* Please note I'm writing this before "Blade Runners" airs so more than likely this is not what's going to happen, but I was in the mood for some sick!Dean and Cain!Dean so... Here you are. Spoilers from season 9. No slash. Enjoy.

The harsh, metallic tick of the clock hanging over the doorframe seemed to be amplified through the bunker. Loud, violent ticks, keeping perfect time with the deep thudding Dean knew to be his own heartbeat. Every noise around him seemed to be boring holes in his aching head. He felt hot and feverish but he was too wired to sleep. The entire sensation was vaguely reminiscent of the torturous transformation he'd undergone and the unbearable thirst that followed when he'd been turned by that mop headed vampire. However, he hadn't ingested any vampire blood recently so what was that fucking sound?!

He knew, somewhere deep in his imploding head, that the source of the fire that was causing his whole system to overheat was the brand that now tainted his forearm. He pulled off his flannel, threw it aside and took a ginger poke at the mark which burned as hot as it had when he'd gotten it. He tried to ignore it, ignore the pain, ignore the rage building inside him, and just work. Just focus on finding a case.

Cases were all he really had these days. With Sam firmly distancing himself, Crowley M.I.A., and Cas in the wind fighting angels, all Dean could do was continue to find cases in an attempt to get his brother back.

His vision went red, dark, blood red. He was literally seeing red. He blinked and normal color had returned except that the bunker was flooded with blood. The entire room looked like the aftermath of the elevator scene from The Shining. His heartbeat was no longer in time with the clock that was still banging each second into the manic, melting mind of the older Winchester. He looked down at the table and saw his laptop and whiskey bottle had been replaced with six or seven mutilated bodies, strewn up and down the dark wood tabletop.

He gave a startled, gravelly kind of yell and jumped up, staggering over the leg of one of the chairs, he stumbled away. He had to get away. Away from the bodies they were so... enticing. His entire sense of self was being peeled away and replaced by the very thing he hunted. Hated. But he'd always known this part of himself, just ignored it, hated it the way he hated those things he knew he could be just like. He felt such an extreme desire to kill, to mutilate bodies like those he'd just seen, though when he looked back they were gone.

He managed to get as far as the bathroom mirror where he got a good look at himself for the first time in awhile. He was pale except for the spots on his cheeks and forehead where he was deeply flushed by the fever. The dark shadows beneath his eyes only accented the clear, visible glint of red lining his green eyes. The neck of his t-shirt was soaked in sweat.

After a failed attempt to regain control by the standard splashing water in your face technique, Dean exited the bathroom. He immediately regretted it. He was hallucinating again, badly. Blood everywhere and the more he saw, the stronger the urge to slaughter became. He heard laughter. An insane, manic kind of laugh that started off softly, and slowly got louder and louder.

"Dean?!"

That was Sam's voice. What Sam could possibly have wanted or what could have woken him at 3 A.M. was a mystery to Dean. That is, until he realized the laughter was real and it was his own.

But he couldn't stop, he closed his eyes and saw dozens of methods of murder, some of him killing Sam and some of him killing strangers, ruthless and skilled.

Sam approached with caution, the psychotic laughter had naturally put him a bit on edge. Especially considering it was still happening. Though it was slowly dying out and Dean stood there, coated in sweat, eyes settling under his lids he opened them again.

Sam took a few steps closer and reached out, setting a nervous hand on Dean's shoulder. Dean practically jumped out of his skin at the slight touch, stumbling back. His eyes darted around wildly, that red glint shining against the light. The nervous energy that seemed to be racing through his system was being laced with a venomous rage he couldn't control.

"What the fuck are we doing here, Sam?!" Dean said suddenly.

Sam was startled and took a moment to respond, "What are you talking about?"

"We should be out tracking Gadreel, stabbing an angel blade through his fucking heart!" Dean barked, his voice was harsh and short, "I gotta find Abaddon and the First Blade and drag it down her meat suit and filet the bitch, hack off her limbs and then carve open her throat!"

That creepy smile was twitching at Dean's lip and another peel of laughter ring in Sam's ears as he stood, frightened of the monster he'd slowly been watching his brother become.

Dean fell silent and then grabbed his arm, the mark burning. His eyes suddenly shot closed like a sudden pain had pierced his head. His knees buckled and Sam ran forward to catch him.

He let Dean sag to the ground in his arms and then shook him gruffly,

"Dean?!"

Dean didn't respond and Sam set him down on the floor to examine him. He laid a hand across Dean's forehead and then pulled back, sensing the heat.

Dean woke feeling dazed from the fever but at least the anger was gone for now. He felt the pleasant cool of an ice pack on his head and in that same moment he became aware of the whipping of fan blades and felt the cold air blowing over him.

He opened his eyes and found the lights had been dimmed but it wasn't complete darkness which he'd likely be lost in. His blurred vision cleared up as he came to and he saw Sam sitting in a chair a few feet away, paging through a book. He looked up and saw Dean blinking, trying to sit up and he pulled his chair up closer, surveying his brother again.

"How're you feeling?" Sam asked worriedly.

"Aside from the hellfire burning in my head, just peachy." Dean groaned, sitting up and pressing the half melted ice pack to his cheek.

He shifted on his bed, sitting up most of the way so to be level with Sam. He set down the ice pack and asked, his voice scratchy and tired, "How long've I been out?"

"About fourteen hours- Hey, hey." Sam pressed a heavy hand down on Dean's shoulder as he saw him panicking, starting to get up, "It's fine, we don't have anything going on right now, it's fine."

Dean shook his head, pressing a palm into his burning temple, "Goddamn, all day...?" He trailed off, searching for words but Sam cut in.

"Dude, you do know you're supposed to sleep more than four hours? Anyway, you should go back to bed, you've been running a fever of 103 for the past five hours, it only just dropped to 102 before you woke up."

"How do you know my temperature?" Dean said suddenly and Sam rolled his eyes, "Oh, god, you're sticking shit in my mouth when I'm sleeping now?"

Sam gave a hollow laugh, "Not your mouth."

Dean gave a start, looking thoroughly violated.

"I used the ear thermometer, you know, for like babies because I knew you'd freak out." Sam explained, smiling.

Dean nodded and then turned to look at Sam, "Why do we have a baby thermometer?"

"Because you're an infant with a high fever." Sam responded.

Dean smirked, pushing his sweaty hair off his forehead.

"But seriously, man, " Sam began, "What's going on? That wasn't your normal delusional."

"Wow, 'normal delusional'. Thanks, Sam."

"I mean that wasn't just the fever. What were you seeing, Dean? I've been with you long enough to know when you saw something that freaked you out and nothing was there, man."

Dean sighed and stuck out his arm, showing Sam the mark, "I think it's the mark. It's been burning since I got it, which was fine but then I started... Seeing things. And... And thinking things that're... You know, a little more fucked up than usual."

Sam nodded, and pressed further, "Like what?"

"Sam-"

"Dean, you can drown your feelings and your anger and pretend you're fine, and I can't really stop you but when the hallucinations and fainting spells start, I gotta know what's going on."

Dean swung his legs over the side of the bed, leaning forward slightly to face Sam, "I was seeing blood all over the bunker, y'know like some Danny Torrance type of stuff, and... Then bodies... And then I kind of just... imagined myself killing people... you know strangers and then..." He swallowed, closing his eyes, he watched himself stabbing Sam again, "And then it was over."

Sam stared at his brother, taking it in, knowing he'd left something out but Sam decided not to press anymore.

"Did Cain say anything about the side effects of the mark?" Sam asked.

Dean gave a cool chuckle, "Uh... I mean, he said, 'great burden, great cost' yada, yada, but I was just thinking we gotta gank Abaddon so I just agreed."

Sam exhaled heavily through his nose, looking frustrated.

"You took on the power of the father of murder without even reading the warning label?!" Sam's voice was rising, "You're just running at this thing blind, Dean, how could you be so-"

"Sam, hey, calm down-" Dean said, closing his eyes, bowing his head in pain, "I know, I know I'm a stupid bastard but can we talk about this later my head feels like it's about to collapse in on itself."

Sam opened his mouth to retort but stopped himself. Bitching at Dean for not taking the mark seriously was always an option for after his fever went down, but at the moment it seemed a little cruel. Dean was rarely sick and even if this was so arrogantly, somewhat unintentionally self-inflicted, Sam had to take care of him. Like Dean always had for him- like he had with the trials.

"Alright, why don't you try and get a few more hours of sleep."

Dean turned over, pushing his face into the pillow, muttering into it, "Why don't you try and shut up."

Sam rolled his eyes and got up to leave, turning off the dim light before he shut the door.