Sam and Castiel stood still for a second, waiting for Dean to take another breath, but it didn't happen. Dean instead involuntarily shuddered, his body starving for air that wasn't being delivered.

Cas ran forward, ripping through the restraints, breaking them off the chair and loosing the hunter's limbs. "Dean, please, talk to me." He cupped Dean's cheek, pulling the hunter upwards to look at him. He saw nothing but blinding terror flashing back at him. He felt Dean start to slip and he pulled the hunter to his shoulder, sinking down to kneel in front of the chair, Dean ending up across his lap and up against his chest.

"What's happening!?" Sam begged, coming to the ground beside his brother.

"I don't know." Castiel readjusted his grip. "Dean please, you have to breathe…" He used his grace to look for injuries but physically at least, Dean was fine.

"Is he-?"

Cas pressed his palm to the side of Dean's head and reached inward to read the hunter's mind. Instead of any coherent thoughts or words, the seraph was instead hit with an indecipherable tsunami of emotion. It stunned him for a moment, making his head spin and he hastily pulled his hand away, gathering himself. Finally he reached up two fingers and neatly knocked the hunter out.

Dean slumped to the ground, his body finally taking over the unconscious function and allowing the former demon to take a breath.

Sam stared at his brother, his heart racing. "So that was what… a… a panic attack?" He looked up at the angel, hoping for some sort of reassurance. He thought back to Cas' episode when Dean became a demon and left. "When you uh… when he left you didn't… you couldn't breathe and you passed out."

Cas set his teeth, looking back up at Sam. "This wasn't a panic attack." He looked back down at the hunter in his arms. "There wasn't even enough thought for a panic attack." He was shaken to his core from the feelings he was hit with.

"What does that mean?"

"I don't know."

"Not enough thought… is he… is that just what's going to happen?"

"Sam, I don't know."

"He was fine for a minute."

Cas didn't respond again, instead reaching down and undoing the last restraints.

Sam moved forward, reaching out to take Dean's pulse. Still a little fast, but steady. "Maybe it was just too much. He'll be better when he wakes up." He said, trying to ignore the shake in his voice and project confidence.

Cas stood, gathering Dean in his arms and lifting him again. "Hopefully." He said softly, heading out of 7b and towards the hunter's room. Sam moved ahead, getting the doors. He helped pull back the covers, watching Cas settle him down.

"Cas… I need to check on Kevin."

"Go, I'll stay with him."

Sam spared one last pained glance at his brother, feeling a twinge of guilt for leaving, but he knew Kevin needed him.

Cas watched him go, hesitating before he grabbed a chair and pulled it to sit beside the hunter's bed. He took one of Dean's hands in his own and closed his eyes, letting out his breath. "I'm sorry." He muttered, feeling entirely helpless at that moment. He watched the hunter breathe for a moment, trying to take comfort in the movement of his chest.

The angel closed his eyes, his mind back to the library. To the feeling of his fist crushing the hunter's ribcage, to watching him crash through that bookshelf. To the way Dean's head listed to the side, his broken neck unable to support it.

He sighed, shaking himself out of that spiral of thoughts, trying to focus on the present. Dean was here. He was breathing. They just had to wait for him to wake up.

.

Cas had stepped out for a moment to clear his head when Dean next woke. Sam was in the chair beside him, and had caught the older hunter's eyes for just a second before the scene repeated itself. Sam found himself calling for Cas who came running into the room, his heart sinking as he saw Dean yet again trapped in a blind terror, unable to take in any air.

Cas tried to get in front of him, tried to get his focus. "Dean… Dean you have to calm down, or you won't be able to breathe."

Sam put a hand on his brother's shoulder and squeezed. "Dean please…"

Castiel only let it continue a moment longer before he pressed two fingers to the hunter's forehead, sending him back into a sleep.

"It wasn't any different." Sam said softly, mostly to himself. He looked up at Cas. "What do we do?"

The angel shook his head. "Hope that next time is better."

"Can't you… I don't know. Take the memories away?"

Cas looked at the ceiling, distress clearly written across his face. "I tried."

"What?"

"I looked through his mind, seeing if it were possible to ease the pain, or if necessary take the memories entirely."

"And?"

"The mark is too woven into his thoughts. I cannot separate them out." Cas looked back down at the unconscious hunter. "I cannot help."

Sam swallowed, his face feeling warm as he considered his next question. "Couldn't you… take on some of them? Like you did with me?"

Castiel threw him a sympathetic glance. "I tried that too." He said softly.

Sam paled, feeling the note of heartbreak in Cas' voice. Of course he would have tried that. Sam guessed there was very little Cas wouldn't try to save Dean, even at the expense of his own well-being. "There has to be something."

"I'm not sure what." Cas looked up at Sam. He paused before pressing forward. "How is Kevin?"

"More than a little shaken up. He's resting in his own room, but he said something about going to stay with his mom at the hotel."

"That is probably a good idea."

"Yeah…" Sam breathed. He closed his eyes, rubbing his hands over his face. "We have an entire library of occult knowledge, something here has to be able to help."

Castiel was doubtful the Men of Letters had anything for this unique set of circumstances, but he was hesitant to dash Sam's hopes.

The younger Winchester stood. "I'm going to look. Through every last book if I have to." He looked back at Cas. "Stay with him?" He asked, though he already knew he would.

"Of course."

.

Cas tried to make the room as comfortable as possible, trying to make the environment stress free and welcoming. Most of the lights were out, leaving just a gentle glow from the one desk lamp. The cassette player on the nightstand played some of Dean's favorite tapes on a low volume.

Still, the next time Dean awoke it was the same. Cas tried to pay attention, to really observe the details of the hunter's waking. He anticipated Dean was entirely unaware that anyone was in the room with him. Unaware of even where he was. Castiel let it go longer this time, hoping in vain that the episode passed, that Dean would rally and come through. No such luck.

"Dean… you're strong enough to fight this. Please." He whispered once the hunter slept again, but he didn't know if that was true. Dean's words echoed through his head, and he worried it really was it. That the hunter was irreparably damaged. That he'd never return to himself. Maybe this was all there'd ever be of Dean Winchester.

Castiel slipped onto the bed next to him, pulling the hunter against his chest, holding him tight. He closed his eyes, pressing the side of his cheek to Dean's head, taking hollow comfort in the warmth.

His eyes snapped open when he heard Sam enter the room. He lifted his head, looking up at the younger hunter as he walked and sat in the chair beside the bed. He had a book in his hand.

"I think I might have found something."

Cas shifted, moving so he could see Sam better, while not letting go of Dean. "What is it?"

"You can read his mind, right?"

"Yes. Though at the moment I cannot see deep into his thoughts. It is too strongly obscured by pain and terror."

Sam winced, but continued. "The Men of Letters had a spell… it's sort of like dreamwalking, but it's meant to enhance a mindreader's abilities." He opened the book, looking over the spell. "It's not exactly meant for angels, but I thought it might be a thing to try." Sam sighed. "You could go into his mind… try to reach him or… or i don't know, but do something."

Cas nodded slowly. "What does it entail?"

"Nothing we don't have here at the bunker. I'll need some of your blood, and his." Sam sighed. "I don't know if this will work."

"We'll try." Cas encouraged.

"Yeah."

Sam stood, heading out to gather the ingredients.

Castiel reached up and brushed a hand through Dean's hair. "Hold on. We're going to find a way to help you."

.

It took almost an hour before the spell was ready. Cas settled down so he was laying next to Dean. He reached one hand up to touch the side of Dean's forehead, the other hand resting on the hand print on his arm.

"You ready?" Sam asked.

"Yes." Castiel said firmly, though he didn't feel prepared in the slightest.

Sam began the incantation, carefully sounding through the complex Latin phrases. He poured the blood into the bowl, before finally dropping a match in, watching the ingredients flare up in blue flame.

Cas' eyes glowed angelic blue before slipping shut, and he found his mind being propelled into the inky blackness in front of him.

Castiel took stock of himself, looking down to find what he could only assume was his mental image. He turned his attention to his unfamiliar surroundings. Cas could feel the pull of Dean's soul.

The angel breathed in, taking the acrid smell of the smoke and blood and he knew instantly where he was. He pushed his legs forward, ignoring the slight wobble in them. The path he walked was littered with corpses, each one more mutilated than the last. The blood trail led him onward towards the sea. Cas looked out over the sandy beach, his gaze finally finding the hunter, alone on the shore, resting on his knees and facing the ocean.

"Dean!" Cas began running, his feet sinking deep into the sand. His knees dropped into the soft earth beside the hunter, his hands reaching out and grasping onto his shoulder. The hunter was once more slicked with blood, as he had been when he returned to the hotel that first night. His hand still gripped the first blade as it dripped crimson onto the pale sand.

The sound of the crashing waves mixed with the howling wind, both threatening to drown out his words as Cas spoke. "Dean, it's me… look at me." He put a hand on Dean's chin, tilting it up towards his face.

Dean pulled his gaze up from the ground, his eyes pure demonic black, and his expression entirely vacant. "Cas…" He mumbled softly.

"Yeah, I'm here Dean…"

"You're not supposed to be here." He muttered.

"I came for you."

"Are you real?"

"I'm real, Dean."

Dean looked back towards the smoke rising on the horizon, a beacon of the carnage he had wrought here. He looked somewhat disappointed the angel wasn't a figment of his imagination. "You shouldn't have come."

"Dean, you aren't really here. You're stuck in some sort of loop in your mind."

"Yeah." Dean said absently. "I know."

"You know?" Cas reached out again, taking the hunter's limp hand, and holding it in his own. "Dean, talk to me."

"I… I did this."

"That wasn't you… you aren't a demon anymore."

Dean's eyes snapped back to face the angel. "It was me." His expression darkened, eyes still black. "They were innocent… screaming for mercy, and I-" His voice cut off and he looked back down at the blade in his hands.

Cas very slowly reached out his other hand, loosening the hunter's grip and sliding the blade from his fingers. He took that hand as well, giving it a gentle squeeze. "It wasn't your fault."

"Please go." Dean's voice was nothing more than a strangled whisper.

"Dean, your brother and I are trying to reach you. We cured you of being a demon, but you can't wake up."

"I still have the mark."

"One problem at a time. Right now you need to come back with me… be aware… aware enough to breathe."

"I can't go back." Dean said softly. "This is where I belong."

Cas dropped one of Dean's hands to bring his hand up and cup the hunter's face. "No, it's not."

Dean closed his eyes, leaning into the touch ever so slightly.

Cas reached up and pulled the hunter forward, wrapping his arms around him and pulling him close. "Dean, you belong with us. With me."

"How can I go back? Knowing what I did here?"

"We'll work through it. Sam and I are going to get that mark off your arm. You can heal from this."

"I can't."

"You can." Cas said firmly. "You have to come back with me."

"Cas-"

Castiel leaned back and tipped Dean's head up to look at him again. "I need you." He pleaded, trying to reach Dean with his words.

The hunter's expression morphed into one of pain, his eyes fading back to their natural green. "Cas…"

"Dean… come back with me."

"Did… Did I kill Kevin?" Dean asked suddenly.

"No."

"I… I remember-"

"You hurt him, but he is fine. I healed him."

"I was going to kill Sam…"

"It wasn't you." Cas insisted. "Or at least, it wasn't all you." He rubbed his thumb back and forth on the hunter's temple, his hand still pressed against the side of his face. "Come back with me… we'll start to make it right."

"I don't know how."

"We'll figure it out." Cas stood, pulling Dean to stand shakily on his feet. He took the hunter's hands in his own. "Please."

Dean closed his eyes, pain still reflecting in his eyes. "Alright." He said softly.

Cas allowed himself to fade out of the dream, dragging the hunter with him.

Cas opened his eyes, still laying on the bed in Dean's room. His eyes watched Dean intently as his eyelids just started to flutter.

Sam waited, his heart skipping a beat as he saw his brother's eyes finally open fully.

Dean focused on the image of the angel's face in front of him. There was a second's silence, but then the hunter managed to pull in a shallow breath.

Cas let out a sigh of relief, pushing himself slightly more upright. He pulled Dean up as well, wrapping his arms around him and holding him tight. He felt him crumple into tears, but still his shuddering breaths were music to the seraph's ears. He kept his grip strong, trying to help offer any support he could to the grief-stricken hunter.

Sam sank back down in the chair, the tension leaving his body. No matter how long the road ahead was, he felt like they could handle it.

Dean was awake.