Title: Hellfire

Author: Mercurie

Summary: 5x10 Abandon All Hope - Lucifer has Castiel trapped and he's not about to let the opportunity go to waste.

Warnings: non-con (forced sexual contact, no rape)

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.

***

"You've been to hell. That's what God did to me for rebelling. Just like you rebelled. What do you think He'll do to you, when you find Him?"

"This is completely different. I'm following His plan. I'm not… evil."

When Lucifer laughed, his eyes crinkled as if he really meant it. The corners of his mouth stayed curled as he watched Castiel across the flames.

"You," he said, "are something else. Out of all the good little soldiers following orders, you're the only one who disobeyed. Why is that, hmmm?"

"Not the only one," Castiel said before realizing that it probably would have been wiser not to answer.

"Oh? And who else is there?"

"I will not help you!" Castiel snapped.

"Oh. But you will. You'll even want to. Nobody likes a fallen angel, Castiel. Take it from me. Who besides me knows what you're going through?"

"You and I are nothing alike," Castiel said, taking an involuntary step forward. The flames and the power holding him trapped stopped him, and so did the fear. He wrestled with it, burying it down somewhere in the depths of his murky human vessel; even so it slipped from his control, bubbling over at the thought that this was the serpent, the great blasphemer, the source of evil in the world, who had dared to raise a hand against God. And there was nothing but a thin ring of holy fire between them. Still he raised his chin and stared as defiantly as he could into Lucifer's eyes. "Nothing you can do will make me help you."

Lucifer's hand shot across the flames and closed around his neck and pulled. And then he was up against the boundaries of the circle, choking half with terror and half from lack of air. The fire was at his feet, its heat blasting him and he wasn't entirely sure he had the strength left to heal from those kinds of burns.

He pried at Lucifer's fingers on his throat, in vain. He had grown so weak, and even in his true form the devil could have torn him in two with barely an effort.

Lucifer leaned in close, seeming unaffected by the flames leaping between them. The shadows jumped on his face and his eyes were dark hollows, but when he spoke his voice was as gentle as ever.

"Can you feel the fire, Castiel? That's where you'll be if God ever comes back. You and me. Just you and me and an eternity of hellfire. Because He'd never take you back to heaven. Not after what you've become. A creature limited by flesh." The hand on Castiel's neck tightened even more. "If I kill this vessel now, would you even survive?"

The darkness in the room seemed to thicken and lower until it was pressing against his head, threatening to burst in and flood his mind and he wasn't sure he would wake up again from that. A wheeze forced its way from between his lips. Then Lucifer's grip eased. A smell of burning cloth filled the air. Lucifer looked down.

"You're going to burn," he said.

His coat was in the fire, Castiel realized. He shrugged it off frantically, letting it fall behind him. Without it, he felt weaker, more exposed. Sweat rolled down his face and he couldn't hide the slight trembling of his limbs, but he felt less afraid, suddenly. Lucifer hadn't killed him. That was something.

"No," he rasped, "I won't. I – am not – you. I – do not – sin."

Lucifer laughed his sweet laugh again.

"Poor Castiel. You're just as delusional, just as desperate as all the sad little humans running around on this planet. Not sin? Don't you think I know why you fell? Don't you think I know who you did it for?"

"No – it was – right – that's why."

Lucifer's other hand fisted in his shirt and again he was pulled up against the barrier of fire and Lucifer leaned across and kissed him over the flames. At first he was too shocked even to think; shocked at the soft lips against his and at the way he could feel Lucifer's power, what had once been grace, thrumming through his body as if he'd touched a live wire.

Then he cried out, muffled, and tried to pull away, but the hand on his throat had moved to the back of his head and gripped his hair painfully so that he couldn't move. And Lucifer had used the opportunity to slip his tongue into Castiel's mouth and the sensation sent shivers through him and he couldn't help, just a little, kissing back. It felt dark and hot. He was trapped in a blazing, whirling darkness, in this room and this circle and this kiss. He realized he didn't know if this was what kissing always felt like or if it was something Lucifer did. He'd never kissed anyone before.

"So you see," Lucifer said, pulling away and leaving him gasping. "You have a body now. And bodies are full of sins. I'm sure you've felt them before this. Wrath? Maybe envy? But I know – I know, little angel, that you've felt lust." He smiled. "I can make you feel it again."

"No, don't – you can't," Castiel choked out the words, trying to pull away, but Lucifer's hands held him like iron and somehow before he could register what had happened his shirt had been unbuttoned and Lucifer's hand had slipped beneath it and he suddenly went still.

Lucifer's fingers traced hot trails over his skin and Castiel whimpered.

"I know," Lucifer said. "Flesh is so weak, isn't it?" And he leaned over and dragged his tongue across Castiel's nipple, biting just a little, scraping with his teeth, and a bolt of heat seemed to sear from his mouth all the way down to Castiel's crotch.

"You can't demean me like this," Castiel said, almost gasping. "It's only a vessel."

Lucifer smiled at him. "I'm just having a little fun, Castiel. And so, it seems, are you." The hand in Castiel's hair tightened enough to make him grunt as Lucifer kissed him again and slipped a hand below his waistband. He couldn't quite prevent his hips from jerking forward and when Lucifer's fingers wrapped around his cock and began to stroke, his knees wobbled a bit and he had to throw out his arms and catch onto Lucifer's shoulders to avoid falling into the flames.

Suddenly, his clothing was too tight and he was hot all over. He couldn't see; he realized dimly that his eyes had slid shut and he was pressing forward as far as he dared. And Lucifer was still kissing him, tangling their tongues as warm fingers pumped him. It was revolting and confusing and yet he couldn't stifle a moan when Lucifer's thumb slid across the head of his cock. He realized what a mistake he'd made, how he'd underestimated this vessel he'd hidden himself in. He hadn't tried – dared – to understand what it could do to him. And now the reality of physical pleasure had him by the throat.

"Amazing, isn't it?" Lucifer whispered in his ear. "How feeble it makes you. Like clay in my hands."

"I – " He swallowed what he was going to say as Lucifer reached down to cup his balls.

"I could show you all kinds of things, Castiel. I could do all kinds of things to you. If I wanted I could make you kneel in the flames and suck my cock. Fuck you until you screamed my name. Fuck you in front of all my demons and make you like it. You'd let me. Because that's what you really are. That's what you've become. Isn't it?"

The hand on Castiel's cock tightened to the point of pain and even as his breath hissed from between his teeth, he couldn't deny it, he did like it. He wanted more. And he couldn't tell if he was burning from the fire or the shame.

But still, fallen or not, human or angel, with God or with Lucifer, he was Castiel. And he'd always had a defiant streak. So he turned his head away and said: "No."

Lucifer pushed him away as if he'd been burned. He landed hard in the middle of the circle and stared, stunned, up at his tormentor.

"Look at you now," Lucifer said, seeming as pleased as ever. "My broken little angel. Do you really think God wants you back? In this state?"

Castiel was sweat-soaked, disheveled and panting on the ground, his erection still straining in his pants. He twisted uncomfortably, not knowing what to do.

"It's hardly a state of grace," Lucifer observed. "Though I think it suits you." Then he grinned and clasped his hands in front of him. "Consider that an appetizer. The rest will have to wait until I have my true vessel." He turned to go before glancing back over his shoulder with one last mocking look.

"Don't worry. I won't be long."