...and he's back on Earth again. His face looks pale and drawn, his eyes vacant. His sword slides from his sleeve into his hand, and then into Samandriel. Castiel calmly lowers the poor, doomed angel to the ground as the light goes out of him. Castiel seems without emotion until the whole awful thing is over. Then he looks quietly devastated to have killed the one angel he was trying to save.
"What did I just do?" he asks, suddenly back in Naomi's office. "You killed a traitor," she tells him. She says that Samandriel told Crowley about the angel tablet, but Castiel's guilt isn't assuaged. "I just killed one of our own to protect a tablet?" She reminds him of what the demon tablet can do, implying that the angel tablet would do much the same to them. Castiel should wonder why God would want to harm the angels, but he's not quite right in the head these days. "You're a hero," Naomi says. "And that's what I tell Sam and Dean?" he wonders.
The Winchesters find him holding Alfie's lifeless body. "You tell them Samandriel had been compromised," Naomi says. He echoes her words to Sam and Dean. She tells him to say he acted in self-defense, and so he does. Dean stares at him. "Cass, are you okay?" Blood runs from the corner of Castiel's eye like a tear. It's really quite an effective visual. "My vessel must have been damaged in the melee," he explains, sounding almost a bit... robotic. Naomi tells him to bring the body back to Heaven so she can see how far Crowley got. As if Samandriel hadn't already suffered enough, now he'll be subjected to what promises to be a gruesome autopsy. Castiel flutters away with Samandriel over Dean's protests.
Later, Sam and Dean take what's left of the spray paint and deck out Rufus's cabin with warding symbols of their own. Thus guarded against peeping angel eyes, they're free to wonder what the hell is going on with Castiel. "I told you something was off with him since he got back from Purgatory," Dean says. "You think someone's messing with him?" Sam asks. Dean scoffs at the idea that angels might be making him kill other angels because he's forgotten just what assholes 90 percent of them really are. But he does remember that Sam's not even supposed to be there. "You know what, man? I got this. You go." Sam is surprised. Dean says he's just tired of fighting. The scene could have ended right there, but no! "You know, maybe I'm a little bit jealous," Dean says. "I could never separate myself from the job like you could." He thinks it would be nice if one of them could be happy. Suddenly, though, Sam is feeling torn. Dean tells him he needs to make up his mind, but not in an overly bossy way. "Both feet in or both feet out," he says, because the show loves its parallels. "Anything in between is what gets you dead."