Four: Realization While On Board

The two teams' drop zone was inside a metal dome somewhere in the ring's interior. There was a wide platform on one wall of the dome, where Foehammer dropped them off, sending Grunts running in terror when the Demons jumped out.

The aliens fled through the hatch in the wall, letting Foehammer get her bird away safely. Less than ten seconds later an Elite came charging out, the Unggoy behind him; seeing the Sangheili unafraid to face the Spartans seemed to have given them some courage.

But having courage did not mean they had skill; they stood with their leader and died with him.

The Spartans engaged the Covenant in the next chamber as well, taking them down before heading through the door on the far side of the chamber. They stepped through - and found themselves on an uncovered bridge spanning the gap between sheer cliffs. What really caught their attention was the pure white snow drifting gently down from grey clouds overhead.

After a moment, Arthur-079 asked, "Cortana? Is the weather supposed to be this way?"

"The weather patterns seem natural," the AI responded, "but given the fact that this ring is entirely artificial, it's possible that the environment systems could be malfunctioning. Catch the sleepers before they wake! Hurry!"

The Spartans jolted briefly; she'd been controlling her personality spikes well. It had been a while since they'd heard one, but they moved fast to obey it, taking out the sleeping Grunts on the bridge shortly before a human voice came over the COM.

"This is Fireteam Zulu requesting assistance from any UNSC forces, does anyone copy? Over."

A Pelican flew over the bridge, firing on the Covenant and being fired upon in return. Cortana answered them, "Fireteam Zulu, this is Cortana; we read you. Hold position; we're on our way."

"Roger that," was the reply, "Make it quick." There were cheers in the background as the Marines caught sight of the Spartans making their way across the bridge.

There was another level to the bridge, slung under the primary path; Black Team went down to clear it out and matched pace with Blue Team as they crossed, slaughtering everything in their path. Ducking through the hatch at the far side, the two teams divided to clear the room, then reunited on the far side and rode the life down to the lower level two at a time, careful not to knock each other off.

By the time they were all on the ground, Linda had taken out al the Grunts and Jackals with her sniper rifle, but the Wraith was still making a nuisance of itself, launching plasma bombs at them like it was going out of style. Sam jumped in one of the Shades and started hosing fire downrange, but the distance was too great, the Wraith's armor too tough. But he held the Wraith's attention while the rest of his teammates piled into Zulu's Warthog, whizzing around to slip in behind the Wraith. Kelly opened up with the LAAG, and that combined with two perfectly thrown plasma grenades from Linda were sufficient to destroy the enemy tank.

The two teams regrouped, slowing their pace to let the Marines keep up. In the next valley, they found the rest of Fireteam Zulu - and their crashed Pelican. In addition to the Warthog, they also had a Scorpion tank, which Black Team took over. The tungsten shells more than took care of the Covenant harassing them as they continued on their way through the passes. There had been a tunnel as well, but the Spartans had been concerned that if a shell went off too close it would have been the end of them.

More Covenant engaged them before they'd entered the next valley, but it took only a single round from the Scorpion to take them out. They left the Wraith floating over the frozen lake to the tank as well, the rest of the soldiers aiming for the Ghosts and Banshees first, then the infantry. Elites died under a hail of bullets, Jackals flew when grenades exploded, and Grunts ran circles of terror before getting picked off like all the rest. The Hunters that came up from a tunnel were also no big deal; a single slug from the tank was sufficient to put each one of them down.

"C'mon, people, let's keep moving!" the sergeant yelled to some Marines who were lagging behind, "We're not in the clear yet!"

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John checked his weapon yet again as they entered the containment facility. The Covenant was there, of course; he and his Infected knew that they'd already opened the facility, but despite knowing what was waiting for them further in, the place still gave him the creeps.

It seemed to be having the same effect on the others, too; even Ferial was visibly unsettled, sweeping the area more times than necessary for more threats.

Even though they were the threat.

The Spartan kept the loose combat forms hidden away in "locked" areas of the facility, ready to slip them in behind while hoping - praying - that they could pull this off. A hundred thousand years of planning and tweaking and training and predicting and it was all finally coming to a head…

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Fred poked his head through the hatch and warily peered around. The Spartans had arrived on yet another bridge, this one ice-covered stone, and there were still more Covenant everywhere. There was a Wraith on the ground below, along with several Ghosts, and two Banshees on the bridge itself. 104 pulled back into the hall without being noticed, and met up with the other Spartans around the bend; a planning session was in order, even though battle plans rarely survived first contact with the enemy. Sam still had a rocket launcher, along with fresh rockets; they could use that on the Wraith. Linda could take out some of the aliens patrolling on the bridge, along with Cal-141, who was almost her equal with a rifle. The rest of Black Team would provide cover fire for Fred and Kelly, who would go for the two Banshees parked on the bridge.

Things went extremely well for them (suspiciously well, in Cortana's opinion): the Wraith didn't notice Sam's rockets until it was too late, and Fred and Kelly took both Banshees while their teammates gunned down everything that tried to stop them. The airborne Spartans cleared the way for the other six as they sprinted across the icy bridge, mindful of slipping. They would be on their own when they went inside, but Fred and Kelly continued clearing the outside while they fought their way to the lift.

By the time the other Spartans emerged, there was nothing left to fight. The Banshees' weapons had cleared out all the Covenant - on the exterior of the pyramid, at least. When they approached the top of the pyramid, a pair of Hunters came charging out of a structure in front of the Control Room's blast doors. The first Hunter was taken down easy enough, but the second was much harder, charging the instant the other went down. Sam arrived just in time to launch a rocket at it and blow it to pieces, preventing it from smashing Fred and Cortana into a bloody smear on the ground.

The Spartans gathered together again outside of the immense doors. All of their motion trackers were picking up enemies just beyond. Cortana reported that there was no way to open the doors only partially, so the Spartans took cover before Fred activated the holopanel, rockets and grenades at the ready. The explosives took out a lot of the Grunts but only a few Elites, forcing them to fight their way through the rest.

Finally there were no more living foes, and the Spartans kept moving through two more blast doors and into the Control Room itself. A platform of steel extended out over a void that plunged deep into the ring, the metal tongue forming a perfect circle around the exact center of the chamber. Both inside the circle and beyond it floated holograms of Halo, the larger spinning beyond the bridge, the smaller complete with models of the gas giant Threshold and its moon Basis.

Black Team kept their weapons leveled at the blast door, which had shut behind them, though the green lights on the doors seemed to indicate that it was still unlocked. Blue Team approached the display in front of the central hologram, examining it carefully, but Cortana felt no such need for caution. She uploaded herself into the control room's systems, appearing as a life-size version of herself between the holopanel and the model of Threshold. Her face conveyed pure delight, and her color cycled through the whole of the color wheel before settling back to her native crimson.

"Are you all right?" Kelly asked her.

"Never been better," she answered with a faintly devilish grin, "You can't imagine the wealth of information - so much so fast! It's glorious!" She actually did a little pirouette.

"Okay. So what kind of weapon is it?" Fred asked next.

"What are you talking about?" Cortana demanded, planting her hands on her hips.

"Halo, how do we use it against the Covenant?"

"This ring isn't a scalpel, you barbarian; you can't tune it like that," she snapped, "This is something else, something much more important. The Covenant are right for once; this ring, it's of Forerunner make… give me a moment to access." She touched two fingers to her temple, eyes briefly closing as she pulled up the intel. "Yes, the Forerunners built this Halo, what they called a fortress world, to-." Her face went slack with shock, horror. "No. That- that can't be right. Oh, those Covenant fools! They must have known, there must have been signs-!"

"What is it?"

"The Covenant found something here - something horrible - and now they're afraid."

"'Something buried'?" Sam repeated.

"What does the Covenant have to be afraid of?" Arthur asked, but Cortana had already jumped ahead.

"The captain - we have to stop the captain!" she cried, "The weapons cache he's looking for - it's not - we can't let him get inside! There's no time to explain - get out, find Keyes, stop him. Before it's too late! Run, organics! All our lives hang in the balance!"

The Spartans finally caught on to the urgency and fled the Control Room at top speed. The blast doors slid shut behind them, leaving her alone.

Or so they thought.

"You are an excellent actress."

Cortana turned to face the speaker, who dropped his active camouflage as he came around to stand before her. The Forerunner's helm turned transparent, and he bowed at the waist. "Greetings, Lady Cortana," he said, "I am Sharp-Wind-from-the-North, but please call me Sharp. The Commander tasked me with bringing you a data archive on all that's happened, along with a few subroutine grafts from our own ancilla to help you process it all, and - a couple of other things from the rest of us, for your viewing pleasure."

"Thank you, Sharp," she replied, holding out a hand, "I'm ready when you are."

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The swamp was everything they expected it to be: dark, deep, and full of danger, a feeling that started in their guts and uncoiled up their spines to choke their throats. It was also very, very wet, rain pouring down through the ancient canopy to soak everything that wasn't already wet. Blue Team clambered from Echo Four-Nineteen's Pelican and dropped into the mud below.

All four of the Spartans moved carefully into the foliage as Foehammer said, "The captain's last transmission came from this area. When you find him, radio in, and I'll come pick you up."

Fred flashed an acknowledgement, then led his team deeper into the swamp, acclimating themselves to the sights and sounds so they would know what belonged and what didn't. As a result, it was easy to find Keyes' Pelican; it hadn't gone very far before crashing into an embankment. Those who'd died in the crash were all naval personnel; it must have been taking off when it went down. They paused to listen to the distress call someone had programmed in - and hesitated when the words "isn't Covenant" came through the static.

Could this be what Cortana meant by "something horrible"?

Fred thought on it as they moved deeper into the swamp, gunning down a few Jackals and some Grunts running around in paroxysms of fear. The Jackals had attacked them instantly, as had all but one of the Grunts. When all the others were dead, Kelly led the way over to the one terrified Unggoy that appeared not to have noticed them, curled tightly into a ball and shaking.

"Hey." She nudged it with her assault rifle.

It jumped to its feet, holding its plasma pistol in quivering hands, then cowered again when it recognized the Demons.

"What happened here?" Kelly demanded, her tone leaving no room for argument, "Where are your leaders?"

"S-something from below!" it squeaked, shaking, "All Sangheili taken! Killed by not-humans and not-Sangheili!"

"What do you mean, 'not-humans'?" Sam asked. They could almost hear his brow furrowing.

"Human-shaped," it chirped fearfully, "but not human, not anymore! All real humans fled!"

"Where?"

It pointed before curling back into a ball. Fred gave it a look before figuring it was too terrified to be a threat and gesturing for them to continue on in the direction it indicated.

It wasn't long before they reached another wreck. This one was a Spirit dropship, bows down in the swamp muck, cargo modules spilling from its hatches like blood from a wound. There were lights illuminating the area as well; an investigation into the crash had been underway, but the investigators themselves were gone.

That put the Spartans on edge. The Covenant didn't just leave things behind - not unless something like the Spartans forced them.

The Jackals that startled them around the next bend were killed with a little more force than necessary as a result.

They were crossing a fallen log being used as a bridge when they saw something run past the empty Shade turret at the top of the opposite slope. It moved like an Elite, but it was there and gone too fast for them to be sure.

The Spartans paused, then continued even more warily than before, climbing the steep slope opposite and topping the rise just in time to catch the tail end of a fight. Grunts and Jackals came tearing out of a large A-shaped structure rising out of the foliage, bullets flying after the aliens and a grenade sending a Shade flying. Kelly was the first to dart down, but the Covenant engaged her the moment they spotted her, despite their fear.

The delay didn't last long, but it was long enough that whatever had been in the structure was no longer there. They swept the room regardless, taking note of the casings near the entrance, before a noise - a cross between a ding and a beep - caught their attention. A lift ascended from a lower level and came to a stop, seemingly summoned by unseen proximity sensors.

It seemed safe enough, so they stepped onboard. Linda tapped a holopanel off to one side and sent them sinking down into the underground complex.

The lower level held a series of overlapping red blobs on their motion trackers, but no one came to greet them when the lift settled. The Covenant standing guard had gotten used to their buddies coming and going, and for that they paid the price. Two grenades and a half a clip of bullets were enough to put them down, along with their fellows in the next room. The rest of that room was empty, though the corpses of two Marines confirmed that Keyes had been through. The bodies weren't anyone the recognized, so they kept moving.

There were three Jackals in the next room, clustered around a hatch. A single grenade was sufficient to put them down, letting the warriors enter the room freely. It was some kind of research facility; there was a glass-walled containment area in the center of the room, displays and readouts on all sides, but whatever it had once held was gone.

The Spartans exchanged looks, recognizing the same wariness in the others that they felt themselves. There was no need for words.

In the next room, two Shades, unmanned, stood on either side of the channel that ran through the middle of the room, cargo modules scattered about, with some Needlers and ammo down in the dip. They each took one as an additional weapon, albeit with only one extra clip; no telling if it would or wouldn't come in handy. Then they kept moving.

There was a live Marine in the room beyond - but he started shooting at them the instant they appeared. "Stay back!" he cried, "You're not turning me into one of those things!"

Kelly snatched the pistol out of the man's hands before he could squeeze off more than a few shots. "Where's your unit, soldier? Where's Captain Keyes?"

"Find your own hiding spot!" he shouted at her, "Those monsters are everywhere!"

Isn't Covenant

The Spartans looked at each other again. Then Kelly handed the pistol back to the Marine, but he didn't start firing on them again, just curled up into a ball, whimpering.

They had no choice but to leave him behind, and moved on up a makeshift bridge to the second level, circling around to an open door.

John listened through the Pure form's ears as the Spartans continued on, then directed it to mutate into a full-blown combat form but to stay silent as it followed the other warriors.

Blue Team crossed an energy bridge and entered the primary storage facility through a hatch broken from the inside. That set the Spartans even more on edge; not even they could achieve the amount of force needed to break the doors - not without breaking a bone or several.

There was a large metal wall immediately beyond the door, and two ramps leading down to another hatch beyond that. They caught a blurry glimpse of the facility beyond through a set of unbreakable panes of glass. There was no movement inside - empty - but they headed down anyway; maybe there was a clue to where Keyes had gone - or been taken.

They knew for sure that something was terribly, terribly wrong when the hatch slid open at their approach and dumped a dead Marine into Fred's arms. The Spartan jerked his head, and the other three swept the area again while he pulled the corpse into the chamber.

All of them felt that they were being watched, but there was no one and nothing to do the watching.

There was a crunch of metal underfoot. They looked down - and found that there were thousands of casings nearly carpeting the floor. What could possibly require so much ammo to kill - or could spook Marines and ODSTs so badly that they'd fire that many bullets anyway?

A lone Marine helmet sat amongst the empties. The others covered Kelly while she grabbed it and removed its camera's memory chip. She slotted it into one of the ports in her own helmet and queued up the playback so all of them could see.

The video quality left a lot to be desired even without the night vision filter, but the video itself began normally enough, starting with the doomed dropship's touchdown in the swamp. Kelly skipped ahead, giving them glimpses of the trek to and through the facility, but things took a turn for the ominous when the group found a Sangheili killed by what seemed to be friendly fire. But the Marines continued on into the facility that the Spartans themselves were in, joined by Captain Keyes and Sergeant Smith and his squad.

But Green Team was visibly unsettled; whenever they were idle for even a minute, they put their backs up against each other or a wall and kept sweeping the rooms.

Something slammed on the recording, making the Marines jump. One of the side hatches was breaking under the force of something inside-

Another slam and the hatch burst open, releasing two dozen roughly-spherical somethings into the facility. Before their eyes, some of them smashed themselves together to form a vaguely insect-like shape, a cylindrical body with two multi-toed feet and two arms tipped with long, sharp pincers. A designator flashed over it - "Flood Pure Form - Stalker Type" - right before it lunged forward and ran Sergeant Smith's twins through with its pincers.

The two women screamed and went down, clutching at the pincers where they broke off in their guts. Their sergeant unloaded his shotgun into the Stalker form, taking it down, but it was too late for them. They writhed in pain - and became something else.

Human-shaped but not human, not anymore

Horrible howls left their throats as they climbed back to their feet and leaped for their squadmates. One of the spheres - "Flood Pure Form - Infection Pod" - threw itself at the Marine whose footage they were watching, and the camera went dark.

Kelly slowly removed the memory chip from her helmet and wordlessly joined the rest of Blue Team in backing up toward the hatch, their weapons pointed toward the other still-closed hatches set into the walls of the facility.

But the hatch behind them didn't hiss open when they got close. Linda hit it first and glanced down to the indicator lights - red. Locked. No other exits. The Spartans moved to get away from the doors, to put their backs up against something solid, their heart rates starting to climb-

Bang.

A hatch out of their line of sight was starting to break open, letting loose the "Infection Pods" that had taken Keyes and his team-

Green Team. Maria, Riz, Joseph, and Joshua had been with Keyes and were no longer here; there was a non-zero chance that they had been taken as well.

The Spartans had never lost siblings before, and more than a little of their fear turned to rage. They leveled their weapons as the out-of-sight door burst open, spilling Infection Pods into the room, and when they dribbled over one of the room's decorative partitions, the Spartans opened fire. Popping one of them set off chain reactions in the others close by, but there were still more of them getting closer.

Some of them merged like before, and Kelly started firing on the thing before it was even fully formed, before another identifier popped up - "Flood Pure Form - Tank Type". It lumbered towards them, seemingly heedless of the chunks Kelly was blasting out of it, and swung one of its huge club-like arms at them once, twice, three times before finally succumbing - until more Infection Pods merged with the remains. It got back up and came at them again.

Blue Team narrowly dodged its attacks, and resorted to stamping on the Infection Pods scurrying around their feet while they fired on the Tank Form. Though they had some uncomfortably close calls, they successfully killed everything in the room, Infection Pods smears on the deck and the Tank Form slumped over. More storage rooms had broken open during the fight, adding to the chaos, but even with the reinforcements the Flood hadn't been enough to take down the Spartans.

And then the hatch that blocked their exit exploded inward, some Infection Pods tumbling in with the shrapnel. Behind them was a Stalker Form and what looked to have once been Elites; another identifier popped up, marking these as "Flood Infected Form - Combat Type, Sangheili Variant". All of them leaped into the room, and the Stalker Form lunged for Kelly. She threw herself backwards, scrambling back over the deck to avoid it, before kicking out hard enough that she launched the thing into a wall with a wet crunch.

While that was happening, the other Spartans fought down the combat forms and the Infection Pods with them. Sam was forced to physically fight one of them, too, when it leaped at him and knocked his assault rifle from his hands; actually tearing it apart was beyond disgusting, but none of the other Spartans could get the right angle to shoot it without shooting him as well.

But the door was open, and they took the opportunity it provided, making good their escape. They charged through the hatch and up the ramps, mowing down everything in their way.

The Covenant was fighting the Flood as well, some Jackals and Grunts against their infected leaders, and the Spartans left them to it, taking advantage of the chaos to slip past unnoticed. They passed through several side chambers, still looking for signs that Keyes had come through or better yet escaped, but they weren't holding their breath.

One of the side rooms had a lift at the heart. The Flood in the room were quickly eliminated, though the Spartans were horrified to discover their first actual "Flood Infected Form - Combat Type, Human Variant". A small mercy; it was no one they recognized, but it was still someone lost to the parasite.

(Corporal Grant had died crash-landing on the ring, but they didn't know that.)

Fred tapped at the holopanel to bring the lift platform down, relaxing a little at the promise of escape -

An explosion from above put a swift end to that. The Spartans scrambled back as the remnants of the platform crashed down past them into the abyss below. That forced them to go back they way they'd come to find another way out. It seemed that they weren't the only ones who'd gotten away; they found the corpses of two Marines on one side of the path. One of them was the third woman from Smith's team, "Feriha"-something, but both sets of dog tags had been collected; that had to mean there were other survivors.

(Right?)

Yet as they moved off, there was a skittering noise behind them, and they whirled around in time to see some Infection Pods plop to the ground and scurry for the bodies. The Spartans opened fire, but one of the pods threw itself onto Feriha's body, tentacles burrowing under her skin. The infection took hold in seconds, and the combat form stumbled to its feet, then growled and lunged for them, swinging a tentacled arm.

The Spartans gunned it down and briefly wondered about Lieutenant Night - Ambi, he'd said to call him Ambi. And Sergeant Smith, whom Cortana was so fond of. Neither of them had yet been seen among the dead, but their chances were grim.

They kept moving through some kind of generator room and what seemed like countless other rooms, lifts taking them deeper into the facility, before they finally found a lift that carried them up and out to a landing on the surface. There were some Marines - ordinary, human Marines - milling around like sheep without a shepherd.

Foehammer came over the COM and said something about losing their signals and a structure nearby where she could pick them up, and the humans were moving out before they'd even really processed her words.

The Flood swarmed them as they left the structure, yet they almost seemed to keep their distance, as if herding them through the swamp. And Fred knew that the only real reason to herd an enemy anywhere was to drive them into an ambush. He took point with Kelly and Sam while Linda served as the rearguard, and they protected the Marines all the way to the structure.

Then strange floating machines appeared through the fog, zapping at the Flood with bright lasers. And they were only targeting the Flood, which was rapidly falling back into the swamp.

Too rapidly.

But there was no time to dwell on it. A few moments later, Blue Team was suddenly enveloped in rings of golden light. There was a moment of disorientation as they appeared on one of the structures' pylons, and another floating machine zipped over to them, smaller and rounder than the others. "Greetings!" it - he? - chirped, "I am the Monitor of Installation Zero-Four. I am 343 Guilty Spark."

The Spartans reluctantly lowered their weapons and glanced at each other.

"Someone has released the Flood," the Monitor continued, "My function is to prevent it from leaving this installation, but I require your assistance. Come, this way."

The golden rings surrounded them again, and they were gone.