Sam was researching in a book when Dean finally returned to the motel room. He walked in, went straight to his bed, and grabbed his bag with Sam shadowing him the whole time.
Grimly, Sam noticed he was packing.
"Dean... what are you doing?" he asked, getting once again no response.
"Are... are you leaving?"
"You dont need me," Dean replied gruffly, "you and Ruby go fight demons."
"Hold on, Dean, come on man..." Sam tried to reason as Dean walked past him.
Dean turned suddenly and landed a heavy blow across Sam's jaw.
Taking a moment to recover, Sam turned back.
"Are you satisfied?"
Dean hit him again.
Sam took another moment, then nodded.
"I guess not."
"Do you even know how far off the reservation you've gone?" Dean said with venom, "how far from normal, how far from human?"
"We're just exorcising Dean," Sam's eyes were low.
"With your MIND!" Dean yelled.
He looked at his brother incredulously.
"What else can you do?" he demanded.
"I can send them back to Hell," Sam said hopefully, "it only works wth demons, and that's it."
Dean grabbed him by the shirt.
"What else can you DO?!" he demanded louder.
"I told you!" Sam defended.
"And I have every reason in the world to believe that," Dean counteracted.
He turned to walk away.
"I should have said something Dean," Sam followed him, "and I'm sorry, I am. But try to see the other side that-"
"The OTHER SIDE?" Dean's voice rose again.
"I'm pulling demons out of innocent people!"
"USE THE KNIFE!"
"The knife kills the victim! What I do most of them survive! Look I've saved more people in the last five months than we've saved in a year."
Dean paused, then shook his head.
"Is that what Ruby wants you to think?" he asked, "is that the way she tricked you into using your powers? ...Slippery slope, brother. Just wait and see. 'Cos it's gonna get darker, and darker, and God knows where it ends."
"I'm not gonna let it go too far," Sam insisted.
Dean smirked, walked to the side, then sent a lamp flying across the room.
"It's already gone too far Sam," he informed him, stepping forward to stare him in the eye.
"If I didn't know you... I would want to hunt you."
Sam nodded, dejectedly.
"And so would other hunters," Dean added.
Sam's eyes welled up slightly.
"You were gone, and I was here. I had to keep on fighting without you... And what I'm doing, it works," he shrugged.
Dean sniffed, then nodded and took another step back.
"Then tell me," he began, "if it's so 'terrific'... then why did you lie about it to me?"
Sam's head lowered.
"Why did an angel, tell me to stop you?"
That made Sam look up again.
"What?" he froze.
"Cas said that if I don't stop you, he will. See what's happening Sam? That means that God, doesn't want you doing this."
Dean's eyes were welling up as well.
"So are you just gonna stand there and tell me that everything is 'all good'?"
And then Sam's phone rang, making them both jump.