While I've written a few fics before, this is my first foray into the Supernatural universe. Be gentle. Needless to say, I don't own Supernatural or the characters.

Warnings: Destiel, Samstiel, major character death.

I highly recommend listening to the slow version of Carry On My Wayward Son from the 200th episode "FanFiction" during the first chapter. It is what inspired this piece.

They ran into the demons just outside Portland, Oregon. Sam and Dean were locked in hand to hand combat with a dozen of the creatures when Castiel arrived in a swish of feathers and landed poised, angel blade already in hand. Dean turned at the sound, missing the demon stalking up behind him in his distraction.

"Dean, behind you!" shouted Cas.

Dean whipped around just in time for the demon to sink a blade in his gut and wrench it upwards. He cried out from the pain and sank to his knees. Cas made a beeline for the demon and dispatched it with his angel blade. He dropped to the ground and caught Dean as the man pulled the blade out of himself and fell over. Sam was left to take care of the last few on his own.

Cas pulled Dean up to rest his head on Cas' shoulder, and cupped his other hand around the side of Dean's face, looking down at the man he loved more than anything. "Dean. Dean! Stay with me."

Dean's head rolled over to lock eyes with his angel. Cas could read the pain in his eyes, but what frightened him the most was the resignation he saw there. Dean knew he was going to die. "Cas," he rasped.

"No Dean, don't try to speak." Cas brought his hand up to brush the damp hair off Dean's face, releasing a stream of his grace into the man in a futile attempt to try to save him. He was able to dull the pain, but nothing more. The blade must have been coated in something before the battle.

"Cas, listen to me." His breathing was still ragged, but not as desperate now the pain was lessened. He reached up and grabbed the lapel of Cas' coat. "Cas, take care of Sammy. You've got to promise me you'll look out for him. Promise me!"

A single tear rolled down Cas' face. "I promise."

Sam skidded to a stop on his knees next to Cas and his brother. His face was full of fear, realizing Dean wasn't going to make it. He watched as Dean started coughing up blood. The blade must have hit his lung. "Dean. Dean! Hold on, we'll get you some help, you're going to be ok."

Dean shook his head. "Sammy, look out for Cas. He'll need you." Sam shook his head, still unwilling to believe he was going to lose his brother. "Damn it Sammy!" He coughed again, a crimson trail running down his cheek. "Please. I need to know you will both be ok. Promise me you'll look out for him."

"I will," Sam said.

"Ok. Ok." Dean's breathing shuddered as he nodded. He buried his face in the crook of Cas' neck. The angel knew the exact moment he lost his human, as Dean relaxed into his arms and released his final breath. Sam knew he was gone when Cas gathered Dean up in his arms and hunched over him, as if protecting him from the world he no longer inhabited settling a kiss on Dean's forehead. He looked up at Sam with tears streaming down his face. Sam sobbed and leaned over from his kneeled position and pounded the ground with his fist. He gasped for air and tried not to throw up as he vowed to hunt down every last demon on Earth and in Hell as vengeance. Castiel silently promised himself that he would do everything in his power to help Sam on his mission.

A long while later, they composed themselves enough to do what needed to be done. Dean deserved nothing less than a hunter's funeral. Cas laid Dean out on the ground. He retrieved a sheet from the back of the Impala and gently wrapped the body in it as Sam built the pyre. They settled Dean on the stack of wood and stood back as Cas used his grace to light the fire. Each was lost in his own thoughts as they diligently watched the pile reduce to ash, taking Dean with it. When the last ember went out, Sam turned on his heel and stalked towards the Impala, climbing in behind the wheel and roared away, leaving Cas staring at what was left. Soon he too departed, leaving behind a single feather on top of the ash. Cas and Sam would come together again when the time came, but for now each needed space to mourn their loss in their own way.