AN: Sam/Gadreel, Destiel, Kevin and Charlie being awesome, Gadreel and Castiel as brothers in arms, issues of vessel consent, fluff and angst, Castiel with kittens: This fic has it all!

You can check my profile for a link to my AO3 account (Archive of Our Own), where I have a version of this fic that's a bit too colorful for FFN's rules. Also, if you choose to bookmark this fic, you'd best do it there. My username is the same on both sites.

Thank you to my beta reader, Furf. This fic would only have been a shadow of itself without your amazing help.

He stumbles through a vast and overwhelming desert, every glittering grain of sand a wound he cannot bear to hold. He won't lift his head to look at the horizon, for he can never reach it, even as its inexorable pull trembles through his nerveless fingers.

Pride tells him the aching years and tests have purified him. Anger presses darkly upon him, even as he drowns in his own culpability, all flaying at his skin like glass. He could have stopped it all. He failed.

Envy of the dead almost destroys him.

He stumbles blindly towards an unbearable horizon he shall never reach. He weeps in agony, tearing viciously at himself, for the desert torments him, thrumming through his very core. And his legs never give him the mercy of faltering. The wind and sand and light burn him no less.

One day, the blistering light runs dry and all his awareness becomes consumed in fire, skinning him clean, evil and bloody and holy. Anguish tears at him anew when he comes to and sees a new desert before him to wander, perhaps as undying as the last.

He just wants it all to be over, but it never, ever ends.

He stands, and walks.

Dean's voice has a thread of a tremble running through it.

"Sit down, Sam."

Alarm pools low in Sam's gut, iron-heavy, forcing the air from his lungs. "What's going on, Dean?

"I got to tell you something, and you're gonna be pissed off." Dean plunks down into the chair, his mouth opening and closing hesitantly. His forehead wrinkles. Yeah, this can't end well.

"Okay…"

"Those trials really messed you up."

That again? Sam sighs, his face tightening. "I know that, Dean, but I've been feeling better—."

"No, you don't know," he interrupts, waving his hands as though he could weave comprehension into form. "I mean messed you up like almost dead. No more birthdays, dust to dust. Well, that messed me up, so I made a move, okay? A tough move about you without talking it over because you were in a coma."

The corners of his lips turn downward, his eyes narrow. "Huh? A coma?" He shakes his head. Weren't they driving around in the Impala for an entire day after the trials? Sure, he'd been knocked clean out, but… "Dean, we ditched the Trials two weeks ago. I feel fine."

Dean's visage darkens. "You don't get it. I made a big choice, okay? You were in the hospital, and they said you were gonna die."

Anxiety curls against Sam's spine, tingling hot through his limbs. Whenever it comes to Sam and dying, Dean has a track record of doing stupid things.

"What did you do?" he demands, voice thick and rough.

"You've got to stay calm, okay? If this goes sideways after I fill you in, you could still die. Seriously, you could drop dead right where you're sitting—."

"Dean," Sam interrupts, "I'm as calm as I'm going to be. Tell me what you did." His nostrils flare as images of crossroads demons and other frightening alternatives dance in his mind.

Dean chokes on the words like they're made of lead. "I let an angel in."

Sam's brain scrambles to make sense of it. Of all the desperate things Dean could have done, talking to an angel didn't sound quite so bad.

"Uh, okay," Sam says, his heart beating rabbit-fast. "Why are you upset? You let an angel in the hospital room to heal me?"

Dean looks away, eyes dark. "Seriously man, you got to stay calm—."

"Dean, whatever it is, just spit it out!"

He meets Sam's eyes, voice whisper-quiet and small. "In you."

Sam frowns, his mind a cloudy storm of confusion, because nothing makes any sense at all.

Dean leans forward, exhaling harshly. "I let an angel in you. He said he could heal you, and he is."

Sam inhales and holds the breath tight, feeling the burn of it in his lungs. Understanding arises all at once, flowing through his entire body in a single, white-hot rush.

"You let," and Sam has to pause, breath tense and heavy, because he knows he's two seconds away from shouting. "You let an angel possess me? The hell is wrong with you, man?"

His brain chooses that moment to play catch-up, and Sam's thundering heart nearly halts. Dean had just finished telling him to stay calm or this would all go sideways; that he might drop dead instantly if he didn't keep his cool.

Oh, god. No.

"Wait, wait, it… Is it still inside of me?" Sam sputters, fear coiling in his gut, hot and startling. Another rush of anger boils over, because this is too much, even for Dean. "How? I never invited it in!"

Dean drops his face into his hands, because apparently looking his brother in the eye has become too much to manage. "I tricked you into saying yes."

Sam springs to his feet, red-faced and shrill. "You… I…! What the hell, Dean?" Fear and anger both run frigid and hot through his veins, because there's a freaking angel inside of him somewhere and obviously, possession never goes wrong. "Why would you make a choice for me like that? You know I'd rather die!"

"You were in a coma and we were under attack by other angels! I didn't have time to friggin' ask, all right?" Dean shouts back, jaw clenched. "Look man, you can kick my ass all you want to, but right now, you need to understand if you kick him out, you're dead."

"Dean…"

He stands slowly, as if any sudden movement might make Sam flee. "Be pissed at me, okay? Yeah, I let him in. But if you kick Zeke out now…"

Sam bites down on his tongue, trying to calm the cascade of pure, white-hot rage encompassing him. "Zeke? Is that his name?"

"Uh, well, that's what I call him," Dean stammers, his voice softer. "When he saved my ass, he was doing the whole 'witness protection' thing to hide from the other angels, going by Ezekiel. But his real name is Gadreel."

"So he already lied to you?" Sam snaps back, his attempt to keep his voice to a minimal level all but forgotten. "Dean!"

"Just shut up, okay?" he says, holding out his hands palms up, pleadingly. "He brought Cas back yesterday, okay? Cas was dead. That reaper iced him, and Zeke brought him back."

Sam pauses, tries to catch his breath—the effort feels like trying to reign in a racehorse bare handed. "Why the hell am I just hearing about this now? If it's been…" He trails off, counting backwards in his head. "Jesus, Dean, it's been more than two weeks! Didn't you think I'd want to know an angel was riding my skin?"

"He thought you'd kick him out if we told you," Dean says. "I thought so, too."

"Damn right I'm going to kick him out!"

"No!" Dean shouts so loud it echoes throughout the room. "Sam, stop! You do that, you drop dead, right here and now!"

Sam brings his hands up and grasps the sides of his head, fingers tangling in hair. "When were you planning on telling me? Never?"

Dean's eyes narrow, but his voice remains steady. "He was gonna heal you and split, and you were never gonna know the difference."

"And why are you telling me now? What went wrong with that brilliant plan?"

Some of the fight evaporates from Dean. "I convinced him to talk, okay? Cas was here, and all these angels are after him. Turns out they don't like Zeke too much, either. And Cas… he would've known, Sam. He would've figured it out."

Sam turns a livid glare on his brother. The topic of Castiel would end up forcing Dean's hand. "Why are you the one talking to me, then? Why isn't 'Zeke' speaking up?"

"Because I knew you'd blow your damn top, man!" Dean hisses. "That you'd boot him out first and ask questions later—oh, except, there'd be no later, because you'd be dead!"

He draws in a breath through clenched teeth, willing his heart to slow, because he really needs to calm down for a second. This isn't his first rodeo. He did all this with Lucifer before, in an ultra bad situation. This is… maybe less bad. Maybe. The angel hasn't made off with his body yet.

He closes his eyes and scrutinizes his mind for any speck out of the ordinary, but finds nothing. He finds not a single emotion out of line, not one stray thought. He hears no voice whispering in his ear.

"Why can't I feel him?" he asks, voice raw. "Last time an angel used me as a suit, I felt like I'd been thrown into an icy river and dragged down into the rapids."

"He doesn't, like, listen in," Dean says, gesturing at Sam's head. "He hides out inside your head, doing his healing thing."

A long silence follows, stretching oppressively between them. Sam shudders as thoughts of possession, of losing his entire body to yet another invading leech, roil deep and anxious within his gut.

Sam's absolutely certain he's never been as enraged at anyone, ever, as he is at his brother.

"I was ready to die, Dean."

"I wasn't!" Dean's entire body goes tense, even as he drops down into the seat. "Look, I just wasn't. I couldn't." He closes his eyes. "You'd have done the same thing for me."

That draws Sam up short, his entire body going rigid.

He really doesn't get it. Dean has never experienced possession from demons or angels. He's had a ghost overcome him before, sure, but it's not the same as an angel or demon wearing his skin. In theory, he probably can imagine it (Michael had been after him a few years ago), but imagination doesn't hold a candle to the reality.

"No, Dean," he finally says, his voice quiet even as it strains and trembles, "I wouldn't."

He can pinpoint the exact moment Dean realizes he's not kidding. An icy wave of revulsion, bitter and cold, rises in Sam. How did Dean actually think Sam would ever willingly let something possess him?

Of course, the short answer is he didn't think.

Dean's vulnerable expression lasts only a moment. He turns his head and nods once, almost as if Sam's reaction had been perfectly expected.

"You can't kick him out, Sammy. Not yet," Dean tells him. "Don't go and do something stupid because I did."

Sam finds himself again confronted with the reality of an angel hiding in his head. Right now. Sam's ready to spit and claw and tear at the thing until it leaves, because his mind belongs to him and him alone, thank you very much. And what decent angel would agree to a coerced 'yes?'

There's just the pesky detail that he'll die if he boots the intruder preventing him from screaming 'no' until his throat bleeds. He had been ready for death, before, but right now he's too busy to die, dammit.

Sam draws in a breath, cool and steady, searching for equilibrium in the sea of emotion. "What does Cas say about all this?"

Dean hesitates. "Cas doesn't know yet."

Sam shuts his eyes, running a hand through his hair. He isn't sure why he's even surprised. "Why?"

"Gadreel is spooked by the other angels. He's on their 'most hated' list, just like Cas."

If true, Sam thinks the two angels should have a lot in common. He ditches the conversation with Dean, closing his eyes to concentrate. He searches mind and body for any trace of the squatter.

"Where are you, angel?" he hisses through gritted teeth, viciously ransacking every far-distant corner of his mind for something he can neither hear nor feel. He makes an abortive gesture for Dean to shut up already, just in case he gets the bright idea to start talking again. Sam doesn't want to hear it.

Something seems to hear him, though, stirring at Sam's call. A hushed presence unfolds inside of his head, expanding slowly. Sam feels a rush of radiant, soothing warmth—as if standing next to a fireplace, burning steady on a frigid winter's day.

A voice that's everywhere and yet not answers his call: "I am here, Sam Winchester."

Sam's blazing fury cools a sliver. The angel feels small and wounded, Grace flickering like a candle in too stiff a wind. Echoes of pain not his own, tender and fresh, thread dully through Sam's body. The soothing heat he'd felt a moment ago remains, but stutters with effort, as if it's all too tiring for the angel. His Grace feels far from robust, bleeding off of the angel like a tap left to drip.

His anger further cools as he considers this unexpectedly damaged presence. Of course. The Fall. Some angels even died, didn't they?

Sam's never felt gratitude to Lucifer (one never quite comes to appreciate status as the Devil's favorite chew-toy), but those hard-won lessons with the archangel may become handy. He's capable of kicking this angel out if it comes to a struggle. Right now, it'd even be easy. He need only tell it to leave.

The warm presence draws in on itself a fraction. "Yes, though such action shall be unnecessary. I will leave if you wish. But Sam, you are not well."

Sam thinks about just skipping the pleasantries and subduing the angel, injured as it is, and forcing him far, far beneath the surface, just as he managed to do with Lucifer. But then, he'd managed that for all of a minute, but it's plenty long enough to kick an angel out. Sam's certain he can pull it off again, if necessary.

The angel shifts within him, a pulse of anxiety aching in Sam's bones, but does not protest.

It actually makes hot, liquid rage boil inside of him again. How dare the angel feel anxious? Consequences be damned, it's Sam's body, and Dean had no right to invite anyone into it. He should make it leave now…

Though, there's a perfectly good reason he avoids big decisions when he's so angry he can't think straight.

Do angels fresh off the heavenly express think any 'yes' will do? Do they not comprehend the importance of a 'yes' freely given? It makes Sam think about Jimmy Novak, and watching him beg Castiel to leave his daughter's body and take his own. Talk about duress.

Mostly, he feels gripping fear, his nerves aflame and stinging. This angel can simply overwhelm him at a moment when Sam's not vigilant and steal his body. Or, hell, while he sleeps.

"I give you my word, I will not," the angel tells him softly, accompanied by a soothing flare of warmth to ease Sam's aches. "I believe in honor, Sam."

Sam doesn't want the angel to whisper assurances in his ear, or to comfort him. He wants his solitude, his privacy. He feels caged with no options, like he's stuck in a ring with powerful lion who promises it won't bite. He can drive the predator out, but fate has rigged the exit and he'll die if he follows through.

Though, Gadreel has had opportunity before now to do just that, yet hasn't. He could have taken Sam over entirely and used him as a vessel. He could have strolled right out of the bunker one night when Sam slept, and no one could have stopped him. Sam may indeed feel caged, but the angel has not done anything overtly threatening.

Or maybe Sam's just trying to convince himself, because kicking it out means he dies instantly.

That'll have to do for the moment, it seems. It's not like he has an actual choice.

His anger cools somewhat, at least towards the angel (Dean remains another story). His anxiety, however, roiling winter-cold and heavy, goes nowhere. He'll deal with it later.

"Since you're wearing me as a suit, let's get properly introduced. I'm Sam. What's your name?" It comes out bitter, cold, and hardly sincere, but it's the best Sam can offer.

"I am Gadreel." If the angel feels offended, he doesn't show it. "I have previously hidden under the alias Ezekiel, but my brothers would know me as Gadreel." At the mention of other angels, Gadreel draws inward minutely, something akin to a shudder trying to escape.

"You're afraid of them," Sam says, a statement rather than a question.

It's not so surprising, really. Angels aren't the friendliest bunch, and helping out a Winchester would certainly do an angel no favors in the eyes of his peers.

Gadreel doesn't answer—doesn't need to, as Sam feels a rush of fear coiling sharp in his gut, feels the angel tucking into himself as if he might disappear entirely into Sam again.

"Hey? You still with me?"

Sam can only feel him through his many wounds from the Fall; a dull, pulsing throb throughout his Grace.

"You will not know I am here," he tells Sam, his voice calm and certain.

But Gadreel feels neither calm nor certain, Sam realizes. Desperation coils hot along his skin, pulsing out in dim swaths of light Sam can almost see behind his closed eyes. Certainly, the angel can hear his thoughts. The fact Gadreel doesn't disagree, or even comment, says enough for Sam.

"I would leave as soon as you are healed." It almost sounds like a plea, a request for safe harbor in exchange for healing duty.

Actually, Sam realizes, that's probably exactly what's happening here. He's still not happy about it. At all.

"You pull anything funny," Sam finally says, "and I'll kick you right the hell out. Got it?"

"Understood."

"And when I'm healed—."

"I leave."

He blows air through tightened lips. "All right. For now."

Tension unwinds between Sam's ribs. The angel's Grace goes soothing and cool against his skin, no longer threadbare and taut. The same warm glow he'd felt before returns, like soaking in the heat of the sunshine.

"Thank you. Fear not, your privacy is honored. I do not eavesdrop."

Sam frowns, because he's worried about more than just privacy. Surely the angel understands?

Gadreel's acknowledgement diffuses through Sam's muscles, fluttering and just a bit dejected.

"If you require my assistance, call upon me."

Gadreel retreats back to his hiding place. Sam's awareness of him fades into a tiny pinprick until he evaporates entirely away.

The warmth does not completely fade, however, even as Gadreel seems tuned out and tucked into wherever he's hiding. The flicker of soothing heat causes Sam to realize he's unknowingly felt an echo of the angel's presence all along.

His eyes open slowly, blinking as he adjusts to the light. Dean stares up at him in clear distress, even as his eyes shine with unasked questions.

"Sam?" he questions softly.

"Yeah, it's me, Dean."

Sam feels alone in his head, for now, though he's painfully aware there's a passenger along for the ride. The faint glow of Grace remains, whisper-soft and gentle despite Sam's anxiety, his fingertips tingling. In any event, the angel isn't present anymore. It strikes him with some measure of relief.

His gaze falls upon Dean. "You and I need to talk."

It's less talking than shouting, and it lasts half the night, but it's the best Sam can manage.

After venting at Dean and cooling down, Sam finds himself determined to learn more about his stowaway. He could just knock on the angel's hidey hole and ask, but he'd rather do the research himself. So naturally, he starts by nosing around in a dusty, acrid tome of angelic lore.

Gadreel: the Wall of God. The Watcher. In Aramaic, the variant is Gadriel, for "God is my helper."

Beyond the name, Sam finds nothing optimistic.

He stars in many roles in Talmudic, Enochian, and Biblical lore. He's the third of five Satans. He's a fallen angel, a high-ranking demon. In one telling, he even stars as the snake, tempting Eve in the Garden of Eden. One book claims he taught war to mankind. He's almost shown in a more damning light than Lucifer.

With a reputation like that, Sam thinks he might hide, too.

It would be easy to dismiss Gadreel by the lore alone, but Sam knows by now the lore doesn't always tell the whole story. The lore paints Raphael as a miraculous healer, and in reality he'd tried to bring about a second apocalypse. Gabriel certainly hadn't seemed much of a divine messenger. And Sam's certain Castiel doesn't have much to do with Thursday (though it's probably worth asking).

He'll just have to wait and see.

If Gadreel listens, Sam notes he has nothing to say. It's far more likely the angel hasn't tuned in at all.

All at once, Sam has an idea.

A special place forms when one becomes possessed, a piece of mental landscape overlapping between host and possessor. Sam knows it well, because twice before he's been there. It feels as sharp and clear as the real world, but it's made of scattered thought, of fragmented pieces of the both of them glued together.

When Lucifer had possessed him, Sam sometimes found himself summoned there, usually because the Devil wanted to have a face-to-face chat. It always had an element of consent—Lucifer could never force him there (or never tried, at least). Meg was different. Sam had found himself locked inside, beating hands bloody on the walls, no escape possible.

This headspace, the genesis of two minds, provides ideal conditions for an honest heart-to-heart. Sam might speak to the angel possessing him directly, but he'd have to endure a level of non-privacy far more vivid than his earlier conversation with the angel.

Sam's already tuned in to the landscape's rules and passive emotional bleed-through, but the angel wouldn't yet have such an advantage. Sam certainly doesn't intend to stay long enough for it to happen, either. He inhales deeply and closes his eyes, thumbing through the wrinkles within his mind for the mental headspace. He has no idea what to expect.

When he opens his eyes, he's standing in a grand library.

It has the ancient feel of the bunker's own library. A set of tables linger between two rows of bookshelves, and the Aquarian Star adorns various fixtures in the room. Featureless brick lines the walls, solid and unyielding, while the floor feels cold and solid beneath his feet. It has the same dusty scent of aged paper, and the faint taste of ink burns sour in Sam's mouth.

Beyond those details, however, it isn't like the bunker's library at all. It dwarfs it in sheer size, with floor-to-ceiling bookshelves stretching to the far-distant corners of the room. Despite the familiar smell of dusty tomes, it remains entirely devoid of books. A hearth crackles nearby with a lovely fire, radiating heat and comfort. A long, plush couch and a sofa linger nearby, tempting him to rest his tired legs.

With Meg, this mental landscape had felt like drowning in a sea of black; dragged asunder in something heavier and sharper than water. He'd never seen any light at all, just blackness and frantic terror he couldn't break free of, no matter how hard he tried.

With Lucifer, it took the form of a lonely, abandoned building, reminiscent of the one in Detroit. Colder than a clear, Antarctic night but brighter than the surface of the sun, it had streamed with eye-searing light, so luminous his bones ached with the raw agony of Lucifer's power.

Both had been awful, awful places. This library seems different.

Sam steps carefully through the grand library, eyes momentarily falling upon immaculate, empty bookshelves. The couch actually seems large enough for his long legs, unlike most. Gentle heat flows from the nearby fireplace, its light flickering steadily. It feels just shy of cozy, like the newness of an empty house just before you begin unpacking.

He pauses to stretch numb fingers towards the fire and sighs, the aroma of burning wood sharp and rich in his nose. Even if this place isn't exactly physical, it yet remains as vivid as reality in every way. At least this time it doesn't strike terror into the fiber of his being.

He's alone, but Sam had expected no less. After all, he'd have felt Gadreel long ago if the angel had dallied here. Even now, with Sam poking around, Gadreel hasn't made himself known. It makes him wonder, briefly, if perhaps the angel truly means to leave Sam in peace, as he claims.

His cheek twitches. He's never heard of a case of possession anything like this before. An angel hiding from its vessel? Healing a body from within, without taking control of it?

Sam sighs. While the scenery intrigues him, he didn't come here for the ambience.

He closes his eyes, focusing on the soft, pulsing warmth seeping underneath his ribcage. In this place, the angel can't hide from Sam, even as small and hidden as he's made himself. He clutches with a mental grip around the warm Grace and tugs, calling the angel forward.

The angel stirs at once, his confusion thrumming hot against Sam's skin. Grace shifts in discomfort, the awareness of Sam's summons leading to a pulse of worry. While he doesn't resist Sam's pull, he doesn't swiftly answer, either.

When Gadreel doesn't immediately show his face, Sam doesn't tug at the angel so much as yank. Hard.

The angel's surprise ripples through Sam's bones as he all but tumbles into the room, eyes wide and breath catching. The sight satisfies Sam more than a little, because so long as Gadreel knows Sam can control him in some manner, the better.

The angel's shock fades after only a bare instant, standing ramrod straight and expressionless.

Sam doesn't recognize the form before him. Lucifer always appeared as Nick, so he's probably seeing Gadreel's former vessel. He's tall, only slightly shorter than Sam. Well-built and solid like a barricade, though Sam still outdoes him in sheer size. Dark, dirty blond hair and green eyes rest in a face framed by a razor-sharp jawline. Verdant eyes shine with intensity, but don't seem unkind.

Wall of God, indeed. With his statuesque posture and stoic air, he's a wall of solid stone.

His skin looks bloodless and ashen, perhaps a representation of the angel's injuries, Sam thinks. He seems solid and strong enough, yet not quite healthy.

No. Stop.

Sam didn't bring him here to feel sorry for him. He pushes the would-be compassion away.

He opens his mouth to speak and stops short, a wave of anxiety not his own sweeping low and tense around his spine. No matter how calm the angel looks or how severe he holds himself, he feels none of these things, and it's all laid bare for Sam to see.

This place in a nutshell: Cruel, brutal honesty. Sam's been through this before, so he knows his way through it. The angel either hasn't caught up yet or refuses to show it.

"So, I've been reading about you," Sam says.

Gadreel's upper lip twitches minutely. As Sam recalls his research, the angel seems to view it for the first time, eyes gone distant.

"I see," he says calmly, as if he weren't awash with apprehension.

Sam quirks an eyebrow. "I thought maybe you'd want to tell me the real story?"

His face betrays only a barely-there frown, but Sam feels dread curl in the angel, shame fluttering on the edges of his awareness. There's more—a well-concealed sadness that pools somewhere cold and dark, and a restlessness rumbling through his core that doesn't fit with his stony guise.

"No, I would rather not," Gadreel finally answers, his breath a steadying one, his intense gaze never deviating from Sam. "I do not suppose that will suffice, though."

He can feel Gadreel within him, drawing thin and burrowing deeper within Sam, as if to hide from the human's scrutiny. He doesn't run away from the library, however, and Sam can't let him. He needs answers from the angel.

"I know you're healing me," he starts, softening his tone for the angel's sake. "And that's…. Look, I have to know your story. If you're a good guy with a bad reputation, I just need to know what's going on." Sam lets his lips curl into an slight, if bitter, smile. "If you're a Lucifer groupie, on the other hand, I need to know that, too."

Gadreel's face contorts, horror-stricken. Well, so much for humor.

"Would that I had ended him myself," Gadreel says, his jaw twitching.

But the angel isn't angry. Shame, frigid and knife-sharp, thrums within his Grace, chilling Sam right down to his bones.

Sam personally knows that kind of shame.

"I made a mistake," Gadreel admits, looking away from Sam to study something interesting on the wall instead. "Lucifer tricked me."

An angry part of him wants to seize upon his words and find fault with the angel before him, even if he doesn't know what they're talking about yet. Yet everything about the way Gadreel carries himself, all his emotions flowing through Sam as vividly as his own, stops him.

It strikes too close to home. He thinks of Ruby and when he accidentally started the Apocalypse. Sam's been fooled, too. And plenty of people found fault with him and didn't care to listen.

Okay. Listening can't hurt. Maybe.

"How?" he asks.

The angel turns his gaze back upon Sam. "The Morningstar appeared to me while I guarded Eden. I refused him entrance. Later, a cherub appeared to me and asked to enter the Garden so it might admire our Father's creation. Angels often came to stroll amongst the beauty of Eden, so I allowed it by." His head tilts, his eyes downcast. "Had I paid more heed, I might have recognized it as Lucifer's deception."

Sam blinks. "So, you are the one who let Lucifer into Eden?"

Well, he probably could have worded that better.

Gadreel's eyes flit up, and he exudes an overwhelming desire to flee, but stands steady. "Yes."

Sam frowns. That's a hell of a mistake, but… Is that all? Just one mistake?

"Yes," Gadreel answers the unspoken thought. "'Just one,' as you say it. But it matters not whether it was one or one hundred. My moment of foolishness ruined all Creation."

Sam watches as muscles in Gadreel's jawline tense and relax, ticking out an anxious cadence. "Can you elaborate?" he asks. "I'm not trying to put you through the ringer. I just want to understand."

The angel's stony face softens a sliver, eyes gone distant and haunted.

"I quickly realized it was no cherub, and alerted Uriel, a fellow sentry. He flew to Heaven to alert the archangels while I searched for the intruder. However, it was already too late. Lucifer had corrupted humanity, ruining the Garden."

Sam's stomach churns sourly, and he's not sure if it comes from him or Gadreel. Or both.

"And so… what? God cast you down with Lucifer?"

Gadreel shakes his head, his mouth set in a grim line. "If only He had been so merciful." He pauses a long moment, weary and exhausted. "My punishment was imprisonment within Heaven. After our Father left, the archangels blamed me for his departure, and Michael decreed I was to remain thus for all eternity. It was not until the Fall that I walked free."

Sam stares blankly at Gadreel for several moments, his words replaying in his mind on repeat. He knows the angel speaks the truth, because lies do not exist here. Somehow, that makes it somuch worse.

The angel says nothing else. He offers no words in his defense. He makes no plea of a wrongful imprisonment.

Sam wets his lips as he tries to find something approaching a calm, passive voice. "You mean to tell me you got locked up because Lucifer pulled a scam on you? For what, like the half-second you were fooled?"

"Yes," he answers. Somehow, the angel tenses up even more. "It was fitting."

Sam's not sure whether he's more surprised Gadreel's not defending himself and pinning blame on Lucifer, or that he seems to completely accept getting tricked makes him worthy of an eternal life sentence.

Sam suspects this interpretation of the angel doesn't ring entirely true. Gadreel probably enjoys his freedom and seems to have no love for Lucifer. He's just not voicing either point, for whatever reason.

Sam halts, and reminds himself again he didn't bring the angel here to feel sorry for him. He's still too angry and worried to deal with sympathy, too. The reminder doesn't quite work, though, because the heaviness weighing down the angel's spirit floods him and Sam's aching with it now.

"That seems kind of heavy-handed, though," Sam finally says, his eyes softening. "I mean, Lucifer's an archangel. Isn't that out of your pay grade?"

The angel blinks, and surprise flares briefly in Sam's chest, even as he appears as still and steady as before. "My brethren do not agree."

It finally clicks. "That's why you're afraid of Cas and the other angels."

"Yes."

Sam reels with the information. It's too much. "Who threw you in prison? God? Michael? One of the other archangels?"

"God commanded it. Michael enforced it."

"He threw you in jail forever? Because you made a mistake?"

Anger, hot and frustrated, threatens to bubble up and spill over for wholly different reasons than before. This might reign as one of the more unfair things Sam has ever heard.

A huff of air escapes the other's nose, his head shaking slowly. "You do not understand. He trusted me. My Father trusted me more than the other angels, and I failed!" He looks away, his heated outburst stilling. "I was distracted. I—."

"Gadreel, stop," Sam interrupts, lips set in a grim line. The angel starts at the sound of his name, possibly because it's passing Sam's lips for the first time. "You made a mistake." He sighs. "You didn't corrupt anyone. Lucifer did."

"If I had exercised better judgment—."

"Stop," Sam cuts in again, flustered and confused. He sighs deeply, irritation sagging with his shoulders. He's not sure whose guilt he's trying to soothe right now. Being trusted and making mistakes and feeling so, so guilty about it all hits too close to home. He swallows hard, his heart thumping as old regrets aching anew. It all pools in his temples, throbbing. "You were fooled. You made a mistake." He pauses a beat. "You didn't do it on purpose."

Sam doesn't know who he's defending, exactly. Probably himself, mostly, and for things long past. He has no reason to speak such kindness to the angel, after all.

Gadreel slips down to the sofa, eyes unfocused and arms open as they rest on his legs. He makes no attempt to hide from Sam's scrutiny. "If not for my mistake, all the ills of the world would have never come to pass." He looks up at Sam. "That is how my brothers view me, and why I took up the name of Ezekiel."

Sam flops down on the couch adjacent, sighing. "You shouldn't pretend to be someone you're not. You should just be you."

Gadreel's stony façade melts away for a bare moment, incredulous, before resuming a solid mask. "Among my brothers, my name is synonymous with the evils of Lucifer and demonkind. I have no chance of redeeming my name among them."

It's silent in the library for a long moment. "You think they'd kill you," Sam finally says, understanding. "And so, you're hiding."

"Yes." The angel's expression twists, regretful. "I am sorry, Sam, that I nearly chased away Castiel. Fear of the others overcame me."

Sam bites the inside of his cheek. Everyone feels fear, sometimes, until they learn how to deal with it, he thinks quietly. The angel may or may not hear him. "Hey, you brought him back from the dead. That's awesome."

The corners of his lips turn upward. "It seemed an unfitting end. Dean was also highly distressed."

Sam smiles faintly, anger momentarily stilled, though a thousand different things demand answers. Why did Gadreel hide from Sam from the beginning? Why did he abandon a perfectly willing vessel for one he had to trick?

"We should talk to Cas," Sam says instead.

Gadreel frowns at the suggestion, and Sam can feel terror wrapping around his spine in all the wrong places. "No."

"Cas will understand—."

"He will not," he interrupts.

Sam huffs, his eyes narrow. "Cas disobeyed Heaven a lot of times. I mean, he disobeyed Michael and led a rebellion against Raphael. If any angel has a chance of understanding, it's him."

He feels the angel before him shrink into a tiny, minuscule space within, yet the image of him here never moves at all.

"I will leave."

It's spoken softly, with more than a flicker of worry, but it's still a threat. Sam thinks he doesn't mean it, but he can't know for sure. He doesn't really think the angel's sure, either.

Sam sighs, his exhaustion bone-deep and raw, and leans against the soft couch. "Look, I… I get it. You've been locked up this entire time, and you're afraid. Fear is a healthy thing."

"For a human," the angel adds.

"And for you, too, now that you're living among humans. Fear keeps all of us safe, lets us know when we should run. But there comes a time when fear paralyzes us and keeps us in dark places for too long. Sometimes fear makes us do things we never would have normally done, you know?"

Gadreel narrows his eyes fractionally, unconvinced. Sam just frowns.

"Look, I spent time in Hell with Lucifer," Sam continues. "So, I know how hard it can be to trust someone after being locked away and tortured." He buries his face in his hands, wanting to get through to the angel, because they can't keep this secret from Cas. They just can't. "So, I guess I'm asking you to trust me on this. If you can."

Gadreel blinks slowly, his eyes settling on the fireplace. "And if I cannot?"

Sam briefly considers pulling rank, in a sense. He could give him the option of talking to Cas or getting out of his body, but knows an ultimatum won't accomplish anything. Besides, Gadreel already knows he can ditch Sam at any time. Though between the angel's injuries and Sam's questionable ability to control a possessing angel, passing around threats becomes kind of pointless. It'd suit everyone better if he just tries to play nice. Sam doesn't have a marvelous track record at that, though, not when he's angry.

"Then, we'll figure something out." Sam says, not wanting to keep Cas in the dark, yet desiring to extend an olive branch to the angel in his head, too.

When Gadreel's eyes meet his, Sam thinks he sees something akin to astonishment there, as though he hadn't expected Sam to compromise (he probably didn't, Sam thinks). He thinks he can feel it, too, a flutter of something moving inside his ribcage. It's probably nothing, but it might provide an opening.

"But if anyone can, he'll understand," Sam tries again.

"I allowed the corruption of God's most perfect creation. Any angel would desire to kill me."

"You made a mistake. You didn't allow anything. And please, humanity is far from perfect."

Gadreel actually recoils at this. Sam's confusion lasts for about two seconds before he realizes exactly what he's just said, and thinks he might as well have thrown acid on the angel's guilt.

"That's not what I meant. I mean we have free will. We make the wrong choices sometimes, too."

After a long moment, Gadreel nods slowly. "God's most treasured creation, then."

The sincerity of the statement resonates through Sam. "You haven't met many of us yet, have you?"

"Just you," Gadreel admits. "And your brother, of course. My former vessel remained asleep for the brief duration of my residence."

Sam snorts at the idea that all Gadreel has to go on for the values of modern humanity are Sam and Dean. God help the poor guy. "Bad examples."

Gadreel's eyes furrow, and he appears deep in thought. "I understand why you say that, but I must disagree. I find your example to be in keeping with my Father's expectations."

Whoa, wait, did an angel of the Lord just say Sam would live up to God's standards?

"Yeah, uh… look. In case you didn't know, I've done some bad stuff. I'm no one's good example. You probably shouldn't take it too seriously."

The lines of his face furrow deeply. "I do not understand. It is your actions now which define you."

Sam tries not to gape, and fails. Yeah, the angel doesn't get it. Yet, his soothing, calm voice does something to Sam, because he's sincere.

His stomach feels heavy, and he thinks he should thank him, but the words stick in his throat. After all, he's still the angel who worked with Dean to trick a 'yes' out of him, and Sam's not ready to offer a 'thank you' for anything just yet.

They sit for a while, the quiet broken only by crackling from the hearth, where the angel examines the fire as if it contains the secrets of the universe. Sam can feel the warmth of the angel's Grace surging through his body bright and clear, a striking contrast to when the angel hides and virtually disappears. Gaps and inconsistencies where Grace has previously torn thrum softly, nearly out of Sam's awareness, yet to heal.

Time will tell, Sam supposes, how this will all work. Hopefully, it won't have to last long.

Something shifts within the angel, his jaw tightening, a thick swallow bobbing his Adam's apple. A strain of disquiet pulses through Sam again, dull and unsteady.

"As you wish, then" Gadreel finally says. "Let us speak to the angel Castiel."

"You won't regret this," Sam reassures him, reveling in the small victory.

AN: Some may have noticed I plucked the story of Lucifer-as-a-cherub fooling Eden's guard straight out of Milton's Paradise Lost(though, in Milton's work, it was Uriel who was fooled, not Gadreel). This explanation may end up Jossed by the end of Season 9, but I like the idea too much to not include it!