So just to clear things up - Sam knew the oldest brother, Gabriel, Dean knew the youngest brother, Samandriel, and now they're both meeting the middle brother, Castiel.

Oh yeah! Forgot to add this in the last few chapters- I do not in any way own supernatural, and am not doing this for financial gain.

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Chapter 4 - The Monster Under the Bed.

Dean.

Dean didn't flinch at the coldness in the man's voice, keeping his gun trained on him despite the chill that ran up his spine like ice. The man - barely out of his teens - had a shock of messy, slightly shaggy black hair that looked like it could do with a trim, a muddy and frayed trench coat and startlingly blue eyes, sharp and clear as they met Dean's stare coolly.

"Outpost 4, I presume?" His voice was surprisingly deep, edged with a rough lilt, as if he wasn't used to speaking.

"Just me." Dean kept his voice level and strong as he and Castiel locked eyes, a battle of wills. Sam tensed behind him and, for all of his strength and height, he seemed to shrink a little under the newcomer's stare.

Suddenly, Castiel smiled. It was a small smile, sure, barely perceptible, but Dean immediately felt the atmosphere in the room lighten.

"Call me Cas," he smiled, as the knife pointed at him slowly started to drop. "Your names are…?"

"Dean Winchester and Sam Campbell," Sam filled in before Dean could answer, stepping forward and shaking Cas's hand rigorously. "I'm Sam, and it's-"

"May you please. Stop. Touching. Me," Castiel said stiffly, and Sam pulled his hand away like he'd been burned. Wiping his hand on his already grimy overcoat, Cas said, "My apologies. Physical contact is not my strong point," in a flat, bare tone. When he turned away, Dean glared at his back.

"Are you leaving now?" Dean asked harshly.

Sam gave him a pointed look. "No, Dean, you can't just kick him-"

"Yes, I will be on my way," Castiel cut in, once again acting like Sam didn't exist. His blue eyes met Dean's for a split second, but it was long enough. "I apologize for causing you any trouble."

As he started to walk towards the door, however, Dean caught a glimpse at how awkwardly the man was holding his left arm; it was as if it had been roughly twisted to the point of damage, and now Cas was afraid to attempt to move it.

"Wait," Dean forced out, "your arm."

Castiel shot a glance down at it, as if only noticing for the first time that something was wrong. "This?" he asked, "this is nothing. I'm fine to go from here on out on my own."

For some reason - a reason Dean had yet to identify - he had the sudden urge to ask Cas to stay the night. Sure, he'd been an asshole to Sammy, and he didn't exactly seem like the warmest soul on the planet, but he was human, and he was hurt - for Dean, that was enough.

"We saved your life," Dean chanced, "it's the least you can do to stay the night, Cas."

Castiel considered him for a long moment, then nodded slowly, looking significantly spooked. "Alright, if that's what you want me to do… but I would suggest against sabotage, Dean."

There it was again – that cold, experienced and dangerous tone that sent a cold thrill through Dean. He tried to ignore it, smiled even, and glanced around the small cave. It was man-made, now that he looked closer, most likely the entrance to an old mine, and was big enough to stay the night.

"Alright Sam, can you find us some food?" Dean instructed, pointing to the entranceway. Sam nodded (scavenging was quickly becoming one of his better talents), and ducked out. Dean turned to Castiel.

"Let's look at this arm."

0o0o0

The arm didn't take too long to patch up after all – a few inches of patchy, purple bruising and a small area of swelling was easily taken care of with some cold water, a rag and some food. Castiel, as if trying to prove a point, slept only a few feet from Dean; and he understood the message immediately. I am not afraid. You don't scare me, because I'm stronger, so try whatever you want.

After the newcomer's breathing slowed and deepened into a rough slur of sleep, Dean exchanged a dark look with Sam, fingering the knife in his belt. Sam shook his head rapidly in the dark, pale eyes warning Dean not to do it and, eventually, Dean stood down. Cas hadn't done anything to them – at least, not yet.

0o0o0

The next morning rose brown and cold, frosted leaves jewelling the ground and glimmering in the cold sunlight. Dean was alert before his eyes opened, wide awake before his senses had even caught up with his surroundings, and his body was painfully tense. Slowly, he peeled open one eye, vision opening onto the dim roof of the tunnel. He couldn't hear Sam, or Cas – and when he looked around, Dean was alone.

Rushing out of the mineshaft entranceway, Dean stopped. Sam was lying face-up on the grass, eyes covered by his hand, and Cas could just be seen slipping up into the branches of a nearby tree, silent, face blank as ever. And Sam was… Counting?

Dean nearly laughed at the ridiculousness of the whole situation. This rugged, stoic warrior, who could apparently fight of a stream of the infected with one hand, was playing hide and seek?

Sure, Dean thought as he watched, it's not your average hide and seek. Castiel was barely a shadow in the trees, sneaking with the grace of a predator, and Sam was in a defensive stance as if he were fighting the battle of his life – but still, when the younger caught sight of Cas, the game was suddenly thrown into the thrill of the chase. The two darted through the trees like arrows, like hunters chasing their last meal. When Sam finally caught up with Cas, it was only because the older misjudged a jump, crashing to the ground gracelessly.

Sam extended a hand to help the other up (which Castiel pointedly ignore), then caught sight of Dean – like a deer in the headlights, he froze.

"Uh, hi! We were just-"

"Training," Cas put in.

"Training!" Sam said.

Dean raised an eyebrow. "Well I hate to admit it, but that looked pretty fun. Mind if I join?"

Sam's face split into a blinding grin.

0o0o0

When the trio returned to the cave, panting heavily, Dean whooped loudly. "Now that, brother," he said, turning to Sam, "was fun."

"Brother?" Sam stifled a laugh, running a hand through his damp, patchy-white hair.

"Oh well I'm sorry mister-no-strings-attached!"

"I don't think you understand what the thing you just said really means."

"Bitch!"

"Jerk!"

Castiel watched the casual banter like a tennis match, face setting into a frown. "Should I… Leave?" he asked, as if Sam and Dean were having the debate of the century.

Dean shot his new friend a strange look. "Why?"

"Well, you two seemed to be arguing and I don't want to intru-"

The identical looks Cas got from both Sam and Dean silenced him. "Cas," Sam said slowly, "when was the last time you talked to a human being?"

"A normal one? I can barely remember." Castiel looked from Sam to Dean. "Why?"

"Nothing, Cas, you just seem a little awkward," Dean said quickly, subtly kicking Sam in the leg. Cas stared for a second, before apparently being satisfied that Dean was telling the truth and turning away, taking off his trench coat and folding it neatly. Beneath, he wore a plain, white shirt, covered in years of deep-set grime. From one of the pockets of his black trousers, he pulled a small book, watching as Sam and Dean drunk a little of the water they had and started to pack their small amount of belongings.

Once everything was put away, Sam and Dean carrying a pack each and Castiel in only his overcoat, Castiel shot both of them a smile in turn. "It's been nice to meet you both – I hope maybe we will meet again?"

Dean gave a small nod, trying to ignore the pit that started to open in his stomach. "Take care, aright Cas?"

Castiel, still surly even now that they had formed some semblance of trust, gave Dean a look that was distinctly unimpressed. "I think you need to worry more about yourself, Dean."

Sam and Dean laughed. "Fair enough," Sam smiled, "see you, Cas."

"Goodbye, Sam, Dean." If Castiel was one thing, it was to the point. He turned away with a tiny smile, head up, and walked away as if he knew exactly where he was going and what lay in his path. Dean watched his back until he was out of sight.

"You think we'll see him again?" Sam asked after a while, as he and Dean traipsed down the dusty, one-lane road to nowhere.

"God, I hope not," Dean said seriously.

"Why?" Sam was confused.

"Because when we do, I have a feeling either he'll be dying or we'll be."

0o0o0

Even as the winter surrounded the sky, snow peppering the ground as a harsh north wind howled through the mountains, Dean's mind didn't wander from Cas. Sam's fingers were slowly turning bluer every night, stinging with the white-hot pain of the beginnings of frostbite, and food was near impossible to find – but everything they did manage to scavenge went straight to Sam, no question.

Usually, Dean would be completely against staying in one place for as long as they were now, but desperate times called for desperate measures, and if Sammy surviving this winter meant staying in the same hut for more than a few days then so be it. Most nights, Dean would wake up in a cold sweat to the sound of the storm outside, climb out of bed as his extremities started to numb, and lean his ear to Sam's mouth just to check that he was even still breathing.

But the coldest, cruelest days of winter eventually started to fade. January dawned on the first silent night since autumn, the storm over now, and the day after that night the rain came. Outside the window, the trees and rockfaces were battered and torn at, but now the rain claimed the frost and small ice cold streams ran silently through the cracks and crevices in the uneven ground.

They'd survived.

0o0o0

Unbeknownst to them, Castiel sat huddled in a bare, rotting tree only a few metres away from the hut where they took shelter as the last dregs of the storm howled. Shivers wracked his body as the freezing wind tore through him, numbing mind and body alike. He knew he couldn't sleep, or he would slip into a deep unconsciousness from which he would never wake.

A sound shattered the frozen air and caused his cold body to flood with adrenaline. A scream. A guttural, bestial, broken scream that came from the small shelter Sam and Dean were hold up in. Cas rolled from the tree, his knees seizing up as he hit the ground sprinting, he stumbled but didn't fall. It might be too late already, but Cas had to try.

He burst through the door to find Dean holding Sam still, hushing him and trying to keep a cold cloth on his forehead. Dean's head whipped round to look at a shocked Cas, his face bursting into confusion.

"Get out, you idiot! Go!" he hissed loudly, trying to be heard over Sam's moaning.

Cas stood still for a moment, his shivers subsiding and his mind sharpening, then he sprung into action. He walked quickly and confidently over to Sam's small, convulsing form, shifting a vocally and profanely protesting Dean out of the way with a gentle, "I'm- I was a doctor. Or at least, I was training to be one, you know, before. I can help."

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I apologize for the 20 hours it took me to write this XP hoping to get out another chap some time soon, so keep your eyes peeled!