Serene.

That's the best way to describe it.

It's familiar and warm. Comfortable. Safe.

All around him, everything is clean and white. As far as the eye can see. That isn't far. A thick fog hangs low and heavy, but pure and heady, unobtrusive, unlike earlier.

Earlier.

Castiel feels the ground slip beneath his feet, a wet slide, the damp of the fog giving way underneath him and his stomach feels like he's been punched, a deep tug in his gut and he's falling,

Suddenly, there's no ground beneath his feet, none at all. He's falling, feet first, scrambling for anything to cling on to, hands flailing, mouth open in a yell that gets lost up above, up in the clean white fog that was once comforting but now as terrifying as the fall, unable to see where he's going, what he's doing, and he's twisted, body contorted as he tries to hide, to climb back up and finding nothing and suddenly he can see the ground, just a few meters below and he can see his shadow getting closer and closer and closer and he's falling and it's going to hurt-

His body jolts, the squishy mattress too soft underneath him, too much give and he bounces as he's suddenly upright, scrambling to find his balance on the unstable surface, disorientated and terrified and the room is too noisy and too dull and he can't see. His throat hurts and it takes him a second to notice that the noise is coming from him, hard and grating and rough yelling out of his throat, the sound forcing its way up.

He's not alone, Sam crowding through the doorway, Dean half a step behind him, both looks of terror on their face. He can hear them asking what's wrong, he can see the fear in their eyes, the panic in Dean's, the sudden recognition as he realises what's happening. He feels a hand on his arm, but he can't tell whose, and he stops yelling, the noise petering out in his throat, scratching and fading and all he can do is breathe and scramble away, getting away, stumbling as he disentangles himself from the sheets that are damp from sweat, pushing past the Winchesters and running down the stairs, bare feet on the floorboards and the rugs and out the door and suddenly on gravel and then on grass and he's still going until he can feel the cool air in his lungs and can hear himself breathe and he can feel his heartbeat and he can hear birds in the trees above him.

He dropped to his knees, palms flat on the ground, the damp grass peeking through his fingertips. It was only then that Cas noticed the cold silver metal in his hand.

Sam looked up when he heard the sound of yelling, deep and dark and desperate, instinctively looking for Dean, not unused to his brother's nightmares. The first few times he'd helped, but he quickly learnt that Dean didn't want him at times like that.

But it wasn't Dean. His elder brother had sat bolt upright the same instant that Sam had, ignoring the ache that he must have been feeling from spending the night on the floor. In the instant that it took them to realise that it wasn't either of their yelling that was ringing through the cold cabin, they were on their feet, clambering for the stairs to Cas.

Sam got there first, faster than Dean, shoved aside as his massive frame took up the entire doorway. Cas was thrashing in the bed, limbs twisted and tangled, his head turned to the side as far as it would go, tendons pulled so far they jut out in his neck. They had only just made it into the room when Cas's eyes snapped open and he was upright, hands clawing at the covers, the metal of the chain tying two fingers together, clearly lost, confused, absolutely freaking terrified. Dean stepped forwards, trying to keep the fear from his face but probably failing, recognising suddenly what was happening. Cas had had a nightmare. A really bad one.

Instinctively he reached out, placing a hand on Cas's arm, trying to anchor him down.

"Dean, don't-" Sam warned him, understanding the instinct to protect, to comfort. He'd tried it a few times himself, and each time was the same.

As Sam had expected, Cas flinched at the touch, jerking out of the loose grip and bouncing in the bed as he scrambled away, almost falling from the bed in a need to get out. Dean jumped back at the movement, and Sam spared a look at him. He looked like he'd been slapped.

They followed as Cas ran down the stairs, lagging back, watching him as hurtled out of the door, running out and under the trees, stopping eventually, tiny in the distance. They had ran after him, keeping their distance, but not letting him get too far.

"Nightmare." Sam commented redundantly, taking a step forward, towards Dean.

"Yeah, I got that, thanks." Dean muttered back, not taking his eyes off the small figure.

"Man..." Sam sighed. "Are you going to go after him?"

Dean glanced round at Sam. "Yeah, like that's gonna help."

"It might."

Dean straightened up, shaking his head, wiping a palm across his mouth.

Cas didn't know how long he stayed there, kneeling in the grass. He didn't notice he was shivering for a long time, aftershocks of panic still running through him, clutching tightly onto the anti-possession charm until the metal dug into the flesh of his palm painfully, the pattern leaving an imprint. The damp sunk through the material of the sweatpants, and his legs became numb, peaceful in the cold.

Eventually, despite the damp and the cold and the shivers, he calmed down. If anything, these helped, grounding him in his body, dispelling the nightmare that was rapidly fading from his memory. The sense of unease stayed, but even that began to drift away, lulled into a state of complacency, the birdsong and the soft rustling of the trees above him soothing away the ache in his chest. Even the cool air felt like a caress.

As he clutched the blades of grass in his hand, he became aware of the soft noise of crunching, footsteps coming up behind him. He sighed, his chin hanging against his chest, slightly annoyed at the interruption just as he was beginning to feel soothed.

"You'll catch a cold if you stay there much longer." A voice behind him softly announced. Cas didn't look round, he didn't have to. He'd know that voice anywhere.

"The common cold can't be caught from cold temperatures." He replied, pulling at the blades of grass with the pads of his fingers.

"Yeah, but pneumonia can be." Dean corrected himself. "That one ain't so fun, either."

They stayed silent for a moment, and Cas could feel Dean's eyes on his back. It was an odd sensation, the feeling of being watched, without seeing it happening. It made little logical sense.

Dean watched Cas, a close eye on him. He was shaking, whether from the cold or the nightmare he didn't know, though perhaps it was a combination of the two. Cas didn't seem to be minding the cold, despite the fact that his arms were bare, and dean sighed, tugging off one of his shirts and stepping up to Cas, putting it around him carefully. He didn't miss the flinch at the touch, but noticed that his friend didn't actually move away, or shrug off the fabric.

Cas looked up, weary eyes looking up at Dean. He had dark circles under his eyes, and the Winchester wondered how much of the night had been spent in restless sleep.

"Is that what nightmares feel like?" Cas asked quietly, and Dean sighed, shrugging slightly as he turned away, looking into the forest.

"Guess you've never had one before." Dean contemplated. He realised how strange it must have seemed, to someone who was unused to it. Falling into unconsciousness only to think you were awake. Being completely safe but thinking that you were not, that something was after you, reliving worst memories. It sucked that he'd started with a nightmare, and not a dream.

"No." Cas agreed. "I can count the amount of times I have fallen asleep on one hand. I haven't had much opportunity to dream." He plucked the blade of grass, holding it in his hand, ignoring a shiver that shook his entire body. "I've walked into yours many times, but it never.." He looked up to his friend standing a foot away, whose face turned to a frown. "I witnessed your fear but never was able to feel it for myself."

Dean took a step back, slouching back against a tree. He knew Cas had visited his dreams on more than one occasion, he knew that Cas had been there at times when he had woken up screaming. They never talked about it, and any other time Dean would protest it, would have shrugged it off, called Cas a lurker, a pervert. But right now? With Cas shivering on the frosty ground, the echo of his nightmare still sitting in the shadows under his eyes.

"One of the perks of being human, Cas." He sighed, scratching at the overnight stubble along his jaw. He remembered one of the many nightmares he had, a specific one, one that was probably closer to memory than to imagination. He was down in the pit, and he was carving and clawing into a soul, reaching the heart, the deepest part... and then the memory turned, flowing bright and clean, whiting out and suddenly there was something else, someone. Familiar bright, blue eyes and a stoic expression, taking the tools from his hands and tugging him away, one firm hand burning into his shoulder.

The second part of the dream took a while to solidify. For the first few months it never would, only staying down there, tearing and ripping and slicing and dicing and he would wake up screaming. The first time that Castiel appeared in his dream to save him was the first time that Cas had been there when he woke up.

He didn't want to think about the fact that he'd probably been calling for the angel in his sleep.

And then he remembered when he was a kid, and all the times that he and Sam had shared a room, a bed. And the times that Sam would wake up screaming from a nightmare, would cling to Dean and fall asleep against him.

"You know," Dean began. "I don't have a bed here. Sammy gets the couch, you have the bed."

"I'm sorry, I didn't mean-"

"No, man," Dean waved his hand, cutting him off. "All I mean is, the floor ain't comfy. And, well, the chair in your room is."

"You want to sleep in the chair?" Cas clarified, peering up, frowning slightly.

"If you don't mind sharing a room." Dean shrugged. "Whatever." He reached out a hand, offering it to his friend. "We should get going. Got stuff we need to get done today."

Cas stared at the hand as if baffled by it, before slowly taking it, allowing Dean to heft him to his feet and make their way back to the cabin.

Reviews are, as always, greatly appreciated.