Title: Cold Smithing

Author: Mercurie

Summary: Castiel makes a deal with the devil; Lucifer has more planned than he lets on.

Warnings: dub-con

Disclaimer: This is an unauthorized work of fanfiction. I do not own the characters in this story and I am not profiting from it in any way.

***

The sky is a fragile blue. It's a cold, cold day and the air is brittle with it. This is a day that Lucifer could break in his palm; and he has every intention of doing so and then putting it back together in the way that most suits him.

"Just remember," he says, "you agreed to this."

Castiel nods once, his face stubbornly impassive. "I will hold to the terms we set. Only those terms."

"It will be just as we agreed," Lucifer repeats. But when he moves, Castiel takes an involuntary step backwards.

Lucifer stops, takes stock. The room is dusty, dark brown floorboards creaking beneath their feet. Its most striking feature is the large windows that take up two full walls, opening onto a view of the gray sluggish sea. From this angle, the ruins of the little seaside town are hidden; there's only the ocean, unaffected by the chaos tearing apart the land. Against the winter light, Castiel is a dark silhouette, head slightly bowed, watching him like a skittish animal.

That look of fear excites him. He knows Castiel can feel his hunger in the air around him, crackling electric.

"Now," Lucifer says, gently chiding, "who's not holding to our terms?"

Castiel visibly steels himself. "Do it, then."

This time he remains still as Lucifer approaches. When Lucifer touches him, he's tense and hard as iron. This is going to take some finesse, but then, Lucifer has a lot of practice with temptation.

So, slowly, he removes Castiel's clothing, one piece at a time. He starts with the tie, coat, jacket, and shirt, making sure to let his fingers trail over neck and arms and chest. Castiel keeps his chin up and eyes staring straight ahead as Lucifer leans in too close and lets his hands drift across an expanse of taut stomach to navel, then strokes his thumb down to where skin becomes cloth. But when he reaches for the zipper, Castiel's hips shift and his eyes jump, meeting Lucifer's with a tiny hint of pleading behind the defiance.

"I'll do that," he says.

And he does, brusquely and with none of the leisurely deliberation Lucifer had planned, until all his remaining clothes are piled around their feet. Even naked, he still has the composure, the icy distance he obviously thinks he can maintain no matter what.

With a slight smile, Lucifer places his hand on Castiel's chest and pushes him against the cold glass of the window. Surprise flits across Castiel's face; his lips part infinitesimally. And then Lucifer, still fully clothed, slithers up against him and lets his hands roam.

He watches Castiel's face as he trails his fingertips along one thigh, lingering on a hipbone before traveling up to glance over a nipple. The fingernails of his other hand dig into a buttock as he grinds their crotches together sharply. He watches the struggle on Castiel's face, a struggle not to react and to make sense of the reactions he can't help having. Castiel's mouth is a grim line and his eyes are staring off to the left as if nothing is happening, but they're a little bit too big, too vulnerable, and Lucifer wishes, just for a moment, that he could keep him like this forever, a frail lost creature cupped in his hands.

He nips at Castiel's neck, lightly, and says, "You're not really keeping your end of the bargain here, Castiel. A little more enthusiasm is called for."

The muscles of Castiel's jaw twitch and his eyes flick to Lucifer's face. He raises his hands from where they've been resting, palms against the glass, and lets them hover, clumsy and hesitant.

"I don't know…"

Lucifer takes one of his hands and guides it down between them, wrapping it around Castiel's cock. His own hand closes around it, trapping it in place. Castiel takes a sharp breath and his eyes lock with Lucifer's and now it's as if he can't look away, even when Lucifer starts moving their hands together on what is rapidly becoming a full-on erection. And his face, his face is a theater of horror and pleasure and a shadow of need blotting out the former clear detachment.

"You've never tried this," Lucifer says.

"It… has not been necessary for my mission," Castiel says, a hitch in his voice.

"Unnecessary things can be worth doing. Do you like it?"

Castiel closes his eyes for a second before saying, "Yes."

"Good." Lucifer stills their hands and says, "Kiss me."

Castiel looks surprised again, unbalanced, but Lucifer is not about to let him bear this passively, as if it were a torment. No. He's going to like it.

He remains perfectly still as Castiel leans his head forward and presses his lips, softly, softly, against Lucifer's. Their eyes are both open. Lucifer slides his hand around to the nape of Castiel's neck, letting his fingertips stroke the short hairs there.

"Open your mouth," he murmurs. When Castiel complies, he delves his tongue deeply into the inviting warmth and presses harder against Castiel's cock. He is rewarded with a quiet, ambivalent gasp and the tentative touch of a tongue against his own.

He decides a little more aggression is called for, so he buries both hands in Castiel's hair and kisses him more roughly, sucking on his bottom lip and thrusting in with his tongue until Castiel is panting for breath, fingers closing on Lucifer's shirt as if he needs something to hold on to under the onslaught. He moves on to kiss Castiel's neck, sucking at the crook of his shoulder. He smiles when he feels hands slip down to the waistband of his jeans.

He pulls back to see Castiel, no longer composed, in fact looking rather ruffled.

"Yes," Lucifer says. "Let's get right down to it, shall we?"

A spark comes back into Castiel's dazed eyes and he closes the mouth that Lucifer has just been savoring.

"Very well," he says curtly. And without having to be asked, he helps pull off Lucifer's shirt and jeans, not even blinking when everything comes off. But the hesitation comes back when Lucifer is finally nude and he's amused to see Castiel trying very pointedly not to look at his erection.

"It…" Castiel says and trails off.

"What?"

"Will this be… painful?" And amazingly, a blazing red flush colors his cheeks. His eyes are very bright and not at all distant when he meets Lucifer's gaze.

"Oh, Castiel," Lucifer says with a little laugh. "I'm not a barbarian. Unless you like it rough."

He presses his full naked length against Castiel and grips his shoulders, pulling them down into a tangled heap on the floor. Castiel looks like he's about to speak, so Lucifer preempts him by quite simply getting into his lap and sinking down onto his cock.

Castiel's mouth opens wide in an O of surprise and his spine arches enough for the back of his head to thud against the window.

"Lucifer!" he says. "This… this wasn't our deal!"

Lucifer responds by riding him slowly, watching in fascination as Castiel tries to bite back little groans.

"Oh," he says. "So you would prefer that I fuck you?"

"I… no! But this feels…"

"Good? Dirty? Do you like it, Castiel? Would you do it again? Of your own free will?"

"This is not me," Castiel says fiercely, glaring up with burning eyes. Behind his head, out the window, dark gray clouds are gathering over the sullen ocean. It's a dull, ominous backdrop to the portrait in front of him, a portrait of wet red lips and tousled hair and fluttering blue eyes. "I am not like this, I don't like – " but the end of the sentence is cut off by a moan as Castiel throws his head back in obvious liking.

Lucifer laughs aloud. He places his hands to either side of Castiel's shoulders and presses their foreheads together as he increases the pace, faster, harder.

"Come on, you great big repressed pansy," he says. "Just admit it. Admit that you like fucking me. Admit that you want me to fuck you. You like my hands all over you. Can't say it? I'll say it for you: you're nothing but a fucking little cock-hungry slut. You'd take anyone, given the chance. You'll let anyone fuck you as long as you don't have to take responsibility for it. And I'll prove it. The deal's off, as of now. You can stop any time. Go on. Show me who you really – "

Castiel cuts him off by kissing him, messily, desperately. Hands clamp down on his hips and now Castiel is thrusting up, quick and rough, and bolts of pleasure are ripping through Lucifer's vessel and he laughs and laughs with triumph and delight. For the moment all pretence has left them both and he can feel Castiel saying yes, yes into his skin and he's already imagining all the things he has planned for the future and what it will sound like when Castiel calls him master. After an eternity of filth and fire and the suffering of depraved human souls, at last he will have something lovely, something he is hammering into shape at this very moment. A renegade in his own image, half-fallen and half-divine.

Then the angel beneath him gives one last moan, tensing, before going slack and opening naked eyes to stare into his. They remain there for a second and Lucifer watches realization seep into Castiel's expression as he comes back to himself.

Lucifer extricates himself slowly and stands up. Castiel slides away until he's leaning against the window; he wraps his arms around his body as if he's cold, but he doesn't look away.

"Our agreement," Castiel says shakily. "You don't actually – "

"No, of course not," Lucifer says. "I was only proving a point. The agreement stands. No harm will come to Dean Winchester as long as I can prevent it. In fact," and he grins, letting the full measure of malice he's capable of infuse the gesture, "I'll even give him to you when this is all over. To keep. Once we complete the bargain, of course."

Castiel's eyes wander and before Lucifer can even say anything, he's on his knees and taking Lucifer's still rigid erection into his mouth. He's sloppy, inexpert, and it's obvious he's trying to get it over with as soon as possible, but Lucifer doesn't mind. He has until sunset, after all. Plenty of time to show Castiel everything else he needs to learn. It will be easy, now that he's proven to be so pliant. It's no surprise: experience has long taught Lucifer that the unbending ones are always the most fragile.

So he leans one hand against the glass as if to ward off the dull, lowering world outside and watches with exquisite satisfaction as his cock slides in and out of Castiel's mouth. Watches as Castiel slows, begins to become absorbed in what he's doing, forgets that he's supposed to be holy, an angel of the Lord.

Lucifer may not be able to create, but he can remake what already exists. And that is as close as anyone can be to God.