Gray-3 didn't get earthquakes.
Not real ones.
The Tower shock dampeners made sure of that. Anything big enough to rattle foundations was soaked up, diffused, turned into a faint vibration you only noticed if you were holding a glass of water just right.
So when the floor in Kael's apartment shivered hard enough to slosh his tea, his first thought wasn't "earthquake."
It was: System event.
His UI confirmed it a heartbeat later.
[LOCAL ALERT: SUBTERRANEAN INFRASTRUCTURE FAILURE – GRAY-3 BLOCK 11.][POSSIBLE CAUSES: SEWER MAIN COLLAPSE, OLD TUNNEL SHIFT, TOWER DAMPENER MALFUNCTION.]
Haneul, mid-yawn on the couch, froze.
"Was that…?" she started.
"Not Root," Kael said, scanning. "This is local. Old tunnels."
Another ping.
[EVENT: UNMAPPED HOLLOW DETECTED BELOW RESIDENTIAL + COMMERCIAL ZONE.][TAG: "TOWER-ADJACENT ANOMALY."]
He swore.
"Towers aren't supposed to have basements," he said.
Haneul sat up fully, blanket pooling in her lap.
"You mean like the sealed floor in Thirteen?" she asked.
"Maybe smaller," he said. "Maybe worse."
Mira's ID started blinking in his chat before he could ping her.
Stay put, she wrote. I'm on my way up.
He stood anyway, adrenaline stirring.
"TRI's calling?" Haneul asked.
"More like shouting," he said.
Mira arrived fast enough to make the elevator suspicious.
She didn't bother sitting.
"There's an old pre-Tower tunnel network under Block 11," she said. "Mostly collapsed, mostly mapped, mostly sealed."
"Mostly," Kael repeated.
"Tower Seventeen's dampeners picked up a localized shock there," she said. "An empty space shifted. Then the System tagged it as 'Tower-adjacent.' That tag doesn't fire easily."
"What's down there?" Haneul asked.
"Old infrastructure, maybe," Mira said. "Maybe an abandoned Node. Maybe an early experiment from the first generation of Tower engineers. ADMIN_0's era."
Kael's stomach sank.
"Don't tell me it's another legacy Node," he said.
"We don't know yet," she said. "TRI's sending a mixed team down. Structural, Guard, one Observer, one EMS unit on standby."
"Let me guess," Haneul said. "You want the bug."
Mira met Kael's eyes.
"You're the only Executor I trust to not poke something until it explodes," she said. "Also the only one whose vector plays nicely with civilian infrastructure. If there's a Node down there, I'd rather you see it first."
He hesitated.
"What about Haneul?" he asked quietly.
Haneul snorted.
"I'm not going into a collapsing tunnel with a fresh hospital discharge tag," she said. "I'll watch from here. Nagging you remotely is my calling."
Mira exhaled.
"Seori's unit got the EMS call," she added. "You might bump into her. Don't spook her with Executor talk unless absolutely necessary."
"New Evaluator?" Haneul said.
Kael nodded.
"City paramedic. Good instincts," he said. "Fine. We keep it light."
He grabbed his shield and jacket.
As he headed for the door, Haneul called after him:
"Hey."
He turned.
"Remember," she said. "Local first. If you find anything that wants to eat the whole city, don't argue with it alone."
He smiled, crooked.
"Noted," he said.