Disclaimer: I don't own Supernatural, and I'm not making any money off this.

Bitter Pill

The thumping was beginning to annoy Castiel badly. Now it wasn't just in his head—Jane bounded down the stairs, sneakers hitting wood with an intolerable clamor at each step. The noise felt like shockwaves through his skull, punching the blood out to hammer directly between his eyes. Castiel rubbed the bridge of his nose futilely, a gesture he had often seen humans perform but was just beginning to appreciate himself.

Jane walking into the study, footsteps mercifully muffled by the tattered carpet. She had a book clutched under one arm. Castiel recognized it. It was one that had been written by Abdiel's vessel, a book on the demonic. An interesting read, not that there was anything in it Castiel didn't already know.

Castiel remained seated on the sofa as Jane replaced the book on the study desk. He bent his head and rubbed between his eyes again. Did humans feel like this all the time? He didn't know how they could function, being so fragile and temperamental.

Jane sat herself in the chair at the desk, swiveling around so she could read the titles on the shelf behind her. She picked one and swiveled back, now looking through the loose papers covering the desk, untidy from Castiel's previous perusal. She examined them intently, seemingly quite oblivious to the angel in the room. She had been running through these books all afternoon, devouring information.

"Are you okay?" she said suddenly, looking up from the desk at Castiel, who was looking rather pathetic on the sofa with his head in his hands.

"I'm fine," he said, although he certainly didn't sound very cheerful as he said it. "It's just this…." He gestured at his aching cranium, uncertain how to describe it.

"You have a headache?" Jane asked. Why did she always have to sound so amused? Was it really any wonder that he was unaccustomed to human sensations? Castiel decided it was a rhetorical question and sat glowering.

"Hold on a sec," Jane said, and she dashed from the room into the hallway. More thumping, this time from somewhere above his head. Wonderful.

She appeared a minute later with a glass of water and a small white capsule. Castiel looked from it to her impatient face. He stared at the capsule curiously.

Jane sighed and rolled her eyes, an expression Castiel was getting used to seeing. "Aspirin," she said, handing it and the glass to him.

Ah, yes. He has also seen humans use this. They swallowed the pill and the pain went away. What a curious invention.

Castiel had a small amount of trouble figuring out how to swallow the pill without choking on it. He eventually managed it, although it left a bitter taste in his mouth. A human expression came to his mind: A bitter pill to swallow. Yes, that made sense now too.

Jane had already returned to the desk, flopping down on the worn leather chair. Castiel's headache did not feel any better, but he supposed these things took some time to work. He decided it would be a good idea to do something to take his mind of it in the meantime, so he walked over to the desk to inquire after Jane's research.

"Anything interesting?" he asked, standing opposite Jane, who was engrossed in some rather morbid reproductions of woodcuts showing demonic activity.

"Yeah. Some of it's kinda…over my head," she said with a grim smile. She glanced up at Castiel, who gave her an encouraging look, so she pressed on.

"The, uh, whole Seals thing…." She rubbed her temples. "We still don't know where it is. If we had it, or could get to it, we could keep the demons from breaking it. Right?" She looked to him for confirmation.

"I told you before—"

"I know, I know, they can't break it yet. For some mysterious reason or whatever. But shouldn't we be looking for it? There's all this information here—" she waved a hand around the stacks of papers "—and, well, what if we can find it?"

"It's safe for the time being. There is nothing of use in this location besides what I've already told you," Castiel said, keeping his exasperation in check. At least his headache was finally subsiding.

"What does Abdiel think about all this?" Jane asked softly, watching him intently.

"Abdiel is under my command," Castiel said, more sharply than he meant to. Immediately he reined in his anger. He turned to Jane apologetically.

Jane looked embarrassed. "He just seems kinda…."

"More capable?" He could not keep a trace of unpleasantness from his voice. He was silent for a long time, the tension in the room growing as he stared at the wall, not seeing it. Leaning against the desk, back to Jane, he finally spoke.

"Abdiel was once one of the highest of the Heavenly forces. But when… Lucifer—" he said the name with distaste "— began his rebellion, Abdiel joined him." He paused, thoughts and ancient memories dancing through his head, collected since before time began. "He would not fall completely, however. When he learned what Lucifer planned…the wholesale rejection of God…he left them. Still, the pride that corrupted those who fell…Abdiel still has a trace of it. A certain rebellious streak that has gotten him into trouble since then. Pride has a stronger grip on him than it should." He looked to Jane to gauge her reaction.

"But he's a good guy, right?"

"He has reformed his ways, so to speak. But it takes a long time to get back into Heaven's good graces."

Jane looked down at the desk top, pondering. "I guess that means he's stronger than you." She looked up suddenly, a trace of a smile on her lips. " Maybe they should have given him this mission, Castiel. Heaven knows you haven't done a very good job of it."

He stared, dawning horror in his eyes. No, not this….

"Who are you?" he asked, facing down the girl in front of him.

Jane smiled, the shape twisted on her mouth, distorted and cruel. Her eyes were black, bare, soulless, reflecting the room and the thundering angel.

"You shouldn't have left her alone—" she paused, as if thinking "—what is it she calls you? Angel-boy?" She laughed, the sound cold and punctured. "It was just too easy, Jane sitting there so angry and unprotected…. I could just slip in…."

Castiel rounded the desk, closing the distance between them, ready for battle, terrible anger in every step, but the demon in Jane's body did not flinch. "You can't hurt me, Castiel. She's still in here." It tapped Jane's chest with a finger, smiling that wicked smile that made anger course through Castiel's body, the physical reaction to this evil that he was just getting used to.

He moved forward anyway, not wavering as he advanced upon her, hating what he was about to do. The demon took a step back, still with the cruel smile, but Castiel was there too quickly. He reached his palm out to her forehead and she dropped immediately, unconscious, body thumping to the floor. He stared down at her, horror in his face. Every instinct told him to recoil, to rebuke this monstrosity. God help him, he knew this was his fault too.

"You know what you must do," Abdiel said. He stood against the wall, motionless as a statue, watching Castiel stand before Jane. The girl was tied to a chair, wrists secured against the wooden arms, small defense against the strength of those possessed, and unnecessary in Abdiel's opinion. This could have been ended already.

"I can't. It will kill her," Castiel said. She was unconscious now, but he felt the evil force inside her. He had the power to cast it out. It would be easy….this was a lower demon, weak and insignificant next to him. He pictured the bright light, flaring up and burning out the evil spirit, but it would destroy that fragile human body until it was so broken her soul couldn't live there anymore….They died too often, the power too much, too pure, too terrible.

"She has been compromised. The entire mission has been compromised," Abdiel said.

His fault. Abdiel was right. Castiel could say nothing.

"So you'll sacrifice everything we are working for? Too much has been risked already. We've had the enemy here in our midst for hours, learning our plans, sneaking into our minds….Send it back to Hell." Abdiel's tone grew more heated until Castiel sent him an admonitory look to remind him of his place.

"No. There is another way. Humans perform exorcisms. It may work in their way," he said.

Abdiel scoffed quietly. "Humans? You are better than that, Castiel."

Castiel stepped up to the unconscious girl, tied to a chair, loathe thought he was to come closer to this vessel of evil. He touched a finger to her forehead, as before white-hot. Her head lifted, eyes rolling up and into place. They were Jane's usual brown, but Castiel could see the demon lurking behind them.

"Tell me your name, demon," he said darkly, not disguising the power and menace in his voice.

The demon smiled, twisting Jane's face into an ugly sneer. "Jane."

"Do you know who you are in the presence of? We are angels of the Lord. We have the power to cast you into Hell and bind you there for the next millennia." He moved closer, face close to hers as blue eyes drilled into eyes now black. "Who sent you?"

There was fear in its eyes, Castiel noted. The thing in Jane's body nudged away from him, cowering as far back as the binding would allow it, but it still managed to summon enough vitriol to sneer back at him. "I don't answer to God's vassals."

Castiel did not let the gaze go. "Where is he?" he said in the deadly calm voice of one holding the power.

"Scared to say his name? You always were a coward, Castiel. Even back in the old days. Never willing to do what needs to be done. You care for these humans too much. You're weak, and that's why you'll fail," the demon said. Even her voice was twisted by its words.

Castiel stepped back, straight faced, and turned away. He tried to collect himself, summoning his strength and praying he would succeed. He turned back. "Strange loyalty you show. Eliul sent you here knowing you would be cast back, willing to sacrifice even his own followers. Are you willing to spend the next thousand years writhing for you master's sake?"

"We all make sacrifices, Castiel. Sacrifices we have to make for the greater…evil. I'll get my reward. You won't be able to chain me long when Lucifer walks the earth."

"It's over for you. Leave this body," Castiel said, feeling his anger beginning to rise, spreading through his soul.

"But it's so much fun here. I haven't enjoyed myself this much in a long, long, time. This human? Oh, if you could see the things in her head…." The demon chuckled as if at a private joke.

Castiel would take no more. He advanced on the demon and pressed his palm to Jane's forehead and let the power flow through him. The demon screamed ferociously, the high-pitched sound of madness in Jane's stolen voice, her eyes glazing over with black ink. Castiel did not let it go on for long, however. It was only a taste of his power. The demon sat trembling in the chair when he stopped, clenching Jane's hands over and over. He stepped back, serious and composed, and glanced at Abdiel, who still stood silent against the wall, keeping his thoughts to himself.

"Don't think you'll escape. We're waiting for you," the demon said quietly, all the more menacing by the soft lilting to used in Jane's voice. It looked at Castiel with black eyes, hate radiating from it.

He looked over, finally getting some response. "Where are your cohorts?" he asked.

The demon smiled and looked at the ceiling, feigning nonchalance. "We have it now. How long do you think it will take us to break it?"

"We will devastate you," Castiel said. He had never meant anything more in his existence.

"You can't even get your hands on the Seal. A poor protector you turned out to be. What will your god say when he finds out you've failed?" it said with derision.

Castiel moved in again, placed his hand on her forehead and let loose. The demon screamed, louder and louder, the sound ripping at Jane's throat as her back arched in the chair. Castiel held on longer this time, but not long enough for the black eyes to fill with the burning light.

"Where is it?" he said finally.

The demon panted, shuddering from the pain. "He'll hurt me!"

"You're going to Hell anyway," Castiel said. He intensified his stare.

"The cathedral in Hartville. That's where they are…they're waiting…." it said in a strained voice, twitching in the chair.

Abdiel stepped forward. "It could be lying." He looked at the demon with distaste.

Castiel shot him a look. "I know. But what choice do we have?"

"No choice," the demon said. It was recovering slightly, panting from the last bout, but strong enough to look at them with terrible hatred as it strained at its bonds. "You're just mindless drones, slaves to your dead god. You talk about free will, but it's all a lie, worse than anything we ever cooked up. We might be damned, but at least we're free, free from your tyrant god. He's got you angels jumping at his beck and call, so eager to give up all the power you have, bowing down in worship to that raging psychopath—"

Castiel spun around, retribution in his soul, anger in his steps as he gripped the demon in his hand and laid his palm on Jane's forehead one last time. This was to be the end.

"I'm sorry Jane," he said, and he let loose the full power of his angelic being. The black eyes disappeared, engulfed in white, blinding light, and the scream of fear, rage, and despair from Jane's lips was terrible. The light shot through her open mouth, scorching out the black smoke that tried to escape, razing through her stolen body. Castiel did not stop.

"Castiel. It's gone." Abdiel laid a hand on his comrade's shoulder. Castiel looked at him and the righteous rage disappeared from his eyes. Jane slumped over in the chair.

Castiel stepped back, eyes wide with horror at what he had done, overcome with shame. He had promised….

Abdiel picked up Jane's chin, lying on her chest, and turned her head side to side. "She's still alive," he said with a glance to his commander. He brushed two fingers against her brow.

Jane did not move for a moment. Then she stirred and drew in a shuddering breath, trying to lift her head up but only half-managing.

"Hey, angel-boy," she said with a weak smile, but this time it was genuine.

A/N: Hot off the press. This chapter almost killed me to write.