Disclaimer: I don't own them, I'm just playing with them, don't sue me.
Author's Note: This is becoming a bit of a habit, isn't it. Season 8 has been so awesome that it's inspiring the bunnies. I'm still working on 'Punch Drunk' but here's an offering for tonight/last night's episode.
Sam loves his brother. He does. Dean's been the one constant in his life. He could always count on Dean, even when they weren't getting along
That being said, he doesn't always like Dean, hell there were times Sam had to restrain himself from punching his brother square in the face. They were as different as two brothers could be. Sam was a homebody, preferring books to going out, Dean liked going out. Sam liked to get all the facts before taking action, Dean was a leap before he looked kind of person. Any way you sliced, they were complete opposites.
Even so, Sam had never in his life been afraid of Dean. He knew his brother like the back of his hand, even when they'd spent long periods of time apart, he'd still known how Dean would react in a situation, like knowing that Dean would be pissed if he knew that Sam had had a dog in the car. That was the Dean Sam knew. Even the Dean who had returned from Hell and suburbia had still been the brother Sam had known and loved all his life.
The Dean that had returned from Purgatory was not someone Sam recognized. This Dean had completely forgotten about the 'saving people' part of the mission. The fact that he was comfortable with killing Kevin's mother, knowing that Kevin was in the next room, scared Sam. He remembered what Castiel had told him about the year he'd been soulless and briefly wondered if that's what had happened.
As they drove away from the auction and possibly, their chance to close the gates of Hell, Sam kept stealing glances at the man he no longer recognized as his brother. His brother would've only considered killing Mrs. Tran as a very last resort, no matter who was inside her. The fact that Dean was so prepared to kill Mrs. Tran just to get Crowley and was so blasé about it made Sam shudder, remembering Crowley's words. He didn't believe they were true, but he couldn't deny that most people who had more than passing contact with the Winchesters ended up dead and usually dead in some horrible way.
He'd never been afraid of Dean, but he definitely was now. If Dean was so willing to kill an innocent woman because she was possessed and then not care, he wondered what else his brother was capable of doing. He also wondered about Cas and if his brother was telling the truth about Cas' demise. A sinking feeling in his gut said that when he did find out the truth, he wasn't going to like it.