A/N: AU from SPN season 05 and presupposes the angels have had dealings with aliens in the past. And that they (the angels) were created before the earth. The Dark World also takes place slightly differently, but it's not particularly important.

o0o0O0o0o

The first time Steve sees him leaves an impression; a kindred spirit to the impression Bucky made when they'd met all those years ago and the older boy had saved him from bullies Steve had been trying to save someone else from.

This situation is more or less the same. Steve had encountered bullies, and he'd done his level best to stop them. As with so many of these encounters, Steve had ended up picking a fight he couldn't possibly hope to win. The only thing that marks this occasion as different is that someone who's not Bucky steps in. It's only when the guys had been run off that he thinks of it as strange.

Steve has spent an inordinate amount of time fighting in back-alleys when he has next to no chance of coming out on top, but he can only recall two people that have ever bothered to come to his rescue. Bucky, and this odd blue-eyed stranger.

Most people don't bother, content to ignore a person in need (even if Steve's not. Really. He can handle it). "Why'd you help?" he asks, accepting the aid gracefully despite his annoyance – he could take care of himself, thank you very much.

The man tilts his head, birdlike, blue eyes watching him intently. "It is rare to see a soul as beautiful as yours. I wished to see the circumstances that shaped it." His voice is low and rough, vaguely like the crush of gravel underfoot.

Steve has no idea what to say to such an odd statement, and the unlikely duo fall into an uncomfortable silence, Steve watching the stranger, while the stranger stared back, unblinking.

"Well, thanks," he says finally, shifting in his discomfort. "I'm Steve. Uh, Steve Rogers. I appreciate the help, Mr…?"

The man ignores the unspoken question, instead nodding once to the first. "Thanks are unnecessary. It was not your destiny to fall here. The outcome is unchanged."

As Steve is left floundering for a response for the second time in as many minutes the man blinks once, cocking his head as though listening to some far-off sound. "I must go," he says, turning abruptly. Steve follows him out of the alley, but by the time he turns the corner, the man is gone.

o0o0O0o0o

The second time Steve sees the stranger he's not aware it's him. He's not aware of anything save the thunderous cracking of ice and impossibly loud roar of the ocean as it bursts through crushed metal and broken glass.

He doesn't really see the man at all. Steve can only feel the gentle burn of holy light as it sweeps through the wreckage of the plane, cradling him as gently as it can and whispering in a voice that breaks what little of the glass is left.

"There is more yet meant for you, Steven Rogers."

The words aren't meant as comfort, but Steve feels oddly at peace as the darkness and cold consume him.

o0o0O0o0o

Steve doesn't see the stranger for nearly 70 years of restful sleep and quiet dreams. He wakes to a new world full of rushing people and bright lights and unfamiliar faces, and for three weeks is constantly overwhelmed by the sheer absurdity of it all.

Then the aliens arrive.

He's just started to get back on his feet when the mess with Loki and the Tesseract begins, and meeting an old friend's son hadn't helped the way he thought it would. Tony is abrasive at the best of times, and Steve's off-kilter and defensive and reacts way more harshly than he should to the unwarranted insults and ill-thought humor.

The crisis helps. Steve's not sure what that says about him, but the opportunity to take charge and fight is so familiar it's as much a release as it is terrifying. It's horrible, as all battles are. Worse even, for the civilian population taken completely off-guard and unable to evacuate quickly enough. But he's got a team, has a fragile understanding with Tony, and most of all, a purpose.

None of that could ever be enough to distract him from the stranger's dramatic arrival.

Still, he misses the very first signs of the stranger's appearance. Lightning flickers, but Thor was flying high, already knocking Chitauri from the sky with bright flashes of electricity. Windows shatter, but bullets (or what passes for bullets from the alien guns) are smashing into practically every building in the city, and if not bullets, then the Hulk.

It's only when every alien in sight collapses with hands scraping over helmets and ears that he notices something is amiss. The Chitauri cry out in pain and even Natasha cringes at his side.

He doesn't hear it. Whatever noise is crippling Manhattan has left Steve totally unaffected, and he takes advantage of the lull to dispatch the Chitauri around Natasha, defending her while she is unable to move.

"Your soul is pure. I had thought…" a voice whispers in awe before abruptly switching topics. "I have not worked so hard to stop the apocalypse to allow these creatures to destroy my Father's most beloved creation. I will aid you."

The pained shrieks stop as the voice tapers to silence. One of the massive, whale-like creatures ceases writhing in the sky, but that is not the reason Steve's gaze is drawn there.

Inexplicably his eyes are drawn straight toward a familiar figure in a trench coat; a presence Steve had both known was there but hadn't expected at all. He knew that man, could easily recognize a face he'd only seen once through his serum-enhanced memory.

Then light flares, blinding and brilliant and burning and the whale-ship falls, a burnt-out husk of scorched flesh and armor.

Panicked and confused voices screech along the comm channels, but Steve pays them no mind. Today Manhattan has not just avengers, but a guardian angel as well.

Loki doesn't stand a chance.

o0o0O0o0o

Steve is surprised when the man appears in the tower, watching the Avengers surround a beaten Loki with an odd expression of mixed sadness and bemusement. He's not though, when at least half of those weapons are turned on the man, who looks entirely unfazed.

He took out something the size of a tower with little more than a touch though, so Steve's pretty sure his lack of concern is warranted.

He steps forward, eyes locking with the not-quite stranger's. "Been a long time," he says casually, noting the wary curiosity he can all but feel radiating from the other Avengers. "Do I get an introduction this time?"

That bird-like tilt of his head is something Steve remembers, but now it strikes him as funny for some reason. His lips twitch in good humor at the man's confused expression.

"I am Castiel," he intones seriously.

"What are you?" Tony interrupts loudly before an awkward silence can set in. To be fair, there's not a person in the room that wouldn't like to know the answer to that question.

That intent gaze turns its laser focus on the billionaire. "I am an Angel of the Lord."

"Bullshit," Tony returns without hesitation. Iron Man's face plate is down, Tony likely taking readings of some sort, but the dismissal is clear.

Loki laughs. Clint's eyes narrow at the sound, fingers tensing on his bowstring. He hadn't so much as glanced away from the Norse deity when Castiel arrived; though Steve understands enough about the agent that he knows the man was aware of every word.

Clint is not the only one to look unhappy. Castiel's gaze meets Loki next and he strides forward, Natasha's sharp warning ignored. She fires without hesitation. Disturbingly, the bullet is also ignored, simply falling to the ground with no blood and only slightly damaged clothes to show for it. That too disappears.

"Humanity's mythical peace-keepers," Loki drawls, "could not possibly exist. We are the gods. We are the power, here."

"My existence does not supersede your own, nor yours mine. And you have no power over the earth, Thanos," he replies, lips curled faintly in disgust.

Thor twitches at the name, eyes going wide.

Loki sneers. "I am not he."

"Nor are you Loki, now." He reaches out, two fingers touching the deity's forehead. Loki's eyes, which had been a piercing blue before, glow white before fading to a softer green. They fall shut as all tension leaves the deity's body.

"What has been done to my brother, angel?" Thor demands, and Steve swears he can hear thunder rumble in the distance.

"It has been a long time since Thanos' presence has been felt so near the earth. Your brother has been freed of his influence," Castiel replies serenely in face of the very real threat Thor presents.

"Wait, wait, wait. So you expect us," Tony sweeps a gauntleted hand around to encompass the six Avengers, "to believe that you," he jabs at Castiel, "are an 'angel of the Lord' and that he" another jab, this time at Loki, "was mind-controlled into attacking Manhattan with an army of aliens?"

Castiel's eyes narrow faintly, and the sound of thunder booms in time with the abrupt flickering of the Tower's lights.

He sees his team staring at shadows on the walls from the corners of his eyes, but Steve can't tear his gaze from the brilliant sight before him.

Immense wings, each feather a prism of shining lights burns into his retinas, and Steve sucks in an awed breath. Castiel's startled gaze meets his own, and the angel, for he can be nothing else, looks inexplicably pleased at his wonder.

He vaguely recalls the words said to him during the battle. Your soul is pure. The angel had shared his wonder. At him. The boy from Brooklyn.

Steve is both terrified and humbled to be so regarded by an angel.

"Your father knows of what I speak," Castiel says to Thor, and Steve is abruptly reminded of the conversation they were in the middle of. "Take the scepter to him, and remove the Stone from Earth. It has no place here." With that, he vanishes.

Thor is so surprised he doesn't argue.

o0o0O0o0o

It's two years later and the world is crashing down around his ears once more before Castiel reappears for more than a few stolen moments. Steve doesn't even bother saying hello, turning a devastated gaze toward the angel.

"You fixed Loki," he whispers brokenly. "Can you fix him?"

Castiel seems to know who Steve is referring to, which he is thankful for, since he's not sure he could bring himself to voice his name. "I cannot," the angel replies solemnly. "Spells are simple to break, but the mind is a strange and wondrous thing. At best, I could make him forget. If he is to be whole, it will not be through my Grace."

Steve closes his eyes with a sigh and they sit in silence for a long moment. The concrete walls are a chilly presence at his back, and he welcomes the cold's clarity. "Fury?" he asks, slightly ashamed it took him so long to recall that there were those outside the Winter Soldier the angel could help.

Sam and Natasha and Maria are waiting for him to get his act together. They don't have time for this.

"Already done," Castiel murmurs.

"Right."

"I would help you, if I could," the angel says softly.

Steve nods, but there is nothing more to say. Castiel has helped him, whether it feels like it or not, but Steve is too drained and too angry at Fury and SHIELD to care all that much. Quiet descends on them once more.

Eventually the angel leaves, and Steve steels himself for a meeting with three spies and a soldier. He has Hydra to deal with, and they can't afford to wait any longer.

o0o0O0o0o

"Steve," Castiel says, and that's all it takes for Steve to know that something is very, very wrong. It's been a year since SHIELD was dismantled, and the Avengers have taken to using Stark Tower as their HQ. JARVIS had alerted him to a call from an unknown number, and the fact that no one but the Avengers and their various friends were supposed to have it had made him curious enough to answer.

"Castiel?" he asks, and the soft chatter from the rest of the team ceases. Loki doesn't bother with subtlety, green eyes fixed on Steve's phone. None of them had seen the angel since the battle of Manhattan, and Loki in particular had wanted to speak with him for some time. "What's wrong?"

"I… I don't know what to do," Castiel blurts out, more emotion packed into that one statement than all the words Steve has ever heard him say previously.

"What's wrong?" Steve repeats more firmly. He's not sure what any of them can do that the angel can't, but he owes it to him to try.

"I Fell," he says finally, and Steve can practically hear the capital on that one word. "I cannot reach Sam or Dean," he adds, voice slightly bitter and unsure, as though Castiel's not sure he wants to be able to.

Steve doesn't know who either of them are, and isn't sure why the thought of the angel turning toward anyone else for help makes him uncomfortable, but that isn't important right now.

"We're in Manhattan," Steve tells him. "Can you get here?"

"I have no means to," Castiel replies curtly. "I possess none of your currency."

Steve wonders at that for a moment (he'd seen the angel 'fly' after all) before it clicks. "Wait," Steve chokes out. "You Fell. You're human?!" He misses the team's reaction to that, completely focused on the conversation.

There's a wounded silence from the other end. "I realize I cannot be of use…"

"No, no, no!" Steve rushes out. "That doesn't matter. I – We don't…" he stops, trying to order his thoughts. "You're a friend, Cas," he starts, the nickname slipping out unnoticed. "You don't need to do things for us for me – us – to want to see you. 'Sides, I think I owe you one. More than one," he babbles, wondering where Castiel's disheartening opinion of himself came from. "Where are you?" he switches tracks abruptly, and heads to the elevator, JARVIS obligingly taking him down to the garage. "I'll come get you."

The stretch of silence lasts so long that Steve is sitting shotgun in one of Tony's cars, Tony himself planted firmly in the driver's seat, when the angel – former angel – finally replies.

"Thank you," his voice is whisper soft, but the warmth in it is unmistakable.

Steve smiles and Tony's car screeches at it shoots out of the garage toward the airport. He's pretty sure he's not qualified to teach an angel to be human, especially not in this day and age. But he can damn well try. That's what friends are for, he tells himself firmly, and talks to Castiel all through the drive, low and soothing.

Cas reached out to him. This time, Steve will make it. And he won't let go.

o0o0O0o0o

A/N: Cheese. So much cheese. (Please keep in mind that I've only seen up to half of season 08 of SPN, so no spoilers in any comments, please!)