With the memory of a promise propelling him, Cas used what little of the borrowed grace he could to force his way into the bunker's entryway.
The sound of the door being blasted back had Sam and Dean running out to him almost instantly.
"I apologize for the door," Cas said, as he stumbled over it, "but I need your help."
He heard exclamations of What the hell, Cas? and Cas, are you alright? before he unceremoniously collapsed on the floor.
He hoped that answered the second question.
From there, it was all anxious touches to his forehead and vain attempts at questions.
All his thoughts, as he lingered somewhere between angel and human, were in light and Enochian.
English was at the edge of his grasp. He tried to speak in it, tried to tell them that the borrowed grace, ultimately sensing that it didn't belong to him, had begun to reject his vessel.
It was burning him up from the inside, making him feverish and tongue-tied.
All Sam and Dean needed to do was remove it.
He'd be human again, yes, but he'd be alive.
"He's running a fever high enough that anyone human would be dead, and he's mumbling in complete gibberish or, god, I don't know, maybe it's Enochian," Dean said.
Then, sounding utterly helpless, he added, "I don't know what's wrong with him, Sam."
"We'll figure it out, Dean," Sam said, all reassurance. "We'll figure it out."
Cas believed they would though he also thought it would help if they didn't need to. He shifted restlessly and ran his hand over his throat and neck, praying that one of them would notice and understand.
Neither did, and, so, trying to find their own explanations, they left him alone.
He moaned softly when, some time later, he heard the rustling of paper on one side of him and the steady click of keys on the other.
Research was unnecessary; they merely needed to understand what he was trying to tell them.
Cas reached blindly for Sam's laptop and tried to close it.
He didn't succeed, but he did get Sam's attention.
"Cas, can you hear us?" Sam asked. Cas tried to nod, but his head felt like lead, weighed down by something much worse than a human headache. The grace was sending a continual flood of light erratically and painfully blasting through his thoughts. It was telling him, in no uncertain terms, that it did not belong to him, and it did not appreciate being stolen.
So, unable to answer the way he wanted to, he reached for where he thought Dean's hand would be and relaxed when Dean took his.
"Can you, Cas?" Dean asked. He squeezed Dean's hand in gentle assurance. "Oh, thank god."
"So, you can't speak in anything but Enochian, huh?"
If Cas were able to glare at Dean, he would have. Instead he gripped Dean's hand tight enough that it was likely to hurt.
"Okay, yeah, stupid question," Dean said. Cas loosened his grip.
Dean started running his thumb in a continuous circle over the back of Cas' hand. "I don't even know what to ask. Angels aren't supposed to get sick. Kind of the whole point of immortality, isn't it?"
Dean sounded upset or possibly angry; Cas couldn't quite tell. He assumed that either reaction stemmed from Dean's belief that he was about to break his promise. He wished there was a way to reassure Dean that he intended not to. Finding his own comfort in the motion of Dean's thumb, he mimicked it with his index finger.
"Cas, is that what this is? Are you sick?" Sam asked.
Cas began kneading all of his fingers over Dean's knuckles in contemplation, uncertain if that were the correct way to describe this.
"I think the answer to that one is a little murky," Dean said.
"Did someone do this to you?" Sam asked.
He kneaded more slowly.
"Still murky, but I think we're getting warmer," Dean said.
"Okay. Did something do this to you?" Sam asked.
He stopped moving his fingers.
"Well, what?" Dean demanded, jumping up but not letting go of his hand, clearly prepared to go out and destroy whatever it was.
Cas pulled Dean forward as hard as he could as he rubbed his other hand against his throat.
"Don't tell me your throat is giving you a 108 degree fever," Dean said. "That doesn't add up."
Luckily, Sam got it this time. "Is the borrowed grace doing this to you?"
Cas squeezed Dean's hand insistently and repeatedly.
"Okay, okay. Cas, chill," Dean said. Cas relaxed his hand. "I think we got Bingo, Sammy."
Sam sighed.
"Okay, so what? We remove it, right?" Dean asked. "Didn't you two do something like this already?"
"Yeah, Dean, we did," Sam said, "but it almost killed me, which is why Cas stopped."
Dean sighed deeply and leaned forward drawing Cas' hand towards his cheek. Cas' knuckles just barely grazed what he believed was referred to as peach fuzz. "God damn it, Cas. You can't do this. Not again."
He was trying not to. As much as he imagined Dean never wanted to be in the position of repeatedly and desperately calling his name again, Cas never wanted to be in the position of hearing the dying echoes of it knowing he could never respond.
If only Sam would think this through all the way.
"Though maybe it's different since Cas doesn't need the grace to stay alive like I did," Sam said contemplatively, "or, at least, I don't think he does."
"Cas?" Dean said. Cas squeezed his hand.
"Okay, is that what you want us to do then? Remove the grace?" He squeezed it again. "Well that settles it."
Dean kept holding his hand as Sam pushed the syringe into his neck and slowly extracted the offending grace. Cas did not see the necessity of this, but he did find it oddly comforting.
The more grace that Sam extracted, the more comforting the constant pressure became. Its presence gave him something to think about besides the increasingly human pain of the syringe and the knowledge that he was losing again the essence of what he was. He supposed that this time, at least, it was by choice.
It was perhaps unsurprising that when Sam finished and humanity returned to him fully, he was suddenly and overwhelmingly exhausted.
He knew he needed to sleep to fight off the remnants of the angelic fever. Yet, he felt it was important to say something to Dean, to tell him he'd kept his promise, to tell him he'd try harder not to break it. But all he could manage was, "Dean."
"Yeah, Cas?" Dean asked, but Cas' tongue felt too heavy to say anything further. Sleep was pulling him under, and he couldn't fight it. Furthermore, Dean wouldn't let him. "Hey, if you can't keep your eyes open, you probably shouldn't. Stop trying."
He felt Dean's hand brush against his forehead once more as he fell into a feverish sleep.
He woke several hours later to find Dean standing over him, staring. He found this simultaneously unnerving and endearing.
"Were you watching me sleep?" Cas asked bemused.
"Yeah, you were, I don't know, you were spazzing out or something. I didn't want you to fall off the bed," Dean said. "But, it's a little creepy, huh?"
"Maybe," Cas said as he tried to sit up. The room spun, and Dean sat down next to him letting his head rest on his shoulder. "But I do appreciate that you were watching over me."
"So, want to tell me what the hell happened that made that necessary?" Dean asked, frustration clear in his tone.
"You know what happened, Dean," Cas said, uncertain as to why further explanation was necessary. "The borrowed grace was not meant to be borrowed. It reacted volatilely."
"Did you know that was going to happen?" Dean asked.
"I knew it was a possibility," Cas said, knowing full well that was the wrong answer.
"So what in the name of anything were you thinking when you took it?" Dean asked.
"It was a means to an end, Dean," Cas said. "I needed it to help the angels."
"Right." Dean looked at him sideways, like he wasn't quite sure he was real. "Damn it, Cas. It could have killed you."
"But it didn't. I knew you and Sam wouldn't let it," Cas said. He sensed this wasn't the right answer either. That it wasn't enough. That it had been too close.
Dean didn't respond immediately, and Cas knew he was right.
"Don't you get it, Cas?" Dean said finally, running his hand along Cas' shoulder. "You and Sam, you're all I've got. And you...well... I need you, okay? Tell me you get it."
Cas frowned and tipped forward slightly, pressing his hand to his temple and rubbing at it. His head was still spinning, and though he sensed Dean found this completely straightforward, he didn't. There was too much emotionality behind the word and too much ellipsis.
He couldn't help feeling that need meant something different to Dean than it did to him. He understood it to a degree but not enough.
"I do," Cas said, squinting into the distance, wishing it would take his next question away. "But why?"
"What...what do you mean why?" Dean asked as though it should be obvious. Cas wondered what Dean was seeing so clearly when he felt like he was looking through foggy glass.
He knew need was there; it always had been. But he simply didn't know what it was.
"Why do you need me? I don't have my powers. I can't answer your prayers. I'm a terrible hunter," Cas listed sullenly, hoping that stripping need to its basest form would give Dean a reason to alter the vocabulary. If he was feeling a little hopeless and helpless too, well, he was only human. "I have nothing for you."
"Cas, you listen to me, and you listen good. I never needed you for your powers. I can't say they haven't come in handy now and again, but Cas, it's about you. I need you, however you happen to be. Angel, human, I don't give a rat's ass. I just want you," Dean said.
In the shift from need to want, the fog cleared and Cas understood what need had meant all along.
"I need you too, Dean," Cas said. He gently and cautiously pressed his lips against Dean's neck. Dean stiffened in response, but he didn't pull away. Cas still stopped and pulled himself back. "Sorry, I thought..."
"No... you...I... oh, come back here," Dean said wrapping his arm tightly around Cas' shoulders. "What's with the neck kissing anyway? Didn't you learn from a porno?"
"I didn't want to upset you if I were wrong," Cas said. "Was I wrong?"
"No, Cas," Dean said. "You took me by surprise. Maybe aim for my lips next time? At least I'll see it coming."
Cas didn't hesitate on that invitation.