Cas had known the calm was never really going to last. Dean seemed to become increasingly agitated every day.

If there was any silver lining, it was that the mark kept him preoccupied enough that the weight of the events in Eastham hadn't really had a chance to find purchase.

It wasn't worth the trade-off.

With no cases, Dean set through the bunker in search of anything he could possibly do to keep busy. Every weapon in the bunker was stripped down and thoroughly cleaned before being put through a firing test and cleaned again.

"It has to be done anyway." Dean had said to Cas, trying to sound casual about it.

The Impala saw more attention than she had ever had before. The angel couldn't believe there was a way for that car to be in better repair, but every single inch of her, inside and out, was given a pass after every drive they took.

Cas tried to give support and comfort whenever he could.

Convincing the hunter to sleep quickly became an almost impossible task. Cas found that the only way Dean could get any rest at all seemed to be watching a movie. He had to distract himself enough from his sins and struggles to allow unconsciousness to find him. Cas found himself asking to put Dean into sleep on more than one occasion, but he never allowed it, only giving him permission to keep his sleep deep enough to stop dreams.

He didn't want to give up that last scrap of control.

When Cas was neck deep in old texts with his brother, Dean decided to take a jog outside around the bunker to clear his head. Sam has been trying to convince him to try it for years, going on about the benefits, and about the clarity.

It had never really been something he wanted to do.

Still, it had to be better than sitting around the bunker doing nothing.

That was how Dean found himself collapsed twenty-one miles from home on the side of an empty highway, leaning against a fence post, barely able to breathe.

"Cas… I need you."

He was beyond relieved when he finally saw the familiar black car pulling off the road in front of him.

Cas took a second to study the hunter, trying to repress the concern he felt seeing him in this state. "Hello Dean." He greeted, careful to keep his voice even.

Dean looked up at him for a second before turning his head away, feeling a touch of shame about needing to call on his help.

The angel approached him, hesitating for a moment. He watched Dean lean forward to lean forward onto his knees with arms crossed, shivering slightly as the early December chill seeped through his jacket. Cas shed his tan coat and laid it over Dean's shoulders.

"Thanks." Dean muttered, pulling the stiff fabric a little closer to him.

Castiel sank down beside him, also leaning against a post, careful to give him a little space.

"I tried to go for a run to clear my head."

Cas nodded slowly, sparing a glance sideways as Dean leaned his head down to rest on his arms.

Dean's voice was muffled by the fabric of the overcoat. "It's getting worse faster this time."

Cas closed his eyes. "I know."

Silence stretched out for a few minutes before the hunter leaned back and gave a bitter snort. "Man, 2014 is not my year."

Cas furrowed his brow, looking back at Dean.

Dean glanced up at him quickly before turning his attention back towards the field across the road. "That other future. The one where I didn't go back to find Sam."

The angel nodded, understanding the connection.

A weak smile crossed Dean's face. "You know, looking back on it, we definitely were sleeping together in that timeline."

Cas raised an eyebrow.

"Just a sense I didn't know how to read then."

Cas nodded slowly.

"Guess I was fated to be a dick either way." He felt his pulse rate pick up.

"Dean-"

"Cas, I don't know how much longer I can hold out."

"You're stronger than you think." Cas replied, hoping it was true.

"I don't know if you're any better off."

Cas squinted at him.

"Now I mean… compared to then. I'm going to drag you down here too."

The angel pushed himself sideways, reaching out and putting his hand on Dean's shoulder. "You are not dragging me down." He said firmly. "And we are going to find a way to get that mark off of you."

Dean looked away again, but Cas just squeezed his shoulder tighter.

"Let's head back to the bunker." Cas said gently, pulling himself to his feet and offering a hand to the shaky hunter.

Dean got up, leaning on him. He let Cas take a fair bit of his weight, following to the passenger side of the Impala and gratefully slipping onto the familiar leather seat. He closed his eyes and let Cas take them back home.

.

Dean eventually stopped asking if there was any news. He didn't really want to know when there wasn't. Sam and Cas didn't comment on it, instead carrying on with their research away from him.

When Kevin called, they kept it to themselves, opting to meet him in person.

"I finally found a passage that mentions the knights of hell."

"Did it have anything useful about removing the mark?" Sam pressed.

The prophet sighed. "Not yet, but maybe something else."

"What?"

"It's sort of a history about how they were made. Cain was the first demon forged after Lilith and the Princes. He got his power directly from Lucifer, and together they forged the knights in that mold."

"Princes?"

Cas spoke. "The Princes were the strongest demons behind Lilith. To my knowledge all but Azazel were killed centuries ago."

"Azazel?" The hunter asked sharply, eyes widening.

"However you and Dean killed him with the Colt." Cas continued calmly.

Sam looked up at him. "I...what?" He sighed, his shoulders dropping. "Okay…" Sam felt like there was to that story he needed to know, but right now it wasn't priority. He tabled it for the moment and turned his attention back to Kevin.

"Lucifer is an archangel. And their power comes from him."

Sam was lost but Cas caught on. "Are you saying that a knight's power is-"

"Angelic for the most part." Kevin nodded. "Twisted and darkened, but still."

Sam leaned back, his mind catching up to the new information himself. "So what does that mean?"

"I don't know." The prophet shook his head. "Maybe we can use that to help the demon warding if it comes to it. I'm reading into the angel tablet on that subject, but it's still not exactly together right which is slowing things down."

Sam nodded thoughtfully. "Yeah, maybe." He agreed. "Anything we can do to help with translations?"

"Not unless you have someone who can break complex biblical codes. This stuff is all jumbled up."

Sam frowned. "I might know someone."

.

Dean pulled the stack of papers closer to him. "So you're saying the mark is angelic?"

"Sort of." Sam said, stacking books neatly on the table. They had decided to loop him in, now that there was a potential break in the research. "It's only a few steps removed from Lucifer."

"And what does that mean?"

"We are looking into ways to use that to lock you down if-"

"If I become a demon again." Dean's voice lowered. "No guys. You gotta stop that. I told you I'm not going to let myself be that thing. You have to take me out."

Cas sank down into the seat opposite him. "Dean, this could be a way to contain you."

"Not an option. I'm not-"

Sam dropped a book onto the table with enough force to quiet his brother for a moment. "Dean, we need to know either way." He left no room for argument in his voice. "If something happens to you, and we aren't nearby enough to put you down, we're going to have to catch and contain you somehow while we work out how to do it."

Dean shut his mouth. He knew Sam was just making that argument to keep the door open to not taking his brother off the board. Then again, he wasn't wrong about the possibility something goes wrong and it's necessary. He grunted and leaned back. "So what does this three steps from Satan mean?"

Cas sighed. "A devil's trap isn't going to hold you long on its own." He shook his head. "Even the cuffs would fail eventually."

"So what are we talking about here?"

Sam settled the last of the pile of books on the table. He sat down and took a drink from the beer his brother had slid in front of him earlier. "Kevin just got the angel tablet together finally. We're looking through that and everything we got for sigils to help power down an angel."

"You think-"

"We're pretty sure the combination of the two would contain a knight of hell for as long as it needed to."

Dean swallowed. "That warding I had… in the hotel…" He fought to keep his mind from flashing back there, from thinking about it too hard.

Cas gave him a sympathetic look. "Containing an archangel will be different. And we will still need a way to combine the two to work together."

Sam shrugged. "But-"

"It's something." Dean finished. "So Kevin has both tablets now?"

"Yeah, it took a while to repair the angel tablet after Metatron, but he got it a couple days ago. Sort of."

"Sort of?"

"It's still kind of mixed up."

"So how do we help get through that?" Dean pressed, feeling a small flicker of hope as they had a direction to turn.

The front door to the bunker clanged open and shut again, drawing their attention.

" 'Sup losers?" The voice echoed as light boot-clad footsteps skipped down the metal staircase.

Dean split into a grin, standing with the rest of them to greet their sudden guest. "Charlie."

"In the flesh." She walked in, exchanging warm hugs with both brothers before turning to the angel.

"Charlie, Cas. Cas, Charlie." Sam introduced.

Cas tensed as Charlie moved in to hug him too. "I thought you'd be shorter."

Dean didn't manage to suppress a snort, which earned him a glare from the seraph.

Charlie hopped up to sit on the table next to the pile of books as everyone settled into their chairs.

"It's wild seeing all three of you guys at once."

Cas furrowed his brow. "Why-"

Sam put his hand up. "Chuck's books."

"Oh." Cas said, making the connection. "How far did he write?"

"End of Lucifer." Charlie offered.

Cas nodded thoughtfully. "Interesting." He himself had only read through a few of the novels, but he didn't feel it would go over well to mention anything about it.

"We don't talk about that." Sam cleared his throat. "You see the things Kevin sent?"

Charlie nodded. "Yeah. I think he's right, it's scrambled in a pretty consistent pattern. We should be able to crack it using his old notes as a reference."

Sam smiled. "We knew you were right for the job."

The young hunter leaned back. "So, who's getting food? I'm famished."

Dean rolled his eyes. "What would you like to eat, your royal highness?"

Charlie looked up in thought. "Let's just go with pizza."

"You got it." Dean pushed back from the table. He squeezed Cas' shoulder. "Come help me carry shit."

The angel stood, following the older hunter from the room without comment.

Charlie watched them go before whipping around to face Sam. She slid down into the newly vacated seat. She leaned in. "Wait wait wait, are they…?"

A small smile crossed Sam's face, and he looked at the doorway his brother had just left through. "Yeah."

"Holy shit. I didn't think they'd actually do it."

Sam turned back to Charlie, his expression betraying his confusion.

"I read the books. Those idiots have been in love for years."

Sam looked back towards the door, his face softening. "Oh."

"Didn't see it coming, did you?"

"No. I didn't." He admitted, picking up his beer again.

"I doubt they did either." She shook her head.

"Was it that obvious in the books?" Sam and Dean had promised each other not to read them. To allow them to maintain some amount of separation and privacy.

"Mostly subtle. Except when the angels sent them to that future timeline. That Cas and Dean were definitely screwing."

Sam choked on his drink, violently spilling everywhere. He coughed, taking a moment to regain his composure before looking up at Charlie's amused look.

"Probably best I don't mention that's in the book to them?"

"Yeah. I think so."