A/N: Written around Christmas; three guesses as to which movie I watched over the holiday, and the first two guesses don't count.

The day after the whole Jack Montgomery incident, the brothers were still distanced. It gave Dean time to think, which was good and bad at the same time.

Because despite Sam saying they shouldn't kill Jack, he'd still roasted him. Saying one thing, doing another: it was his brother's pattern these days. Yet when Sam had told him he'd stop using his powers, Dean had almost believed him.

Almost, and thank god for the almost, because if he'd believed whole-heartedly, finding Sam talking with Ruby that night would've killed him.

He'd come out of the shower to hear voices, muffled by the door of their latest hotel. Dean had crept forward, pressing his ear to the door and frowning.

"-powers, Ruby, I've told you-"

"And I've told you that we're helping people. We are, and you know it."

"I know," Sam had said after a sigh. "But I'm still not going with you right now. Dean's waiting for me. Later, okay? We'll head off and talk about-"

That was when Dean had opened the door wide. Ruby had crossed her arms from where she'd been leaning against the Impala, and Sam had jumped, a wide-eyed emotion crossing his face that Dean hadn't been able to pin down. Sam had glanced from Ruby to Dean, then had hesitantly said, "Dean, listen to me, this isn't-"

Dean had slammed the door shut on his face, clenching his fists and feeling as if he could punch Sam again. Hard.

An hour later, and the air was still frigid and tense between them. Sam had come back in immediately, and was now still sitting right where he'd sat down in the first place. Dean was still pacing around, carefully and tersely putting things away in bags so as to leave a smaller mess when they left.

Sam tentatively cleared his throat. "I, um, could go get dinner, if you wanted...? There was that Chinese place down the road you thought sounded good-"

And it was the last straw. "What, so you can go meet up with Ruby and get your psychic freak on?" he spit, watching Sam wince at the word 'freak'. Dean didn't care at that point, too wrapped up in his own hurt and anger. "You lied to me, Sam. Again. You tell me you're not going to use the powers again-"

"I'm not," Sam insisted desperately. "Dean-"

"Then you tell me you're not gonna waste Jack, and you do-"

"W-What?" Sam stammered, eyes widening even further. "No, he-"

"Excuses, Sam," Dean bit off. "That's all they are. You...how am I supposed to trust you if you can't keep your word? Or any of the promises you've been feeding me since I got back?" Dean took in a sharp breath, and the words tumbled out before he could really think about them. "Or did I come back too soon for you and your psychic fun? How hard did you try to get me out, Sam, really?"

Sam went pale, his mouth dropping open in shock. Dean pursed his own lips, feeling incredibly stupid now but still angry enough to not apologize. "Do whatever you want," he finally muttered, stalking towards the door. "You obviously don't need me."

The door slammed shut behind him, and Dean stalked over to the Impala, wrenching the driver's door open and sliding inside. The car door shut with a bang, and Dean sat back and waited.

Sam didn't come out.

Three minutes of glaring at the door, and Dean finally sighed and rested his head against the steering wheel. He hadn't really meant it, any of it, but Sam just made him so angry and...hurt. Sam had never really lied to him before, had never started keeping all of these secrets, and had never, ever dared to touch a demon's power. Castiel's words ran through Dean's head, and he shuddered.

When the hell had they lost the trust between them? When had Sam stopped trusting him enough to come to him with this? When had Sam decided that heading down this path and shutting Dean out was the smart thing to do?

Dean closed his eyes and leaned back in his seat, trying to focus on breathing before he went back in there and...god. Dealt with the fallout of Sam's lies and his own words.

"This was not what I intended when I spoke with you last."

Dean didn't even jump this time, simply turning to Castiel with a weary glare. "You told me to stop Sam. I'm trying."

Castiel turned to face him, his gaze stoic and his state one of apathy. Closer examination showed something a little closer to...concern. "You were brought back to save him."

"Yeah, tell me something I haven't been cryptically told a million times," Dean snapped, turning to the door of the hotel room again. The lights were all still on, and Sam still hadn't come out. Dean shoved the twinge of guilt and hurt down deep. "Sam still wants to use his powers."

"He told you he wouldn't," Castiel pointed out.

"Yeah, and he was talking to Ruby earlier," Dean said, swiveling back to Castiel. "Tells me a lot about his trust."

Castiel narrowed his gaze. "And says quite a bit about yours, too. You don't really know what they were talking about."

Dean began to answer, then stopped, a small frown beginning to emerge. Sam had looked guilty, earlier; he wouldn't have looked guilty if he hadn't been pursuing what he told Dean he wouldn't.

No, Dean realized a second later, Sam hadn't looked guilty. The emotion he hadn't been able to peg before wasn't guilt: it was fear. Dean's gut twisted as his own guilt filled him again.

"Then why did you bring me back?" Dean asked. "I want a real answer, this time. If I'm supposed to stop Sam, and you're pissed at me for trying to now, what the hell good am I? What am I supposed to do?"

Castiel slowly turned to gaze out of the front of the car. "If you insist on knowing, I'll show you what 'good' you are to this world. I'll show you this world if you hadn't been brought back, and why it was so crucial that you were saved."

"Don't do that finger thing again," Dean warned, already leaning back towards the door. "That made me dizzy."

Castiel sighed but kept himself still. "Then go look at the world without you."

Dean still eyed him warily, but turned towards the front of the hotel room and frowned. The lights were off, and everything looked grimier. He blinked a couple of times, then reached for the handle to let himself out. His hand went through cobwebs, and Dean pulled away, startled. "What the...?" he muttered, glancing around the car. The seats were in disrepair, and there were cobwebs and dust balls all over. Like it'd been abandoned.

And Castiel was gone.

Figured. "Yeah, good job keeping the car clean, Sammy," Dean muttered again, stepping out of the car. The creak the hinges gave made him wince, and he shut the door as carefully as he could. He stepped up to the hotel room, digging through his pockets for the key. When he didn't find one his frown deepened. "What the hell," he said, digging through all of his pockets again.

"It's not there."

Dean rolled his eyes and turned to Castiel. "What is this? You're playing Clarence, and I'm playing Jimmy Stewart or something?" Dean asked. "Hate to tell you, but Christmas isn't for another couple of months."

Castiel merely nodded towards the door. "Sam's not in there anymore. Hasn't been there for almost two weeks. This was the last place he stayed at."

Fear slammed into Dean's gut hard enough to make him flinch. "What do you mean? Where is he?"

It was only then that Dean glanced around the entire town. The place was deserted and looked like a bomb had been set off. Buildings were falling apart, glass windows were smashed, and not a speck of light was seen anywhere. Everything was dirty, dusty, and empty.

"It happened," Castiel said quietly. "The End."

Dean swallowed hard and stepped out towards the street. Cars were abandoned, looking just as filthy as the Impala. A sudden gust of wind swept old newspapers and leaves down the street. Otherwise than that, it was silent.

"The entire...?" Dean hazarded the guess, then didn't even let himself finish it. If this was the End, then this was what the entire world looked like.

Was this Sam's power? Was this what Sam would've done if Dean hadn't come back and stopped him? Dean shut his eyes tight, trying not to believe it. Not Sammy. Sam wouldn't destroy the world. Doubt still lingered in the back of his mind, and Dean tried to quash it down.

"Some humans survived," Castiel continued. "A small band of resistance fights against Hell right now. What angels are left are fighting with them, but...they're limited in number. And Hell is growing by the day."

Staring out at the barren wasteland that had been a shiny, happy city only a short time before, Dean found himself shaking his head. "I will take you to anywhere, anyone you want to see," Castiel said, no longer far behind Dean but right beside him. "But I caution you, you won't like what you see. And you can't change anything."

Names flashed through Dean's mind. Bobby, Ellen, Jo, Pamela, Missouri...but all of them paled to the one he came back to again and again. The name was a silent mantra in the back of his mind, racing around and around with fear and a terrible knowing feeling. The feeling that this one person had been the cause of all the destruction. "Sam," Dean said hoarsely. "Take me to Sam."

"I thought as much," Castiel said, placing his hand on Dean's shoulder. The landscape changed in a blink of an eye, and Dean was left standing in the middle of an empty field. Everything looked darker, and when he glanced around, he realized he was standing in the middle of a vast crater. The sides of the crater stretched up for possibly miles, jagged and harsh points reaching to the night sky.

Yet everything was still quiet, silent. The only thing Dean could hear were his own breaths, and the frantic beating of his heart. He glanced around, this time in the crater itself, but still didn't see anything moving. "Where's Sam?" he asked, and his voice echoed.

Castiel merely bowed his head. "Cas, where's Sam?" Dean asked again, panic starting to set in. It emerged as anger. "Is he gonna show any minute, Lord of Hell? Huh? Is that what you wanted to show me? What, is the ground going to open up and let him out?" When the silence was too much, Dean finally yelled, "Did Sam do this? Castiel, did Sam do this?"

Castiel finally regarded him then. "Your brother was the cause of this crater, yes. He fought against Lilith with his powers, and the resulting clash hollowed out the earth in this way."

Dean felt sick, and stumbled backwards, wishing there was somewhere for him to sit. His foot landed on something and cracked it, and only then did Dean look down at the ground.

Bones. Bones and skin and bodies covered the entire bottom of the crater. Various sizes of bodies, some adults, some children, even some that were obviously animal. They hadn't been here long; only a few bones were beginning to show through.

"Oh god," Dean said, his hand covering his mouth in horror. What had Sam done? What had he done?

"Dean," Castiel called softly, and Dean turned to where the angel pointed. He stepped forward with trepidation, eyes searching until he saw what Castiel intended for him to see. A small, shining gold amulet, one Dean knew all too well, was on the ground, hanging from dead, cold fingers.

Dean's eyes betrayed him and followed down the arm to the body. The chest was ripped wide open, blood stains everywhere. The inside of the body was empty and burnt.

And Sam's vacant eyes were still wide open, even in death.

Dean didn't even know he was screaming until Castiel covered his mouth and pulled him back against the angel. "Sam found Lilith and went up against her, using nothing but his powers. They were enough to hold her off, but not enough to win. She decimated him. He was the only one that stood in her way, and with him gone, the earth became her playground."

Dean let the words flow over him as he stared now in horrified silence, his eyes locked on his brother's face, on his open chest, on his outstretched arm with Dean's amulet wrapped around his fingers.

"This was why we brought you back," Castiel continued in his ear. "Sam is not the threat we fear. He could be...perhaps. But if he was that much of a threat, do you not think we would've ended him ourselves?" He twisted Dean around, tearing Dean's teary gaze from Sam to him. "We brought you back to save him," Castiel emphasized. "He is lost in himself, in his doubts and fears. If he does not find Lilith and confront her and bring this future about, he will fear himself and end his own life, and the outcome will be the same."

Dean couldn't even breathe. Tears burned his eyes and slid down his face, Sam was dead and rotting behind him, and he couldn't breathe. "But you told me-"

"I told you to stop him from using his powers," Castiel said. "Every time he does, he sends out a beacon. Lilith is hiding from him, but seeking him. Every demon he sends back to Hell is a flag to her because she can feel the power he uses to do it. A normal exorcism wouldn't reach her, but Sam's powers can and do. And she will end him, and this-" he extended his arm towards the crater, "will happen. If Lilith finds your brother, it's all over. We will reach the End."

And if Lilith didn't find him, Sam would kill himself. Sam had been wary and afraid of the powers, a 'whole new level of freak', and Dean had shut him out, Dean had left him in their hotel room with bags full of weapons-

"Take me back," Dean choked out, shutting his eyes tight. "Get me out of here, Cas, please, I can't-"

"Dean."

"Don't make me look-"

"Dean!"

Dean's eyes snapped open, and he blinked several times, pulling in gasping breaths. A black panel met his vision, and then the leather seat beneath him registered. Dean turned his head, realizing that not only was he laying down in the Impala, but nothing was grimy or dirty.

And Sam was bent over him in the car, hands on Dean's shoulders, eyes wide and panicked. "You're okay," Sam soothed as soon as he realized Dean was awake. "Just a bad dream, man. You're okay, I promise."

Dean blinked the last of his tears from his eyes and felt them roll down towards his ears. He glanced down at the hands on his shoulders and breathed out a sigh. No amulet clutched in them, no open chest, no vacant eyes. Sam was alive.

Dean wasn't entirely sure whether to thank Castiel or slap him the next time he saw him.

The welcoming pressure on his shoulders was suddenly pulled away, and Dean focused his attention back on Sam, who was backing out of the car, his eyes anywhere but on Dean. "Uh, I, um..." He fidgeted uncomfortably, darting a quick glance at Dean before looking away. Dean sat up, and with his vision clear again, he could easily see Sam's red-rimmed eyes and the blood on his lower lip where he'd more than likely bitten it.

Sam finally sighed and hung his head. "I can get a different room," he said, his voice quiet enough that the wind would've taken it away. Dean cast his eyes for a minute to the clock in the dashboard, then back to Sam. He'd been outside for only seven minutes.

"I know...I know you don't want to hear it, but I really wasn't going to use my powers. I was telling Ruby no, and she didn't seem to be getting it, so I was going to meet up with her somewhere else so you didn't have to deal with her because I know you despise her," Sam continued, swallowing convulsively. He took a short breath and kept going when Dean didn't interrupt him. "And Jack was right there next to you, swear to god, and I thought he was going to attack me and then hurt you again, and I tried to talk to him through the door when he locked me in the closet but he wouldn't listen."

Sam stopped himself and gave a bitter chuckle. "Which is probably how you feel with me, and I...I'm sorry, Dean. I swear that I was going to tell you everything, but I...I didn't want you to be sca-"

Dean shoved himself forward to the edge of the seat and wrapped his arms around Sam's waist, pulling his brother in and hugging him tight. Sam's words were cut off at the sudden movement, and for a long moment, it was nothing except Dean hugging Sam and Sam standing frozen.

Then slowly, hesitatingly, Sam wrapped his arms around Dean's shoulders and placed his hands against Dean's back. Dean shut his eyes and rested his right cheek against Sam's ribs. His brother's heart was racing a million miles an hour in his chest.

He'd had it all wrong. The reason Castiel had brought him back, the reason Sam was to be saved, the reason for Dean stopping Sam from using his powers. And he'd lashed out with his mistaken reasons, had been hurt because of them, and had hurt Sam in return. He didn't even know where to begin to fix everything between them.

The trust that Sam hadn't given him had been because of fear. Fear of Dean's reaction, fear of where Dean's trust was. Fear of Dean being afraid of Sam.

"I'm sorry," Sam offered again, a whisper that made Dean wince at the plea buried within it. One last plea for Dean to listen to him, to believe him.

And this time, Dean did.

"No, Sammy," Dean whispered, his whisper harsh and grated. "I'm the one who's sorry. God I am so sorry. When Castiel told me to stop you, I was so scared for you, that the same angel who'd dragged my sorry ass out of Hell could slam you right into the pit." He pulled Sam in tighter. "And then I was scared when I saw you with the powers, terrified you were gonna fall right into whatever Azazel had planned for you, but I was never, ever scared of you. I swear, Sammy."

He'd explain all his other emotions later, all his anger and hurt and how he'd been so wrong. How he should never have let his trust in Sam be pushed away so easily. What Castiel had really meant, and what the future would never hold if Dean had his way.

But at that moment, the only thing Dean cared about Sam understanding was that Dean wasn't afraid of him, and that Dean was sorrier than he'd ever been in his life.

Hands gripped into his coat suddenly, and Sam was squeezing him tightly. "You better mean that," Sam whispered hoarsely. "Because I'm trusting you to mean it."

Dean swallowed hard and mouthed a tiny thank you to wherever Castiel was. "Good," was what he said to Sam. "That's good."

They stayed there for several minutes, clinging to the other, finally reunited as partners, as brothers for the first time in too long.

This time, Dean wasn't letting them break apart.

END