The Blood in your Veins - Part 1

Dean splashed the warm water on his face, closing his eyes for a moment to reflect on the day he'd just had. The day that had changed everything in the blink of an eye. Sam as he knew him, was gone and the road he was on just seemed to be getting narrower. He'd promised his servitude to the angel who had pulled him from Hell, but now regretted his decision as he watched his little brother slide over to the dark side he feared. He let out a sigh and opened his eyes, jumping slightly when he caught the reflection in the mirror of the angel standing behind him in the small motel washroom. "Dude, you couldn't wait till I was done?" He groaned, turning to face the angel that had suddenly appeared.

"We need to talk." Castiel started, eyeing the busted lip and bruised cheekbone.

"I'm not really in the mood Cass." Dean growled, passing a towel over his face to dry the dripping water. "In case you haven't noticed, I just had my ass handed to me by the only person I had left."

"That's what we need to talk about." The angel continued. "Dean, your brother is getting stronger by the second and the demon blood is taking over what little human nature he has left. All he cares about is killing Lilith..."

"So let him kill the bitch." Dean interrupted, tossing the towel on the side of the vanity. "Let him do the dirty work for you, if she's dead she won't be breaking the finale seal, right?"

"Dean, killing Lilith is the finale seal." Castiel cut in, silencing the other man mid sentence. "Sam doesn't know that he is doing exactly what she wants him to do, and I'm starting to think that Ruby is helping Lilith lead him astray."

"So why are you here telling me all this?" Dean growled, pointing to the closed bathroom door. "Go tell Sam, he might actually listen to you."

"He won't, and we're running out of time." Castiel replied sternly. "Your brother has chosen to follow a dark road and you need to stop him before he unleashes the Four Horsemen of the Apocalypse." Castiel paused for a moment as he watched Dean's eyes fall to the floor. "I gave you time to talk him out of his addiction, I gave you time to reason with him, but I can no longer sit and wait for the two of you to sort this out."

"So let's throw another intervention, get him off the demon blood before he does any damage."

"Dean, Sam will not get better." Castiel said quietly. "He's passed a point of no return and what he's doing will only get worse." The angel paused for a moment as he watched the man in front of him struggle with the severity of the situation he now found his brother in. "This isn't your fault." He started. "The time has come and Sam made his choice; what he is doing is no longer considered to be human. He will free Lucifer from Hell and I can't let that happen.... I can't let you, let that happen."

"Why me?" Dean curtly replied, looking back up to catch the angel's eyes. "You're the freakin' angel; you were powerful enough to drag me out of Hell, you should be able to stop Sam..."

"I'm afraid it's not that simple." Castiel started calmly. "Only a mortal soul who willingly sacrificed himself, for the good of another has the strength to stop the demon's chosen son."

"And by the demon's chosen son you mean Sam, right?" Dean asked, already knowing what that meant about his little brother.

Castiel gave him a nod. "I know this must be hard for you to understand..."

"You think?" Dean barked.

"You are one of a kind." Castiel continued. "By selflessly devoting your life, for the good of your fellow man, you proved yourself worthy of this task. Dean, you are a true warrior and I pulled you from hell for only one purpose... to stop your brother from opening the gates of Hell. To save mankind."

"Yeah, and how do you suppose I'm going to do that?" Dean asked, crossing his arms in front of his chest. "I already tried talking to him, he's not going to listen..."

"You tried it your way and you did everything you could... but we're running out of time, so now we try it my way." Castiel cut in, pulling a knife from the inside pocket of his overcoat. "The reason your brother is so strong, is because of the demon blood he's put into his system." Castiel paused for a moment as he watched Dean's eyes drift down to the silver blade in his hand. "This works both ways, with angel's blood, you will level the battle field."

Eyeing the sharp silver blade, Dean couldn't help but feel sick to his stomach. "You can't be serious, you want me to drink your blood?" He asked, the very thought making him gag as Castiel gave him a nod. Dean shook his head. "No, I am not going to...."

"This is no longer a choice." Castiel interrupted. "With the blood of an angel, you will be as strong as your brother and you WILL kill one, to save millions."