"You betrayed me, Dean."
Dean must have let his skepticism show in his eyes. She went on.
"I don't think you fully understand the situation you're in, Dean. I told you we were bound together forever, did I not? Let's suppose for a moment that your little plan works. God wins, manages to lock me away again."
She pulled her dress slightly off her shoulder, revealing the Mark of Cain on her skin. "Then what happens to this? Who do you think God will assign to bear the key?"
Dean felt a chill. "He gave it to Lucifer before..."
"And look how well that turned out," she scoffed. "Lucifer's a has-been. God won't ask him again. No, Dean, don't try to avoid the truth. There's no one but you who will take it. And then it'll be just like before, except this time you'll know it's me, whispering away inside your soul."
Dean shook his head. "No... I won't listen to you..."
"For the rest of your life, Dean, I'll be there. And the rest of your life will be a very, very long time, you know. Like Cain, like Lucifer, the bearer of my Mark can't be allowed to die. Not until you're ready to give it up, and let me out again. Eventually you will welcome me, Dean. You'll embrace the nothingness that only I can offer you. Your life has been one long, weary struggle already; you've been courting Death for years. Are you so sure you won't consider skipping to the good part?"
He gave her a look of bald horror, flinching away from her outstretched hand. "Never," he said, but his voice shook, lacked conviction. "I never asked to be bound to you."
"You wanted the power to eliminate a threat you saw - Abbadon, wasn't that the name? - and you didn't care what happened to you in the process. All this is simply an extension of what you begged Cain for then, Dean. Our fates are bound now, as I told you from the beginning. Either I'm in you," she stepped closer to him, dropping her voice, "or you're in me. That's the only way it ends. You've never been one for wasting time." She pressed her body up against his. He stared down at her. "Come on, you know the best part about sand castles is knocking them down."
But finally she'd said the wrong thing. "You maybe never let your little brother build up anything of his own, but that's not me. I'd'a given Sammy anything I could. I let him hang onto all his stupid illusions as long as I could, about Dad and hunting and our lives and Santa Claus and praying to God and fucking apple pie normal life," Dean gasped, bitterly. "I let him go to college. I died for him, I let him go to Hell for me. You and God, you're still fighting over the nursery toys. And you can count me out."
He shoved himself away from her, blindly stumbling back until he could turn and run. He half thought she'd lash out after him: if she pursued him, he knew he wouldn't make it.
But she let him go. He ran until he got to the sweet old car he'd dug out of the Men of Letters garage for this trip. Amara wasn't behind him, so she must have finally realized Sam was getting away with Lucifer (and Cas). Hopefully, had gotten away by now.
He'd stalled as long as anyone could possibly be expected to. The rest was out of his hands. Dean ruthlessly shoved everything they'd talked about to the back of his mind, dialled the Metallica tape he'd brought up to eleven, and floored it back towards the bunker.
"So in other words, adios." Dean jerked his chin and Sam fell into step with him as he walked.
"Hey, um, you know how Cain was trying to wipe out his bloodline? Because he said they were all tainted, more inclined to violence and murder, or whatever?"
"Yeah," Sam nodded.
"That's us, too, though, isn't it? The bloodlines that damn cupid was so gung-ho about Mom and Dad for, one of'em was Cain's."
"If you're waiting for me to freak out on account of some nebulous and unspecified evil in our blood, Dean, you're a day late and a dollar short on that score." Sam kept walking at the same pace, unflustered.
"No," Dean huffed. "I mean, just cause we've been killing things our whole lives, ... That's not... Amara says me'n'her are inevitable. That it doesn't matter how long I fight her. But is that all there is? Fighting until you can't fight anymore, and then you lose and someone kills you?"
Sam's face went still. "Sometimes, it seems like it. I fought Lucifer like that. He kept saying there was no choice... They all said it ... And all I could do was go down swinging, so that's what I did. But today, it was the craziest thing, you know. I thought I'd have to fight him to agree, to stick to the plan, - I didn't trust Lucifer as far as I could throw him, and I trusted Metatron even less not to sell us up the river."
"Instead, Lucifer agreed right away. He was just too weak to get us out. And Metatron, I thought I'd never say a good word about him after he ordered Kevin's hit, but he did make a real sacrifice play. He bought us time."
"I had to help Lucifer, or we wouldn't have gotten out, did I tell you? If I had thought about it, I'd have thought I'd want a swing at him. After everything he put me through in Hell..."
Dean flinched. "You remember that? Even after Cas cleaned out your noggin?"
Sam looked faintly guilty. Then he sighed, "Yeah. Not all of it. I'd been trying to process it all year, but it was just too big a flood, you know? I was getting washed away. What Cas did, he left me with what I'd processed, all the stuff I could bear to remember, and took the rest himself." Sam saw Dean's fists clenching, and added, "I figured you didn't need to know. It's gotten better, over time. This past year especially, I've even been happy again, sometimes."
Dean breathed, in and out, a couple times. He tried to drag himself back on topic. "I'm amazed you didn't pound him to a pulp the second you had the chance."
"That's what I'm getting at, Dean. I could've given into that, sure. But what would that accomplish? In that moment, he was just a broken mess. When I looked at him, all I saw was someone else who needed saving."
Dean looked at him incredulously. "Lucifer, a victim?" Then another thought occurred to him and he brightened. "Maybe you just had a sympathetic reaction to Cas's face."
Sam shook his head. "No. I care about getting Cas through to the end of this, don't get me wrong; but Lucifer fooled me once when I wasn't looking for him." Sam's voice was flat. "Now, I couldn't unsee him if I wanted to."
"But you weren't even tempted to kick him while he was down?" Dean looked wistful.
Sam gave him an amused glance. "I put my shoulder under him, and helped him walk out of there."
They kept walking in silence for a while. Dean wasn't really sure what to do with that.
Then he furrowed his brow. "Are you trying to say that my bond with Amara might not seem so bad once something even bigger and badder comes down the pipe at us? Cause, that's not comforting, Sam."
Sam threw back his head and laughed. Dean had missed seeing his brother laugh like that. "I'm only saying, Dean, you never know what the future holds."
Dean nodded. “That makes sense, I guess.” Then his gaze got caught by something ahead of them and he scowled. “That better not be a tow truck pulling up next to Baby. Hey. Hey!” He broke into a run.
Sam shook his head. Some things never changed. He started jogging, before Dean got too far ahead.