A/N: So, you all might be thinking 'blah blah blah, don't care, get on with the fic already!', but I just have to spazz a little bit right here, because I finally finished the original story that I have been working on for four years! It's a 315,000+ word behemoth, and it's DONE! *spazz spazz spazz* There's just some editing left to do, then it's on to seeing if I can actually manage to get this puppy published. Excuse me while I FREAK OUT! And, you know, if there are any published writers out there, don't be shy with the advice ;) I'm going to need all the help and luck I can get!

Okay… now back to your regularly-scheduled fanfic.

Because hunts seemed to find Dean about as often as he found them, he and Castiel started hunting together. Having an angel on his side made hunting just about the easiest thing he'd done in a really long time. Sometimes he thought shaving his face was more dangerous. He tried to harangue Castiel into backing off and letting him get dirty once in a while, but the angel wasn't interested in watching Dean get hurt. When Dean teased that he'd have to test out the immortal human theory sooner or later, Castiel was not amused. In fact, furious was a pretty good word for it. Dean wasn't too big to admit that seeing Castiel pissed off at him was scary as shit. He had finger-shaped bruises on his arm for a week from where Castiel hauled him out of the alley they'd been standing in after taking out a gremlin, when he'd made that ingenious comment.

It wasn't just the rough manhandling that made Dean start watching Castiel more closely. Dean lived a brutal lifestyle. The life of a hunter shearing jagged edges out of people wasn't abnormal in his world. Dean had had his own dark days. He'd seen Sam go about as dark as a human could possibly go. His childhood was spotted with memories of his father raging and drunk when it started to get to him. So Dean was used to that. But he wasn't prepared to see that happen to an angel.

Castiel used to be righteous, and some ferocity went with the territory, but lately it wasn't righteousness so much as hostility that would creep in and make Castiel do things or say things that made Dean's eyebrows climb toward his hairline. He watched Castiel rip the head off a vampire with his bare hands, and Dean was astounded at the sight because he knew Castiel was too mighty to need to even touch the vampire in order to destroy it. But he did, seemingly for the gratification of feeling bone crunching between his hands.

That wasn't the Castiel Dean knew, and he started to wonder. And worry.

But in typical Dean Winchester fashion, he skirted the serious talk as long as possible. One would think he'd have learned his lesson about avoiding the issue with Sam back in his demon blood guzzling days, but Dean was a master at burying the serious shit if it was apt to hurt. He let Castiel do his thing (because an angel of the Lord, it turned out, was a fucking amazing hunter – not so good at pretending to be human law enforcement or lying to witnesses, but when it came to finding evil and killing evil, hell yeah), and hoped it wasn't so different from humans going through a rough patch and needing to work stuff out.

Until it just couldn't be avoided any longer.

They were staying in a motel in Arizona when Dean was woken in the middle of the night by a metallic, rhythmic sound. He opened his eyes blearily, frowning at the scraping sound. He knew it in just a few seconds… blade on whetstone.

Dean looked toward the window and found Castiel sitting on the sill, the curtains open to let in the pale blue light from the Sleep Tite Inn sign. The angel was dressed in boxers and a plain white cotton t-shirt (when Castiel seemed amenable enough to adopting human wardrobe habits, Dean bought him some of his own clothes). His arms, mostly bare of clothes to mask their shape, were gangly and seemingly made entirely of bone and sinew. The light fell on Castiel's face in stark, savage patches of electric blue against pitch black shadows. The guy still hadn't put any weight back on his body, no matter how much Dean fed him. Dean was starting to think it was Castiel's true form that was emaciated, though how that worked was beyond Dean. In Castiel's lap was a hooked blade (once Sam's, the one blade in addition to the one gun Dean had coerced his little brother into taking to college). Castiel slowly, methodically sharpened the edge. Scrape, scrape, scrape.

It was the look on his face, most of all, that made Dean sit up in bed. Castiel looked dark, dangerous, but most frighteningly of all, human.

"What's up, Cas?" Dean asked in a sleep-roughened voice.

Castiel paused his sharpening to look at Dean, and it was a look that sent a chill down Dean's spine.

"This weapon was dull."

"Uh huh." Dean leaned over and turned on the bedside lamp, just to throw some warm light on the angel. Not that it did much to soften his expression.

Dean frowned and realized that that long-avoided talk couldn't be put off any longer.

"Cas… what's going on with you?"

Castiel stopped his task again to look at Dean. "What do you mean?"

"I mean, you're not yourself." Dean took a breath. "And you never answered my question about whether or not you'd live forever."

That made the angel cock his head, and the gesture might have been familiar if it wasn't for the perturbed look in his eyes. "You're still thinking about that?"

"Thinking about the fact you never answered me, yeah."

With deliberate slowness, Castiel put the blade and whetstone down on the small table and shifted to face Dean. He considered him quietly a moment, during which Dean felt he dare not break eye contact. Not if he wanted answers.

Finally, Castiel said wearily, "I didn't answer your question because I don't know the answer."

That definitely wasn't what Dean had been expecting. "What do you mean? Why wouldn't you live forever? You're an angel… angels don't just die."

Castiel moved from the windowsill to sit on the bed next to Dean. The grace in Dean was eager for Cas to be closer, but he tried to ignore it and focused on Castiel.

"I mean," Castiel clarified, "I don't know how much longer I'll be an angel."

The room temperature dropped a good ten degrees. "What the hell are you talking about?"

Castiel looked crossly at Dean. "I told you, in the war in Heaven, regrettable things were asked of me. Do you remember why I chose to hide a part of my grace in you in the first place?"

"So you could cleanse yours when it was all over," Dean answered, starting to feel a little sick to his stomach.

"But I can't do that now… I can't reclaim my grace."

"And yours was damaged in the war," Dean said needlessly.

Castiel nodded. "The blackness will spread, and when the corruption is extensive enough, I will fall." Castiel sighed. "At which point I will no longer be an angel. I'll be mortal."

When that sank in, Dean surged to his feet. He paced. His temper rose. "Why didn't you explain that before?"

"I didn't see the point," Castiel retorted.

"There's a big fucking point to it! That's not a little detail, Cas. That's big."

"Don't you think I know that?" Castiel asked sharply. "I am facing the prospect of life as a human, and not even a full life at that. Trust me, the significance of it has not escaped my notice." Castiel titled his head and smirked. "Though I have been amused by the irony of it. Dean Winchester living forever while Castiel, angel of the Lord, dies of old age."

Dean's whole chest clenched. Oh hell fucking no. The only reason he'd been able to deal with the very thought of life eternal was because Castiel would be there with him for it. In fact, it was kind of comforting to think of someone who couldn't die on him. But this? This?

"There must be something you can do to cleanse your grace."

Castiel looked put out that they were even having this discussion. "There is only one way, and it's not an option anymore. I won't do that to you."

Dean perked up. "Wait a second, do what?" When Castiel didn't answer, Dean crowded up in his personal space, like Castiel himself was so wont to do. "You won't do what, Cas?"

Castiel looked up impassively at Dean, not moving from his place on the edge of the bed as he did so, and if Castiel had any clue about human body language he'd feel the submissiveness of his position, having to crane his neck to look Dean in the eye as the hunter towered over him. But Cas, of course, didn't. "I told you at Bobby's, though you did seem to be tuning us out by then. Technically, I can take my grace back, but not without taking parts of your soul with it."

For a second, Dean just stared down at Castiel. Waiting. But the fucking angel would make him make the next move. "And what if you did? What would happen to the pieces of my soul you tore out?"

"They would become part of me, hopelessly merged with my grace." Castiel frowned. "And I would not be able to completely remove my grace from you. Just like pieces of you would end up in me, pieces of me would remain in you."

"So what makes that such a bad plan that you wouldn't even consider it?"

Castiel's eyes flashed surprise and annoyance. "Sometimes I think I would enjoy slapping you."

"Hey, hasn't stopped you in the past. Do it, if you think it'll make you feel better, but you're still answering my question."

With a grunt, Castiel shook his head and slowly rose to his feet. Dean didn't back off to give him room, so it brought him nose to nose with Dean. For a second, Dean thought Castiel really would slap him. He peered closely at Dean, as if studying the details of his soul in his eyes. Damn that man's relentless stare.

"You have to understand that keeping a piece of my grace inside you permanently would make you in some small degree an angel. You would no longer be entirely human." Castiel lifted his chin fractionally, because he knew how monstrous being inhuman was in Dean's book. "Most likely we would be spiritually connected, as you felt connected to me while I was at war. But with pieces of a human soul – your soul – in me, I would feel connected to you in return. And in some small measure, your soul in me would render me in some small sense human."

"Oh…" Dean hummed in comprehension. "Oh, I see. So you're phobic about getting tainted by the mud monkey, huh?"

Fury flashed in Castiel's eyes and it almost made Dean step back. Almost.

"I'm doing this for you, Dean. Like always, it's all for you." The angel's bitter tone only got worse. "I sacrifice again and again for you, and you never show me the least appreciation for what I do in your name. Only God has ever had more from me."

Dean thought that was unfair and inaccurate, but instead of tell Cas that, he asked, "And if you don't get your grace back, spoiled or not by a human soul, what happens to you?"

"Sooner or later, I will fall. It will only be a matter of time. Then I'll die… when this body gives out." Castiel suddenly looked depressed. "Do you see now what I'm doing for you?"

"Yeah," Dean growled. "Yeah, I do, and you can just stop it."

Castiel blinked, startled.

"Look, I'm sorry that I promised to hold on to your grace and got my filthy human soul all over it, but I'm not going to let you go human just because of my screw up."

The fire left Castiel's eyes, bit by bit, and he started to frown. "Dean…" his voice softened. "I'm not revolted by your soul. It's beautiful, and I'm proud of it."

"Proud?" Dean asked, baffled.

"Yes." Castiel smiled. "I remade your soul when I pulled it out of Hell. You're the most amazing thing I've ever done."

Dean's mouth opened but no sound came out.

"And I won't tear pieces of it away from you. I would rather die than deface such a work of art."

Without ceremony, Dean gave Castiel a firm push that knocked him back on to the bed just behind his knees. "Damnit, Cas!"

From the bed, Castiel looked up, puzzled. "What?"

"You mean to tell me you've been balking at taking back your grace because you're concerned about me?"

"Of course. Why did you think I refused to take it back?"

Dean rolled his eyes. "You better hope we both live forever, because it'll take me that long to figure you out."

"Dean…" Castiel began warily.

"No, just shut up and listen." Dean took a breath when Castiel seemed inclined to obey. "I get it. You don't want to hurt me. I'm touched. But I'm not going to let you commit suicide, no matter how slowly, because I'm the fucking Mona Lisa to you."

"Who is –"

"So this is what's going to happen," Dean forged on, not letting Cas get a word in edgewise. "You're going to take your grace back, you're going to undo whatever damage Raphael and his stupid lackeys did to you in Heaven, and if I end up with pieces of you where pieces of me used to be…" Dean leaned down to look directly at Castiel. "I am okay with that."

"I'm not. Dean, I can't do that."

"And you know what I can't do, Cas? Lose you."

That made Castiel stare up at Dean, astounded and seemingly on the verge of a hugely chick flick moment.

"So don't do it for yourself," Dean pressed. "Do it for me, because I swear to god, if you die on me, Cas, I will never forgive you. No matter how long I end up living, I'll hate you until my last day for dying."

"That's rather petty," Castiel noted with a sneer.

"You bet it is. So are we clear?"

Castiel seemed braced to fight him, all the way if necessary, then he just gave in and sagged back on the bed. "If you are absolutely certain."

"Absolutely," Dean assured.

"Very well," Castiel relented. Then he looked around the motel room. "But not here."

"Then where –" Dean began to ask as Castiel reached out and touched his hand.

And in the next split second, they both disappeared from the crappy motel room in Arizona, spirited elsewhere in the blink of an eye.

To Be Continued…