[Strider Room – Aethertech Academy, Afternoon]
The low hum of massive engines echoed gently across the steel walls. The air inside carried a dense mix of oil, heated metal, and the faint smoke of still-running coolant systems. Rows of Striders stood side by side along the hangar, bathed in the pale glow of cold white lights overhead.
Kaito walked slowly beneath the towering shadow of the Lellium-37 Strider's steel legs. His footsteps rang softly against the floor, his dark navy coat rippling as a draft from the ventilation shafts swept through the narrow aisle between machines.
Harusa looked up, eyes wide with awe.
"Whoa… it's huge. This thing's even taller than the Juantice Tank," she murmured, her eyes glimmering with amazement.
Rio, standing beside Kaito, was too busy checking the data on his modified smartwatch.
"Twelve meters tall, model Lellium-37. Dual-plasma core reactor…" he mumbled. "Its power regulator's design… it's almost identical to my old project."
Ahead of them, a short-haired boy stood atop a maintenance platform beside the Strider. He wore a gray mechanic's suit, a tool belt around his waist, and a glowing 37 insignia on his chest.
"Zero!" Rio called out.
The boy turned from the Strider's mechanical arm he'd been working on. His face was young — maybe fourteen — but his eyes were calm and focused like a seasoned technician's.
"Oh, Rio. Haven't seen your face in the Strider Room for ages," Zero replied casually, lowering the wrench in his hand. He jumped lightly from the platform, landing on the metal floor with a soft clang.
Kaito watched his movement.
"Good landing," he remarked simply.
Zero smiled politely.
"Thank you, sir… You must be the new Flying Teacher, right? My name's Zero, operator of Lellium-37."
Kaito nodded. "Major Kaito," he said in a calm but firm tone. "New Flying Teacher — Alke's replacement. And don't call me 'sir.' Just 'Teacher.' Makes me sound less ancient."
Zero met Kaito's gray-silver gaze for a second — it sent a slight chill through him — but he quickly smiled again.
"An honor to meet you in person, Teacher."
Meanwhile, Rio had already projected a holographic display from his wristband.
"Zero, I need to ask you something. You know where Sigma's Strider — the Hugo unit — is parked, right?"
The question made Zero's hand freeze mid-air. The smile on his face faltered slightly.
He glanced at Rio, his expression sharpening.
Zero's thoughts:
❝Why is he asking about Sigma all of a sudden? Wasn't Rio the one who swore never to speak that name again… after the Invisible Power project failed?❞
Zero tilted his head slightly.
"Didn't you… stop caring about him? After he ditched you and the Invisible Power project?"
The hum of machinery seemed to pause with that question. Harusa turned toward Rio, curious.
Kaito said nothing — only watched the exchange with a cold, unreadable calm.
Rio didn't answer right away. He exhaled slowly, eyes locked on the holographic map of the hangar.
"Listen… I don't care about that project anymore. But Sigma's Strider still has an old archive that was never wiped. That archive's the only lead I have to find Harusa's sister."
Zero's gaze shifted toward Harusa, who now stood firmly beside Kaito, her face resolute.
"I see…" he murmured softly, lowering his head.
He walked to the console near Lellium-37 and typed a rapid string of commands. Clicks and beeps filled the air between bursts of hissing steam.
A few seconds later, the screen flashed an access code:
GARAGE 79 – STRIDER HUGO (SIGMA).
Zero turned back to them.
"Sigma's Strider is still stored in Garage 79. But be careful — someone tried breaking into that section last week. Security's tight now."
He reached into his pocket and pulled out a black access card, a small golden chip embedded in its center, marked SH54 in the corner.
"Take this," he said, handing it to Rio. "It's the key to the lower garage. I don't know what you're looking for in there, but…"
His gaze softened, meeting Rio's directly.
"…I hope whatever's left of your friendship — can still be repaired."
Rio took the card slowly, staring at it for a moment. The white lights reflected off the golden chip, flickering across his face. His expression was unreadable — somewhere between anger, longing, and regret.
Kaito gave him a light pat on the shoulder.
"Let's go. Before Aru finishes her observation."
Harusa adjusted her cap and slung her weapon over her shoulder.
"Garage 79, huh? Alright then. Let's hope Sigma's Strider isn't buried under a ton of dust."
Rio gave a faint smile, stepping forward.
"Trust me… dust isn't what worries me. It's the memories still clinging to that place."
Zero stood in silence, watching the three of them disappear into the dim corridor lit by amber lights. Their footsteps echoed between the rows of massive steel machines, blending with the low drone of turbines and the whisper of cold air from the vents.
---
The air inside was warm and slightly dusty — yet strangely, not a speck of grime touched the Strider itself.
Flickering ceiling lamps cast a pale glow across the massive silver-blue frame of Hugo, standing still at the heart of the room.
Kaito, Rio, and Harusa stopped before the heavy door.
A sharp click–zzzt! filled the silence as Rio pressed the SH54 card to the magnetic scanner.
The garage door opened slowly. A cool metallic scent washed over them — no rust, no decay, as if the place had been used only yesterday.
Harusa stepped in first, eyes widening at the sight of the Strider's exposed skeleton — thick cables hung down like metallic veins.
She crouched and nudged a loose bolt with her boot.
"You sure this thing's abandoned, Rio? The floor's spotless. Feels like someone just used this place last night."
Rio walked toward the workbench in the corner. Amid scattered blueprints and rusted screws stood a small photo frame.
It showed Rio and Sigma — both young, both grinning like overconfident scientists — standing in front of the same Strider when it was still intact.
Rio fell silent. His hand trembled slightly as he lifted the frame.
Kaito spoke in his usual calm tone.
"You knew him well, didn't you? Sigma — the one who built Hugo."
Rio stared at the photo for a long moment, then smiled faintly — almost bitterly.
"More than well. We were friends — two maniacs who thought we could defy the laws of physics."
Kaito leaned against another table, his eyes steady but softened with quiet understanding.
Harusa lowered her cap slightly, watching Rio with gentle concern.
"What happened between you two?" Kaito asked.
The ceiling fan rotated slowly, filling the silence with its dull whir. Rio took a deep breath.
"We built something called Project Invisible Power — a system that could make an object disappear from reality and return it unharmed. A crazy idea, one even Aethertech's council wouldn't fund."
He let out a small, humorless laugh.
"We worked for weeks without sleep. But every test failed. The system kept rejecting reality itself. Sigma… he started losing patience."
His voice grew softer.
"That day, he punched me. Not because he hated me — but because he hated himself. He said I was too 'normal.' Then he left. Never came back to the lab. No calls, no messages. Just one note—"Reality is just a bug, Rio. I'll patch this world myself."
Silence. Only the fan and the distant groan of metal filled the air.
Kaito bowed his head slightly.
"Maybe he still wanted you to finish the device."
Harusa smiled faintly, patting Rio's shoulder.
"Yeah. Maybe it's not too late to debug that friendship of yours."
Rio chuckled softly, though his eyes remained dim.
"Heh… maybe."
He switched on the old computer on the workbench. The green CRT screen flickered to life with a piip–bzzzt!, displaying the aged Aethertech logo.
His fingers danced over the keyboard, summoning old Strider data.
Kaito narrowed his eyes at the display.
"It's still active? Sigma's internal access wasn't revoked?"
Rio frowned.
"That's the weird part… His last login was three days ago."
Harusa straightened abruptly.
"Three days ago?! You mean Sigma's been here recently?"
Rio froze, eyes widening as he read deeper into the data.
"…Or someone used his ID."
Kaito turned toward the motionless Strider Hugo — its blank metallic face seemed to be staring back at them.
"Or maybe," Kaito murmured, "Sigma's not done patching his version of the world."
A breeze swept through the half-open garage door, scattering blueprint papers across the floor.
On the flickering screen, new text appeared — faint, broken lines forming a chilling message:
"HELLO_RIO_its_me_Sigma.EXE"