Sorry for the wait, I've been a-vacationing!

fact of the day: did you know that einstein would help out a family friend's daughter with her homework in exchange for jelly beans?

TIMESTAMP: SWAN SONG

What she saw made her heart plummet. She'd know Sam was planning this. Cas had told her he'd failed. That was why she'd gone to the Sage. To be sure. To have a failsafe. To be sure.

She looked at the metal stamp the Sage had given her. She thought about what Joshua had said to her, after reviving Sam and Dean. He'd told her that she was different, that Cas had been right – there was something special about her, too. He'd told her about Cain and how she was one of maybe a dozen viable candidates in the entire world to bear his Mark. She thought about Zachariah trying to hurt her and Sam to use them as leverage, about how she hadn't been affected.

Do you really want to do this? Said a little voice in her head. You can never go back. And he's the devil – who knows if it will even work on him?

But she had to do it. She couldn't let Sam jump into that hole, couldn't let him get stuck in the Cage for the rest of eternity, not if there was even a sliver of a chance that she could stop it.

She knew Sam had to die. But he didn't have to die like this.

"I've been to the deepest of pits and the highest of mountains, felt the coldest of ice and the hottest of flames. I've seen and understood and I have acted and my punishment is nigh," she recited under her breath.

Claire threw herself out of the stolen car, feet pounding against the dead grass. She almost screamed with pain as she felt the stamp burn white hot, imprinting the Mark into her palm.

Lucifer raised a hand and she flinched, still half expecting to explode into tiny little bits – an instinct reinforced by the fact that she had just sprinted past Bobby's dead body and what she could only assume was the remainder of Castiel – but nothing happened. He merely smiled and beckoned.

"The sister! Good, I've been expecting you," he said. "Now it's the entire family!"

"Claire!" Dean shouted. She saw him for the first time. He looked… scared. More scared than she'd ever seen him. And small. "Where have you been?"

"I've been thinking," she said, summoning every ounce of confidence, cockiness, sarcasm, lilt, calm she had in her body so her words sounded condescending. "I've been thinking long and hard and I've come to the conclusion that this entire thing is a big joke."

To her credit, both Lucifer and Dean looked appropriately stunned. She flashed an obnoxious grin and continued.

"I mean, Satan? The Devil? What the hell is all that about? No pun intended," she said. "What evidence have we seen that you are actually a threat to anyone, Mr. Lucifer? Precious little, I'd say."

"It's too bad you weren't here to see me slaughter your friend. And my – foolish brother," Lucifer smirked.

"Yes, it really is," Claire continued brusquely. "Now I will never have visual evidence, and no matter how hard you try and convince me that that really happened, I will not believe you. Not unless you caught it on tape by some miracle."

"Claire, what are you doing?" Dean snapped. She ignored him.

"You have really reached a whole new level of stupid, haven't you?" Lucifer laughed tightly.

"Have I? Am I really the stupid one here?" he was beginning to look annoyed. Good. "Let's think for a second. Which one of us has been forced to spend an entire year trying to get some random mortal to let himself become possessed by someone who is regarded by many as the embodiment of all evil? See, I never got myself chucked in a hole, so I've never had this problem."

Annoyance melted into intense irritation.

"Stupid is too kind a word for you," he amended. She tsked.

"But the kicker is that Sam only said yes in a last-ditch effort to kill you," Claire continued. "I kind of feel sorry for you, Luci. But you know, that whole plan could end up working out anyways. We're the heroic type, you know? Shit like this always works out in the end for us. Or at least, it does in movies."

He was now looking downright furious. If she didn't have a part to play she would be pissing her pants by now. Now all she could do was pray that he was unaware of her inability to be killed by angelic means.

"Yeah," she pressed. One more thing, to send him over the edge. "I do feel sorry for you, Lucifer. In fact, I pity you. When you were a kid, did you ever imagine you would become this… sliver of a sentient being?"

"Well," Satan pursed his lips. "Why don't I display exactly what this sliver is capable of?"

He theatrically raised his hand.

"No!" Dean screamed, but Lucifer snapped his fingers.

And he exploded.

She had succeeded in killing the devil. But she had killed Sam, too.

note: if you are unfamiliar with the mark of cain – it is part of a story in the bible wherein cain, a son of adam and eve, kills his brother and as punishment is cursed with the 'mark of cain', which provokes the vengeance of god on anyone who attacks him. so basically if you try to kill him you die. anyways, that's what's goin on with claire here.