Castiel wings into the war room in the middle of the night, because that is where Dean is, because he can't sleep. Dean's eyes shift from the laptop screen to the angel for what is supposed to be only a moment; but then there is that telltale finger movement at Castiel's side and the flash of his sword.
Dean is out of his seat in less than a second. His chair clanks on its side six feet behind him. "This again?" It's less of a question and more of a battle cry, because really, he can't be surprised. He won't treat this like it was never going to happen again. An expected blow doesn't sting as long. He will admit it sucks that he doesn't have the Word of God to use as a shield this time. The only other thing that ever Houdini'd him out of this kind of fight was Cas' vessel melting, and that body of his isn't bleeding blood or black ooze or light or whatever the hell else.
Cas is halfway across the floor when he lifts his blade and deftly flips it. Dean holds his ground, being neither a coward nor fool enough to believe he can outrun an angel (without a sigil painted already, anyway). "No," Cas says, and when he stands toe-to-toe with Dean, the hilt of his sword butts up against Dean's chest. With finality, Cas repeats, "no, not again."
It's impossible not to notice the blood on the blade. The changing gears in Dean's head are almost audible. His expression hardens, and he all but growls, "what did you do?" His thoughts fly, his imagination grips Cas and pulls him low. Dean dares him to disappoint him. Right now, so help him, he is ready to drive the blade's point through Castiel's heart. If it was anyone else, he would have done it already. Any second now, he might realize he should have done it yesterday. Where is Sam—
"I killed a nephilim," Cas tells him, candid as ever. And maybe, Dean thinks, he was mistaken in assuming Cas' vessel is fine, because the angel's eyes are reddened and his face is full of urgency. "I thought I could complete the trials, fix what I'd done—"
"The hell are you talking about, man? Nephilim? That's not in the trial! And even if it was, it's gotta be Sam. Not you. I told you to stay here!"
Cas waits for his chance to explain, unwilling to interrupt. "Dean," he begs. "Once before I told you I didn't know what was right and what was wrong. I thought, after everything, I had come to understand. I realize now that isn't true. Everything I do is wrong. No matter what move I make, I feel regret. And I won't—" Their too familiar stare is broken as Cas bends to take Dean's hand, guide it to the grip of the sword. "I won't." Castiel searches hopelessly for words to express the thought in his mind. It's difficult to think with the memory of years-ago-Dean so loudly telling him, no, you had a choice. This would be easier if he was surrounded by holy fire, or maybe standing on a lawn littered with autumn leaves. "Dean, I'm here. I'm asking for your help." He says what he needs to say by squaring his shoulders and pressing his vessel against the blade.
Dean gets it. It shows in the creases around his eyes and the tension in his jaw. His fingers tighten around the hilt of the sword and he surveys Castiel with dangerous severity. Dean's shoulder rolls and Cas shuts his eyes. Cas is certain… and then there's another metal clang on the far side of the room. The angel blade joins the toppled chair on the floor.
"You chose wrong," Dean says. "Again." When Cas opens his eyes, Dean's already on his way out of the room.
Author's Note: Because damn it, Cas, stop it.
Cross posted from AO3, May 9, 2013
