A/N: Yes, the title is from a Black Veil Brides song, I had to get this idea out of my system. lol. As always thanks to my lovely beta reader, AbnormalOwl :)

"I can give you the Mark, Dean, if that's what you truly want."

"We will find a cure."

"He thinks he's closing in on Cain, Dean, you gotta give him that."

The Doctor stands at the center of Sam and Dean's dungeon at the bunker. His feet and left arm bound to the cuffs with the Devil's trap engraved on it. Sherlock stands guard at the door away from the scene while John keeps close to the Doctor, watching him and Dean.

Dean Winchester, who, once again, is overwhelmed by the power of the Mark of Cain is standing a few feet from the bound Timelord, shaking and gasping as he tries to control himself. Sam is talking to the Doctor, telling him he doesnt have to do this, but really, let's face it. He's bound, he cant back out now.

Besides, what life does he have now? Amy and Rory are gone, he doesnt have anybody aside from the humans (and an angel)surrounding him. If he can help them, he will, maybe he could help himself with this too.

"Dean, we dont know if this is going to work. But please, believe." Castiel pleads standing in front of Dean and into the hunter's personal space.

"I dont know what to do, Cas." Dean said, his voice cracking, his eyes glistening with unshed tears. Castiel can see the fear in them. "This isn't going to work. He's an alien for fuck's sake!"

"He's still a creation of God, Dean. It's a possibility we have to consider."

"We may not have concrete facts that this is going to work but we know what happened when Cain transferred the mark to you, Dean." Sherlock suddenly said, his deep voice booming at the sudden silence of the room. "And the Doctor passed, according to your standards. We can try. If we fail then so be it. If not..." Sherlock trails off.

"If not. I'll do my thing." The Doctor said grinning brightly at his family. "Come here, Dean. You promised. And I passed, I'm entitled."

"I'll just turn you into another demon, Doctor. It's not a cure! Its just stupid!" Dean insists. At one point he's right, Cain gave the mark to him whilst keeping the one on himself and simply asked Dean to come and kill him when the time comes.

"Maybe not this time? I'll –"

"Cain told me that I'm living his life in reverse." Dean says, looking anywhere but the people around him. he hasn't told anyone about that conversation with Cain.

"My story began when I killed my brother and that's where yours will inevitably end."

"He's right, it's called the Mark of Cain for a reason."

"Dean what are you-?" Sam said but he is stopped by Castiel who raised a hand in gesture for silence.

Castiel knows the story. This story. Cain was Adam and Eve's firstborn. He killed his brother Abel using what is known to be the First Blade.

But then, there's also the backstory involving Lucifer.

"First, you will kill that demon Crowley, there'll be some strange mixed feelings on that one but you have your reasons, you'll cope."

"His story started when he killed his brother, Abel, or saved him from Lucifer and then he was turned into the first Knight of Hell."

"And then you'll kill that angel, Castiel. Now that one – that I suspect, would hurt really awful."

"And then he killed Colette, the love of his life –his wife." Dean says.

"And then would come the murder you'd never survive, the one that would finally turn you into as much of a savage as it did me…"

"And then he marches on, killing every single Knight of hell -except for Abaddon."

"Yes," The Doctor smiles proudly, "You got that one."

But Dean doesn't hear him, he hears Cain "Your brother, Sam. The only thing standing between you and destiny, that destiny is this Blade."

John Watson frowns and turns to look at Sherlock, raising his eyebrows at the detective then it clicks.

"Oh!" Sherlock exclaims. "Oh!" Sherlock paces around the room, gesturing his hands wildly, "You are living Cain's life in reverse. First Cain killed his brother, if we look at it, you're going to kill Crowley. Now that is saying something, I imagine you'll feel some strange mix of emotions but you'll get over it."

Sherlock continues his deductions while Sam, John and the Doctor listens to him intently. Castiel keeps staring at Dean but the hunter won't look at him in the eye this time, he's hiding something.

Dean smiles that small, sad smile of his as he stare down at his feet. Sherlock gets it, of course that clever bastard will get it. He'll catch Cain's every word like he heard it himself, like he was there during Dean's fight against the Knight.

"And then Cain killed Colette, his wife, the love of his life as you and he puts it. And…" Sherlock stops pacing and looks quizzically at Dean.

Dean gulps nervously and maintains his eye contact at the floor. Sam coughs a bit causing the Doctor and John to raise their eyebrows.

"And then you're going to have to kill Castiel." Sherlock finished.

Castiel tilts his head, frowning in confusion. Dean took a step back, nailed it Sherlock, he thought. Now, Cas wouldn't understand it, probably just ignore it and go on being an angel perched on Dean's shoulder. He'll move on as if nothing happened, will continue to find a cure for the mark and Dean will be left hanging and on the verge of succumbing to the Mark's power and he won't be ab-

"Dean, I know you find me attractive or that you fancy me, it's no news to me." Castiel suddenly said.

Dean nearly fell to the floor struck dumb when he heard what Cas said, his eyes wide and his mouth opening and closing like a goldfish. Sam has to pinch his nose to keep from laughing because really, they were so angsty earlier and now everything is so amusing to him. Sam is gonna give Dean the biggest "I told you so" in the whole of universe.

"I thought you guys were already a thing?" John asks pointing a finger to Dean and Castiel, "I mean, it's the whole point of it right? The whole "I will rip you heart out, stomp on it and feed it to the lions while I bathe in your pool of blood if you touch Dean" charade, right Cas? Or the "first we find the angel. And we kill every monster in purgatory that come on my way to seeing my angel" charade, right Dean?"

"Oh, what year is it?" The Doctor suddenly asked.

"2015." John answers, pondering. "Oh, the one we saw! That's the future versions of you." He finishes, scratching the back of his ears sheepishly.

"What future version?" Dean bluntly asks, frowning.

"Castiel is going to be your future second husband." The Doctor said.

"And what happened to the first?" says Sam, amused at the sudden turn of events.

"Like Cas told us, 'Nothing you can prove.'" John said.

Castiel blushes lightly and turns his gaze shyly away from Dean. The hunter's face turning red at the revelation of whatever will happen in his future because- hawt damn, really?! He scored two guys? Wow, that's gotta mean he'll live through this. Through the obstacles caused by the Mark of Cain, through the troubles of being a hunter. Through his own self - loathing and commitment problems.

That's an ultimate wow on Dean's part.

"We walked in on you riding Cas and like what you said "cockblocked your beautiful morning" but its still in the future, you're starting to know too much." Sherlock interjects, smirking conspicuously.

Swallowing thickly, Dean shook his head a bit as though trying to clear his head of the mental image before saying, "Yeah, TMI. Let's just get this over with."

"Dean, I have to tell you. It's okay, I know." Castiel said.

"What?"

"I told you!"

Sam and Dean said at the same time. John laughs lightly at the brothers. Hmpf, it's like Sherlock and Mycroft minus the British posh-iness and suits. This is more plaid.

"Oh well good for you!" Dean retorted.

"I raised your angst ridden ass from perdition, Dean. I think I know your body and soul perfectly to know that you desire me. Romantically or sexually." Cas deadpans.

Really how could the guy keeps a straight face when he's talking about things like that? And since when did he talk like that?

Cas gave him a look that says, right now apparently, stop being an imbecile will you Dean?

Dean chokes on air and he coughs a bit making the other boys aside from Cas chuckle. "Alright, alright. I get it." says Dean, trying to regain his dignity by standing straighter and keeping his eyes on Castiel.

"And then of course, the end of your story Dean. Sam...but." Sherlock paused, pacing in front of the others and keeping his hands firmly clasped behind him; thinking. "If you give the mark to the Doctor. What story would he live?"

The detective continues to pace. Sam sighs and runs his fingers through his hair, he has to admit they haven't thought of that. Well, its not like Dean told them that before, or Sherlock deducing that before but he's right -its a factor they have to consider because if the Doctor have no story to live, Chuck knows what he would do.

"He'll live it all over again." John suddenly says, dropping the hand he had on his waist. "He lived it before -With the destruction of Gallifrey, the Doctor lived all of it at once-"

"Hey, I'm still here." The Doctor interrupts then smiles a small smile, "but yes, you're right."

"And then with the 'saving' of Gallifrey, he can and probably will live it all over again." Sam finishes, slightly throwing his head back at the realization. "Peachy!"

"It's alright. It's not like I know where Gallifrey is right now." The Doctor says, trying to comfort them but failing miserably. They all know that the Doctor badly wants to go back to his home planet. How he wants to live normally again with the balance of the universe in the safe hands of his race. "Because it's not time yet. It's not yet time for me to go back to Gallifrey."

John nods and pats the small of his back; checking his gun before nodding to Sherlock, "Alright then, I guess that's settled."

"What now then?" Dean asks.

"Try to give the Mark to the Doctor." Sherlock matter-of-factly answers

"And then what?" Dean asks, raising his eyebrows. "Have a raging Timelord for a Knight of Hell and destroy the whole universe?"

"If he heals himself using his regeneration energy then he can also use it to heal you."

"And on the process he'll kill himself. Awesome. Peachy!" Dean says, pacing around the devil's trap where the said Timelord is bound.

"I have enough regeneration energy to get the both of us out of this mess, alive. Don't be skeptical and just get on with it." The Doctor says, giving Dean his own bitch face.

"If it doesn't work, it doesn't. We'll find another cure. But we have to try this Dean." Sam says, using his irresistible puppy dog eye to his brother.

"Fine! Man the holy water Sammy. Cas, John guard him and bind him immediately when I'm done. Sherlock-" Dean rattles his instructions, "observe."

They all nod and get to work. Sherlock is nervous, he knows the risk they are taking here and it's big. The Doctor is, after all, the most dangerous person in the whole universe. He can call an army at the mention of his name; people are willing to do things at the mention of his name. He can scare off aliens back to their planets. And his vast knowledge of all of time and space makes him all the more formidable.

But then there's also the fact that he saves lives. Rescues those who are in danger. Save races and gives inspiration to people. That blue box of his? Just the mere sound of it gives hope to anyone. And above all that, is the fact that no matter what he can do, the Doctor is still just a boy who ran away and travels the universe.

Sherlock stands outside of the devil's trap, right in front of the Doctor who is offering his right arm to Dean. Beside the Timelord stands John Watson, hands firmly gripping the bind he's going to use after the process of giving the mark to the Doctor is done.

Sam then waits beside Sherlock, they're going to rouse the Timelord using the holy water in his hands if he ever passes out. Nodding to each other in confirmation, Castiel motioned for the door to lock; its loud bolt echoing in the awaiting silence of the room.

Dean takes a deep breath, his right arm shaking and the mark faintly glowing -the outline starting to glow an angry shade of red as the hunter firmly grasp the Timelord's unbound arm. Castiel stands behind Dean and as always, well into his personal space -leaning in, he whispers. "Take control, Dean. Do not submit to the mark."

"Hm?" Dean simply grunts.

"Yes, that's right. Because you will only submit to me, Dean Winchester." Castiel whispers, slightly growling the words out.

Dean gasps at the same time as the red coloured veins appearing on his arm snake their way quickly to the Doctor's and plants the seemingly f-shaped Mark of Cain into the Timelord's arm. As an aftermath, the mark on Dean's arm flashes bright red before taming into its normal color whereas the mark on the Doctor's arm seems to be warring which colour to take: red or gold.

John quickly catches the Doctor's falling arm as he passes out and binds it firmly, tugging at the chains to ensure its securely bound to and under the ground, then sitting him on the chair waiting beside them. Sherlock eyes dart between the Timelord's still glowing arms and to his face; checking for any signs of emotion.

Castiel puts his hands firmly on Dean's waist, anchoring the hunter to his presence and this moment. Walking Dean outside the Devil's Trap the five stare at the Doctor's limp body, his head hanging low so they can't clearly see his face. Sherlock sits on his haunches with his hands in a prayer-like position under his chin. The consulting detective closely observes the bound Timelord's arm which is now faintly glowing -the outline of the mark glowing red while the mark itself glows a faint shade of gold.

Once the glowing thoroughly disappears, Sherlock gestures for Sam to wake the Doctor using the holy water -this will prove if the mark ever took effect to the Timelord or his biology deters the curse of the Father of Murder.

Dean lays a hand on his brother's shoulder, signaling him to wait before saying. "The Mark didn't effect me, or turn me into demon. Not until after I died. It won't let me die, it's one of its...perks." Dean trails off. "I imagine it could... could be the same for him."

Sam nodded and sprays the holy water on the Doctor. Oh how shocked they were when the skin where the water came contact sizzles a bit and when the Doctor hisses irritatingly before jerking his head up and glaring at them.

"Well, well, well. Hello, everyone." The Doctor says, smiling.

Well at least he still has his dark green eyes.

"Doctor. How do you feel?" Castiel asks, the arm he has around Dean's waist tightens but the Hunter doesn't seem to care.

"Ah, Castiel." The Doctor pauses, pouting as though he's thinking deeply before answering. "I'm good. I feel new, I guess."

Dean gulps nervously, "How new?"

"Very... new." The Doctor says. Then he blinks, his once dark green eyes now a pool of depthless black; a sign of his now new status as a demon.

"Bollocks!" John shouts, irritated he stomped at the ground and paces -looking anywhere but the Timelord.

Well, the demon -No, the Timelord Knight of Hell.

"Now we have a Timelord Knight of Hell. Thats just great!" Dean sarcastically says but stays in his place with Castiel's hands.

"I'm thinking... Gallifreyan Knight of Hell. It does have a nice ring to it." Tho Doctor comments, smirking.

Sherlock stands and walks directly to the Doctor, frisking his body he found the key to the TARDIS at the inner pocket of his suit jacket. Without saying a word Sherlock walks out of the scene with the TARDIS key in his hands. The Doctor knowingly smiles at him as the Consulting Detective unlocks the door and disappears.

John stopped pacing and as if on second thought he follows his detective without a word. Sam drops his head in his hands and sighs deeply.

"Well?" The Doctor prompts. "To be honest, watching the three of you angsting is not that enjoyable. Well I guess it is, but I'm slightly not in the mood."

Sam huffs and shakes his head, "I'll get back to you, Doctor." He says before walking out of the door too.

Dean felt his phone vibrate in his pockets, bringing it out he read the new message sent to him by Sherlock.

Dean, have Castiel install CCTV cameras around the dungeon where the Doctor is bound. Strategically place it where we can clearly see his face. I'll have Sam and John monitor him. I have business to take care of. SH

Dean shows Castiel the message and the angel nods. The Doctor is smirking at them as they walk out of the room. Castiel comes back moments later. Like Dean always thought, Angel mojo, man, can get you anything. The Angel installs the cameras so they focus solely on the Doctor's now resting form.

Sam and John are sitting in the kitchen watching the Doctor through the CCTV footage when Sherlock came back, closely followed by Dean. Sitting around the table, Castiel appeared behind Dean and places a hand on his hunter's shoulder.

"Submission." Castiel simply said.

"What?" Dean asked, confused.

"It had a certain effect on you… earlier. Didn't you notice, Dean?"

That caught Sam's attention, he did noted that Castiel said something to Dean earlier while the process of giving the mark is ongoing and it seemed to have an effect on his brother, yes.

When Dean didn't answer, Castiel elaborates. "You were able to control it when you were told to submit. It may be a tactic we can use if a problem ever comes with the Doctor."

Oh, Dean and Cas can use it alright.

Sherlock didn't say anything at nod but simply nodded before he placed the key to the TARDIS at the center of the table and opens the book he's carrying. The others waiting for him to speak but the detective kept thumbing through the pages of the book until he stops and places his hand on the page, his fingers skimming through the printed letters while his lips mouth the words.

"He's going to undergo a process similar to regeneration." Sherlock suddenly says as he resumes the prayer - like position of placing his hands under his chin. Contemplating on what he just read, he continues. "If his body will remove the curse of the mark and the mark itself, then yes, the process of regeneration is required since it enables him to change and therefore remove any unwanted substance in his body."

"And that requires regeneration energy." Sam says, now leaning forward on the table.

"Naturally, yes." Sherlock answers. "Which means-"

"Which means there is, after all, a hope in all of this." John simplifies and finished for him.

Sam smiles disbelievingly and stares at the TARDIS key in the table. John grins at Sherlock and the detective smiles back.

Castiel tightens the hand on Dean's shoulder reassuringly and the hunter nods, both of them not noticing that Castiel's hand is placed directly where his handprint used to be scarred on Dean's skin.

There is, after all, a hope in all of this.

A/N: The reason this happened and Eleven became a demon is bc I saw a pic of him with demon eyes and you know... stuff happens.

So what do you guys think?