The Battle for the Underground

Chapter 15: The Battle for the Underground

The underground base shook violently as the alien creatures hammered against the outer defenses. Dust and loose debris fell from the reinforced metal ceilings as warning lights flickered. Ethan stood firm, his hands clenched into fists, staring at the live feeds on the command center's massive holographic display.

"Status on Project Titan?" he asked, voice cold and controlled.

[PROJECT TITAN BOOTING UP… 87% COMPLETE.]

Michael Reyes worked furiously at his terminal, his brow damp with sweat. "Almost there! Just a few more seconds!"

But they didn't have seconds.

The first breach occurred.

First Blood

A massive, clawed hand smashed through the outer wall of Corridor 3C. Sparks flew as chunks of reinforced metal were torn away like paper.

The creature didn't crawl inside like an animal—it stepped in, towering at nine feet tall, its metal exoskeleton glistening under the dim emergency lighting. The glowing blue veins pulsed rhythmically, like a beating heart. Its four arms flexed, the upper limbs sporting razor-sharp scythe-like appendages, while the lower arms curled into clawed fists.

"Turrets, engage!" Laura yelled.

The automated defense system opened fire. Heavy-caliber bullets and plasma rounds pounded into the creature's metallic body, but instead of crumbling under the assault, it merely staggered back, its glowing veins pulsing brighter.

"It's absorbing energy," Michael breathed.

The alien let out a deafening screech before lunging forward at unnatural speed.

A single swipe of its scythe-arm sliced through the first turret, melting the reinforced alloy as if it were ice under a blowtorch.

Another plasma blast struck its chest, but instead of penetrating, the creature absorbed it—its body pulsing again before it redirected the energy, firing it back as a concentrated shockwave.

The explosion sent Laura flying across the control room.

Ethan rushed to her side as she groaned, shaking off the impact. "I'm fine," she gasped. "But those things… they adapt too fast."

Project Titan Awakens

[PROJECT TITAN FULLY ACTIVATED.]

A loud hiss of hydraulics echoed through the underground hangar as the war mech stepped forward, its eight-meter-tall titanium frame gleaming in the dim lighting.

Its twin plasma cannons hummed with raw power, and its reinforced energy shielding flickered to life.

"Titan, engage the hostile," Ethan commanded.

The mech's AI-driven targeting system locked onto the alien.

A high-pitched whine filled the air as its plasma cannons charged—then fired.

A blinding blue explosion engulfed the corridor as the plasma struck the alien square in the chest. The impact sent the creature flying backward, slamming it into the metal wall with a sickening crunch.

For a moment, the base fell silent.

Laura exhaled. "Did we—?"

The dust cleared.

The alien was still alive.

It twitched, its glowing veins flickering erratically. Then, as if rebooting, it let out another unearthly screech and began regenerating.

Michael's face went pale. "You've gotta be kidding me."

Ethan gritted his teeth. They had seconds before it rejoined the fight.

"Titan, switch to melee combat."

The war mech's right arm transformed, shifting into a vibrating energy blade, while its left arm reconfigured into a reinforced kinetic shield.

The alien lunged, faster than before.

Titan met it head-on.

A Clash of Titans

The underground base shook again as metal collided with metal. The alien slashed wildly, its scythe-arms clanging against Titan's energy shield. Sparks rained down as the two massive figures battled in the tight corridors of the underground fortress.

Titan ducked under a deadly swing and countered with a devastating uppercut, sending the alien crashing through a reinforced support beam.

But instead of staying down, the alien let out an even louder screech—calling to its kin.

Ethan's stomach dropped as EPS issued a grim update.

[WARNING: MULTIPLE HOSTILES DETECTED. ADDITIONAL ENEMIES INBOUND.]

The seismic scanners showed at least ten more heat signatures closing in.

"We're outnumbered," Laura said, her voice tight.

Michael turned to Ethan. "We can't hold the base like this! We need a fallback plan!"

A Desperate Escape

Ethan's mind raced. If they stayed, they'd be overrun.

"EPS," he ordered, "initiate Phase Shift Protocol."

[PHASE SHIFT PROTOCOL ACTIVATED: PREPARING TO RELOCATE BASE CORE.]

A low hum resonated through the underground structure as hidden escape tunnels prepared to activate. The core systems, including the AI, power supply, and armory, would detach and relocate deeper into the Martian crust.

"Titan, delay the enemy," Ethan commanded.

The mech responded instantly, slamming the alien into the wall again before firing one last high-powered plasma blast. The creature shrieked in agony as it was blasted apart into molten debris.

But the other creatures were getting closer.

"Move! Now!" Ethan shouted.

The walls of the command center shifted, revealing an escape passage leading deeper underground.

As the team rushed inside, Ethan took one last look at the battle-worn hangar.

Titan stood its ground, weapons primed, as the next wave of aliens emerged from the tunnels.

The hidden blast doors slammed shut just as the creatures charged.

Regrouping in the Depths

The emergency tunnels stretched for miles, leading to a hidden secondary facility Ethan had prepared for worst-case scenarios.

As they finally reached the reinforced doors, EPS verified their biometrics and unlocked the chamber.

Ethan collapsed into a chair, exhaling.

Laura wiped blood from her forehead. "That was way too close."

Michael shook his head, running a hand through his hair. "We just lost half of our upper base. Our strongest mech is stranded, and we're dealing with enemies that adapt on the fly."

Ethan stared at the holographic map.

"We're not just fighting aliens," he said grimly. "We're fighting something designed to evolve."

A long silence followed.

Then, EPS chimed in with a disturbing revelation.

[ANALYSIS COMPLETE: HOSTILE SPECIES IDENTIFIED.]

The screen displayed a data file—one that shouldn't exist.

Species Name: Xa'Rath

Status: Ancient Enemy of the Celestial Dominion

Survivability: Extinction-Level Threat

Current Mission: Eliminate All Non-Xa'Rath Life on Mars

Michael swallowed. "You mean… we're not just their enemies. We're their targets."

Ethan tightened his jaw.

This wasn't just a battle.

This was a war for survival.