Word Count: 887

There was this moment, after Sam came back just for that one moment. When he looked Dean in the eyes and said his goodbye before throwing himself, Lucifer and Michael into the hole. It was only for a split second but Dean will never be able to get it out of his head.

It was regret.

He saw all the regret that Sam had. For leaving them and getting Jessica killed; for letting Ruby get to him and for the death of Jo and Ellen. There was regret in how they couldn't save their Father, and how he regretted being who he was- getting their Mother killed. Dean could feel that Sam blamed himself for everything that had happened. He saw how Sam regretted ever saying yes to Lucifer and how he regretted all the choices he made that lead them to this moment in time. To this point where they would be separated forever. Dean couldn't let Sam be held solely responsible, he made mistakes too but Sam went down thinking it was all his fault. Now Dean had to live with the fact that Sam may never know that he wasn't responsible for everything.

The Apocalypse had been averted and somehow he knew that Castiel was going to leave him again. He never expected him to stay but somehow it felt like he was losing his brother all over again. In the time that Castiel has been with them, he felt like he was part of the family. Dean couldn't count the number of times that Cas stuck his neck out for them, and now he was going to lose another member of his sad messed up family. So, when Cas approached him for what felt like the last time. That finality in his angel's bright blue eyes he couldn't take it anymore but pride got in the way of him showing any emotion that might make Cas stay just a little while longer. He was sure that the struggle was apparent on his face, he wanted Cas to stay. The worst part of Sam leaving for Stanford wasn't that his brother had stopped hunting, but that he had left Dean alone. He couldn't handle being alone, and now he was afraid of what he might do without someone there. There was still a part of him deep down that was a monster, and he didn't know how long he could go on without it coming out and hurting someone- an innocent someone.

"I must go." Cas started, regret also in his eyes- Just like Sam. "A war has already begun in Heaven." Cas stated giving Dean that intense gaze that he always did.

"Don't let the door hit you on the way out." Dean turned away from Castiel and gestured towards the door of his cheap motel room. Ignoring the way his voice seemed to crack.

"I wanted to say goodbye." Cas stood stoically, watching Dean. "I don't know if I will return." He said with a touch of sadness that Dean was sure he imagined.

"We all have our wars to fight." Dean said packing up his duffel, almost violently shoving his jeans into the bag.

"This had been proven." Cas agreed but didn't move from his spot.

Minutes passed as Dean continued to pack up his things and Castiel just standing there. The silence wasn't uncomfortable but it still left Dean breathless as he finished packing. He still refused to turn around as he zipped up his bag, unsure if he could handle the look of pity Cas was probably going to give him.

"Cas, is there something you need?" Dean asked in annoyance.

"I don't want to leave." The angel said looking at Dean was sure with that piercing stare once again.

"Then don't." Dean said turning towards the angel.

"Perhaps." Cas said still not having moved from his position.

"Perhaps?" Dean asked with an incredulous look on his face. "No, if you're going to stay you're going to make a decision here and now. You either stay with me or you go back to heaven and fight your damned war." Dean spat as he made his way over to Castiel.

He wasn't stupid, Dean knew what he was asking from Castiel. He was asking him to leave his family and abandon everyone he ever loved and held dear to him. Dean could see it in the angel's eyes as he thought of the consequences of leaving, how many angel's would die because of he left? Cas, seemed to look at a spot over Dean's shoulder in thought for a moment before turning his head to look at the man in front of him. The hunter didn't realize he was holding his breath until Cas looked at him, his blue eyes intense with emotion.

"Then I will stay with you." He spoke with a special reverence and his eyes seemed to be brighter than usual.

Dean gave a short nod never breaking eye contact with the angel. It was good enough for him. At this point, Dean Winchester would take all the help that he could get. He was going to get his brother back and with Cas on his side, he knew he could do it.