So yeah, this is probably the darkest, most horrible thing I've ever gotten the Winchester boys into. I'm literally in pain. Please forgive any OOC-ness, I tried my best to keep everyone in character but the situation was so intense that I wasn't sure how to make everyone react. Let me know what you think! I personally will never be able to watch this episode again without wincing.

Love 'Em and Leave 'Em_SEX AND VIOLENCE

What if Bobby had been delayed by traffic on his mission to save the boys?

Dean woke up. Bobby was leaning over him. He could feel a hard bed under him and realized that he was at Bobby's house. There was no mistaking the lumpy mattress he had crashed on since he was fourteen.

"Bobby?" Dean gritted through a parched mouth. He was suddenly filled with a horrible hollow sense that something was wrong. His brother was in trouble. "What happened. Where's Sam?"

Bobby's face instantly hardened, his eyes were red and glassy, but he didn't say anything. He wasn't even looking Dean in the eyes.

Dean sat up, ignoring the pain that was spiking through his head. He felt as though he were hung over. "Bobby, where's Sam?" The bedroom's other bed was empty.

Getting up from the bedside, Bobby ran a hand over his face and left the room. Dean stumbled after him and followed him down the creaking stairs. "Damn it, Bobby, answer me! What happened to my brother?"

"He's dead, Dean," Bobby hollered suddenly, whirling on the younger man, anger distorting his face. "You killed him while you were under the siren's spell."

Dean's face went blank. He froze, the mention of the siren bringing it all back with terrible clarity:

"Do it," Nick urged. "Do it for me, Dean." The siren's eyes glimmered as he stared in vague mimicry of Sam's puppy dog look. The song was undeniable.

Dean breathed heavily. He shouldn't be killing a human, he knew that. Killing humans went against every rule in his book, but the hatred, the pure uncontainable anger he felt toward Sam was enough to push him over the edge. He would do it. He would do it for Nick.

"Tell me again how weak I am, Sam, huh?" he grunted, holding the axe in one hand as he stared down at his brother, who was prostrate on the floor with the broken door underneath him, still struggling to catch his breath. "How I hold you back."

Sam said nothing, but he didn't need to. The condemnation in his eyes was plain enough as he stared Dean down. Dean, who had pulled him from a fire twice. Who had sold his soul to Hell in order to save his life. Who had rescued him time and time again . . . Sam hated him after all that, kept secrets, didn't trust him. Dean deserved trust, he deserved to receive the same amount of loyalty he gave, and he wasn't getting it. Not from Sam, at any rate. And that's why he had to die.

Dean hefted the axe and brought it down hard. He was aiming for the throat, to make a clean cut, severing the head from the neck, but at the last minute he switched direction and brought it down across Sam's chest instead. Better to make him suffer. Why should it be over so quickly?

Sam's torso was ripped open, blood rising in gushers from the wound as he cried out in pain. Dean brought the axe down again and again, the sound of metal chopping through flesh and bone filling the corridor long after the screaming had stopped.

"No," Dean said finally, blinking rapidly, an unsteady, incredulous grin attempting to worm it's way onto his face. "No, no, that was – that's not real. That didn't happen, it was . . . it was, uh . . ." He looked away, licking his lips, before finally brushing past Bobby. "Where is he?" he shouted, bursting into the living room, the dining room, the kitchen. "What did you do with him?"

"Dean . . ." Bobby attempted to grab the other man's shoulders, ready to try and talk sense into him. If there was one thing Dean did not need right now, it was to see his brother, gutted by his own hand. Even though Bobby could strangle Dean for what he had done, the sensible part of the old hunter, the part that wasn't overcome with emotion, knew that it really wasn't his fault, no more than it had been any of the other of the siren's victims' faults.

"No, no, no, no," Dean shoved Bobby out of the way and wrenched open the basement door, pounding down the rickety flight of wooden stairs. Bobby followed, ready to incapacitate the younger hunter if need be.

Pulling open the panic room's door, Dean walked in, feeling reality slipping away at the sight of his giant brother lying sprawled on a cot, his whole torso a mess of shredded internal organs and shattered bone. "S-Sammy?" he called hesitantly, as though he expected an answer. "Sam."

There was a long silence, perhaps the longest Bobby had ever known. Any minute he expected Dean to do something self-destructive – so when Dean finally did move from his frozen place at the doorway, Bobby jumped.

"He is going to pay," Dean murmured with murder in his eyes. "I swear to God."

"The siren's dead, Dean, I killed him myself," Bobby whispered.

"Siren? What are you talking about, Bobby?" snapped Dean. "This was the yellow-eyed demon, damn it!"

Bobby's heart dropped into his stomach. "What?"

"He killed Mom, he killed Dad. And now . . ." Dean glanced over his shoulder back at Sam's body. "Now he killed Sammy. Of course he did, it makes sense, doesn't it? Well I'll hunt him down. I'll kill him with my bare hands!" he screamed.

"Dean, Yellow Eyes is dead."

"Not yet," Dean said. "But he will be. I swear. I'm not going to rest, I'm not going to stop driving, until I find this son of a bitch. Then I'm going to make him give me Sam back. Don't worry, Sammy," he called in his gruff big brother voice as he strode purposefully toward the basement door. "It'll all be better when you wake up. I promise."

"Dean, you're not going any . . ." Bobby was sent spinning into unconsciousness as Dean's fist clipped him in the jaw.

. . . . .

Five days later, Bobby got a call from the Kansas state police, asking if he had known someone named Dean Winchester. "This was one of the two numbers on his speed dial, and we can't get a hold of his brother."

"I know Dean."

"Well, he's dead. He shot up a gas station in Lawrence. When we got there he was yelling something about everyone having yellow eyes. He wouldn't stop firing. We had no choice but to take him down."