AN: First off I promise I am finishing The Power Within! I am just having a bit of writers block so I am branching out a bit to give myself some breathing room. This will probably end up Destiel, because why not?
This fic WILL have spoilers, just to be safe Season 8 to Season 9's current episode. This is my take on the consequences Dean will face for taking the Mark of Cain. I'm not sure how long this will be or anything, so bear with me. Feedback is very greatly appreciated!

Disclaimer: Nope, not mine. Not even a bit. No money is being made here.

The impala rumbled comfortingly beneath him as he sat, parked in front of the Bunker; his home. Or at least it was until he left, fucked everything up, killed Kevin and once again lied to Sam. He just couldn't run anymore, every hunt had ended up a dead end and truth be told he missed his bed. He winced as the mark on his arm burning slightly as the fabric made contact everytime he moved. He wondered if Sam had told Cas, about the Mark. The hunter secretly wished he did, so he didn't have to deal with the disappointment or the possible ass kicking that would come along with the news. He shifted, killing the engine and pulling the keys out the ignition, the weight of the key to the bunker settling in his hand as he locked the doors and made his way to the entrance of the Men of Letter's headquarters.

He almost felt a heat as he walked down the steps, his vision blurred a bit as he unlocked the door. Shaking it off and shouldering his bag, he stepped a foot into the bunker for the first time in over a month. It looked the same, but quiet. Kevin was no longer sitting at the table complaining about tablets, headaches and the lack of vegetarian opinions in the bunker's vintage kitchen.

Dean clenched his jaw and made his way down the stairs, his stomach flipping as he heard someone make their way down the hall towards him. He had told Sam he was coming back, so not to surprise them too much. And to give him a say on if he even wanted him back. Sam had been quiet on the other end of the line for a few beats, and it hurt Dean more than he let on as he waited silently for his brother to reply.

"Yea, come home Dean." He had finally muttered quietly, hanging up without waiting for further information from the older Winchester.

Now he waited awkwardly at the bottom of the stairs, his bag digging into his shoulder as he tried to remain calm. He was relieved to find the footsteps belonged to Sam; he looked healthy, his eyes were brighter though they still held the stain of mistrust as they fell on his older brother.

"You made it," He said simply, standing a few feet from him.

Dean nodded, "Yea, just rolled in." He sat the bag down just in time to see Cas come in from the library. Dean smiled despite himself- the angel had his trench coat back, though it was different from the one he had before. It even fit him a bit better.

The hunter held back a wince as a particularly strong bolt of pain ran up his arm from the welt, twisting his stomach. He chose to ignore it as he saw Cas smile slightly.

"Dean, when did you get-" He stopped, his brows furrowed as he looked the older Winchester up and down.

Dean's eyes flitted to Sam's nervously, who only shook his head minutely. He couldn't sense it could he?

Dean's question was quickly answered when without warning, Cas came striding up to him with fury apparent on his face, pushing Sam aside he stood close enough to Dean that he could almost feel the ghost of his breath on him.

"Hey Cas," He muttered warily, his hand going instinctively to the mark he bore on his arm. Covering his sin as discreetly as possible.

"What did you do Winchester?" Cas growled, his voice deeper and more menacing that Dean had ever heard. At least not since that nerve wracking moment in Bobby's kitchen only a few days after Cas had revealed himself to them. When he had threatened to cast him back into the pit.

"I, uh-"

He heard Sam yell as Cas pushed him up against the wall, his bag dropping next to the stairs as he landed with a thud against the concrete wall. Dean scrambled for footing only to realize he was being held a few inches off the floor by Castiel's firm grip on his jacket.

"Cas, get off me!" He growled, pushing at the un moveable being in front of him.

Dean's arm start to burn with a righteous fury at this point, catching him off guard. He winced, his fist tightening in response to the deep burn he felt. Cas noticed the movement and set him back down, holding him in place with one hand on his chest.
Dean resigned to his fate; he knew this would happened even as he stood face to face with Cain, even as he stalled in the driveway waiting for his courage to give him enough of a boost to walk through that door.

"Cas!" He heard Sam snap at the angel. But Castiel ignored him, his full attention on Dean. Dean kept his eyes trained on Cas, his jaw set and clenched as the angel took a free hand and all but ripped his jacket and undershirt up to his bicep, revealing the ugly, raised mark branded into the Righteous Man's flesh.

The hunter watched as Cas stared at it, his eyes wide and a small vein in his forehead throbbing, in only what Dean could assume was unadulterated rage. He saw the angel move to place his fingers against it and he winced in anticipation; it was burning, wrapping up around his arm to his chest.

As soon as the angel's finger tips brushed the raised edges of the mark white hot tendrils of pain exploded through Dean, causing him to lurch away from the touch.

"Cas, don't please!" He pleaded, the seraph's iron grip still holding him in place. Castiel seemed as caught off guard as he was at the sudden pain and stepped back, allowing Dean to wrap a hand around the Mark as he heaved through the waves of nausea.

"I guess you didn't tell him," Panted Dean, trying to shake off the unkind aftermath of Castiel's probing.

Sam straightened, relaxing a bit as Cas stepped away from Dean. "It wasn't mine to tell."

"That is the Mark of Cain, Dean. Where did you get it?" Castiel snapped, his gaze still set on Dean's forearm.

"The man himself. Said it would let me use the blade to kill Abaddon," Explained Dean cautiously, staying a comfortable distance away from the angry celestial being.

"You can't be here," The angel replied, finally meeting Dean's gaze.

The older Winchester felt his heart plummet and his stomach twisted at the words. They didn't want him, not after what he had done.

"I-I'm sorry, I thought-"

Cas shook his head, seeing the devastation that washed over Dean.

"No I mean literally, I don't understand how you were able to pass through that door," Cas pointed to the bullet proof, circular door at the top of the stairs. "This place is warded against every evil known to man. That mark you carry on your arm is the beginning and cause of most it."

Dean shut his eyes against another wave of nausea that threatened to overtake him, using the wall behind him as support.

"Dean? Are you okay?" Sam asked concerned, stepping forward as Dean blinked several times.

"Whats happening?" He muttered, gripping his forearm tightly as the Mark pulsed again.

"Whats are you feeling Dean, please explain," Cas exclaimed, coming closer to the suffering man. Dean could tell he was legitimately confused.

"Fucking hurts, never done this before," He panted in response, letting himself sit on the steps beneath his feet.

He felt Castiel kneel next to him, closer this time. "How long Dean?" He asked. "How long have you had the Mark?"

"I dunno, a week? Maybe two?"

"Cas whats going on?" The younger Winchester asked.

Castiel didn't answer him, didn't take his eyes off Dean.

"Dean, there is a price of bearing his Mark. It was not meant for a mortal," He explained tightly, pointing at the offending brand. "You need to remove it as soon as possible."

Dean snorted, "I'll do that as soon as that black eyed bitch is dead."

"Dean I don't know what this will do to-"

Cas was unable to finish his warning as Dean suddenly felt a burst of pain originating from the Mark, he cried out, gripping his arm and falling back.

"Sam get a cold cloth!" The angel turned to the man still standing in complete shock. "Now!"
Sam snapped to attention and ran to the kitchen, his footfalls echoing through the bunker even as Dean gasped on the stairs of his home.

He barely felt Cas next to him until the angel gripped his shoulder and brushed two fingers across his cheek, immediately dulling the agony he felt pulsing beneath his skin. Dean opened his eyes cautiously, the twinges of pain still persistent but thankfully more bearable. He looked to Cas, who had stayed next to him though the revulsion of the mark was apparent on the being face.

"Cas whats happening? I was fine, I swear," The hunter panted, trying to get Cas to look at him, at the wall, anything but the welt on his arm.

"I don't know Dean, this is the first I have ever dealt with something of this magnitude."

"Here!" Sam gasped, clearly having just run from the other side of the room, a cold, wet compress in his grip.

Cas took the offered cloth and set it on Dean's arm, who winced and tried in vain to pull away from the cool cloth.

"Holy shit," he whispered as steam rose from his wound and into the air.

"There is nothing holy about this," murmured Cas.

AN: Ok so heres the first part! Thoughts?