"Bit presumptuous, don't you think?" Dean said with an amused smile, walking in and tossing a silver knife into the duffel bag on the bed.

Cas tilted his head, his brow furrowing in question.

"Ring's supposed to go on your right hand."

"Oh." Cas said. He didn't understand the difference, but he slipped it off his left ring finger and replaced it where advised.

"Most people shake hands with their right." Dean further explained. He went into his closet, pulling a garment bag from the back and laying it down across the bed. "Excited to see you in proper formal wear."

Cas gave a small smile, focusing on putting things into his own bag.

The case was a werewolf couple, on a well organized rampage through the elite of Kansas City.

The three were pretty sure they were likely to run into them at a gala taking place the following afternoon. The silver rings had been Sam's idea. It wasn't exactly like they could be too obvious when they were trying to weed them out at a fancy party. Handshake ought to make it easier.

Sam poked his head in. "You two ready?"

"Yeah, just about." The older hunter replied, a couple spare magazines getting tossed in as well. He swung the bag onto his shoulder and followed Sam.

Cas frowned, watching him go for a second before following behind. Dean was focused… alert. The promise of the hunt was carrying him for the moment. He wished these moments lasted longer when the fight was over.

They spent the night at a motel in town, and Cas found himself sitting with Dean in a bar long after Sam had called it a night. He didn't expect Dean to sleep anyway, but he was saddened nonetheless.

Dean was battling the growing pit in his chest, urging him to move, to fight something. They had until tomorrow afternoon to even have a chance at the werewolf, and it felt like it was a lifetime away.

"Dean?"

The hunter snapped out of his trance. "Hey, sorry." He took a sip of his beer. The renewed focus faded quickly though, and he was back to staring off at nothing.

Cas sighed. He knew he couldn't do anything, but it was still hard to fight the urge to ask anyway. He watched Dean absently pick at the plate of nachos Cas had ordered him. He felt an uncomfortable sorrow at thinking how the four chips Dean ate was an improvement over yesterday.

He knew Dean was only still upright because of the mark, and he knew the mark was burning him out in trade.

But for tonight at least, the promise of tomorrow's kill would keep him functioning. He'd let Dean take the edge off with drink instead of blood, and brace himself for whatever was going to come next.

.

Sam was the first one to notice when it went sideways. He clocked Dean's hasty exit, and identified eight sets of eyes locked on him too. Their theory of a two-wolf pair seemed to be a vast miscalculation.

He caught Cas' eyes, glad he seemed to have caught the same thing. He nodded towards the door his brother had gone through before heading to follow the now-moving pack from a cautious distance. He wasn't sure what exactly they were walking into, so he kept his guard up, his hand in his suit holding the silenced pistol just out of sight.

The angel hurried after Dean, expecting to catch up with him just outside the party, but the hunter was nowhere to be found. He kept his concern in check, quickening his pace and making sure he was thoroughly checking anywhere Dean could have gotten to.

He rounded the corner and froze, looking at the empty spot where the impala had been.

Sam ran up behind him. "Cas, I lost them-" He cut himself off, seeing what Cas was staring at. "Shit."

Cas nodded, pulling out his phone and quickly locking onto the gps he had on Dean's phone. "He's heading towards the edge of town." He let out a breath as a text came up on his screen. "He texted." He said, his tone betraying his tentative relief that the hunter hadn't just fallen off the map entirely. "Warehouse, edge of town. He's following him there."

"Yeah, and every other wolf is following Dean. Let's go." He ran towards the back of the lot to find a car no one would miss right away.

Cas sent Dean a text warning him of the incoming trouble.

Dean never read it.

.

The older Winchester stepped out of the car into the cool air, feeling a chill run down his spine as the wind kicked up for a second. He pulled his gun out, keeping it down and at the ready as he hurried towards the imposing shipping warehouse.

Dean was careful to be silent as he opened the door, closing it behind him just as carefully. He listened for any sound, hearing the footsteps, but unable to source them as they echoed through the dark and largely empty building.

He crept through a stack of palettes, entirely unable to see more than a few feet in the dim light. He had to rely on his other senses to pick up what he couldn't with sight. Purgatory had made him adept at this type of fight.

The shuffle immediately behind him warned him just in time to turn, arm up to block the razor sharp claws that ripped towards him. He snapped his gun up sideways, bashing the werewolf in the mouth, staggering him for a moment.

He had a clear shot, but he hesitated, instead deciding to throw his gun to the side, stepping forward on his own, the mark burning hot on his forearm. He threw his fist, catching the wolf by surprise, the force knocking him back against the wall. He reached down and grabbed his suit jacket, pulling him up and throwing him to the ground. "Nice party, huh?" Dean quipped. "Shrimp cocktail. Champagne. Real classy stuff."

"You hunters have some new tricks up your sleeves." He nodded towards Dean's ring.

"Yeah, we do alright for ourselves." The hunter grinned, spreading his hands.

"The Dean Winchester." The wolf said, shaking his head, spitting out blood to the side and putting on a dark smile of his own. "I'm flattered."

"I'm going to give you a chance here, one chance, tell me where she is and we can do this quick and clean."

"Oh that doesn't sound like very much fun."

Dean clenched his fist. "No. It doesn't."

"Well then, let's choose option B."

The hunter moved forward without hesitation, throwing and landing the first punch. He redirected the werewolf's momentum when he lunged again, managing to come up behind him and catch him in the back of the neck.

Claws tore his arm slightly, but he managed to grab him by the wrist, pulling the limb towards him, up, and twist in a brutally flawless tug, neatly dislocating it at the elbow and shoulder simultaneously.

His target cried out.

Dean held the werewolf's useless arm in one hand, his other reaching and pulling out his knife in one fluid motion. He yanked him forward and then slammed his head back against the brick so hard he could hear the fracture. He pressed the knife against his throat, just tight enough to his neck to draw blood. He leaned forward to hiss directly in his ear. "You're going to tell me where she is."

The wolf only laughed though. "Right here."

Dean turned, eyes widening as the figure was already on top of him. He pushed back, a tangle of limbs as he tripped to the ground, forcing himself to roll through it and jump back up to his feet. As soon as he readjusted his grip on the knife, he looked up, his heart sinking as he caught the final headcount of new characters.

"Don't tell me you're not having fun anymore." The werewolf mocked, standing up straight and rubbing at his neck with his non injured hand.

Dean's stare hardened, and he felt the static start to creep through his head, tingling through his body as a rush of adrenaline was stoked into a fire by the mark. "Oh buddy, I'm just starting."

When the pack got ready to make their move, the hunter felt a brief flash of regret, his eyes catching the glint of his gun across the warehouse, well out of reach. He tightened his fingers around the knife, body tensing and ready when the group rushed him at once.

He did well for a long time. Of the ten, only three remained when he made his mistake. He plunged his blade into the torso of the closest, his face set in concentration, blood splattered across the skin. His heart raced with the thrill. His teeth clenched as he kept eye contact, relishing the expression when he twisted the knife, watching her drop.

When he whipped around, the original wolf was just a foot away, and he felt the claws rip through his abdomen and across his chest like a hot knife through butter.

The pain ignited like a wave from his torso through his limbs and head, and for a second it even blotted out the burn from the mark. He sputtered, already tasting the faint iron at the back of his throat.

It took him a moment to push through it, to grab onto the adrenaline of the mark, to force himself back into the fray.

The smug expression on the final wolf couple faltered, and they got ready to fight again as the hunter bore down on them once more.

They didn't last long, and Dean let the last one fall away from his knife before it slipped from his hand. He staggered, almost managing to steady himself before his legs gave way.

His head swam, and he struggled to keep his eyes open, but just seconds later he lost that battle, and they fluttered shut.

.

As soon as they entered the warehouse, Sam hit the industrial switches that turned on the lights, potential ambush be damned. He saw the blood on the floor, and his eyes scanned from body to body until he saw his battered brother laying on the far side. "Dean!" He started across the room right behind Cas, his heart hammering in his chest. "God Cas, is he-"

Cas skidded to his knees next to him, putting his hand on Dean's shoulder, feeling out the damage with his grace. It was immense. He withdrew his hand. "He's alive."

"Heal him! What are you waiting for?" Sam asked, his voice raising a touch with his anxiety.

Castiel reached his hand out again but before it made contact with Dean's shoulder, he stopped. He stared down at the broken hunter for a moment before deciding to speak. "Sam…" Cas started, hesitating as his mind continued turning through the grim idea he just had.

"What is it?"

"He's losing his fight with the mark." He said slowly.

"Yeah, and if he dies here, he becomes a demon again."

"Exactly."

Sam pulled a face. "What are you saying?"

Cas spoke quickly and with urgency. "Think about it. Cain has resisted the mark, as a demon, for centuries."

The younger hunter stared at Cas. "Yeah, and last time Dean was a demon he all but leveled a town."

"We could be in control this way. We bring him to the cabin, lock him down." He watched Sam reel and he pulled himself to his feet. "Sam, listen to me." He commanded sternly. "Dean's body is starting to break under the strain of the mark. Faster than last time… you admitted to me just last week you thought that would kill him on it's own."

"Cas, this is ridiculous. Just heal him." He pleaded.

"We should give him the option, Sam."

"And we just what? Let him stay a demon forever? Hope he gets in control of it faster than Cain did? Before he commits another massacre? Or twenty?" Sam snapped.

"If it comes to that. But ideally we keep him locked down. Buy some time, try to find out how to get the mark off. Then we can cure him for good."

Sam's head reeled. "I can't believe we're discussing this."

"He will wake soon. We need to give him the option."

.

"No way."

Sam had expected the answer before the angel had even begun to explain the idea to him.

Cas knelt by his side "Dean, your body is breaking under the weight of the mark." he pleaded. "I don't know how long you can keep fighting even if I heal you now."

"So we just give up? We're looking for a way to get it off." Dean strained to speak up to emphasize his point. He tried to keep the waiver out of his voice as the effort it took to talk sapped his energy.

"Dean, this buys us time." Sam spoke up. He tried to keep his voice as even as possible. "We have those sigils that should easily contain a knight of hell."

"Should." Dean focused on that.

"They will." Cas insisted.

Sam continued, "We lock you and Cas down in the cabin, and Kevin, Charlie and I will keep looking for an answer."

"Oh sure, you really want to play house with me as a demon?" Dean spat at Cas.

"Dean." Cas said firmly. "We aren't going to leave you alone. You'll be safe."

Dean shook his head. "I can't." He looked up at Cas with an accusation in his eyes. "You promised me. You'd take me out before you let that happen again."

"Your body can handle it as a demon. It may be our best bet to save you." Cas begged.

The older hunter closed his eyes, taking a second to try to catch his breath. He brought up an arm to wipe the fine layer of sweat from his brow, but the only thing it accomplished was smearing blood across his forehead. "I don't-"

"Please Dean." Sam came to rest next to him.

Dean fell silent. The world halted, silence crashing down on them as they waited for the hunter to speak again, letting the storm pick up force and run through his mind. He scrunched his eyes, feeling like he had to fight to get any air. His voice was barely above a whisper when he managed to find it. "You're sure it'll hold?"

Sam gave a firm nod. "Yes."

The older hunter looked up at Cas. "You have to keep yourself safe." He coughed. "At any cost."

"Alright." the angel replied softly.

Dean closed his eyes for a moment, his face tight in pain, both physical and emotional. Fear was reflected in his expression when he relaxed it slightly. "Fine." He grunted, knowing the false bravado was ruined by the waver in his voice.

Both Cas and Sam felt a conflicting and crushing wave of emotions. They watched Dean let himself slump fully back against the ground, not bothering to struggle to keep himself up anymore.

Sam swallowed. "Uh…" He blinked back tears, feeling a flood of adrenaline as he even considered his next words. "How do you… I… do you want to uh… make it faster?"

"You mean, do I want to shoot myself?"

Sam winced as he listened to his brother's slowing words. "Yeah or I… I could."

"No."

"Or Cas could put you to sleep… you don't need to be awake for-"

"No, none of that." Dean caught Cas' pained eyes. His expression pleaded with the angel to understand. "I need this."

Cas closed his eyes. He did understand. Dean wanted to take the last scrap of control he could before the mark infected him fully.

"Yeah… uh, ok. Good." Sam stammered. He was reeling. He hadn't had a great feeling about the hunt, but he hadn't expected to be going through this. Again. And they were letting it happen. Right now all he could focus on was his brother dying in front of him.

"Hey… Sammy." He put his hand out and Sam took it. He gave it a squeeze. "It's okay… but you listen to me. If you can't find a way to get this off… you just find a way to lock me down permanently. You hear me?"

"Dean-"

"I'm serious. Head and body in two different oceans if you have to. Anything."

"I'll find a way to get the mark off."

Dean gave a weak smile. "Yeah…" He coughed again, splattering fresh blood onto the floor when he rolled. He looked back to his brother. "It's okay." He tried to assure him one last time.

Sam nodded, tears openly falling down his cheeks. He moved back, needing a bit of distance to try to regroup.

Cas carefully sat beside the hunter's head. He slipped his hands under Dean's shoulders, pulling the hunter up and leaning him back on his lap in one fluid motion.

Dean hissed with the pain of being moved, but he relaxed back against the angel and felt the warmth of his arms against his rapidly cooling skin. He pulled his eyes up to plead with Cas. "You promise me… you don't lose control…" He let out a choppy breath. "And don't let me hurt you." He found Cas' hand and grasped onto it.

"I'll be fine."

The hunter managed a weak smile. "I'm getting blood all over your suit."

"It's okay."

"I'm sorry." Not for the blood… for everything.

Cas knew what he meant. "Dean, it's okay." He repeated firmly.

Dean took another deep breath and coughed again, more blood staining the corners of his lips.

Cas felt himself lose his own battle with tears. "You don't have to say anything else." He tried to encourage Dean to stop pushing himself to talk.

The hunter leaned into Cas' touch as the angel ran his fingers through Dean's hair. He began to sag against the angel, and Cas repositioned to grip him tighter, hold him closer.

The older hunter looked up at Sam. He struggled to get his words out, but he needed to say it. In case it was the last time he ever would... "I love you both." He looked back up at Cas, tears finally welling in his own eyes and spilling over his cheeks. "I love you." He whispered.

Cas clenched his jaw to keep some semblance of control over his emotions. His face contorted with the pain as the gravity of those words threatened to choke him. He looked Dean in the eyes and could only give a tense and jerky nod. "I love you." He managed to choke.

Dean gave his hand one last weak squeeze before he allowed it to fall back. He was too tired to keep it up any more. He could feel his mind shutting down, the numbness creeping down his limbs as his body gave its last efforts to survive in spite of the rampant blood loss.

Cas just held him, still running his hand over Dean's head, trying to impart any small comfort he could give. Sam sat against the wall, his head back against the cool brick, giving everything to keep himself from falling completely to pieces.

The waiting was the worst part. The slow crawl of minutes felt both like decades and mere seconds. No one spoke again. The stillness of the warehouse was only broken up with the sounds of their own sorrow.

Dean's breath was coming in short shallow gasps now, his body fighting for every last scrap of oxygen it could get, trying desperately to make up for the lack of blood to carry it. He tried to say something, but he couldn't quite manage. He gathered up every scrap of energy he could, making eye contact with Sam and giving him what he hoped was one last reassuring smile.

Sam looked back at the ceiling, trying to regain any control of his emotions at all. He took a deep breath, feeling sick at what he was watching. Even knowing the end game. Knowing Dean would be back as a demon. That they could figure out the mark and turn him back.

It was temporary.

Dean laid his head back against Cas completely, his eyes blinking rapidly for a second before he finally slipped unconscious.

"Dean?" Cas looked down, shaking Dean's shoulders, but he got no response. He let out a shaky breath, feeling the renewed sting of knowing the end approached.

The angel and hunter could do nothing but remain quiet with their thoughts. They listened to the stuttering breaths get slower and further before eventually, finally, they ceased entirely.

Sam rubbed his hands over his face, shakily pushing himself off the wall. "Fuck." He muttered, his voice set in sharp grief.

Cas gathered the hunter in his arms, pulling himself up to his feet.

"You got him?"

Castiel nodded. "I do."

"Good luck."