Ok, I have to clear a few things up for you lovely people before you start reading this, just in case you all get pissed at my haphazard writing every time an update is posted (my writing isn't always haphazard, I promise…this is just kind of turning out muddled).

This eh, 'story' is a running timeline of the present, intercepted by a collection of flashback 'moments' between Dean and Castiel leading up to their 'union'.

It takes place pre-apocalypse, but I am planning on re-locating the 'pizza man' scene from season 6 simply because it fits with my timeline. I think we'll all agree that it could have happened at any time and is not absolutely relative to season 6. Some other small facts might be tweaked.

Paragraphs written in normal text are taking place in the present timeline, post-angel-sexyness. These are in chronological order.

Paragraphs written entirely in italics are flashbacks. They relate to incidents that have some sort of importance to the Dean/Cas dynamic. They can be read as separate incidents not really in any specific order, but will generally be presented in order of increasing significance…

Text in italics during normal paragraphs, and text in normal form during flashbacks, are inner thoughts (pretty self-evident, but it doesn't hurt to explain anyway)

I really hope this little list hasn't put you off reading this…So I'll leave you with the summary and hope you stick with me through my madness.

Title: Secrets
Rating: M (for the content of some flashbacks and later chapters)
Pairing(s): Castiel/Dean

Warnings: The ever-present obvious blasphemy, male-on-male action (again, pretty obvious), general descriptions of sexual acts. Also, my jumbled and completely ridiculous writing might drive you to insanity…I feel it's appropriate to include this in the warnings.

Summary: Sam has noticed a change in Dean's behaviour, and with it a change in their hunts – every creature seems afraid of Dean and Sam can't work out why, but he knows it makes him nervous. Dean is keeping the reason hidden from his brother, for reasons of his own.

Day 11 – 1.02 AM

It had not been a subtle or gradual change, Sam thought to himself. It had happened very suddenly, and after one week, it had been undeniable.

He lay awake, sprawled on his back and staring straight at the ceiling, in the latest cheap motel bed he was temporarily calling his own.

The circumstances of their lives were constantly changing; the situations they found themselves in were unpredictable and chaotic and always a new experience…and yet, some things always remained the same.

The motel rooms changed, but were always comically class-less establishments with suspicious stains on the mattresses, a smell of mildew in the kitchenette cupboards, mould on the bathroom tiles.

There were often creatures they had dealt with before; they had established protocols, rules and go-to weapons. When the creatures were new, they could always count on Bobby. When the situations were over their heads and threatened to overwhelm them, they could usually count on Cas.

The all-night diners changed; Dean's order didn't.

The motels changed; the state of the rooms hardly ever did.

The names on their drivers' licenses and FBI identification cards changed, but the air of authority and confidence was unwavering, always unchallenged.

Their schedules always changed, but the essentials remained the same; a running set of core details that never varied all that much.

So why now, deprived of sleep and fidgeting with the sheets between his fingers, did Sam feel an uneasy feeling climbing up his spine?

He had lived with this feeling for ten days now. Ten days had passed since all this started. At first he thought it was an incredibly awesome stroke of luck, that the nest of vampires they'd tracked across three states turned out to be clumsy, fleeing cowards that proved incredibly easy to kill. That the rogue psychic in Wisconsin who used her powers for increasingly evil deeds had seen them coming, and their meticulous planning on how to surprise her had been unnecessary; she was imprisoned the day before they reached her town, after apparently turning herself in to police.

By day six Sam attempted to convince himself that it was a bunch of weird coincidences. The pack of young skinwalkers - who banded together and staged killing-frenzies on large groups of police officers for kicks – had just happened to flee for their lives before two humble hunters for some completely rational reason.

Day seven brought with it the point where Sam's denial had crumbled, and he had accepted that the instinctual sense of unease had a justified reason.

He had sat alone in the motel room, mentally scolding Dean for taking so long collecting their food. Anna had appeared without warning, and his initial curiosity about her appearance had quickly led way to an understanding that this was not a pleasant visit. She looked void of emotion, like a machine, and Sam had sensed she had entered some sort of detached battle-mode. She had accidentally short-circuited the entire block and the surrounding area just because Sam had cautiously asked her if anything was wrong.

He recalled, with a sick feeling in his stomach, the way her eyes had trained straight on his; boring accusing but saddened holes into him. He had instinctually backed away from her, until his back had bumped the wall beside the door, maintaining eye-contact. She must have just acquired her knowledge mere moments before finding him, the initial shock having just given way to the strange robotic way in which she conducted herself. She found an air of calm in her voice, and spoke. She had visited the prophet Chuck, who had envisioned the future; a future in which Sam had 'fallen off the wagon', as Bobby or Dean would put it, and had turned once again to tapping into a reserve of demonic power. This was unacceptable, and in doing so Sam was jeopardising the entire 'plan'.

Anna had taken it upon herself to eliminate this threat.

Sam had gaped at her, wide-eyed and disbelieving. She stated calmly, completely emotionless, that Sam had to die. She had thought this through, she explained, and had decided to disobey her orders and take on the problem. Leaving Sam unattended to 'flourish'; that was just foolish.

Sam braced himself; there was nothing he could do under such a sudden attack, by a being that was more or less un-killable. She had raised her hand in preparation, her mouth appearing to want to say something, but she was interrupted.

The door swung casually on its hinges to reveal Dean standing on the threshold. His eyes had shot open when he realised what Anna's intention was, and he had instantly dropped the food he carried to place himself between the angel and his brother. Not even knowing the reason behind her decision, Sam had thought. He's sacrificing himself for me, and he doesn't even know why. He could sense Dean didn't care; he never would. Family comes first, no matter what.

Sam remembered how his heart had experienced a painful tugging sensation at that; Dean's unwavering and infinite loyalty to family, his complete and utter trust. Dean held his head high and his arms taut, staring down a being neither of them could dream of defeating.

"Touch him…and you'll die. I'll make sure of that."

Sam almost flinched, knowing this would at best have no effect on their fate, and at worst would enrage her again.

"Please, Dean." She calmly requested, a hint of disapproval and regret in her eyes. "I don't want to harm you. Stand aside."

"Hurt him, and you hurt me." Dean had replied, his head dipped slightly in warning. Sam watched, waited, on baited breath. A twitch of annoyance passed Anna's angelic features.

"Dean, this must be done. Stand aside." Dean allowed a moment of silence to hang between them.

"I don't think you understand." He said slowly and deliberately, his voice lowered in pitch and volume.

Anna looked as though she was preparing another angry retort, or perhaps preparing to simply smite them both, when suddenly Sam saw her face undergo a rapid and dramatic change, as though reacting to words that weren't being spoken. Her annoyance and calm faded; replaced by something that resembled mild panic.

Panic?

Sam had studied her intensely, searching for a better explanation. But no, it definitely appeared to have been a flash of mild panic. She had quickly suppressed it, and now something that looked like unease and severe annoyance crossed her face. It was a different look of annoyance than before, Sam noted. She gave a half-hearted smile, an acceptance of defeat that also showed hints of amusement.

"I see." She said, her eyes focussed solely on Dean. For a moment Sam had felt that he was no longer even in the room, despite being the centre of the disagreement.

When she spoke next, Anna was no longer angry, or bored, or irritated. She sounded almost…pleading. Apologetic. Cautious, as though suddenly speaking to Dean was like treading on delicate eggshells.

"Dean, you have to understand…"

"Oh, I understand alright." He cut her off and she fell silent. Sam could see her evaluating the situation in her mind; weighing up options. For some reason, she appeared to come up empty-handed.

"Like I said - you hurt him…" Dean repeated. He paused, for…dramatic effect? "and you're hurting me." He emphasised the last word and Sam's brow knitted together in confusion.

She physically took a step backwards, while Dean stood rigid; unwavering. With a look that Sam couldn't decipher, she had vanished in a flutter of wings, leaving both of them alive.

Yes – there was definitely a reason for his creeping sense of unease; Sam knew it. He just couldn't figure out exactly what the reason was.

And now it was day ten. Well, technically, very early in the morning of day eleven. He still hadn't figured out why Dean suddenly seemed to inspire fear in the lowly creatures they hunted, or how he had deterred even the vengeful plan of an angel. At first he had barely registered it; put it down to luck. Then he noticed, but denied it to himself because that would be too damn weird, but after the Anna incident… it couldn't be put down to coincidence. It couldn't be supressed or ignored.

It made his skin crawl, not knowing.

7.32AM

"Sammy, you awake?"

Dean's voice slid over him like a ragged blanket, rousing him from sleep. His head felt heavy, his eyelids protested at being forced to open. Sleep clung heavily to his entire body.

"I am now." Sam had hissed through gritted teeth. He flicked his eyes lazily to the alarm clock by bed; 7.32AM. He had got approximately 3 and a half hours of sleep.

Not enough.

He pulled himself into a sitting position, back resting against the head board, letting the sheets fall around his hips and legs. Dean had already jumped into the shower, and was belting out Nobody's Fault But Mine in an over-exaggerated manner, complete with a god-awful imitation of the nonsensical wailing vocal parts. Sam grimaced in the direction of the bathroom.

It was unusual for Dean to wake up earlier than Sam at all, never mind this early. Sam worried at the inside of his lip with his teeth; it seemed that anything and everything Dean did now was subconsciously added to Sam's growing list of side-effects… symptoms…of this new and unexplainable change.

Dean emerged from the bathroom, still humming the bizarre guitar-vocal mish-mash parts of the song, a towel wrapped around himself. He stopped in front of Sam at a particular part in the song, pointed towards him, and again over-exaggerated the vocals, like he was on stage at a concert and Sam was his adoring audience. Sam raised his eyebrows at his brother, huffed disapprovingly, and made his own way to the bathroom.

10.04AM

After showering and grabbing coffee and sandwiches (well, Sam mused, at least he had the sense to start the day off on sandwiches. I mean, blueberry pie for breakfast? Who does that? Urgh) they loaded themselves into the Impala and headed out.

To another nameless, faceless town in the middle of nowhere.

It was almost certainly going to be a standard hunt. Sam might even have gone as far as to brand it as easy – a simple demon problem (at least one but at most possibly four, according to the testimony of the panicked girl who had contacted them on John Winchester's cell phone). The demon had taken the body of the frightened student's room-mate, and she strongly suspected that her boyfriend and at least one of his friends had also been…changed. They had been travelling around campus causing trouble just for the sake of it, but then it all changed – they began murdering young women.

Even before all this began, Sam might have risked a feeling of optimism before the hunt even began; demons weren't nearly as hard to dispose of as some of the other creatures they encountered. Exorcising the occasional demonic scum was almost like a break for the Winchesters.

Almost.

Now though – Sam chanced a sideways glance at Dean with gritted teeth – he was simply intrigued as to how the situation would play out. Skin walkers and vampires fled in fear; humans with supernatural abilities would apparently rather rot in prison than face it, whatever the hell it was, and even angels retreated.

Sam forced himself to relax his tensed jaw. He kept looking at Dean in his I-hope-this-is-subtle sideways glance, studying his profile. He drummed his fingers on the steering wheel in time to whatever mindless radio-station-crap was being pumped out the Impala's speakers, gazing thoughtfully out across the road.

What are you, Dean? What's…in there?

"Dean?" Sam chanced, turning his head towards his brother in a mock display of only just acknowledging him. Luckily, Dean didn't seem to realise Sam had been watching him before.

"Mmm?" Dean's eyes flitted to the radio, back to the road. He fiddled with a knob, emitted a satisfied 'ah ha!' when he found a worthy station.

In the wake of Sam's silence, Dean's shoulders tensed. He gently pushed on the knob he had twiddled before, and a blanket of quiet filled the car.

"Sammy…" Dean's voice was low, exasperated. Sam knew he would be met with this reaction. His brother didn't want to discuss it, any of the three previous times Sam had tried to bring it up.

"Come on, Dean." Sam replied, keeping his own voice cautiously lowered and filled with as much patience as he could manage. "You know you're gonna have to explain it to me. Is something wrong? Did something bad happen?"

"No, and no."

Eyes glued to the road.

Sam pushed more persistently, aware of the line he was treading on but unable to drop the topic yet another time. He continued in a calm tone. "How am I supposed to trust you, if…"

"You don't trust me, Sam?" Dean cut him off, sounding suddenly angry, but also as though he was trying to mask hurt. "You know I would never do anything to hurt you, come on man."

Dean's brow furrowed deeply, and the gaze he had momentarily moved to Sam returned to the stretched expanse of highway.

Sam did trust his brother, with his life. If there was one person he could count on to never betray him, to keep his word, to always just be there – it was Dean.

Which is why this recently-acquired feeling of wariness picked at his brain so uncomfortably, squirmed inside his skull like a parasite.

"Ok. I trust you."

Four failed attempts.