The next several hunting trips were not better. Sam and Cas watched in fear as Dean threw himself harder into every case, making choices even more reckless than the first time he fought the mark.
A couple weeks later, Sam sent Charlie and Kevin on a trip to Iowa, careful to keep it from Dean. Cas and him had agreed they needed a separate space prepared and warded for him if things went sideways. A demonized Dean would not be so easily tricked to the bunker, but maybe somewhere else. They chose an old cabin of Bobby's to ward as well.
Just in case.
As the weeks dragged on, Dean was more and more agitated between jobs. They had barely been back five hours from another vamp nest before Dean was talking about a Demon on the other side of Kansas.
"Dude… we just got back." Sam protested. "We need to sleep."
Dean scoffed. "Cas will drive, we'll sleep on the way."
Cas looked up at the mention of his name, growing concerned as he looked at the hunter. Dean was fighting hard to repress the shaking in his hands, but the angel could pick up on the slight movement.
His brother frowned. "Dean…"
The older hunter shrugged, leaning back in an attempt to look relaxed. "Cas and I probably got this, if you want to sit one out."
"Dean-"
Cas frowned, not sure if he should chime in or not. He didn't actually know what he would say.
"Sam, I need this."
His brother closed his eyes. "Alright. Just at least let me shower and grab some new clothes."
Dean grinned. "You got it, Sammy." He replied, standing and heading off to do the same.
Sam exchanged a concerned glance with Cas.
.
Dean would say the case went well. Cas instead felt a sickening dread.
The group had gotten split up pretty quickly. When Sam and Cas finally rounded the corner on Dean, the older hunter was practically on top of the demon. He whipped his head up to look at them before pulling the demon knife back and neatly putting it up through the demon's lower jaw and into his skull.
He pulled back from the corpse, putting the knife back into his coat. He gave them an abrupt nod before simply walking past them and towards the car.
Cas meanwhile approached the now dead demon, noting the same things that Sam did. He had been cuffed, and if the precise cuts were anything to go by, Dean had been… encouraging him to talk.
Not that they particularly needed information from him.
Cas knew Dean had just been in the moment.
The car ride home was tense. No one wanted to speak, for fear of whatever fight might follow. Dean had been on a particularly short fuse as of late, and both of them knew it wasn't worth the argument. Nothing would change.
As soon as they were at the bunker, Dean was off to strip and clean his gun. It had become a sort of ritual. They return from a case, Dean cleans and replaces his weapons, and then he heads back to the car, cleaning her thoroughly as if the single trip had managed to make her dirty beyond belief.
Cas usually let him have that time in peace. Dean listened to music, and kept his mind focused. He needed the small privacy to keep sane.
.
That evening Sam took it upon himself to make dinner. Kevin was spending the night with his mother, and Charlie was off reading some rare texts in a college library two states over. The younger hunter figured they could use a meal that didn't come from take-out.
Dean hadn't much felt like cooking in a while.
Sam pushed the heaping cheeseburger in front of his brother, sitting down, prepared to dig into his own.
Dean looked down when he felt Paka rub the side of his leg, turning and wrapping around the other one, purring with force. He broke off a small piece of meat from his burger, putting it on the ground for the cat to snatch up.
He looked up to catch Sam's amused smirk. "What?" Dean asked, voice flat.
"Nothing." Sam replied. He didn't think he'd ever get used to seeing Dean interact with this cat. He had always been such a no-pet type of person.
Cas frowned when Dean pushed his plate away after only eating maybe a quarter of his food.
"Are you not hungry?" He asked. He knew it was a pointless question. Dean hadn't been hungry since they turned him back, but it was the only way he knew how to try and prompt the hunter to eat more.
"Yeah." Dean said simply.
Sam opened his mouth. "You sure-?"
"Yeah I'm sure." He snapped. He stood, throwing the rest of his food in the trash before heading out towards the library.
On reflection, Castiel should have known better than to push it.
In the moment however, Cas gave him an hour before he entered the library with a slice of pie. "I thought you might want this." He offered lamely.
Dean glanced up sideways for a second from his laptop screen, and pulled a face. "No thank you."
"You haven't eaten properly for weeks." The angel pressed.
"Not hungry." Dean said simply, returning to scanning through articles.
Cas was silent for a minute, putting the plate down on the table. "About today…"
"I don't want to talk about it." The hunter interrupted, his voice almost a growl. He was getting annoyed.
"Dean, you tortured the demon…"
"And?" Dean snapped. "It's a demon, Cas. The vessel had a hole in it, and I wasn't there to make nice with him."
"You didn't have to-"
"Enough."
Cas shut his mouth, watching as Dean's rigid posture only seemed to tighten.
The hunter tried to ignore the uncomfortable silence building around them. He wanted to leave… he knew he should leave. The anger was building in his body, and the last thing he wanted was to direct it at Cas.
Still, another part of his mind urged him to stay. Cas was an anchor… something to hold onto to ride out the storm.
If only he'd stop pushing for a damn second...
Castiel however didn't seem to get the hint. "Dean, you really should try to eat some…" He pushed the plate forward, closer to him.
The tension snapped. Dean slammed the laptop shut at the same time he grabbed the plate and threw it across the room, the china shattering against the bricks. "Shut up about the damn pie, Cas." He hissed, fingers coming to curl around the edge of the table to brace himself.
"Dean, I-"
"You, what? Are tired of being useless? Not my problem. You can't do anything, so stop putting it on me to make you feel better." He spat. He stood, pushing his chair back and standing, intent on getting out of there before he could make it worse.
The angel stood, walking around the table, reaching a hand out to place on his shoulder. He tried to stop him from leaving.
Dean's fist flew before he even realized it. He hit Cas square in the face, the angel staggering for a moment, hand instinctively going to his nose where it began to just barely leak blood.
The hunter hesitated for a moment, his face morphing into pain and regret. "Cas…" He tried to form an apology, but he could feel the static rising with his anger, and he knew he had to get out now. He grabbed his laptop and hurried out of the room, shoulder knocking past Sam's as sped towards his room.
Sam had heard the plate break and got there just in time to see Dean deck Cas. He walked over to the angel. "Are you okay?" he asked gently.
"I have already healed." Cas said gently, indicating the disappearance of blood.
"I meant-"
"Yeah." He replied. He took a moment to take a deep steadying breath. "I pushed too hard. I'm not great at reading the warning signs."
Sam closed his eyes, leaning back against one of the tables, feeling all of the sudden like he was years older, exhaustion settling into his bones. "God Cas, it's killing him." He breathed. "I think it's actually going to kill him. I don't know how long he can fight it."
The angel let out his breath, sinking back against the opposite table.
"Each case seems to bring less and less relief."
"I know." Cas said softly.
"We just got back." Sam whispered. "He's already like this."
"I'm sorry." Cas offered, empathizing with Sam.
The younger hunter gave a weak smile. "It's not your fault."
"We'll figure it out." But the words were hollow. Cas wasn't sure he believed that any more.
"I'll start searching for a new case." Sam sighed, knowing it was going to be necessary.
.
Cas tried to give Dean his space that night. When Cas finally came into the hunter's room, Dean was sitting on his bed, arms crossed and headphones on. He jumped when Cas had sat on the edge of the bed.
Dean's expression folded in on itself, and his face betrayed his guilt. "Cas… I'm so sorry."
The angel put up a hand to silence him. "It is forgiven." He said firmly. "It was already when it happened."
The hunter let out his breath, his eyes closing. He wanted to reject his forgiveness. Wanted to remind him that he didn't deserve to be let off the hook. But he had promised Cas he'd stop doing that. And he was trying to be true to his word.
Castiel was relieved Dean managed to accept his absolution without a fight. "Come on." He said simply, reaching out his hand and pulling Dean towards the door, intent on finishing their nightly routine.
Once Dean had passed out in front of the television, Cas pushed him the rest of the way to a deep sleep before heading off to research a few new books they had in the library.
He kept careful watch of the time, knowing that most nights he had about three or four hours before Dean required another dose of grace to keep his dreams at bay.
As the three hour mark approached, Cas got up, retracing his steps to his room. He found the door open, and frowned when he looked in to find Paka curled up on an empty bed. He headed next door to Dean's room but found it similarly unoccupied.
He headed down the hallway and found Dean in the bathroom, violently ill.
Cas' heart sank. He walked in, settling down against the wall next to the hunter, placing a supporting hand on his back. It was a testament to how spent Dean was that he didn't even flinch with surprise.
After Dean was done he fell backwards into Cas' arms, face flushed and covered in sweat. He shook as the angel held him, his eyes closed with exhaustion. "It'll be okay." He mumbled, barely managing to get through the words.
"It will." Cas lied.