Disclaimer: I don't own Supernatural and gain no profit from this at all
Silence.
"What... why would Dad kill you?" Dean finally managed to get out in words. Sam looked at Dean with a patient yet pained expression.
"Because that's what Dad has become. He's ruthless, hostile, a vengeful spirit that doesn't need a reason. He thinks of us as the cause of his death and we're humanity. His fight against humanity is everything to him now," Sam explained.
"But why you, why wouldn't he just wipe out an entire town to get his fix?"
"He could, sure, but they're not a threat to him. They're just... side dishes for him. It's hunters like us that are the main courses. Every hunter he devours, the stronger he gets. Not physically but... powerfully, more determined. It gives him the illusion that he's taking down each threat one at a time. The less of us there are, the higher chance there is of his survival."
"But we... we burnt his bones the night he died. We burnt all of him. There should be nothing left of him," Dean argued.
"We physically got rid of him, yeah. But Dean... part of him survived. Part of him lived on even after that, which is why he was one of the spirits freed from Devil's Gate. That tiny part of him that lived has grown since then, getting stronger by night and day. Now it's barely controllable."
"What part of him? What part could've survived being burnt?" Dean asked.
Sam paused and looked hesitant, but then tentatively said, "The part that lives in you."
Dean stared at Sam with an incredulous expression of a lack of understanding combined with doubt. "Lives in me?"
"Yeah... it happened the night he died. I know you told me about how you met the reaper and you were meant to be the one dying, and how at the last minute Azazel stopped it and Dad died instead. But that deal that Dad made had far more serious consequences than his death. You were the one who was meant to die. He was meant to live. When it was reversed, part of the life that Dad gave to you contained a part of him. It was never intended, and Azazel certainly didn't plan it to happen. But it did happen, because you and Dad have what is, I guess... an unbreakable bond. It's strong, Dean, we all know it. You were truly his son, right from the day he first taught you anything about our world. And that's what makes him part of you and, well... what's making him live on."
"But if I died... then why didn't that part die too?" Dean asked.
"The spirit is stronger than that, Dean. It's been to Hell once, it won't be stopped going back again."
"And where is it now?"
"Terrorizing a small town near the border between Arizona and Nevada, along the Colorado River. If you go there and find Dad – find his spirit – then you can kill him and end his vengeance. You know as well as I do that the future can be rewritten. If you kill him, you'll not only be saving ten years worth of victims but our memory of him, too."
"And you..." Dean murmured.
Sam slowly nodded. "Yes. Me too."
Dean paused, then looked back up. "But even if I kill the spirit, he won't really be dead. You said part of him is living in me."
Sam nodded again and continued. "Yeah, but you can get rid of that part. The thing is, Dean... it has to be you who kills him. I'm a good hunter, and continuing on without you has made me even stronger, but ultimately you have to be the one to kill him, because you have that part inside you. If you kill him, it'll be like he's being killed by himself. His own spirit will kill him. But if I kill him, there's a likely chance that he still won't really be gone."
"But it's Hell... I can't just leave Hell."
"I know. Alastair holds the key to that. And he knows we're talking here, but he can't see or hear me. Only you can, and I promise, as a spirit still floating up there on Earth, I will do whatever I can to get you out so you can find Dad. You won't be alive but that's all we can do."
"Okay..." Dean said uncertainly.
"So, you have to be sure that when the time comes, you are ready. Alastair would probably rather put himself on the rack and let you have at him than see you go back upstairs, even as a spirit. The time frame won't be long but do whatever you have to do to get out. Maybe I can open Devil's Gate again or something... regardless, you need to track him down."
Sam suddenly flickered as if the body was covered in visual static. "Time's running out, Dean. Find him while you still can," Sam hurriedly said and with that, disappeared. Dean, bewildered, looked around but saw nothing.
"Sam!" Dean shouted out, trying and desperately hoping that somehow he was still there in the room. But no answer came. "SAM!"
Silence.
Dean staggered over to the rack and leant his weight against it, reflecting on what Sam had just told him. John couldn't be a vengeful spirit – maybe he was gruff, a warrior and one of the most brutal hunters, but at the end of the day he was still John Winchester. The same John that had thrust baby Sam into Dean's arms in the fire that had shattered their once-idyllic lives and killed Mary.
"Take your brother outside as fast as you can, don't look back! Now Dean, go!" The words still lingered in Dean's head, unable to be removed or forgotten. Twenty-four years had passed since then, though being in Hell, it seemed closer to nearly sixty years. That was the John he'd never forget, the one who had scooped Sam and Dean up together in his arms as they raced away from the house right before the upstairs window exploded.
The same John who had taught Dean everything, everything about the supernatural. Dean remembered the first day he fired a gun. He remembered the cold feeling of his finger around the trigger, but more than that was the comforting warmth of John's finger wrapped around Dean's own finger. He'd helped Dean squeeze the trigger together, all while reinforcing the importance of having the right aim. On their first hunt, when Dean had stared into some demented phantom's soul (or lack thereof), Dean had been burning holes into its face not with fear or being paralyzed, but of determination, defiance and a thirst to make John proud. His birthday should've been spent in front of a cake and a camera, but no, with John it was in front of a clearing in the bush where they had been waiting for the witch to appear. She had, and Dean had finished her off effortlessly, much to John's delight.
Dean had other memories too, but these ones he pushed down deep into the hollowness inside him. Sometimes John's gruffness and expectations didn't mesh with Dean well, ranging from anything from his overly-strong need for Dean to watch Sammy to criticizing the upkeep of the Impala. "I wouldn't have given you the damn thing if I thought you were gonna ruin it," were the words Dean remembered, but he ignored them, just like he ignored the fight between Sam and John when they were finally reunited. Hearing him berate Sam for walking away when John and Dean needed him and Sam's hostile rebuke that it was John who had closed the door and said not to come back... Dean knew he'd be lying to himself if he claimed not to have heard the fiery wrath in John's voice. Thinking back, maybe it was, in a way, foreshadowing of the soul he would once be.
Dean heard the concrete door to the room slowly open with a low crack and whipping noise of torment. Alastair stood there and was smiling. Not as bright as he usually was, but almost as if he were uncertain.
"So, Dean? Did you appreciate the fang?" Alastair asked with a smirk. It took all of Dean's strength not to charge at him – Alastair was purposely taunting him with seeing Sam, otherwise he would have never given him anything containing the spirit. But Sam had told Dean that Alastair had no idea what their exchange was because he couldn't hear any of it. If Dean had any hope of getting out of Alastair's clutches – however temporarily it would be – until then he had to act natural. And he was, after all, Dean Winchester so putting on his resilient poker face was second nature.
"Nope, why would I?" he growled, staring back into Alastair's eyes. Finally breaking the contact, he reached behind for the machete that he'd dropped and looked back at Alastair with a questioning look. Holding it up, he asked:
"So who's next?"