"It's a new war, and the Covenant is a completely new enemy. Make no mistake, the list of known unknowns is as thick as a textbook, and lives will be spent to find answers to each of those unknowns. As soldiers, it will be your job to make sure those are Covenant lives."
-Admiral Preston J. Cole

"The known unknowns are easy. It's the unknowns you don't see coming that'll kill you."
-Colonel Jane Pedersen, UNSCEF Harvest Command

0935 Hours, February 15 2526 (Military Calendar)/
Epsilon Indi System, Operational Area Plumbob, Harvest

It was on the Edda supercontinent, where the river Ratatoskr flowed into the Hugin sea, that Corporal David Bordowicz found the last bit of green on Harvest. The Covenant had yet to visit this region with their glassing beams, and the marshes of the Ratotoskr delta seemed to be thriving in spite of the coming nuclear winter.

There was another kind of green. As Bordowicz's squad crept through the marsh, they occasionally caught glimpses of a sickly green glow reflecting off the overcast skies to the east. That was the squad's target, a Covenant facility known as Facility A1-30. Aerial recon showed a cluster of snailshell-shaped buildings surrounded by a maze of pipes. Maybe it was a refinery, or maybe it was a communication array, or maybe the Covenant were constructing an artillery gun that could reach out and touch warships in high orbit. Who knew?

'Who knows indeed?' Daniel thought darkly as he pushed through a shrub ahead of Sergeant Sanchez and the rest of his fireteam. The war against the Covenant was barely a year old, and the list of known unknowns could fill a textbook. Where did the Covenant come from? What environments did they all evolve from? How was their chain of command structured, and how did they organize patrols?

Well, if the squad was lucky, their mission would answer some of those questions, and they'd-

"Bandits!" Private Sandberg called. "Everyone take cover!"

Eleven members of the squad darted for cover, crouching under shrubs or pressing against cypress trees or, like Daniel, dropping prone and letting their adaptive camouflage do the hard work.

Moments later, a dozen Covenant aircraft roared overhead, one after the other. They were flying low and fast, hundreds of kilometers per hour. Head turned to his side, one eye exposed, Daniel was relieved to see that the aircraft all had the tuning fork profile of the Covenant cargo-carrying dropships. They could carry troops too, but the odds that they could peer down and spot India-2 were slim.

The troopers of India-2 were clad in the UNSC's latest and greatest in infiltration gear. From head to toe, save for the soles of their boots and the eyeholes of their balaclavas, they were covered in a fabric that adapted its color, texture, and albedo in response to signals from a hip computer. As a result, their armor was constantly shifting to match their surroundings. At twenty meters, they were invisible to the naked eye. Even the AI back at Camp Keel had trouble tracking them in the bush.

Daniel knew how to use the adaptive camouflage, and he had the utmost confidence in the technology. And yet, he couldn't shake a small, lingering doubt. It was hard to know what the alien bastards were capable of.

Another team, Hotel-7, had been wiped out three days ago in the Vigrond Highlands. And a Marine Force Recon unit two days before that. Cutting edge adaptive camouflage hadn't helped them one bit.

The roar of the dropships receded, and then the echoes died away, and then came silence. At long last, the insects of the marsh started chittering again, and Sergeant Sanchez gave the order to continue. The squad got to their feet and marched in the same direction that the dropships had gone. Toward the refinery, and who knew what was waiting for them.

"Damn," Daniel breathed. "Wish we were still fighting Innies."

1122 Hours, Perimeter of Facility A1-30

The Covenant had cleared three square kilometers of marshy forest away from the shore of a lagoon. Most of the brush had been plowed under, but enough had been bulldozed outward to create a perimeter mound that stood shoulder-high and about five meters deep.

Beyond that mound was about fifteen meters of open ground, after which the labyrinth of pipes, domes, and columns started. At the center of it all stood a cluster of buildings shaped like conical shells, with catwalks strung between them like a cat's cradle. Off to one side was a hollow spire with a pillar of brilliant green energy in its core, so bright it hurt to look at.

For several minutes, the squad studied the facility, noting the positions of sentries and anti-aircraft turrets. Then Private Korria leaned over to Daniel and whispered "That's just a refinery."

"How do you know?" Daniel shot back.

"I grew up in Sao Antonio de Vácuo. I know a refinery when I see one."

"Alright, then, what are the Covenant refining?"

Korria shrugged. The motion was almost invisible beneath his shifting camouflage. "I dunno. Swamp gas?"

"Cut the chatter, get to work," Sergeant Sanchez ordered. "I want us done and gone as soon as possible."

Daniel ducked, dropped his pack, and retrieved a half-dozen Concealed Remote Observation devices. Each device was the size of a chatter phone, and would monitor the facility until they were discovered or some faceless intelligence officer decided that he'd seen enough. They weren't that different from the trail game cameras that Daniel's father had strung up all over the Esposz Highlands, back on Reach.

He boosted Korria up into a sickly-looking cypress tree and climbed up after him. As Korria strapped the Crow to the trunk, Daniel linked the device to his tacpad and initialized the sensors.

"I can't see anything," Daniel muttered. "The light from that spire is washing the image out."

Korria reached out and waved his fingers in front of the lens. He moved slowly and deliberately. Even half-covered behind the boughs of the cypress tree, he did his best to conceal his movements. "Better?"

"No." Daniel slid the Crow further up the trunk, so that the optic lens was covered by the hazy shadow of a branch, and then he half-buried it under the shaggy moss that half-covered the tree. "That'll have to do. We'll get a better angle with the other-"

He heard a sound like a ringing wineglass, and then a long shard of pink crystal buried itself behind Private Korria's ear. The trooper blinked, lost his balance, and tumbled out of the tree.

Daniel was already on his way down. More crystal needles tinked off the tree where he'd sat a moment before, and those were like the first few drops of rain before the cloudburst. By the time his feet were back in the mud, a hailstorm of crystal and plasma bolts was ripping through the treeline. His radio came alive as the whole squad started shouting at once. Sergeant Sanchez came out on top, screaming for everyone to fall back to the rally point. Then a torrent of plasma from one of the anti-aircraft guns washed through the bushes, and Sanchez was gone.

Not even wasting time to check on Korria, Daniel scooped up his pack and ran as the whole Ratotoskr delta went to hell.

A/N: This is something quick I threw together. Should be three chapters long when it's all well and done.

Sharp-eyed readers will notice that this story is filed under "science fiction/mystery", and that's because it is. This is a sort of first-contact story, where the characters have to discover one of the Covenant's more obscure abilities if they want to survive. The ability isn't exactly canon, but the rules will be explained in the next chapter.

In the meantime, work continues apace on the next chapter of Not All Who Wander. I'm afraid that I've let work and long Stellaris playthroughs get in the way of writing, and I'll try not to let it happen again.