*I don't know when these cliff hangers are gonna stop. I'm kinda just doing this as I go, I hope I'm disappointing any of you. I had no idea where this story was going until I started adding more. Thank you for all the rad reviews so far, I appreciate your readership. Read and review.
Dean took a few steps back, pulling out his knife as the Mark heated up on his arm.
"Woah, woah, Dean." Standing Sam said, "You okay? You look a little... Homicidal."
Standing Sam gave a nervous kind of half-laugh that Dean knew very well to be his but he also that a Shifter would have no problem duplicating it. He raised the knife threateningly at standing Sam.
"You're not my brother."
He started towards him, knife shaking in his hand, eyes set dark and hard.
"Hey, hey, easy to test that. You know the drill, cut me and see if I burn but..." Sam raised his hands cautiously, "I think maybe you shouldn't because your perceptions haven't been particularly uh... reliable, as of late."
Dean felt his head starting to swim, the desire to kill sending heat sweeping through his body in violent waves. He was sweating again, and starting to shake, despite this. He raised his own hands, and moved slowly towards tied up Sam. He removed the tape from his mouth.
"Don't listen to it, I'm me, Dean, go ahead and cut me," he exhaled heavily through his nostrils and said, a little softer, "But I think it's right. I don't know if you'll see what's real."
"Alright, I don't have time for this." Dean said harshly, and he sliced tied up Sam's arm and watched through focusing and unfocusing vision as the the skin surrounding the fresh cut burned.
Dean looked up at the face of tied up Sam, but he didn't wince. Just nodded and said,
"See?"
"It burned, you saw it burn, don't let this thing mess with your head, Dean." Standing Sam said as he approached.
"Just-Just hold on, stay there." Dean said, standing up and pointing the knife warningly at standing Sam.
He cooperated and raised his hands in surrender again. Dean wanted nothing more than to just kill one of them. Either of them. No! Not either of them, not Sam, never Sam. Either. No, God, please, no. Both of them. I'm not killing Sam! Cain didn't have to kill Abel. Abel was going dark side. Sound like someone we know?
"Dean." Standing Sam said nervously, watching Dean with a familiar kind of concern in his eyes.
He stepped forward and standing Sam backed off a little. Dean grabbed his arm and cut him. That burned too.
"I'm not a Shifter." Standing Sam said.
"Dean, you know what you saw, it burned, please." Tied up Sam pleaded.
"Just-Just shut up, both of you." Dean said shakily.
His bloodlust was pounding hard against the inside of his skull and he just wanted to know. Just wanted to be certain that he was not going to kill Sam. His vision was tilting from side to side, blurring and clearing and all he could do was pace and try not to fall down.
His fever was spiking again and he knew it but he couldn't pass out now, he couldn't fall into a hazy state of delusion. He had to stay sharp because even fully healthy, identifying the difference between the real person and the Shifter imitating them was a tricky job. If it wasn't for the burning cuts they'd be impossible to distinguish the difference between them, and now Dean was too uncertain of his own sanity to be sure which really burned.
"Just kill both of us." The standing Shifter said.
"No! Dean, I read about the Mark, you kill your brother, you go to Hell, you become a demon, like Cain did-"
Dean stopped pacing. He couldn't think, his brain was about to melt. His entire system was so completely fried that he couldn't trust himself to decide who was telling the truth. But on the other side of things a voice told him the only way to clear his mind would be to kill. Properly.
"Just do it, there's no other way-"
He covered his ears, bowing his head in pain. They wouldn't stop. He couldn't tell. Not for sure. And he couldn't kill Sam. Won't. But you can. LEAVE ME ALONE.
"He's fucking with your head!"
There's no way out. You're either going to have to make the choice. A fifty-fifty shot of killing your brother or the Shifter. Or you can skip all that nonsense and kill them both. Imagine how satisfying two murders. To slow, painful deaths at your own hand and the power...
"SHUT UP!" Dean screamed.
"Dean," Tied up Sam said slowly, "You need to calm down, that Mark is gonna kill you if your temperature goes up anymore-"
"Dean-"
Dean sank to his knees, his mind was being torn apart by a complicated combination of rage and confusion. He blinked, was seeing blood again. Two dead Sams. And nothing hurt more than that. You can't imagine the amount of power it will give you, Cain.
Stop calling me that.
Kill your brother and the fight between Crowley and Abaddon won't matter. You'll kill them both and you will be Hell's new king.
"Dean-"
He stumbled to his feet again and untied the Sam on the ground. He stepped back from the both of them. He raised the blade and looked at both of them. Met each Sams eyes and watched their faces carefully as he stabbed himself through the stomach.