Author's note: This is just something that popped into my head after watching the awesome Crossroad Blues tonight.. Hope you enjoy it:)

"Pull over, Dean." said Sam suddenly.

Dean looked at him with a frown. "Why?"

"Just pull over, ok!" he said, his voice rising.

"Sam.." said Dean but his brother cut him off.

"Now Dean! I mean it!"

"Ok, ok! Jesus Sam, what the hell is wrong with you?"

Dean barely had time to stop the Impala before Sam had the door open and got out, slamming it behind him.

"Dude! Do not slam the door!" said Dean as he got out, but Sam was ignoring him.

Pacing up and down in front of the car, Sam looked ready to explode. Dean watched him warily as he leant against the hood. Finally Sam seemed to come to a decision and he stalked back to stand in front of his brother.

"You were actually gonna do it weren't you?" he said, his voice part anger and part fear.

Dean sighed and closed his eyes for a second.

"Sam, come on – do we really have to do this?" he said wearily

"Yes, we have to do this! You can't just imply that you were about to give up your life to a demon and then expect me not to have a problem with that!" said Sam with frustration.

Dean looked away, not wanting to meet Sam's gaze right now. He should have said no when Sam asked him but he'd never liked lying to his brother and the truth was right now, he was too tired to come up with decent lie anyway.

Sam waited for Dean to respond but the silence just stretched between them. Sighing Sam sat on the hood next to Dean and thought about how he could get through to him. This was possibly the most important conversation they would ever have.

"You remember that wooden train I had when I was about 6?" said Sam suddenly.

Dean gave him a 'what the hell?' look but answered anyway.

"Ok - random? Yeah I remember - what about it?" he said, frowning.

"I carried it everywhere with me, even to bed. Never let it out of my sight." said Sam, smiling at the memory.

Dean snorted. "Yeah, that I do remember. When you slept in my bed I ended up with the damn thing wedged in my ribs most mornings." he said dryly.

Sam laughed a little at that too. He could remember 10 year old Dean's muttered grumbling about that even now.

"You remember when it got broken? I'd left it outside for just a second, when we were living in that house in Ohio for a year, and someone must have run over it. I found it in like a million pieces." he said.

Dean swallowed. Hell yeah he could remember. His little brother, standing in front of him, chest heaving and face soaked with tears as he held out the broken remains towards Dean. The hiccuped 'Fix it, Dean' that had followed and the sinking feeling as he'd realised that for once he might not be able to take care of this one.

Aloud he just said "Yeah, I remember. Tell me there's an actual point to this trip down memory lane or are you just revisiting your childhood trauma?"

Sam rolled his eyes and nudged him with his shoulder before continuing. "Hilarious. You said you'd fix it for me but Dad was out and he kept the superglue and other dangerous stuff in the top cupboard in the kitchen. You had to climb on a stool to get it."

Dean winced at the memory. "Yeah, and I promptly fell off it when the thing shifted. Hard to forget that Sammy, it hurt like hell." he said and Sam shook his head.

"I'm not surprised. You were out cold for about a minute. I nearly passed out myself I was so hysterical." he said, stomach clenching at the memory of Dean lying there even now.

Dean waited, knowing there had to be more to the story and that Sam was working his way towards some significant point with more to it than just memories of an old favourite toy.

"When you woke up you kept telling me it was fine and that we didn't need to tell Dad." said Sam and Dean shook his head, cutting him off.

"Yeah, like he wasn't going to notice that huge gash on my forehead. I don't know what the hell I was thinking. I ended up telling him within about 3 seconds of him walking through the door."

Sam smiled. John had for once been pretty reasonable about the whole thing, knowing Dean had learnt his lesson and seemingly just glad that it hadn't been any worse.

"Yeah, it was a pretty big cut. I helped you clean it up didn't I?" he said and Dean smiled softly at the memory of small chubby hands holding cotton wool in a vice like grip while Sam wiped away the blood with a fiercely determined look on his little face.

"Yeah, you did a pretty good job from what I can remember." he said and Sam ducked his head a little at the praise.

"Afterwards we sat on the couch together and you said you were sorry you couldn't fix the train. Do you remember what I said?"

Dean could indeed remember. Sam practically on his lap, holding him so tight there was a danger of circulation being cut off, and Dean feeling guilty that he couldn't make things right for his little brother this time.

He could see Sam watching him intently and he shifted uncomfortably, aware that his brother was most likely about to drag them - kicking and screaming in Dean's case - into a Hallmark moment.

"If I say no, will you leave it there?" he said hopefully and Sam just raised his eyebrow.

Dean sighed. "Fine! Yes, I remember what you said, ok? You said it didn't matter."

"That's right and you said of course it mattered, it was my most favourite thing in the world and I said.." he paused, indicating he wanted Dean to finish the sentence.

"That it wasn't your most favourite thing." said Dean softly, aware now as he had been then what his brother was referring to and feeling no less embarrassed by it.

"And then I said something else. I told you that I didn't want the thing fixed if it meant you getting hurt." said Sam quietly.

Dean said nothing, but swallowed and looked down at the floor. He had a funny feeling he knew where Sam was going with this. He wasn't disappointed.

"Nothing's changed Dean. There is nothing that has happened to us since then, nothing that could ever happen in the future, that I would want fixed if it meant something happening to you. All the bad stuff – Jess, Dad, all of it. As much as I would love for none of it to have happened I wouldn't change any of it, not if it meant sacrificing you, Dean. And however much I may disagree with the kind of father Dad was sometimes, I know that he would agree. He wouldn't have done what he did without knowing the consequences and the fact that he went ahead and did it anyway should tell you all you need to know."

"Sam.." Dean began, a million arguments in his head, but Sam wouldn't let him finish.

"No, Dean. How would you feel if someone told you you could have it all back. Mom alive, a normal home, a happy family, all of it. But without me. Would you do it?" he said quietly and Dean looked at him horrified.

"No! Of course not, Sam! How can you even ask that?"

"How can you think I don't feel the same?" said Sam simply and Dean stared at him.

The look on Sam's face, the quiet conviction in his voice. It all told him that Sam really did feel that way. It was humbling, and touching, and confusing all at the same time.

"I just wish I knew how to fix this, Sam." he said, his voice barely a whisper.

Sam sighed and shifted so that his shoulder was leaning against Dean's.

"I know. But you can't fix everything, Dean. And you don't have to. Some day you gotta realise that, man."

Dean still wouldn't look at him. The part of him that was pure big brother still refused to believe that there were some things in the world that he couldn't make right for Sam. That he couldn't protect him from everything. He knew it was irrational, but he couldn't change the way he felt.

Sam recognised that he needed more to get through to Dean, that he had to make him understand completely or he would forever risk losing his brother to the next evil that offered a clean slate in return for Dean Winchester's soul.

"I lived without that train, with losing Jess, with losing Dad. I lived through all of it because I still had you. You do something like this, you sacrifice yourself, even if you think you're doing it for my sake. You won't be – you'll just be taking away the most important thing in my life. If I don't have you here, as my brother, then none of it matters. Do you understand, Dean?" said Sam gently, his voice soft but desperate.

Dean swallowed the lump in his throat and blinked back tears he would never admit to. Hearing Sam's words, it brought back feelings long since buried. Feelings from when he was the centre of his little brother's world. When Sam had thought he was invincible, that there was nothing he couldn't do or fix. Days he'd thought were long gone but that had perhaps just been buried that little bit deeper after all. Sam no longer thought he was invincible, no longer thought he could do everything, but maybe that hadn't really been what it was about. Maybe he really did have to do nothing more than be his slightly flawed, slightly battered self to still be the centre of his brother's world.

"I do understand, Sammy. I think it's partly why I couldn't go through with it. However much I wanted to bring Dad back, to save him, to get all that back for you, I couldn't do it. I couldn't leave you behind like that." he said softly.

Now it was Sam's turn to swallow. "Promise me you'll remember that then. Promise me you won't ever think that doing something like that is the solution to any problem we might have. Promise me you'll remember what I said."

Dean nodded. It was almost imperceptible, but Sam saw. It had been a crappy few days, the demon's words loading yet more weight onto shoulders already bowing under the pressure. Sam wished he could take some of that weight away from Dean, that he could be the one to fix things. But he knew he couldn't. There was something he could do though.

Even though it broke all the 'Winchester rules', even though it put it him in danger of bodily harm, as far as Sam was concerned this was the final straw. Reaching out before Dean could object, he put his arm round his brother's shoulders and pulled him towards him.

Dean tensed up for a minute, but his feelings were so raw right now and he was so tired. Deciding that he could always shoot Sam later if he ever brought it up, he gave in. Putting his arms round Sam he returned the hug and for a brief moment the years rolled back. A hug from a brother couldn't fix everything the way it had back then, but it was reassuring to find it still went a hell of a long way even now.

Dean pulled back first, ducking his head and finding the floor infinitely interesting again. Sam smiled, knowing the matter would be raised again on pain of death, and got up.

"We should get going. See if we can find a decent motel before it gets too late." he said simply.

Dean looked up at him and nodded. He knew Sam understood him well enough not to mention what had just happened, but the important thing was they would both remember it. And maybe it would help, next time things became too much.

As they got back into the car and Dean gunned the engine, a thought occurred to him and he grinned.

"Hey Sammy?" he said and Sam rolled his eyes at the nickname but let it go for once.

"What?"

"You want to check out the toy stores next town we get to? I'm sure they still make those little wooden trains you know."

Sam looked up at Dean's smirk and gave a long suffering sigh. Sometimes it really was a good thing he loved his brother so much. Cos otherwise he'd have buried the body long before now.

"You know you really should let me know when you get past puberty. We can have a party" he said.

Dean just snorted at that and nudged Sam with his elbow as he reached out to switch on the radio.

As Metallica began to blare out of the speakers Sam thought about their Dad. He hoped that the demon had been lying. He hoped that wherever he was, John wasn't really suffering like that. But most of all he sent him silent thanks. For doing what had been necessary but what Dean would never have allowed.

As Dean began singing along to the track loudly, Sam just shook his head fondly and slid down the seat, closing his eyes as he laid his head back.

"Wake me up when we get there." he said.

As Dean glanced across at his brother he saw not the 23 year old sat beside him but a 6 year old, curled up against him on an old, brown couch. He smiled softly. Maybe Sam was right – it was the important things that stayed the same, whatever happened.

Making a final silent prayer that the demon had been lying, Dean pushed down the accelerator.

Maybe, just maybe things might turn out ok after all. It was like Sam had said – they were doing it for John. And for now, that would have to be enough.