First, here's the legal bumf: If it's not an OC, I don't own it. Simple as.

Second, content warning. This fic contains spoilers for various games in the series, some strong language, self-insertion and severe sad git moments.

Now that all that pretentious bollocks is out of the way...

Halo: Cypher.

Chapter One: The darkness before the dawn.

Reach.

The fortress of Humanity amongst the stars.

And one of the few worlds they had left. For the past twenty-seven years an alien alliance known as the Covenant had pushed humanity back, burning every colony they came across until only a glass ball remained.

UNSC Forward Operating Base Vampire, Reach. July 24th, 2552, 0743 hrs.

Jon was laying on his bunk in the barracks, thinking. Like most of the other SPARTAN-IIIs, he was an orphan. In his case, he'd lost his parents and his sister when the Covenant attacked and subsequently glassed Jericho VII not long before his third birthday. At five, he was conscripted into the SPARTAN-III program. After that, he was simply Jon-B251. However, unlike most of the others, he was pulled from the company after augmentation. No-one ever told him why, but it had been hinted that there was something about him and the others who were pulled that made them too valuable to lose. He only really understood the gravity of that after hearing about what happened to the rest of Beta Company at Pegasi Delta. In that operation, all but two of the three-hundred SPARTAN-IIIs sent to destroy a Covenant fuel refinery were killed, but the mission was a strategic success. He leaned over, and picked up an MC-5 Datapad. Normally, this would be slotted into the left forearm of his MJOLNIR Mk.V armour, which he used in his role as his team's hacker. But at the moment, he wasn't wearing it, wearing instead a black BDU with a SPARTAN insignia on one arm, and his rank on the other. An eagle above a crossed anchor, trident and pistol and two red chevrons; that of a Special Warfare Operator, Second Class. Eventually, he set the pad down and went to use the head.

Having finished, he looked at himself in the mirror. He was the youngest of his team at only twenty, and one of the youngest SPARTAN-IIIs in what was left of Beta Company. His brown hair was beginning to touch the top of his neck; he wondered if anyone cared enough to enforce physical appearance standards on SPARTANs. Certainly they weren't suicidal enough to try to pin him down to shave it off; most SPARTAN-IIIs could break a man's jaw with a single punch, and the brawl that John-117, one of the SPARTAN-IIs, had with some ODSTs at the age of fourteen that left three of them dead was something of a legend. The fact that another of the S-IIs, Kelly-087, had disarmed the Marine trying to shave her at a very young age didn't help matters.

And then the siren went off.

"Attention all personnel, attention all personnel. CENTCOM has declared WINTER CONTINGENCY. I repeat, CENTCOM has declared WINTER CONTINGENCY. This is not a drill."
Jon ran for the Armoury, to find the rest of the team suiting up. There was Skye-B136, the only other Beta in Cypher Team, and the sniper, who was securing one of her boots. Her armour was a two-tone brown and khaki, with a Recon helmet, part of a ghille suit draped over her shoulders and a hydration tube running down one and across her chest. Next to her was Marcus-A257, who was strapping down an ammo pouch on his leg. He was the team's Heavy Weapons and Demolitions specialist, and as such was wearing a blocky and almost skull-like EOD helmet, a large number of grenades and tubes filled with demolition charges strapped to his belt and a pair of shoulder straps, and a set of reinforced shoulder armour in Green and red. Behind him was Asuka-A146, the team's scout, who was hooking a com-set over her right ear. She was wearing a set of lightened shoulder guards intended for hazardous operations use, and a Recon chest rig, and was there was a CQB helmet on the bench next to her, with its distinctive T-shaped visor, all finished in Red and Orange. And lastly, there was Alex-A176, the team leader, who was wearing Silver and Gunmetal armour, with a chest rig loaded down with shotgun shells despite it being rare for him to even use an M45, and a JFO helmet.

Jon slid his helmet on. It was an Air Assault helmet, finished in Cobalt Blue and Red just like the rest of his armour, which also included a set of LRP pouches and a pair of Recon guards on his shoulders. Finally, he slotted the MC5 pad into place, and tapped the screen to interface it. Alex spoke up.
"All right, we knew this would happen eventually. The Covenant have found their way here. Noble Team checked in with Colonel Holland over at SPECWAR-Three at 0735hrs, who pinged CENTCOM, who declared WINTER CONTINGENCY."
"So what are we being sent to do first?" Skye was easily the most talkative of the team, something that was a little bit counter-intuitive for a sniper, a job that traditionally required a fair amount of emotional detachment and otherwise cold behaviour.
"We're being sent to knock out an enemy command post near their LZ in Visegrad. Grab your gear and get ready for dust-off."

Jon and Asuka walked out to one of the waiting UH-144 Falcons that would deliver Cypher team to the CP. He was carrying an MA-37 assault rifle on his back, along with an M6G Magnum attached to his thigh. She was carrying an M392 DMR instead of the Assault rifle. Skye was sat opposite as they climbed aboard, cradling an SRS-99AM Sniper Rifle. Eventually, the pair of Falcons dusted off and headed for Visegrad.

Covenant Command Post, Visegrad. 1042Hrs

"The planned LZ's too hot. We're gonna have to drop you off up the hill." One of the Falcon pilots checked in.
"Understood. Just get us there in one piece."
The first plasma bolt zipped past, and Skye shouldered her rifle, taking the shot.
"Got him. Scratch one Elite."
Outside, Jon could see the Communications Relay that the Covenant had hit as part of their vanguard action earlier that morning.
And to think everything pointed to the Innies being behind it.
The Falcons hovered two feet off the deck, and the team disembarked. Jon heard the whine of the four tilt-rotor engines powering up as the two aircraft lifted off and climbed away, out of range of the hostile fire.
"OK. We need to get down the hill and secure the enemy CP. Our priority is to secure as much intel as we can, so try to keep the comm-system and databanks intact. All right? Let's move."

The initial march down the hill was quiet. Far too quiet.
Why do I get the feeling we're walking right into an ambush? I mean, we didn't exactly come in quietly.
Asuka stopped, and raised her left fist.
"Contact. Grunt patrol. I don't think we can slip past them."
"All right. Let's smoke 'em."

There were five grunts in the patrol. They'd only been planetside for a few hours, and weren't expecting to see much action patrolling a secured zone. Sure, they'd seen the human aircraft overhead, but assumed they were headed somewhere else. So none of them were expecting the hail of 7.62mm fire that butchered them. However, as the last grunt fell, spouting methane from the tank on its back, a hail of plasma fire drove the SPARTANs into cover.

"Well, they know we're here now!" Marcus shouted. Skye levelled her rifle, and fired, dropping an Elite from 200 yards and before its shield had a chance to react to the shot. Not that it would have helped; the 14.5mm round was designed to punch through armour like a knife through butter. Asuka shouldered her DMR, and put a round into a Jackal, managing to just get it through the gap in the shield, making it bolt for cover; at least until Alex finished it off with another DMR shot. Jon stood up and put a burst into a Skirmisher, sending it into the dirt.

Then the first mortar round thudded into the hillside behind their position.

"REVENANT!" Alex called.
"I got it!" Marcus shouted back, and raised his Spartan Laser, the red targeting beam latching onto the scout vehicle before the main charge fired, obliterating it.
"We need to get to the CP. Keep moving!" Alex began to run down the hill, taking pot-shots at the Covenant forces.

The team then began to fight a running battle, until they reached a ruined homestead mid-way down the hill.
"Well, it's quiet. Could be an ambush; want me to check it out?" Asuka re-loaded her DMR.
"Go for it. But keep it quiet. If there is an ambush, I'd prefer to get the drop on it."
She moved up the stairs and on to the upper level. There was a shing, then the sound of a blade being driven into flesh, and then a thump.
"Found a Jackal. Never saw me coming. Nothing else on the tracker."
"Nice work. Now get back down here."
"Gotcha."

The command post was a small pre-fabricated structure, apparently brought down from orbit by a Phantom or some such craft. A number of communication aerials poked out of the top. A Jackal could be seen at one of the consoles, before a sniper round painted his brains onto the far wall. This emptied the building fairly fast, with two Elite rangers and a crowd of Grunts trying to find the sniper. Jon dropped one of the Grunts with a burst from his AR, before Alex ran out, tackled one of the Elites to the ground, and stabbed it in the throat. The other turned round, and was about to back-stab him with its wrist-blade, but Marcus smashed it across the back with his Spartan Laser, making it crumple, before pulling out his magnum and executing it. The grunts broke and ran, only to get picked off one by one.

Jon wired his MC5 into the communications relay.
"Right. Download's started. Enemy targets for at least the next week; with luck we can head them off."
"Yeah, then they just change tack and hit other targets to draw us out. How many facilities do they have listed?" Alex covered the approach.
"Highest on the priority list is the ONI Sword Base, plus a few others they were able to ID from orbit. There's at least thirty targets on the list."
"Right." Alex hit a button on his gauntlet, activating the portable holo-tank embedded in it. These were more commonly used for distractions, but here Alex was carrying an AI. "Sora, I want you to transmit the target list to CENTCOM. Even if it's only good for a short time we're going to need all the advantages we can get."
Sora's avatar shimmered into life on top of the Gauntlet. She had taken the form of a UNSC Naval Officer in her early-mid twenties.
"All right, but I'll need the list first."
"Here." Jon pulled a data chip from his MC5 and tossed it to Alex.
"Thank you. Uploading now."
"Command, this is Cypher One. Mission Completed, we have intel on potential Covenant Targets, over."
"Copy Cypher One. Intel received and logged. Proceed to extraction at point Echo-Two. Command Out."
"OK gang, we're heading for extraction. You get anything else out of the relay?"
"Not that's going to be useful in the here and now. Maybe the geeks at ONI can do something with it, but beyond that..."
"I'll take whatever we can get. If the eggheads can use it, then take it."
"Gotcha." Jon unplugged his MC5.
"All right. The Falcons are gonna be waiting at the extraction zone at point Echo-2. Let's get moving."

The exfiltration was, if anything, easier than the insertion. But then again that was only because the SPARTANs had cleared out most, if not all, of the potential threats on the ground.
"Well, that was easy." Skye noted with a hint of sarcasm as the Falcons dusted off and sped away from the CP.
"Yeah. We won the battle. Now comes the War." Asuka was playing the realist. None of them knew how long this campaign was going to last, and if any of them would make it out alive. But they all knew one thing; Reach was doomed. It wouldn't matter what they did, Reach would fall eventually. It might take months, it might be all over in a few days, but it would happen eventually. All they could do was limit the long-term damage; keep the Covenant from gaining anything they could use to potentially find Earth or one of the surviving Inner Colonies.