The deployment pod disengaged with a pressurized crack.
Caleb hit the floor of Sector Four's subterranean transit line in knee-deep water.
Cold runoff splashed over his surplus gear and soaked through the canvas trousers immediately. Rust, stagnant mildew, and ozone filled his filters. Above them, reinforced bedrock groaned under the distant weight of the Class-Eight Titan moving through the surface streets.
The behemoth's sound never reached the tunnel, but its pressure did: a slow, god-sized weight pressing through the earth and making every support pillar complain.
Emergency floodlights flickered along the curved concrete walls. Shadows stretched over flooded rails and broken service platforms.
Vice Captain Iris Calder splashed down ahead of the formation.
Her phase-blade came alive with a white hum.
"Lock the perimeter," she said over tactical link. "Rookies behind shields. Hold the choke. You do not break the line, and you do not chase stragglers."
Caleb waded forward.
The water dragged at his shins. The surplus armor dragged at everything else.
He took position behind a towering veteran carrying a tungsten ballistic shield. Hiro flanked left, breathing too fast over comms. Iharu Furuhashi held right, scatter-gun ready and jaw tight beneath the bandage across his nose.
Caleb brought his rifle up.
The suit's one-point-two percent kinetic assist whined through his arms. Not enough to make him strong. Just enough to keep the fifty-pound barrel from sagging into the water.
The veteran ahead of him shifted the shield by inches, not feet.
Caleb noticed that. Good shield work had no drama to it, only boredom with correct angles. The man kept the lower lip of the tungsten plate dug into the rail bed, turning his body into a hinge. Every rookie behind him lived or died by whether that hinge held.
"Stay on my right shoulder," the veteran said without looking back. "If you see water move against the current, call it."
"Copy."
"If you panic, do it quietly."
"Also copy."
His ribs throbbed from the morning drills, and he filed the pain somewhere useless for later.
"Contact," a point veteran called. Chittering bounced off the tunnel walls.
The sound multiplied until it became a metallic scream.
Scavenger-class Yoju burst from the darkness.
They were the size of starving wolves, with segmented black exoskeletons scraping along rusted rails. They were not charging because they saw prey. They were fleeing the Titan above, flooding the underground the way smoke found cracks.
"Hold," Iris ordered.
The swarm closed.
The water churned white beneath them.
Acidic blood and wet chitin hit the filters thick enough for Caleb to taste the idea of rot.
Hiro's rifle barrel trembled against Caleb's shoulder plate.
"Twenty yards," the shield veteran said. "Fire."
The shield wall slammed down, and gunfire tore through the enclosed space.
Caleb pulled the trigger and let the veterans' tracer lines guide his first burst. Heroic targets could wait; he fired into the places where the horde was densest and where bodies would trip bodies.
The first lesson came fast.
Tunnel fighting worked like carpentry with bullets: build a wall, repair the gaps, keep the pressure from finding a seam.
Every time a Yoju corpse floated high enough to give the next wave a ramp, Iris or one of the shield veterans kicked it aside. Every time a rookie fired too high, a veteran's bark snapped him back to center mass and leg joints.
Nobody had room for glory. That helped Caleb. Glory had never paid him on time. Chitin shattered. Black fluid sprayed.
The recoil punched into his shoulder socket until pain bloomed under the healing collarbone.
The public broadcast icon glowed green in the corner of his visor.
Six thousand viewers.
Chat crawled past the edge of his sight.
User402: Seventh always gets the worst deployments.
GunnerFan: I cannot see the back of the swarm.
TitanSlayer: Calder is carrying the flank.
Credits, Caleb reminded himself. Not praise. Credits. He kept the thought ugly on purpose.
If he let the chat sound like admiration, it would distract him. If he let it become money, it became useful. Every viewer was a fraction of rent, a fraction of medicine, a fraction of another month where his mother's door stayed untouched.
The tunnel ignored all of that, so Caleb cared harder.
He ejected a spent magazine. The hot cylinder steamed when it hit the water. Fresh mag in. Bolt racked. Barrel back up.
A tremor shook the tunnel.
The Titan shifted above them.
Water surged another inch up Caleb's legs and stole his balance for half a second.
"Reloading!" Iharu shouted.
The redhead dropped to one knee and fumbled shells from his bandolier.
Caleb shifted sideways and changed his firing angle to cover him.
"Do not make this emotional," Iharu snapped.
"Then reload faster."
A crawler vaulted the shield wall, using the bodies of its own swarm as a ramp.
It came down at Hiro.
Mandibles snapped inches from his visor. Hiro stumbled back, boots slipping in muck. He pulled the trigger.
Empty click.
Caleb dropped his rifle onto its sling and drew the combat knife.
Five years in disposal yards took over.
He skipped the skull, stepped inside the guard, and drove the blade under the primary jaw hinge, into the pale membrane hidden beneath the plates.
His wrist twisted.
The jaw unhinged with a wet tear.
Caleb pivoted, borrowed the heavy suit's momentum, and drove his boot through the compromised knee joint. The crawler collapsed into the floodwater, thrashing black fluid across Hiro's chest plate.
Caleb grabbed Hiro's harness and hauled him upright.
"Ammo counter before sightline," he shouted.
Hiro nodded hard, face pale behind the visor, and slammed a new magazine home.
Caleb dragged his rifle back up.
Pain tore through his right shoulder.
The knife work had pulled stabilizing muscle against the healing collarbone.
Heat ignited behind his sternum.
The thing inside him woke to damage.
Starvation opened in his stomach like a trapdoor. Acid climbed the back of his throat. The anomaly demanded fuel to repair tissue, and his body had almost nothing left to give.
His vision blurred.
Knee-deep water. Live rifles. Swarm pressure.
Passing out here meant dying face-down in runoff.
He forced oxygen through his nose and checked the corner of his visor.
Fourteen thousand viewers.
Scrap_King: Did the scrubber just melee a crawler?
RedLine: He cut under the jaw. Bypassed armor.
G-Corp: [Automated] engagement spike detected.
GunnerFan: 1.2 sync and brawling in mud.
The algorithm caught the spike.
"Maintain spread!" Iris shouted, cutting another beast from the air. Her armor was stained black. "Do not let the bodies pile high enough to compromise shields. Push them back!"
The shield veteran in front of Caleb grunted and shoved forward three steps.
Caleb moved with him.
Hiro followed half a step late, then corrected. Iharu's scatter-gun boomed to the right, tearing two Yoju off the wall before they could drop behind the line.
For the first time since drop-in, the squad moved like a squad: ragged, ugly, and enough.
Caleb braced the rifle against his aching shoulder. His limbs had gone hollow.
The tunnel narrowed to recoil, breath, and the math of survival.
He squeezed the trigger.
The slaughterhouse carried him forward.