A/N: This is the next story in a mild AU/canon divergence series called The Other Guardian 'verse. There's a detailed note about it on my profile page, but in brief: after Dean is raised from Hell by Castiel, an entire year passes before the Lilith rises and the seals start to break. During that time, Castiel is assigned to watch over the Winchesters, and finds himself growing closer and closer to Sam. All stories are co-written with my friend AccidentaLeft.

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Afterthought

Since the moment he had first been assigned to the Winchesters, Castiel had never stopped listening. He had listened before, from time to time over the millennia: an impartial observer tapping occasionally into the chorus of dreams and radio signals rising up from the human cacophony. His name had made its way into books, and every once in a while someone would pray to him specifically, a little voice tugging at the back of his mind; Castiel listened to those prayers with detached curiosity, the wishes of beings so much smaller than him that their desires were often unintelligible to him, though he spoke every tongue. But answering prayers was not his responsibility, and Castiel had never come to those who called out his name. Not until the Winchesters.

The Winchesters he came to. Not because Dean Winchester was a brazen, irreverent creature who called Castiel at his whims, just to see if he would come—they were an assignment from Heaven, and so Castiel could not bring himself to ignore any call, no matter how strong his suspicion of its insignificance. Sometimes he appeared to Dean and disappeared again just as quickly, as soon as he understood the human's motives. But there had been other times, at least a few, when he had genuinely been needed. Those were the times he could not dismiss, and that was the reason Castiel had not stopped listening since the brothers were assigned to him, but instead remained ever open to communication, one ear cocked toward the Earth for the softest mention of his name.

Dean Winchester preferred to shout.

Hey, Castiel! You up there?

Castiel halted midway through a thought, his conference with the archangels who oversaw his garrison giving way at once to the summons of that clamorous, impetuous voice.

Not trying to bother you with our, uh—what did you call it? Oh, yeah—problems of lesser beings. But if you've got a second, we are royally screwed at the moment and we're gonna be ant food if you don't get your holy ass down here. You know, when it's convenient.

Castiel didn't bother to dismiss himself. He felt a flutter of confusion from the archangels as he disappeared, hurtling toward the Earth in intangible form—but in a fraction of a second he was too far away to sense them anymore, and he put aside the lingering impression of their disapproval to land, a fully corporeal being, under the dark boughs of a pine forest, the yellowed needles and patches of stale snow that carpeted the ground glowing in the last of the sunset light filtering between the trees. Castiel folded his wings and peered through the labyrinth of trunks. The Winchesters were nowhere in sight, and for a moment Castiel wondered if he had somehow landed wrong, for the first time in his immortal life. Then the voice that had paused in its call to wait for a response started up again, and Castiel realized where the Winchesters were: in a pit twice as deep as they were tall, littered with broken sticks and fallen leaves, and diving into the earth like a chasm a few centimeters from the tips of his shoes.

Dean appeared to be in a foul mood.

"Come on, you overgrown cockatoo—we're in a serious jam here," Dean shouted from the depths of the pit, his head thrown back to address the pine boughs shutting out the last of the daylight. Sam was standing at his brother's side, slumped over to lean heavily against the dirt wall with tangles of pine needles snarled in his hair. Dean waited a beat and then threw up his hands. "Damn it, Cas—you're turning out to be a pretty crappy guardian angel, you know that? Is it that much to ask for you to pull your head out of your ass for one minute and—"

"I'm here, Dean," Castiel broke in. He shifted at the edge of the pit, sending a few crumbles of dirt down into the hollow as both Winchesters spun to search for him, green and hazel eyes locking on his form silhouetted against the darkening forest. Dean exhaled heavily.

"Oh," the older hunter said, the closest to gratitude Castiel was likely to receive from him. Then the momentary flash of relief on his face morphed into a scowl. "Well, say something next time, you awkward jackass. Don't just stand around in a trench coat staring at people down a hole." Dean blinked twice. "I've seen that horror movie."

"Shut up, Dean," Sam said through his sigh, sending Castiel the smallest sliver of a smile in greeting. Dean twisted to punch his brother in the shoulder, but he turned around again before he could see the sharp wince that flashed across Sam's face. Castiel noted the younger hunter's expression and then bent carefully to kneel at the edge of the pit, examining the sheer clay walls.

"Why are you down there?" he asked.

Dean rolled his eyes. "Gee, I don't know, Cas—maybe we got tired of running through the forest after a psychotic werewolf-slash-mountain-hermit and getting slapped in the face by Douglas firs every five seconds and we decided to take a break in here—you know, have a barbeque, invite some friends. Why do you think?"

Sam tipped his head back against the wall of the pit. "They're not fir trees, Dean—they're Ponderosa Pine."

Dean spared a glance at Sam over his shoulder. "Well, look who's the Jolly Green Giant all of a sudden."

Sam wrinkled his nose. "That's not… whatever," he finished with a sigh, pulling weary hands down his face as he closed his eyes. "Just stop screwing around, okay, Dean?"

"That time of the month again already?" Dean shot back. Then his attention returned to Castiel, green eyes angry as usual above his impatient frown. "Basically, we're down here because Carl Jagen, werewolf-slash-hermit-slash-conspiracy-nut, built pit traps all over the woods to throw off the government scientists he thinks put a microchip in his head, and it was a dumb move to pull our FBI badges." Sam tipped his head as if to agree with that, though his eyes were still closed. Dean lifted his eyebrows. "Your turn. Why the hell'd it take you so long to get here?"

Castiel narrowed his eyes. "I was in a meeting."

"Are you shitting me?" Dean demanded.

Castiel felt himself frown. "No," he decided after a moment.

"Perfect," Dean grumbled. Then he glared up at Castiel again, his palms up, though the angel doubted his pose of supplication truly conveyed his sincerity. "Well? You going to get us out of here already, or should we just wait until the full moon comes up and see if Carl's any less homicidal once he needs a full-body wax?"

Castiel pressed his lips together, trying not to feel a ripple of annoyance. This was Dean Winchester as Castiel had come to know him over the span of the long days: brash, blunt, impatient rather than thankful for the graces he was given. He looked at them down in the earth, such children of men—their chests heaving with labored breath, their clothing torn and matted with badges of blood, their fingernails caked with black dirt from trying to scratch their way out of the pit. And Dean Winchester was impatient with him. Then he caught Sam's eyes, peering up at him with a darkness like remorse, and Castiel reminded himself that it didn't matter, because he wasn't here for Dean—he was here for Heaven. Castiel unfurled his wings and knew them again for children, just children, and then he stretched out one arm, reaching into the pit as far as he could.

"Take my hand."

In the fraction of a second before he took flight, Castiel noted that Sam's fingers were much colder than Dean's, and wondered why.

He set them down again a short distance from the trap, landing carefully on the carpet of needles. Dean bent to brace his hands against the knees of his ripped jeans, and Sam lurched backward until his shoulders collided with the trunk of a large Ponderosa; the younger hunter flinched but showed no signs of stepping away, sagging back against the tree instead and raking dirty fingers through his disheveled hair. Castiel caught his half-lidded eyes and Sam struggled to stand a little straighter.

"Thanks, Cas," Sam said, his voice a rasp in the gathering dusk. "Sorry. We weren't exactly watching where we were going, and… just, sorry to pull you away from something important—"

"You know what's important, Sam?" Dean broke in. "Us not getting ganked by a paranoid werewolf because we couldn't climb out of a damn hole and he'd already taken out the cell tower. What were we supposed to do?" Dean clenched his fingers into the white threads of jean strung across his open knees, and then hissed, jerking his right hand up to his chest. "Fuck and a bucket of monkeys," Dean growled under his breath, cradling his fingers against his stained green jacket. "How did he dig that fucking pit in the first place? That clay is hard as concrete—I think I broke eight fingers just hitting the bottom."

Sam retreated back against the tree as Castiel took a step toward the older hunter, assessing his charge with a brief flare of grace. "Only one finger is broken," he told Dean, unsurprised to find the man's expression pinched into a glare.

"Oh—well, that's fine, then," Dean returned. "Who wants ten working fingers anyway?" Castiel decided that was sarcasm—Dean's primary form of communication, in the angel's experience. Dean took a hard step forward and a twig splintered under his boot, punctuating the thin distance between him and Castiel. "Would you fix it already? We've still gotta finish this hunt and I'm not doing it without my middle finger. Probably gonna need that."

Castiel narrowed his eyes but chose not to inquire. He just lifted two fingers to Dean's forehead, and heard the hunter suck in a breath as his healing grace flowed through him, righting his broken bones and erasing the superficial cuts and bruises of a careless pursuit. As Dean reeled back from his hand, Castiel turned his gaze momentarily to the other Winchester, so still and pale on the other side of the stand of pines.

Sam's eyes were still half-closed, his brows drawn together as if he were concentrating intensely on each shallow breath moving in and out of his lips. Castiel felt himself frown. Sam was quiet today—quieter than he usually was when Castiel appeared to him. Sam was always full of information, about snow angels and cold weather practices and card games and old books, and the folklore of so many different places. Castiel didn't know why Sam told him about these things, and he didn't understand most of them. But he listened all the same—hadn't stopped listening since he had first been assigned to the Winchesters. Sam's silence now bothered Castiel, made some part of him uneasy. But he reminded himself that Sam was always quieter when Dean was present to talk for him, slipping at once into his brother's shadow—especially in Castiel's presence, Sam stepped back, as though the angel had come for Dean alone. And as Dean caught his breath, surged back to his full height and shook off the last of his grace, Castiel dismissed his disquiet, turning away from the younger hunter. Dean never held anything back, after all, had never hesitated to ask for what he wanted. He had no reason to think Sam would be any different.

"Shit, Cas—you guys should package that," Dean was saying. He flicked his wrist once and then cracked the knuckles of his right hand, a smirk creasing his face. "Next time I have a hangover, you're definitely getting a call." He looked up and gave Castiel a flippant nod—a dismissal, Castiel assumed—and then turned to stride off into the trees, summoning his brother with a glance over his shoulder. "Sam—let's move it. I dropped the gun somewhere between here and that tree where he strung up the missing hiker. See if we can't find it before Ugly comes back."

Castiel wasn't certain why he didn't disappear. He had done what he was called to do, and he had unfinished business in Heaven—the archangels would accept the reasons for his abrupt departure, but they wouldn't be pleased. He had no interest in loping after the Winchesters through the twilight woods. Still something made him hesitate, and against his instincts Castiel stood where he was for a long moment and watched the hunched forms of the hunters moving away from him, scouring the ground in the last of the light. It took him a minute to realize that he was watching Sam, his sharp eyes picking apart the details of the young man's movements—an intermittent limp, the way his left knee crumpled when he took a bad step, he way he dug his fingers into the trunk of every passing tree as he trailed Dean through the forest. The thick crimson stain disfiguring the back of his jeans just above the left knee—and then he caught a glimpse of a tear in the fabric, a rip in the flesh of Sam's thigh, and his wings came unbound at his back. Castiel landed in front of Sam at the same instant that Dean straightened with his gun in one hand, and the younger hunter nearly slammed into him, pulling up short with a gasping inhale.

"Cas! What are—"

"You are injured," Castiel interrupted him. Sam tried to take a step back, but the angel reached out and fastened one hand over his shoulder, his fingers anchoring in the dirt crusted to Sam's brown coat. Castiel squinted up at Sam through the thinning light. "You did not tell me. Why?"

Sam worked his tongue against his teeth. "Cas…" The young hunter shook his head and reached out to brace one hand on the nearest tree, working his fingers into the crags between the thick flakes of bark. "It wasn't… it's not really like that. I…"

"The hell do you mean he's injured?" Dean demanded, as he tucked the gun into his waistband and shouldered his way back into the conversation, past Castiel. He knocked the angel's hand from Sam's shoulder and replaced it with his own. "Sammy?" he pressed, pinning his younger brother's gaze.

Sam's eyes followed Castiel's arm as it fell back to his side. "Dean—"

"His left thigh," Castiel interjected.

"Show me," Dean ordered, shaking his brother's shoulders. Sam looked between them both and balked.

"Dean, it's not that bad," the younger hunter insisted, lifting one hand to grip Dean's arm in return. His eyes flitted over to Castiel, and the angel saw supplication in them, as if pleading with him to intercede—but though Castiel did not understand Dean's fingernails digging into his Sam's collarbone or why he shook his younger brother again, Dean knew Sam far better than he did, and he deferred to the older hunter's judgment. Sam's eyes darted back to his brother. "Plus, I can't really show you without taking my pants off, and I'm not going to do that in the middle of a forest when there could be a werewolf—"

Dean was not a patient soul. Castiel knew that all too well. So he was not surprised that Dean abruptly tired of his brother's protests and dropped to his knees in the dead pine needles, jerking Sam's leg around to reveal the rent in his jeans and the jagged wound within, four inches long and still bleeding—but as Sam cried out and nearly collapsed to the ground, only a tight grip on his brother's shoulders keeping him upright, Castiel wondered if there had been a better way, and wished, for just a moment, that he knew what it was.

Sam was breathing through his teeth. "Ah—shit. Dean—"

"Shit is right," Dean growled back at him, ripping the hole in Sam's jeans a little farther so he could get a better look at the wound. He glanced once at the sky, far beyond the canopy of pine boughs, as if cursing the oncoming darkness. "This is bad, Sam—really bad. How the fuck did this happen?"

Sam threw a glance at Castiel and then focused on his hands, bunching the worn leather of Dean's coat into new folds of wrinkles. "Um… you remember those sharp sticks in the pit? When I fell… yeah."

"Damn it, Sam," Dean swore under his breath. "That was half an hour ago. Why didn't you say anything when Cas was fixing me?" Sam took a breath as though to answer, his expression indecisive—but Dean had already moved on, and he jerked his head back far enough to glare at Castiel, his anger simmering behind those narrowed green eyes. "And you—the hell is wrong with you, Cas? Standing around like a jackass while Sam's bleeding out through his sneaker."

Castiel met those eyes but said nothing. He had nothing to say. He had not checked Sam over, in spite of his suspicious—had not even asked the younger hunter if he were injured. He had failed in the duties given to him by Heaven because he understood so little of Earth, because he had assumed that all humans would behave like Dean Winchester in the presence of an angel, even Sam—Sam who always apologized for Dean's excesses, who often cleaned up his brother's mess, who left so many sentences unfinished—Sam who had given him a cup of tea to hold in his hands though angels needed no warmth from outside. Sam who had reached for his hand with such awe, the day they first met. Sam who always stepped back when Dean pushed forward. Castiel didn't know why he'd assumed that Sam, of all people, would be just like Dean.

Sam was looking down at the top of his brother's head, breathing heavily now; Castiel could hear his ribs vibrating, just a little, with each inhale. "Seriously, Dean, stop it—okay? It's not that big a deal. It's not like I opened the femoral artery or anything."

"How do you know?" Dean demanded.

Sam gave a hoarse laugh. "If I had, I'd have bled out, like, twenty minutes ago."

Suddenly Castiel understood it all for what it was: the shortness of breath, the dryness of his tongue, his shaking hands—the symptoms of a heart slowing down. "Stand aside," he ordered, stepping forward until he was right behind Dean. The older Winchester seemed reluctant, but he got to his feet and out of the way all the same, leaving Castiel face to face with Sam. The angel studied those dark hazel eyes as he raised one hand.

"Be still," he said, the words soft under the twilight. Sam flinched when Castiel's fingertips settled on his forehead; and Castiel wasn't sure why, but he found himself speaking again, in the fractions of a second it took to gather his grace—qualifying what he was about to do as he had never done before. "This will not hurt," he promised. Then he let his grace go, and it surged through Sam, snapping the younger hunter's head back in a harsh intake of breath.

In an instant it was gone, and Sam's face cleared, the pain disappearing along with his wound. But even in its absence, Sam wore a strange expression, one Castiel couldn't read—somewhere between relief and longing, doubt and resignation. Castiel didn't know of any emotion that sat at the crossroads of those four.

Dean's voice broke through their stalemate.

"Sammy? You okay?"

Sam shook himself, backing away from Castiel as the angel's hand slipped back to his side once more. The younger hunter reached behind him and braced one hand against a tree, then lifted his left leg, craning his neck to get a look at the site of his wound. "Yeah, no—all better," he said, giving Dean a reassuring nod. "I'm going to need a new pair of pants, but—"

A sudden crack split the air above their heads, and Castiel glanced up in time to see a branch of lightning splitting the darkening sky, leaving behind the scent of ozone and disapproval. Dean swore under his breath. "Great—because the day's been going so well. Now it's going to rain, too."

Castiel turned away from Sam to meet the older hunter's eyes. "That isn't rain," he said. "I'm being called back to Heaven. I've been away too long."

Dean raised his eyebrows, one accusing finger leveled at the sky. "That's for you?"

Castiel shifted his feet. "I told you I was in a meeting."

"Shit," Dean said. But his face was blank and his posture loose, and somehow it sounded more like a compliment than profanity. He shoved his hands down in his pockets and sent Castiel a shrug. "Well, you better get out of here, then. I don't want them smiting anybody just 'cause they're pissed at you."

Castiel nodded once, wondering if that were what gratitude looked like on Dean Winchester, when it didn't just make him angry. Then he turned back to Sam. The younger hunter had managed to pull some sort of a smile onto his face.

"Cas…" he started.

"Sam," the angel returned. Then he stepped toward him, moving until the tips of his shoes touched the tips of Sam's, and stared up into those wide hazel eyes—such a complicated color. Castiel searched his mind for the right words. "You are not an afterthought," he said at last. "I come for both of you. Do not conceal your wounds from me." He wanted to say more, because he wasn't sure he had made himself clear, but another flash of lightning overhead reminded him that his time had already expired. He glanced up and then took a step back from Sam, his gaze oscillating between the Winchesters. "Be more careful," he told Dean. But without intention he found himself looking at Sam as he finished, "If you need me again… I am always listening."

Sam wore that complicated expression once again. Castiel caught himself almost wishing he could stay a short while longer, try to decipher the meaning behind that look. But he took his leave without another word, letting his wings uncoil from his back and lift him out of the mortal frame. His allegiance was to Heaven, not to the Winchesters—but all the same, as the Earth fell away from him and his corporeal form disintegrated into light, Castiel found himself thinking that he would have to pay more attention to Sam, from now on, and that caring for the Winchesters might not be as simple as he'd originally guessed.