Disclaimer: I do not own either Kantai Collection or Halo, nor do I gain any monetary funds from either them or this fanfiction.

Author's Note: Well, I was inspired by several other fanfics devoted to this particular crossover, and I hope that I don't shame them in the process of this. This fiction was the joint effort of myself and a writer who I only know by the name of Carlos Andare, not his real name of course. Hope you all enjoy it, and don't forget to read and review!

"I, being of legal age, of my own free will without coercion, promises, or inducement of any kind, after having been duly advised and warned of the consequences of this oath, swear to uphold the institutions of the Unified Earth Government against all enemies, foreign and domestic; to protect and defend Earth and her colonies; to obey lawful orders of the High Command of the United Nations Space Command, I hereby accept responsibility for the defense of humanity. So help me God."

Explosions topside shook dust from the ceiling of the bunker that was the base's warehouse. The dim red emergency lighting flickered, died. Darkness filled the octagonal chamber and the smoky hallways beyond, momentarily banished by a stutter of gunfire or the week, ill-looking pool of light cast off by the occasional glowstick. The smell of spent cordite mixed with that of blood, ruptured intestines, and burning metal.

"We're fucked, Sarge," a Marine whimpered as he dropped back down behind the makeshift barrier.

The Sergeant in question snorted. "You figure? That's why we're going to fuck 'em back."

He loaded a fresh magazine into his rifle and took aim down the hallway. The fighting hadn't quite broken past the thick steel door at the end of the hallway, but that was due to change any time soon.

The assorted Marines and other personnel had been in the middle of their now-daily routine, preparing supplies to be picked up, dropped off, or shipped out to other bases along the Pacific in order to try and keep the war effort going. They hadn't known what hit them. No warning, nothing but the vaguest idea that the Abyssals had been in the area, and suddenly they'd been struck.

The fleet assigned to the supposedly hidden port had already sortied out to intercept, and later, hunt down two other Abyssal battlegroups in the area, leaving just a token force to defend the base. Nobody knew whether it was just a stroke of luck, or a malevolent intelligence that brought the Abyssals here, but everyone knew that it wouldn't be enough to drive off a truly concerted effort on the enemy's part.

Behind them, technicians were hard at work setting up the spare summoning equipment-the main chamber had been destroyed in the initial bombardment. It was a longshot, but right now, every little chance was worth taking.

Sgt Garrick had been stationed with his platoon as little more than babysitters, and while they had initially resented the posting now found themselves as being the only ones even holding off the tide of pale-skinned horrors attacking them. Toothed aerial craft swooped into the hallways to try and pick off the defenders, only to be presented with a wall of lead from the dug in platoon as they used the underground corridors to their advantage, making the Abyssals pay for every inch with blood. Sadly, the only blood being spilled that didn't come from the nearly disposable enemy drones was instead coming from Garrick's fellow marines, having lost more than half of their number during the defence in the first ten minutes. And the veteran soldier knew that even that was a near miracle given what they were up against….

"INCOMING!" came the cry from another marine as the sound of shelling came once again, and somewhere within the complex Garrick heard one of the demonic explosives strike true, a hallway bursting with flame and ejecting smoke into the chamber as the Abyssals tried to blast them out of the reinforced bunker. It wouldn't be long until the true thrust came from their ship-women, those infernally calm females with skin like a corpse as they hunted humanity…

Tracers lept down the hallway like a shower of meteors, sparking off the ink-black hulls of the destroyers that made up the Abyssal vanguard. One of them opened its mouth. Its cannon peeked out from between those shining white teeth, took aim, and belched fire and smoke. One moment, Garrick had been firing his rifle. The next, he was a splash of red on the floor. But the round didn't detonate, not yet. It burst into a ball of smoke and flame against the door to their back, denting the metal.

Beyond it was the makeshift summoning chamber.

Beyond it was their last hope.

Following the leader's example, another of those infernal creatures opened its mouth. Instead of sending a round downrange, it ate an anti-tank rocket courtesy of a Japanese Petty Officer. The rocket sent a lance of molten copper deep into the creature's gut, ripping through its relatively thin skin and weak flesh, igniting its ammunition stock. The gunners quickly ducked behind the barricades as shrapnel sailed overhead. It took but a moment for the defensive fire to resume. Every moment spent fighting and dying meant a moment bought for the engineers, another chance for a miracle to happen as they exhausted the base's stock of materials.

The Abyssals didn't care however, and their advance was only slowed, not stopped. Again the leader opened her jaws and sent another round downrange, slamming into the reinforced door and causing it to buckle. Armsmen fired a veritable hail of small arms fire, while the Petty officer tried to aim another rocket, only to have one of the aerial drones ram the unfortunate soldier and cause him to fall back, the rocket flying upwards to impact on the ceiling. Glowing blue eyes watched impassively as the bullets bounced off chalk-white skin, and a return volley of anti-aircraft fire was spent to rip human bodies apart, casting a momentary silence into the hallway.

The clacking of heels echoed in the sudden silence as the destroyer stepped up towards the damaged portal. Delicate looking hands grabbed at rents in the thick metal and pulled, causing the steel to scream in protest as it was hauled out of its moorings and cast aside like the scrap that it had been reduced to. One of the wounded Marines picked himself up and pulled the pin on a grenade, rushing towards her with a ragged scream. He knew he was going to die. If not now, then soon. And with that thought in mind, he clutched the grenade between them as he held her in his arms. "Die you fuckers!"

The grenade did in fact go off, and the Abyssal let out a shriek as it exploded, obliterating the marine and leaving a savage wound in the destroyer's torso, spilling black fluid like blood along the floor… yet her inhuman constitution kept her alive. "Systems… damaged…" she seemed to mutter, while another Abyssal came up behind her. Sparing only a glance for her fellow, the new one looked at the frightened technicians. It had been close. So close. If they'd had another ten, even five, minutes more… They might have succeeded indeed. There were enough materials to bring forth a battleship, and enough personnel that their combined wishes would have pierced the veil of life and death to call on even a ship's soul.

Not close enough though. The Ri-class looked condescendingly on the gathered humans before summoning her weapons, the cannons pointing at the assembled techs with the finality of the grave before unleashing their first glimpses of hell.

Flames and shrapnel flew through the air as shells exploded, humans screams mixed with the curses that only those who knew they were dead could issue. Through it all the Abyssals watched impassively, unfeeling as they slaughtered without mercy those within. After a minute, only torn bodies and strewn materials were left, with only a few still breathing their last. Seeing that all resistance was crushed, the Ri-class turned away and strode through the open door, leaving the blazing inferno behind.

Engineer Aki Ishikawa looked up through the smoke and flames as he coughed bloody phlegm from ruined lungs, and he saw the Abyssals leaving with contempt, and a world of sorrow and grief came down upon him. His vision blurred and darkened as his hand clutched itself into a fist, bleeding over the lines and circles one of the techies had drawn on the floor. It was a shot in the dark, but he'd done something, hadn't he? Buying time was all that mattered. The summoning process had begun, but he could see that without others around, there was no way that it would result in any way that they had wanted. 'Fuck you... bitch,' he thought as he let out a last sigh.

Light washed over his face as glassy, lifeless eyes stared back. Within the smoke and flame, something moved, dragging itself up as items all over the room began to disappear. Steel, wiring, ammunition, all began to slip away into the void as the ritual continued haphazardly. Though no one could see it, other things were drawn in as well. The weapons of the marines that had fought and died, their dog tags, their bodies… If others had been able to witness some might have even said their souls were drawn in.

Nor was it only the defenders at the mercy of the ritual-gone-awry. The damaged and destroyed Abyssals too were slowly dragged to the epicenter of the summoning chamber, their bodies devoured by the empty black hole that was forming in the center. A Ho-class was swallowed feet first as her lifeless face remained blank, a Tsu-class torn in two was dragged next, and several destroyed drones followed suit. Only once there was nothing but the flames dying down did it seem to cease, leaving nothing but a darkened chamber, and the faint sound of something moving…