The long awaited last part of this story. As usual you can follow me at JollySnidge on twitter.

Dean wakes up in the middle of the night when something whimpers against his chest. In a reflex owing to a childhood of Sam and his clinging-limpet-arms, Dean twitches awake and wraps his arms over the shivering body on his chest before he's conscious enough to open his eyes. Moses whimpers again, the kind of soft, snuffly whimper that speaks of childhood fevers and flannel pyjamas. Dean makes 'shush-ing' sounds and raises one hand to the back of Moses' head, feeling the warmth of sleep there, the comforting heaviness of his coconsciousness. Memories of Sam, memories of Ben, prick at him and he unconsciously tries to move away from the humidly warm body that's resting on his chest, from the memories that it invokes.

Moses curls his hands against the cotton of Dean shirt and whines in the back of his throat like a scared animal trapped in a dream. "No." He whimpers, though is comes out more as 'Nnnn'. Dean gets the point and stops trying to shift him.

"Moses?" He whispers, and the body stirs unhappily.

With his heart in his throat Dean chances – "Cas?"

"Dean." It's a sigh in the shape of his name, and the child's restlessness ceases almost instantly. Dean squeezes the fragile body and leans to rest his nose on the top of his head, feeling the tightly curling dark hair bristle against it. Back when he used to sleep beside Sam (small, younger and freer) this is how they'd rested.

Painful as it is to recall, Castiel is close, closer than he's been for years - and Dean can still feel the boy's voice resonating in his ears - Castiel saying his name – recognising him.

It brings him no small measure of peace.

So the weeks pass, turning to months and finally a year. Dean raises Moses as he would have his own son, caring for him day to day, looking after him when he's sick like a worried mother hen, and taking him out hunting nothing larger than the crows that attack his primate vegetable garden.

Moses has helped him to paint the rusting metal fence that surrounds the property, and the boy became obsessed for a short while with hanging empty beer bottles on furls of string from the dead tree behind the barn. Now whenever the wind blows strongly the glass vessels chink and rattle together, a song of destruction and chaos.

Sam has visited only once from England, bringing a set of supernatural books over for Moses and watching the dark haired boy curiously as he went about his business, chirping the odd songs he sometimes sings under his breath. Dean wonders if they're ancient greek, or Hebrew, but Sam couldn't identify the language and told him so.

Dean has dubbed it colloquial Enochian – the language of Castiel's heavenly past.

Moses for his part has loosened up a little, he reads a lot and plays outside in the yard, although 'plays' might be the wrong word. He builds odd heaps of stones and stray sticks, augmented with leaves. Once or twice Dean recognises a symbol from his Dad's journals. The boy also climbs trees, sits on the roof and on one occasion Dean swears he saw him talking to a fox that had strayed onto his land.

Moses has a soft spot for all creatures, but particularly birds, and Dean has a cupboard full of boxes of trill seed, scraps of soft felt and pipettes because of the sheer number of wounded fledglings that Moses brings in to nurse.

Although the boy now sleeps in his own room, Dean has cracked open an eye on some nights and found the pale form of Moses standing in the corner of the room, watching him sleep. At first it had scared the hell out of him, now he just lets it slide and asks Moses if he'd like to lie down if he's intending to stay the night. Sometimes he does.

Moses' attraction to the supernatural novels has only increased, and he's read all the old ones, and also the new set published just before the apocalypse that wasn't. Dean's concerns that Moses might recognise himself in Castiel proved unfounded, though even Dean had trouble recognising his friend in the stoic warrior presented in Chuck's work. He was very stern and very seldom mentioned, and Dean put that down to Chuck (and most of the fans) wanting to focus on the epic-totally-not-gay-honest love between Sam and Dean.

And then comes the night Dean has been dreading.

The night the demons find them.

Dean wakes up suddenly to the sound of the bottles in the tree rattling together, the branches thrashing, and just like that he's back in Lawrence, the night his mother died, listening to the tree in the yard bend and sway in an unnatural storm.

He's out of bed, running to the kid's room in his t-shirt and boxers, bare feet slapping on the boards.

The door is bouncing it its frame, rattling and groaning. Dean struggles with the handle, but it refuses to open.

Then the screaming starts.

"Moses!" Dean hammers on the door.

'Take your brother and run, Now Dean, Go!"

He's battering down the door with his shoulder before he has time to think, listening to the sibilant hissing of the demon smoke beyond, and the sounds of struggling and screaming as the boy inside the room attempts to fight. Then the screaming stops, suddenly, and Dean feels a spike of fear.

"Pater noster, qui es in caelis, sanctificetur nomen tuum. Adveniat regnum tuum..." Moses begins to chant, voice quivering in fear even as he does so.

"Fiat voluntas tua, sicut in caelo et in terra. Panem nostrum quotidianum da nobis hodie, et dimitte nobis debita nostra sicut et nos dimittimus debitoribus nostris." Dean joins in, and the boy's voice grows stronger as he hears his surrogate father's words, strong and level from just outside of the room.

"Et ne nos inducas in tentationem, sed libera nos a malo. Amen." They finish together, and the door stops shaking, Dean shoves the remains of it aside and skids on the slivers of wood scattered over the floor.

Moses is standing in the middle of the room, a cut across his lip and his eyes huge in his pale face. He looks especially small in his plaid pyjama pants and t-shirt, shivering and shaking. Behind him the window glass has been blown out, the salt line that had been across the window is scattered in particles across the boards.

Dean wraps his arms around the shivering boy and lifts him up.

"Ok, we need to get downstairs." He murmurs. "It's going to be ok." He cups the back of Moses' head, "Ok?"

The boy nods fitfully and Dean hurries out of the room and down the stairs into the kitchen. He shoves open the door beside the refrigerator and runs down the wooden stairs beyond. Behind him the windows smash, rain and wind blustering through the salt lines. Whatever is after him it's powerful, possibly more so than anything he's ever faced.

In the basement is Bobby's legacy, a panic room. Dean cranks open the solid iron door and steps inside, lowering Moses to the floor and turning to slam the door closed behind him. Inside the vault is much like Bobby's, only painted white with the protection symbols scrawled in black. There's a bed, shelves of provisions, a gun rack and boxes of salt rounds, holy water vials and miscellaneous supplies.

"It's the same thing that killed the preacher." Moses whimpers.

"They can't get in here." Dean tells him.

"We'll have to leave eventually." The kid balls up on the bed. "They'll take said it would take me."

Dean casts about but there's nothing he can use down here, not if it really comes down to it. The demon isn't in a body, it's free flowing, so the colt in the vault and ruby's knife strapped to his ankle won't really do much.

"You're not going to win." The voice comes from outside the room and Moses closes his eyes and whines when he hears it. "We're going to cut him open, leech the grace from his bones."

Dean has never felt so powerless in his entire life.

Something bangs against the outside of the door, the wheel at its centre begins to turn and Dean snatches up the colt, for all the good it'll do. Nothing is going to shred what's left of Castiel, not while he's still breathing.

The door slams open and Dean braces himself for anything. What he's not expecting as a great, empty, nothing, a square of howling darkness.

Invisible force flings Moses at the door and he disappears into the dark.

Dean throws himself after the boy, only to have the vault door shut in his face. As he hammers on the reinforced iron all he can hear is screaming, soft laughter and the rushing of demon smoke. Dean shouts every curse word, every piece of holy writ and every Enochian syllable he knows at the door. Nothing helps, nothing will get him to Moses now, and the only son he ever had a claim to, the friend he promised to protect, will die in unspeakable pain.

"Cas!" he struggles with the crank on the door.

Light floods the tiny cracks around the door, static noise shrieks through the air and Dean's heart thumps once, loudly, against his ribs.

He's never been so glad to hear angels.

He backs up from the door as the crank twirls open and it swings towards him. Moses comes through the door, bourn unconscious in the arms of a thin figure swaddled in jeans and a hooded sweater.

Dean takes the boy from the angel without hesitation, cradling him close and checking for injuries.

"He's fine."

Dean looks up and feels a flood of relief so intense it's almost painful.

"Why don't you put him down on the bed?" The angel says gently.

Dean lowers Moses to the bed and sits down beside him.

" are you here?"

Castiel sits down beside him, lowering his dark hood, and he looks the same as he always did underneath.

"I've been here for a while."

"Playing invisible again?" Dean huffs.

"No." Castiel strokes the child's hair. "I've been here, Dean."

"Any chance of a straight answer...I heard you obliterate yourself Cas."

The angel nods gravely.

"I fell, I became Moses, I still am...Moses." He breathes softly. "And you raised me...and then something happened, where my grace fell...and I was just me again..." Castiel looks at him sideways. "Yesterday you died. Aged 79."

"Surprised I lasted that long." Dean says quietly. "So you just...came all the way back here to save your own skin?"

"This is how it always happened." Castiel tells him. "I remember it, when I was him." He touches his younger self with supreme affection, almost too hard to watch. "I was saved by a light, and when I woke up, I had two father's instead of one."

"You raised yourself?" Dean says, instead of 'You're staying?'

"Yes...and when I recovered my grace we became one and the same again." Castiel says instead of 'I won't leave you again'

"Figured you wouldn't get a nice normal family." Dean murmurs.

Castiel smiles at him.

"When have I ever been normal?" He raises a hand and touches Dean's face gently. Moses stirs between them, a small content sound sighing out of him.

"What about heaven?" Dean asks. "About, forgetting what happened..."

"You promised me a family, who loved me." Castiel says lightly. "And you have been, my friend, my brother, my father and my lover...that is all I needed."

"You could have told me that." Dean says, managing a half smile.

"I don't think even He knew." Cas says sagely, the capital 'H' evident in his tone. "And there will be time for heaven, when we are done here, young Moses will leave me, and return to this moment...and the older part of me will journey on with you."

"As long as you have a plan."

"I've never had a plan Dean." Castiel sighs, lying down slowly and curling up beside his younger self. Dean lies down on the other side, and together they lay their arms over Moses' sleeping form.