"Come back to the bunker," Sam says, his voice rough, pulled thin by the poor phone reception, all static and noise. "You need to come back."
Cas pauses, swallowing around the knot twisting in his throat. "There's nothing I can do."
"Just come back." Sam heaves out a sigh, then sucks in a breath that rattles in Cas' ear like the wind. "Cas, I -- please."
Muncie to Lebanon is a long drive, and years of traveling with the Winchesters have him taking back roads and desolate county highways out of habit, but he makes what he thinks Dean would consider "good time." He passes through central Illinois and northern Missouri, skirting the Nebraska line when he pushes into Kansas. It's a part of the country most humans find boring -- flat expanses that stretch endlessly toward the horizon, yellow grasses that burn gold in full sunlight, wave in the winds that come at dusk -- but Cas watches as it rolls by, another of his Father's enumerable creations. By St. Joseph a hollow ache is spreading through his chest, digging deeper with every mile; Sam is praying now, a low mumble of profanity mixed with Cas' name, unwilling to believe that his faith might actually exceed Cas' reach.
Angels are the essence of light and intent, were gifted by their Father with the strength to raise the dead, but Cas weakened himself when he healed Gadreel, and again when he braced his body against the sudden flare of Gadreel's sacrifice. His grace is less than a spark, a sickly itch at the center of him, a place that grows harder and harder to reach, nothing like the brilliant, white-hot power than had poured through him when he raised Dean from perdition, when he remade Dean's body from rot and bones.
It is well past midnight when he finally arrives, and the bunker is quiet and dark. Cas finds Sam waiting in the library, his elbow resting on the tale and a bottle of whiskey tilting out of his hand. He looks tired, white around the mouth; his soul is dim with sorrow, with the shadowy weight that comes with grief, but the set of his shoulders suggest he is anxious, perhaps uncertain. Of the brothers, Sam carries his emotions closer to the surface, but Dean has always been easier for Cas to read.
"I'm sorry," he says, his voice loud in the bunker's silence, the words brittle and not enough.
Sam shakes his head, setting the bottle down to rub his hand over his face. "It's not what you think. He isn't --" he shakes his head again, clears his throat once, twice "-- he's alive."
Relief washes over Cas like a wave, easing the harrowing sense of loss that's threatened to choke him since Metatron first taunted him with Dean's death. "How?"
"Crowley? What did he do?"
"I don't know. He's gone now, and Dean -- he won't talk to me. He won't even let me come near him."
Cas heads for Dean's bedroom. He smells the sulfur just as he opens the door; Dean is sitting on the foot of his bed, his shoulders hunched and his elbows on his knees, and when he looks up at Cas his eyes burn black.
"Cas." Dean straightens a little, enough to skirt the corner of his bed and back away, one hand clenched into a tight fist, the other shaking as it trails along the mattress. He has a deep cut across his cheek, blood staining the side of his jaw. "What are you doing here?"
Looking at him is strange. A demon always has two faces, one just behind the other, the twisted soul using its vessel's features like a mask, but the shadow hiding beyond Dean's face is his own.
"Did Sam call you?"
Cas shuts the door and moves closer to the bed. His palms are sweating, another sign of his dwindling grace. "He said you won't speak to him."
"No. Not when I'm --" his eyes burn black again, and his lip twitches, ready to curl with rage --" I don't want him to see me like this." He shifts, the mattress creaking under him, and eyes Cas askance. "You, either."
"C'mon, Cas. Do you even need to ask? Look at me."
Cas looks, knowing full well what Dean wants, what Dean expects, but he only sees Dean's humanity -- the crooked set of his shirt collar, the freckles across the bridge of his nose, the crinkles at the corners of his eyes, the soft swell of his mouth, a mouth Cas has thought of kissing recently. He has been in love with Dean for years, has even been aware of it on some level, but it took losing his grace and living as a human to fully understand it, the constant pull beneath his ribs, as relentless as a second heartbeat, how it aches when Dean is away from him, warms when Dean claps him on the shoulder, squeezes his arm. Dean's soul has begun to darken, choked by the bloody rage that fuels the Mark's curse, but he is not lost, bears no resemblance to the furious, snarling, hell-ravaged creature Cas once tucked inside his wings.
Dean shifts again, a frustrated noise humming in his throat. "How much juice have you got left?"
"Enough smite me?"
"No." Cas sits on the edge of the bed, in spite of the way Dean inches away. He probably could do it, if he called upon every scrap of grace still inside him, but it would burn him out completely, and he doesn't want to. He doesn't want to lose Dean.
"Ruby's knife is in the trunk of my car," Dean says quietly. "I can't ask Sam, he's too stubborn. But you --"
"Damn it, Cas. I'm not human anymore." Dean sighs under his breath, all anger and dust. "If I was anyone else, you'd --"
"I don't love anyone else."
Dean looks away, silent, a muscle ticking in his jaw, and after a moment, Cas moves closer; he know Dean loves him as well, even if he is unable to say it. He wraps his arm around Dean's shoulders, drawing him in, letting his hand rest at the back of Dean's neck, brushing his fingers through Dean's hair the way he's always wanted. Dean starts to jerk back, every line in his body pulling taut, ready to snap, but Cas presses a kiss to Dean's forehead before Dean can push him away, strokes his thumb over the skin behind Dean's ear.
"Cas," Dean says, his voice thick. He tips his head up a little, his lips moving against Cas' jaw. "You can't -- you don't want any part of me."
Cas kisses him. It feels surprisingly easy, like something he should've done months ago, perhaps years, but it is also frightening, overwhelming him with an unexpected flurry of human responses -- the tightness in his chest, the warmth spreading across his cheeks, the dark heat pooling low in his gut, everything sharp with only a minimal amount of grace as a buffer. He brings his other hand up to cradle Dean's jaw, letting his thumb trace the curve of Dean's cheek; Dean makes a slow, pleased sound against Cas' mouth, but it quickly burns into a growl. He kisses Cas harder, turning it filthy and wet, all tongue and teeth, fisting his hand in the front of Cas' shirt, twisting until the buttons pop.
"Dean." He catches Dean's hand, rubs his thumb over the inside of Dean's wrist. "Dean."
Dean pulls away, taking a sharp breath as his eyes return to green. He reaches for Cas' face with a shaky hand, runs his fingers over the split in Cas' lip. It's a tiny cut, and already starting to heal, but Cas can taste blood in the back mouth.
"I told you, you don't want any part of me. I'm not -- I can't control it."
Cas shakes his head. He draws Dean in again, lets Dean hide his face against the side of his throat. "Of course I do."
"I could hurt you. I could --" Dean makes a low, frustrated noise that hums against Cas' skin "-- It feels like it did before. You know, when I was downstairs. After I -- after I, um."
"It's not the same. Your soul is not nearly as black."
"But it will be. Just a matter of time."
Cas slides his hand up Dean's arm, stopping just shy of the scar on Dean's arm. "Not if we separate your soul from Cain's curse."
"Is that even possible?"
"I'll find a way," Cas says, kissing Dean again. He raised Dean from perdition once, and he'll do it again if he must, even if it kills him. "I'll find it."