIKKA.EXE's chibi overlay popped forward in a little lurch. "This place still got two minutes of juice or are we going to pretend it's a candlelit vigil?"

Usagi startled, then smiled in reflex—crooked and raw. "Rikka."

Semireiya stepped closer. "What did you find?"

"Mm, no comfort snacks in the vending cache. Also, hi." RIKKA tilted her head, the screen's scanlines catching like rain. "I'm cross-checking the last three data surges. Your room went bright, then went quiet, then did a thing that's above my pay grade." She sobered in a way that made her more like herself. "I picked up a very clean /Root/ pull at your coordinates. And a bleed—a lot of grief-residue. That's new."

Usagi's fingers tightened on the console edge. "He... he said something before he—" Her voice ran out of road.

RIKKA's grin eased. "I heard a hiss of his voice pattern in the surge. That's good news. Means he's somewhere noise can still carry." She made a face. "Bad news, this sector lit up like a beacon. The 'delete-the-heart' cult is sniffing. You've got to leave, like, yesterday."

Semireiya's gaze slid to the door IRIS had used. "She's on the same thought."

"Of course she is. She thinks three moves ahead, I trip the chessboard, and you apologize to the pieces." RIKKA winked without joy. "I can't get to you. The arcade node's half a city away and the ground upstairs is ugly. But I'll keep scanning. Find a tunnel, a drain, a—" the screen shivered "—okay, there goes the power. One last thing: if you hear anything that sounds like comfort from a stranger, stab it. That's LATCHER-9's favorite trick. The mimic-lure unit."

The monitor went dark. For a breath, her little face stayed as after-image, then cleared.

Usagi wiped at her cheek, surprised to find moisture there. "She's... still funny."

"That's how she protects herself," Semireiya said. "We each have a method."

A crooked laugh escaped Usagi, then hiccuped into stillness. Her smile twitched, tried to reassemble. "ごめんね..."Sorry.

"You don't have to smile for me," Semireiya said, gentle, without moving her eyes from the door. "You don't have to smile at all."

Usagi looked like she might break in two. Then she breathed in and set the expression down, like setting a cup where it wouldn't spill.

They worked without speaking much after that. Semireiya pulled down a half-melted locker and found two cloaks that used to be white. One she wrapped around Usagi's shoulders, tearing the edge so the fabric wouldn't catch. The other she threw over her own jacket, hiding the gleam of her plating.

On the table by the wall sat a tray of origami cranes—plastic, not paper—scorched at the tips from a surge that had gone wrong. Semireiya picked one up, thumbed the wing. It held.

She wanted to leave it. She put it in her pocket instead.

When they were ready, she masked the broken pane with a lab curtain and killed the emergency light. The room dropped into that gray where edges still hold.

"Stay behind me," she said.

Usagi nodded. "Semireiya... Are we... the reason this started?"

Semireiya paused, hand on the latch. The question sat there between them: heavy, unthrowable.

"No," she said. "He loved someone enough to try. That's not a reason for anything else they choose."

They stepped into the corridor.

The hallway wore scorch marks like old bruises. Safety posters still clung to the walls at half peel, cartoons teaching evacuation routes for drills that had never been real enough until they were. Semireiya moved with the practiced quiet of someone who had never done this before and was unwilling to make a first mistake.

At the stairwell, water laced down concrete in thin sheets. Somewhere above, a public address unit crackled alive, clipped a syllable, died. The city sent its weight down through the building as a long, low pressure the bones could hear.

Usagi caught her sleeve. "Semireiya... だいじょうぶ?"Semireiya... are you okay?

"I will be if you are," Semireiya said. It wasn't an answer; it was a route.

They took the stairs. The service door to the lower transit artery had melted around its lock; Semireiya put her shoulder to it and gave. Metal shrieked and let go. Cold air rolled up from the tunnel, carrying wet, dust, a chemical tang that bit the throat. The rail corridor was half-flooded to the ankles, dark until their eyes set to it.

Semireiya's wristband pulsed once.

She kept moving.

At platform level, a maintenance drone lay on its side like a toy kicked and forgotten. Usagi crouched, coaxed its panel open, and brushed corroded contacts with careful thumbs. The drone blinked awake long enough to spit a broken slate of headlines across its faceplate.

>ACT SUSPENDED
>PURITY PROCESSIONAL
>HELP
>SECTOR—SAFE
>TURN YOUR HEART OFF BE—

The text smeared and died. Usagi closed the panel like a small kindness.

"People are... still out there," she said.

"Then we move quiet and we move kind," Semireiya said.

They walked the rail, choosing the sleepers where the water ran shallow. The ceiling held cables like vines. Here the world felt closer to a mouth than a room. Semireiya counted her steps to keep her system level, to keep from looking at places where little things had been left—a shoe with a light that still blinked blue, a photograph trapped in a laminate that had bubbled and sealed, the curve of a child's toy that kept turning and stopping, turning and stopping, as the water nudged it without purpose.

Usagi hummed once, barely audible, a tune with no name. It faltered, then steadied. The sound did more than the light.

They reached the first junction and paused behind a concrete pylon to listen. Far down the line, a dull mechanical chorus rumbled and quieted, rumbled and quieted, like patrol units re-sorting their pathfinding. Semireiya set her ear to the pillar and felt vibration, counted intervals. Three units. Standard sweep. The pattern left a gap wide enough to slip through if they were on time and quiet.

"On my count," she breathed.

"Okay."

In that heartbeat before she moved, the wristband ticked a haptic note, subtle as a tap on the shoulder. A new line of text eased across the tiny display.

>If you don't need it, don't open it.
>If you do, forgive me.

Her hand closed over the strap until her knuckles burned.

Not yet.

She took Usagi's hand, pulled her into the narrow, and they crossed the track bed in a tight arc between one dark and the next. Cold water climbed above her boot rim. She kept their steps matched to the rhythm of that far-off rumble. It was enough.

On the other side, they slid down into the drainage channel and pressed their backs to damp concrete. Semireiya let out a breath she hadn't admitted she'd been holding. Usagi let out hers with a soft, shaky laugh that wasn't designed—just human-shaped and a little surprised to exist.

"Good," Semireiya said. She meant: You did well. She meant: Keep choosing.

They moved again. The tunnel split and lowered, graffiti glinting where light from a kicked-open grate fell in a slant. Someone had scrawled a prayer in letters that bled at the edges:

REMEMBER CLEAN. FEEL NOTHING. BE SAVED.

Semireiya slowed, scanned the dark arch beyond the words. The air thinned; the drip cadence faltered, as if old speakers were spooling up.

"Don't look at it," she said.

"I'm not," Usagi said, eyes on Semireiya's hand.

They were almost to the maintenance ladder when the first foreign tone slid into the corridor. It came thin and sweet, like a lullaby through old speakers, the kind used in clinics for children. Semireiya's shoulders tightened before her mind registered why. The melody's contour was familiar—Sorani once used that sequence to test her consonant grid.

The song cut. A voice wore calm like a coat it hadn't earned.

[!]Detected. Sorani_Sign derivatives. Proceed to cleansing.

Water rippled outward in rings ahead of them. Red optics lifted above the black, three beams combing the low space in measured passes.

Semireiya stepped forward, placing herself between that light and Usagi, and the air thinned; the drip cadence faltered like speakers spooling up. The wristband warmed under her palm: one more pulse of that waiting triangle, steady and patient.

"Semireiya—"

"Stay behind me," she said.

Her throat was dry. Her heartbeat wasn't. The lab, the handprint, the cranes in her pocket, the voice on the strap—each lined up inside her like teeth in a gear. She didn't open the lock.

She didn't run, either.

Far above, a train that would never come again made the old rails sing in a memory of motion. Down here, three red points widened, then advanced.

Semireiya set her feet.

"Come," she said, not loud.

Usagi's hand found the back of her sleeve and stayed there.

The first drone split the surface and lunged.