THE ARM

"HOLY SHIT!" was the only warning Sam got before the Impala was stopping too fast and there was an immovable object slamming into his chest.

It took a matter of seconds before Sam to realise that the object was Dean's forearm, slamming across as a makeshift seatbelt. He'd done that several times once he'd learned to drive and Sam was still little - "Mom-arm", Sam had affectionately teased him about it.

Sam's eyes went huge as he realised two things simultaneously. One, that they'd barely avoided being a statistic in a pileup - and two, that the arm hadn't moved from across his chest. Slowly, he turned his eyes to the left to find Dean staring at his arm, at the rolled-up sleeve that bared his arm because of the warm weather and the fact that it was resting across...

...oh.

Slowly, Dean's wide eyes rose to his face and he removed his arm, sliding the Impala to the side of the road so they wouldn't contribute to any more cars piling up in the fog.

After the crisis was over and the pileup was cleaned up and the brothers had stopped for the night, Dean turned to Sam once the motel room door was closed. "So."

"So." Sam smiled at him. He was thankful for the arm Dean had thrown across his chest. That instinctive move had told him without words that he was still important to his big brother.

"I felt the horns."

Sam just nodded.

"Why?"

"Because I wouldn't let you throw us away."

Dean frowned. "I wasn't throwing us away, I was throwing the amulet away! Because it's a useless thing that can't find God!"

"I kept it because it's a treasure that I gave you and that means that we're brothers. No matter what."

Dean recoiled as if he'd been slapped. "...it means that to you?"

Sam nodded.

Dean looked away. "I..."

"I know you didn't know, and it's okay. I know and I'll keep it safe."

"Do you think you-"

"No, Dean. I'm holding onto it. To us. Until I know we're really brothers again."

Dean met his eyes. "How will you know?"

"Trust me, big brother." Sam curled his hand over the amulet under his shirt and smiled. "I'll know."