As the screen went dark, a sudden urge to fight and destroy the creature arose inside Kaizoo. The entity was no longer a phantom in the system or a shadow in a recording. It was a physical presence, a trespasser in the one place that was supposed to be his sanctuary. The digital quarantine had blinded it, but it was still here, sharing the air, the walls, the very atoms of his world.

Kaizoo’s mind, cleared by the flood of oxygen but frayed by relentless terror, snapped into a new mode: hunter and hunted. He was an engineer. A problem-solver. And the problem was a hostile, non-human intelligence loose in his machine.

MOVE. ISOLATE. EXPEL.

His first move was systematic. He sealed the internal bulkhead doors, dividing the Nautilus-07 into three sections: the cockpit, the central living area (with the bunk and storage), and the rear compartment with the airlock. He watched the status lights on the console. The cockpit door sealed with a satisfying hiss. The central door... jammed. The indicator light flickered erratically between red and green.

"I know you're here with me! After all this, you're not going to hide anymore, are you?" Kaizoo felt it; the air around him was different. It was in the central section with him.

DRIP. DRIP.

A soft, wet drip echoed from the bunk area. It was the same sound from the Nautilus-04, but now it was here, in his home. He spun, wrench in hand, his headlamp beam cutting a trembling path through the blue-lit gloom.

Nothing.

Then, a flicker of movement in his peripheral vision. He whirled toward the storage locker. The door was slightly ajar. He was certain he had locked it.

He took a step forward. The ship's main lights flickered and died, plunging him into the stark, lonely pool of his headlamp. The emergency battery-powered strips along the floor glowed a faint, sickly yellow, creating long, dancing shadows.

SKRITCH. SKRITCH.

The sound was closer now. Not a drip, but a deliberate scrape. It was coming from inside the ventilation shaft above his head. He looked up, his light illuminating the metal grille. A thick, black, viscous fluid began to seep through the slats, dripping onto the floor with a soft plink.

It was in the vents. It was everywhere.

His original plan to flush it out through the airlock was useless. He couldn't get to the airlock without going through its territory. He was trapped in a shrinking box with a thing that defied physics.

A new idea, born of desperation and his innate, almost preternatural understanding of the ship's systems, surfaced. The Nautilus-07 had an emergency fire-suppression system. It could flood a compromised section with an inert, oxygen-displacing gas to snuff out a blaze.

"I could suffocate it. Or at least damage it. The important thing is I have to do something. I have to get rid of it." He was talking to himself, thinking through the plan.

He lunged for the console, his fingers flying across the screen. He isolated the central section and initiated the purge sequence for the nitrogen tanks. A warning flashed:

CONFIRM MANUAL OVERRIDE. LIFE-SUPPORT IN COMPROMISED SECTOR WILL TERMINATE.

He slammed his palm on the override.

A deafening hiss filled the cabin. White clouds of pressurized nitrogen erupted from nozzles in the ceiling. The temperature plummeted instantly. Kaizoo held his breath, his eyes stinging, and scrambled back into the sealed cockpit, slamming the bulkhead door shut just as the freezing fog billowed against the thick glass viewport.

He watched, heart hammering, as the central compartment filled with the killing fog. For a moment, he saw a shape—tall, thin, and impossibly agile—thrashing against the storage locker, its form seeming to ripple and distort in the chaos. A high-pitched, frequency-shifting shriek, like feedback from a broken speaker, pierced through the hull, a sound of pure, alien agony.

"Shriieennkkkkkkkkkkkkkkkk...... YOOUUUUUUU... SHHOOUULLLLDD... DIIIIE... KAAIIIIZOOOOOOO..." The creature wasn't just loud; it was speaking, forming the same words he had heard during his hallucinations. But now the sound was more alien, and it seemed to be calling out to something, or someone.

After a few minutes of this terrifying sound, there was silence.

The nitrogen tanks emptied. The vents began cycling, slowly replacing the inert gas with breathable air from the cockpit and rear reserves. The temperature normalized. The central section's status light on his console glowed a steady green. The door was un-jammed.

He had won. He had purged the parasite.

Cautiously, his breath still held, he cracked the bulkhead door. The air was cold and stale, but clean. His headlamp swept the room. It was empty. The black fluid was gone. The only evidence was a faint, acrid smell of ozone and something else, something organic and burnt.

He had done it. He had fought the unseen and won. A grim, exhausted smile touched his lips. He was Kaizoo, Maintenance Engineer, and he had fixed the infestation.

His eyes fell on the storage locker. The door was still ajar. Driven by a final, morbid need for confirmation, he walked over and pulled it open.

Inside, nestled among spare parts and tools, was the black box. His gaze was fixed on what lay on top of it: a single, perfect handprint etched into the wall of the locker. It looked as if it had burned or melted its way into the metal. It was humanoid, but the fingers were too long, the palm too narrow. In the center of the palm was a small, perfectly formed hole, as if it had been welded through the metal.

Had he really killed it? Or had it escaped the submarine by some physical means unknown to Kaizoo?

It hadn't been killed. It had been hurt. Forced to retreat. And in its retreat, it had left him a message. A final, mocking proof that it was real, it was physical, and this was far from over.

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