A/N: This prompt was given to me by my wonderful friend spuffyshipper. I couldn't resist. A sequel to this story, inspired by yet ANOTHER prompt by another fantastic friend, has also been written.

Lilith was gone, Chuck was gone, Castiel had apparently been around and was gone. Dean was gone. New hotel, new city. Nothing had changed, really. Except everything that mattered.

Sam shut his eyes tight and rolled over onto his side. Dean had headed out for a late-night supply run, but whether it was food or something else Sam didn't remember. Dean had told him, but Sam was trying not to focus on Dean's words. Not after...

"You think I'm gonna go darkside, don't you?"

"Yes, okay? Yes!"

...well. Not after that.

Sleep wasn't happening, and Sam sat up, trying to breathe deeply. He'd held it together while they'd packed up and left, while they'd dropped Chuck off, while they'd headed down the road. He'd even tried to talk in the car, tried to put on a bold exterior.

While the inside fell apart.

The angels he could handle distrusting him. Really. Wasn't like he'd prayed to them for help, believed in their goodness for years. Or been hurt when they and the rest of heaven had so easily condemned him.

But Dean? Dean had always been his constant, even while the angels had dismissed him as pure evil. Dean was the one he always knew would have his back, would always believe in him, wouldn't condemn him or hate him.

Except now he did. Dean thought he'd go darkside, thought he'd turn evil.

"The way you've been acting lately, the things you've been doing..."

Sam swallowed and pressed the heels of his hands into his burning eyes. He thought he'd had a chance, thought maybe he wouldn't turn. He didn't want to, wouldn't become the thing he'd hunted for years.

But if Dean thought he'd go darkside, no hesitation in his words, then Sam was already damned. He couldn't fight this on his own. And the firm belief that Dean had had in his words made Sam's chest tighten painfully. For Dean to give up on Sam, for him to see Sam past saving, it meant that Sam had passed some line that there wasn't any coming back from. And somehow, Sam had missed seeing the line.

Dean hadn't. If Sam had missed it, then Dean was right, and Sam was already too far gone.

Sam raised watery eyes to the table across the room, where his handgun was laid out. His hesitation was no longer than Dean's had been the day before, and he pushed himself up from the bed, eyes locked on the gun. He wouldn't become the thing Dean feared, or what he hated. Or what he'd have to hunt. No.

Sam would finish it before he turned any further.

His hand wrapped around the gun just as the door opened. "Some lights would be nice," Dean said, and the lights came on. The door shut as Dean continued lightly. "There a reason you're sitting in the..."

Sam closed his eyes as Dean trailed off, but kept his grip on the gun firm. "Sam?" Dean finally asked, voice soft and cautious, and Sam flinched. He sounded...afraid. Afraid that Sam was going to shoot him.

He opened his eyes and turned away from the table to gaze at Dean, who was lowering a paper bag down to the ground. "Take it easy," Dean called out, wide eyes on Sam, and Sam's heart kept splintering, piece by piece. Already damned. No hesitation.

"Please don't," Sam choked out. Dean froze, hands just lifting from the bag, and Sam shut his eyes tight. "I mean, you don't...have to."

He opened his eyes again, blinking away the stinging moisture. Dean looked even more afraid than before, and Sam had to finish this now. "Have to what?" Dean asked.

Sam swallowed hard, feeling sick to his stomach. "Be afraid. Of me," he added in a whisper. He tried to smile but felt it die on his face.

"Little too late for that, Sam," Dean said. "Just...just listen to me, okay? It's-"

"You should've told me sooner," Sam blurted out. Dean stopped talking, and Sam gripped the gun even tighter in his hand. "About the line being crossed. About knowing I was going darkside. If you'd just told me, I..." Sam felt himself shaking and tried to steady his movements, but he was out of control. Had been for too long, and he should've known. Dean had known he was past saving. Had he always known?

Dean's eyes were even wider now. "Sam, no-"

"I'd have done this sooner," Sam whispered, and brought the gun to his temple. He shut his eyes, cocked the hammer back, and pulled the trigger.

The gun went off just as something strong pushed his arm back, sending the bullet straight through the wall. Sam gasped and flew backwards, Dean following him to the floor. The gun tumbled harmlessly from Sam's shocked fingers, bouncing away beyond his grasp. "No," Sam whispered, then called again, this time louder. "No! I need to-"

He struggled to push Dean off, but Dean had his hands wrapped around Sam's wrists, pulling Sam's arms in and away from the gun. "Sam, stop fighting me, dammit, just stop-"

"I have to," Sam choked out, and the sudden sob surprised even him. Once it was released, though, the floodgates opened, and he couldn't stop, even while he kept struggling, eyes on the gun. "I have to do this, Dean, you know I-I have to before I turn and let me go let me-"

"Not gonna happen," Dean grunted, "and I don't just mean the gun, either. You're not going darkside-"

"You said I would!" Sam shouted with hitched breaths, and Dean's stunned face was enough for Sam to pull away just enough to almost reach the gun.

Arms wrapped around his, pulling his arms firmly against his body, even while he was being pulled up and away from the gun. "No no no, let me go, I have to...I won't be...I have to..."

When his words finally tapered off, the tears slowed, and he could breathe again, Sam realized he was being held, cradled, and gently rocked. Above him was a litany of words, all whispered.

"-sorry, god Sammy I didn't mean it I'm sorry, I'm so sorry, Sammy, I'm sorry-"

No hesitation with these words. Spoken with the same firmness, the same belief and sincerity. But...

Sam shut his eyes and leaned further into Dean. Dean's voice suddenly halted, and before he could say anything, Sam spoke up. "I thought you did," he asked, his voice rough and shredded. "Mean it."

"Yeah, I'm getting that," Dean replied, but the sarcasm was spoken with a trembling tone. "I didn't, though."

Nothing was making any sense, which Sam was sure had to do with crying for...god knew how long. But his insides still felt twisted up with anxiousness and hurt, and he spoke again, softer this time. "But you-"

"I know, but I was..." There was a quiet sigh above him, before Dean continued with regret. "You weren't leaving, Sam. Lilith was coming, and considering who Chuck wound up being I knew damn right well that she was coming, and you weren't...you weren't leaving. I was angry and I was freakin' scared, and I lashed out before I had a chance to think it through.

"But I didn't mean it," Dean said softly, and Sam thought he felt Dean's arms tighten impossibly further around him. "I swear, Sam. I don't think you'll go darkside. Maybe. But I don't believe it. I really don't. You just...can't. You're Sammy. I don't care if you went and grew up while I was gone and can handle yourself, you're still the Sammy I know. And that Sammy won't ever turn."

Not with Dean standing by his side. Sam finally opened his eyes, the lids swollen and tender. "You better mean that," he whispered. "Because you're not getting a do-over."

Dean snorted a hitched laugh, and when Sam glanced up, Dean's eyes were red and shining. "No, no do-overs, promise," Dean said, giving Sam a small smile. It fell away in the next moment, and Dean swallowed hard. "I'm sorry, Sammy. God, I almost stopped to get something out of the trunk before I came back in." He clenched his eyes shut and pulled Sam back in, with Sam freeing his arms enough to hold onto Dean.

The world seemed to tilt back to the right side up. Dean hadn't abandoned him, and Sam wasn't the only one fighting against a possible future of turning evil.

He wouldn't. Not with Dean. Not with his big brother clinging to him as much as he was clinging to Dean.

END