The rain outside Luma Labs hadn't stopped.It fell in slow, slanted ribbons across the mirrored windows, washing the neon signs into streaks of light.
In the underground lab, the air smelled of ozone and dust — the kind of stillness that only existed before something woke up.The monitors hummed softly.And on the central console, the old prototype clock — the one that wasn't supposed to exist — began ticking backward.
11:59:59 → 11:59:58.
The hum turned into a faint heartbeat.A sound Ha-rin didn't just hear. She felt it — deep, low, like a pulse crawling under her skin.
She leaned closer, watching the second hand move in reverse."It's not a glitch," she murmured. "It's remembering."
Behind her, Jae-hyun's reflection flickered faintly on the glass wall — one silver flash, then gone.He stood a few feet away, sleeves rolled up, hair messy, eyes sharp in that unreasonably distracting way he had when he was focused.
He looked at her, tone calm but edges frayed."Echo's always tied to emotional states. You and I just signed a contract we don't fully understand."
She arched a brow. "You think our fake marriage is making time nervous?"
He smirked faintly. "Wouldn't be the first time we broke reality by holding hands."
Seo-jin, pacing with a clipboard, groaned. "I swear, you two flirt like the universe depends on it."
The lights flickered once.A soft chime echoed through the lab — the system voice of Echo, distorted but recognizable:
"AUTHENTICATION COMPLETE. PRIMARY CONSTANTS REBOUND: KANG JAE-HYUN. YOON HA-RIN."
Ha-rin froze. "Rebound?"
Jae-hyun turned to the console, eyes narrowing. "It's binding us to the system again. Like it did the first time."
Seo-jin backed up toward the elevator. "Right, so… congratulations, you're now literally married to a quantum clock. I'm gonna get snacks."
The doors closed before Ha-rin could throw a wrench at him.
The hum deepened, threads of light spilling from the console like liquid silver.The patterns crawled along the floor, winding toward Ha-rin's shoes before fading.
She knelt to examine them. "It's… reacting to us."
Jae-hyun crouched beside her, close enough that his breath brushed her temple."The Echo core's syncing with our biometric signatures. It sees us as one unit now."
She turned, voice low. "You're saying it recognizes our contract?"
His lips curved slightly. "Apparently, the machine ships us."
Ha-rin shot him a look, but she couldn't hide the way her mouth twitched upward.Even after two timelines, he could still disarm her with a single line.
The clock's glow pulsed again — brighter this time.And then, across the room, one of the dormant monitors lit up, lines of code scrolling too fast to read.At the top, in red text:
"Twelve Constants Detected — Synchronization in Progress."
Ha-rin frowned. "Twelve? But there's only two of us."
Jae-hyun's expression darkened. "Then someone else is still linked."
He typed rapidly, tracing the source.The display fractured, then stabilized into an image — a digital map of twelve glowing points, each one pulsing in different parts of the city.
Ha-rin's stomach dropped. "These are—"
"Replicas," he finished quietly. "The earlier test subjects. Echo copied pieces of them during the trials."
Her voice shook. "You mean… they're alive?"
He hesitated. "Not exactly. They're fragments — memories given body."
Ha-rin's hand drifted toward the screen, fingertips brushing the glowing lines.The nearest pulse blinked faster, responding to her touch.
Jae-hyun caught her wrist gently."Don't connect yet. We don't know what happens if you do."
She looked up, eyes searching his. "You came back wrong once, remember? Maybe this is their chance to come back right."
He sighed. "You never could walk away from broken things."
Her smile was small, bittersweet. "That's why I found you."
The words hung between them — fragile, dangerous.Something inside him softened; the glow under his skin flared faintly.He raised his hand, hesitating before brushing a strand of hair from her face.It was such a simple, human gesture — but her pulse raced as if time itself paused to watch.
"Ha-rin," he whispered, voice rough. "If this goes wrong, promise me you'll run."
She met his gaze, unwavering. "I didn't come back to run."
For a heartbeat, the air shifted — that quiet, electric tension that always lived between them.Not loud, not desperate — just the soft gravity of two people who'd found each other through too many timelines to let go.
Then the console chimed again.
"SECONDARY CONTRACT INITIATED."
Ha-rin blinked. "What now?"
A document appeared on the screen — not legal text, not code, but something else entirely.
In glowing letters:
"To preserve continuity, one constant must surrender twelve minutes of memory."
Jae-hyun stared. "It's asking for a sacrifice."
Ha-rin's voice cracked. "Whose memory?"
He looked at her. "Whoever signs first."
For a moment, neither moved.The hum of the machine filled the silence like a heartbeat counting backward.
Ha-rin's hand trembled, hovering over the console. "Maybe if I—"
Jae-hyun's hand closed over hers. "Don't."
"Someone has to—"
"I already lost you once," he said softly. "You're not vanishing again."
Her eyes shimmered. "And you think I could live knowing you forgot me?"
His jaw tightened. "Then we find another way."
The monitor flickered, red text flashing like a pulse.
TIME REMAINING: 12:00 → 11:59
Ha-rin whispered, "The countdown's started."
He reached for her, fingers brushing hers as the lights dimmed.Every clock in the lab began ticking backward.Their reflections in the glass walls shimmered — not dark, not bright, but different.
And for the first time, Ha-rin saw their mirrored selves move before they did.