A/N: A series of linked one-shots set primarily in the fifth season of Supernatural, tracing the development of Sam and Castiel's relationship from uncertainty to deep friendship. This isn't intended to be a pairing story in the traditional sense, but it is meant to draw as close to that line as possible without stepping over. I hope you enjoy reading.

Note: This chapter is set after 5.04, "The End," when Dean and Sam have reunited.

Pairing: Castiel + Sam, light.

.x.

Castiel always came in the dark.

In the long-stale shadows of a one-night motel room, Sam lay awake against the scratch of starched sheets and stared at the cracked ceiling, listening to Dean snoring in the next bed. From the bathroom the feeble wheeze of the fan stirred the too-warm air; beyond the windows, semi-trucks rumbled endlessly down the interstate, their headlights breaking through the half-drawn curtains and splashing the walls white, whirling like searchlights. On the nightstand between their beds, plastic cups of flat Coke and melting ice rattled like loose teeth with each passing roar.

Sam stretched his long legs, sore from so many hours folded up in a small car, until his toes dangled over the end of the short bed. He let his head flop over on the pillow, staring at his sleeping brother through a few strands of brown hair. Dean had been out like a light the second he hit the mattress, never one to miss his beauty sleep. Sam had lain awake for an hour already and felt no closer to drifting off.

Sam curled one elbow under his head, scooting one way and then the other, but nothing felt comfortable. Maybe it was the room—hot and airless as a tired furnace, and too close to the highway, the reverberation of carriage after carriage of thirty-four tires slicking asphalt only a few hundred feet beyond their windows—sensations that had faded in Garber, Oklahoma, even if he never really forgot them. Maybe it was Dean's snoring, another sound he hadn't heard in over three weeks. Or maybe it was just being here again—in a cheap motel, in the bed next to Dean's, his ears still throbbing to the beat of classic rock wailing from the outdated radio, which Dean had kept on until the moment he tumbled into bed, leaving no room for silence or words between them. Maybe it was just that the last thing Dean had said to him all night was almost three hours old, just a simple question—Want a Coke?—before his brother slipped out for a walk to the gas station down the road, because there was no beer in the motel vending machine.

Sam rolled onto his back again, his hair spreading out against the bleached pillowcase, and tried not to read the glowing face of the digital clock, the hour back in the single digits now. He held his eyes closed for a long moment before they struggled open on their own. He wanted sleep—needed it, before getting back in the car at dawn for the drive to their reunion job, six more hours at least. But somehow he couldn't get his mind off of Dean's expression as they stood at the base of the dam, together for the first time in a month; the nervous tingle in his hands as he'd climbed into the Impala, a space he knew better than any room; Dean's promise for a fresh start ringing in his ears—and not an hour later, trying to explain a shortcut on a state highway, an accordion map collapsing in his large hands, the twitch in his brother's lips as Dean said, Yeah, no offense, Sam, but I'm not going to be taking directions from you anytime soon. The stinging in his throat that he couldn't fight down, sour like car sickness—because Dean hadn't forgiven anything, forgotten anything. Dean had decided he didn't want to lose Sam, but he didn't really want Sam back yet, either.

Sam blinked hard in the darkness, fighting down the thick feeling in his mouth. It didn't matter, he told himself, not for the first time since kicking away the covers. Dean was lying right there, four feet away from him. His backpack was stuffed into the Impala's trunk, a smudge of deep red dust the only proof it had ever been anywhere else. All the rest could come in time. He told himself that, but somehow he still couldn't sleep.

Sam threw an arm over his eyes, catching the tear on his cheek before it could roll down into the pillowcase. He pressed his face hard into the crook of his elbow, and the pressure soothed the prickle behind his eyes, but it did nothing for the ache in the center of his chest, a slow collapse like he was missing a rib. It was the Dean ache, and nothing ever got rid of it except forgetting for a little while.

Another tear slipped past his arm and escaped into his hair, the saltwater itching on his skin. Sam squeezed his eyes shut. Please just let me sleep, he begged himself, or anyone else who was listening. I don't want to think about this. I can't fix this. I just want to sleep. Please. Please.

"Please," he whispered aloud to the silent room.

The hum of the fan hid the rustle of familiar wings.

"Sam."

Sam jolted up in the dark, sitting up fully from the tangled sheets and blinking the pressure spots away from his eyes. "Cas?" he asked in a croak, the fingers of one hand digging into the resilient mattress as his eyes swept across the room. A truck growled in the distance and its headlights raced along the mottled walls; Castiel appeared suddenly in the shadows between the dresser and the mini fridge, the fleeting light stark on his stern features, his eyebrows drawn slightly together in concern or contemplation. Then the truck was gone, and the image of the angel vanished with it—but Sam could feel his presence now, that meditative gaze fixed on his face through the thin illumination of far-off streetlamps. Sam sunk back into the bed, leaning on his elbows.

"Hey," he whispered, swallowing against the dryness in his mouth.

Castiel moved forward with slow strides, silent as a shadow, and stepped into the corridor between their beds. He glanced once at Dean's sleeping form—a cursory check for any disturbance caused by his arrival, Sam thought—before the angel's attention returned to him. Castiel was backlit by the window and Sam couldn't read his expression at all; he was momentarily embarrassed to be stretched out in shorts and a ratty Sooners t-shirt under divine scrutiny, his visitor eternally unchanged in a suit and trench coat. A sudden urge to explain welled up in his throat—that it was the only t-shirt Garber's tiny general store had carried in his size, the day he spilled tomato sauce on his button-down and realized two shirts and a pair of fraying jeans were all he owned in the world—but before he could put the words together, Castiel spoke, his gravel voice almost lost in the noise of the fan.

"I came as soon as I could."

Sam blinked up at him through the dead air, his eyelashes stiff from their brief brush with saltwater. Already the skin around his eyes felt too tight. "I wasn't calling you, Cas," he said, clearing his throat as quietly as he could. He rolled up onto his left elbow so that he could face the angel squarely, and his right hand drifted to cover his chest, the heel of his palm digging absently into his aching rib cage. "I was praying, kind of, but…"

Castiel tipped his head to one side. "Do you want me to leave?" he asked with typical bluntness.

Something flared under Sam's hand at the question, a little spark of unease, but he crushed it down into his skin, looking across at Dean instead of Castiel as he searched for an answer. Dean snorted and rolled over and Sam swallowed something that went down hard. "I don't want to wake him," he murmured under his breath, risking a glance up at the angel.

Castiel took another step forward, the sweep of his trench coat obscuring Sam's view of his sleeping brother. "I will not," he assured the younger hunter, and even though Sam couldn't see his face for the shadows he knew somehow that Castiel's expression was earnest and far too serious. Sam fought down a small smile.

"I know, I just…"

He inhaled and held his breath for a long second, long enough to catch the glowing digits of the clock face out of the corner of his eye. He wondered what Castiel was normally doing at 2:36 in the morning. Sam let the stale air go before it could burn his lungs.

"You don't have to stay," he said at last.

Castiel studied him for a moment without speaking. Sam dug his hand into his heart, bracing himself for the flutter of departing wings. But after uncountable heartbeats pressed into his palm through the thin cotton of the t-shirt, the angel seemed to make his choice, and he shifted in his stance, the lights of the passing semis raking over his back. The hands at his side smoothed imperceptible wrinkles from the slope of his tan overcoat.

"You're traveling together again," Castiel said.

Sam's breath hitched on the inhale. Maybe it was the afterburn of cigarette smoke drifting through the room, a memento of other guests who had cared less about the scratched-up No Smoking sign on the back of the door. The lettering had worn away until Smoking was almost completely erased; every time Sam's eyes had drifted to the sign, away from Dean's face alight with the flicker of crap television, all he saw was the word No.

Sam exhaled carefully to get all of the smoke out. "Yeah, we are," he replied, trying not to hear his own sigh.

Castiel nodded once. "This is what you wanted," the angel continued.

Sam found he had to swallow again. He pressed his palms flat against the sheets. "Yeah, definitely," he tried, cringing to hear the hollowness of those words echoing in his bones. He was sure Castiel could hear it, too. His will flagged and he lost the end of the sentence to a whisper. "No, it's—it's great. It's perfect."

Sam hung his head, squeezing his eyes shut for a moment before they lifted to Castiel once more. There was silence between them as he studied the silhouette of the angel towering over him; in the darkness he seemed immutable as stone and equally unreal, some figment of a dream that had risen from Sam's mind to torture him with questions he didn't want to think about. Then Castiel bent and very slowly lowered himself to sit on the edge of the bed, back straight but his face turned to Sam, startlingly real again as he braced his hands on either side of his spilling coat. Sam shuffled over on his awkward elbows to give the angel more room.

There was just enough light now to piece together Castiel's thoughtful frown. "Then why have you been crying?" he asked.

Something lurched inside of Sam at the question, like there was a weight suspended in his chest and Castiel had yanked on the other end of the robe. Sam pressed hard against his missing rib and wished the pressure pain was as strong as whatever hurt on the inside.

"I'm not—um… it's just…"

Sam shifted to wipe the salt away from his eyes, but Castiel beat him to it—the angel reached out and settled his left hand along the side of Sam's face, the contact so light that Sam could barely feel anything but the warmth blazing in all five fingers. He held still and so did Castiel, not stroking his face but simply resting his thumb over the curve of Sam's cheekbone, as if guarding the last traces of the tear on his skin. Sam studied the fuzzy image of Castiel's hand out of the corner of his eye and then looked up, reluctantly meeting the angel's gaze, those irises more black now than blue in the shadows. Castiel simply waited.

As last Sam closed his eyes. He resisted the urge to rub his throbbing temples, afraid of upsetting the angel's hand—the touch felt too close to insubstantial already. His sigh got lost in the thrum of the fan. "It's just… me and Dean," he said. "We're… we're wrong."

"Wrong," Castiel repeated.

"We're not… how we were before."

Sam felt the words catch in his throat, and he had to cough to get them out. His eyes darted across the room with sudden terror that Dean would wake up and hear him, and they'd have to fight about this, too—but Dean was quiet in his bed, his mouth hanging open in careless unconsciousness. For a moment Sam just took him in, his pulse aching in his hollow chest. Then he glanced up at Castiel. The angel seemed to be listening intently, staring back into his eyes as though he were watching for the first glitter of tears. Sam blinked hard.

"We're broken, Cas," he told the angel, surprised by the rawness of his own voice. "Broken like… like I don't think we've been before. I'm not sure we can put the pieces back together. But what scares the hell out of me is that… I'm not even sure if we should." Sam swallowed against the darkness, feeling the shadows of doubt creep into his collapsing lungs. "I'm not sure together was really together, either."

Castiel said nothing—just stared down at him with unfathomable eyes, his hand warm like an ember on Sam's cheek, looking, as always, more through him than at him. Sam stared back until he couldn't take the silence anymore.

"Um, Cas?" he prompted, clearing his throat lightly. "You still listening?"

Castiel bowed his head a little, shifting in his place on the edge of the mattress. "I'm sorry," he said, a thread of discomfort weaving through his voice as his eyes lifted to search Sam's face. "Could you repeat yourself, more slowly? I didn't… follow that."

Sam breathed out into a little laugh, shaking his head softly, as softly as if it were a butterfly and not an angelic hand perched on his cheek. "Sorry. I guess that was pretty tangled."

"Yes," Castiel told him frankly.

Sam's lips twitched up into a half smile, but it only lasted a moment, fading steadily as he fought for words the angel would understand. Anything that was simple enough for Castiel was almost too simple, cut too directly to the center of the wound Sam had been circling, feeling out, but never looking at directly. He wedged the heel of his palm under his breastbone and pushed up until he felt his ribs creak.

"Dean just doesn't… trust me. He's angry at me," Sam tried again, shaking his head as a sardonic smile twisted over his lips. "Not like it's the first time, but…" He hesitated, then let his eyes drop, staring down into the furrowed sheets. Castiel's hand was suddenly heavy on his face, and far too warm, like a brand searing into his skin, and Sam wished that touch would disappear, taking all his stifling thoughts with it. He made himself inhale. "The thing is, this time… I don't think he's angry with me for the things I've done. I think he's just angry 'cause he finally realized I'm more trouble than I'm worth."

Sam tried to keep his voice level, but the words came out hoarser than he'd intended, crackling in the air between them like static electricity. Castiel's hand tensed against his cheek, a butterfly unfolding its wings to keep its balance.

"Why would you say that, Sam?"

His name caught him off-guard—Sam choked a little on a hard laugh. "I'm a grade-A screw-up, Cas," he said, keeping the words simple this time. They burned like razors in his own ears. Castiel just stared down at him, his expression lost as ever, and suddenly Sam felt so heavy, like he was going to slip through the bed and plummet all the way down into the fire. He pulled his elbows in and let himself collapse onto his back, leaving Castiel's hand deserted in the air as he sunk into the pillows. He inhaled through the cloud of fabric dust. "I'm a curse. I've wrecked everything I've ever touched. Mom and Jess and… Dean went to Hell for me and I still started the apocalypse. And now I'm…"

Sam looked up at Castiel's fingers slowly closing over empty air, slowly retreating to the spread of his trench coat, and couldn't make himself say it—because surely Castiel already knew that he was Lucifer's vessel; because he couldn't face another reaction like Dean's, tired and distant, or the realization that he might be the only one who was actually afraid of this… because some part of him was terrified that if he said it, that name that was subversively becoming entangled with his, that Castiel would disappear from the side of his bed, banished by the specter of the devil. The headlights of the semis rolled over the room in great swaths of black and white, illuminating the angel hovering on his mattress, but Sam was too far down, and the light didn't touch him.

Sam squeezed his eyes shut, and then wished he hadn't—it just made the prickling behind them more intense.

"I think Dean just gets it now," he said, a shiver racing through him in spite of the stifling air. It shook the tears behind his eyelids and Sam flopped his arm across his face again to hide his blurring vision. "He sees that I'm past saving. That I'm…" A word reverberated in his head—that word his brother had said three times, each repetition making Sam's lips tremble. "I'm a monster," he whispered.

The bed creaked a little, as though Castiel's shoulders had slumped, or his wings shuddered down against his back. Sam kept his arm clamped over his eyes. For a moment the silence set in around him, deeper even than the midnight darkness. Then the air stirred, and he felt Castiel's hand wrap around his wrist, the angel's thumb pressed into his palm.

"Sam, look at me." Castiel pulled his arm away from his face and held it down against the pillow, his fingers digging into the bones of the radius; Sam felt the breath of the fan cooling the tears on his cheeks, but he kept his eyes tightly closed. Something nestled into the sheets on the other side of his head, brushing the shoulder of his ragged red shirt. Castiel exhaled hard. "You are not a monster."

Sam shook his head once, the motion so soft it made his neck ache. "Cas, it's okay—I'm okay, honestly. You don't have to lie to make me feel—"

"Look at me."

The roughness of the angel's voice startled Sam's eyes open, chasing a tear down his cheek. Castiel was leaning over him, staring down at the young hunter from only a few inches up, his hands braced on either side of Sam's head. Looking up at him Sam felt suddenly small, like a child, like the angel could have picked him up with one hand, crumpled him into a ball against his chest. Sam swallowed hard as Castiel's shoulders relaxed, the angel hanging over him like a shadow.

"Sam," he said simply.

For an instant Sam couldn't see anything, his companion's face losing all its features in the pitch-black room. Then the glow of headlights burst through the window like a symphony and exploded over Castiel, illuminating his whole body for one blinding moment, and the angel's image burned into Sam's blinking eyes—Castiel's grave expression, his splayed hands, the pale fingers coiled around his wrist, the desperate sincerity in his intense blue eyes, staring down into Sam's from so close that he could see his own dark reflection mirrored in them. Sam breathed in and the air shuddered in his chest like it was knitting his bones. Then the truck was gone, and the darkness poured over them again—but Sam could still see Castiel, every line of his face. He closed his eyes and let his breath go.

"Cas," he whispered.

Other things rose up between them for a moment—Dean's light snores and the whirr of the fan and the growl of passing semis, the drone of tires leaving black scars on the asphalt. Then Castiel's coat rustled like a low sigh, and the bed rasped as the angel leaned forward a few inches and pressed their foreheads together, his breath suddenly warm on Sam's face. Sam kept his eyes closed, his skin tingling as the salt tracks disappeared from his cheeks.

"You are no monster, Sam Winchester," Castiel told him, the words less than a whisper. "You are not the best man I have ever known, but you try the hardest to be."

The angel's voice sent a shiver through him—but somehow the feeling was warm, and wonderful, and it made Sam feel light, like his skeleton had been replaced by hollow bird bones, like Castiel had cut the rope inside him and the weight in his chest had tumbled down into Hell without him. He wondered if it was Castiel's grace he was feeling, wrapping around him like sunshine and making them both glow, or if this was just how it felt to have an angel's breath on his cheek.

Castiel shook his head softly, brushing their skin together with each turn. "Every evil you have committed has been done in pursuit of good," he said, a sliver of regret twisting in his voice. "I understand that… more than anyone."

Sam's eyes flickered open at last, gazing up into the angel's face in the distant blush of streetlights, studying Castiel's lips pressed tightly together, the self-reproach haunting his expression. Sam shook his head, too. Then he lifted one hand and rested it against the back of Castiel's neck, his fingers loosely curled into the angel's collar.

"Have you found God yet, Cas?"

Castiel closed his eyes, his body pressing down into Sam's as if suddenly too heavy for his arms.

"I've found nothing."

Sam nodded softly. Then he closed his eyes as well, and let Castiel rest against him, relaxing into the warmth of the angel's touch and wondering which of them was leaning on the other.

.x.

Three more to come. Thanks for reading.