Hey everyone I hope you enjoy this short story. This came to me after watching the heart-wrenching season 9 finale. Still cannot believe I forgot about the foreshadow of this event in season 3. :D

"What are you going to do about your grace, Castiel?" Hannah questioned me, her eyes full of admiration and respect inferring that whatever decision I made she would bestow me her upmost support. I remained silent. Contemplating deeply what my next move should be. However, Metatron's patronising tone sharply entered from the deep crevices of my mind 'Your grace is burning out Castiel and when it does you will cease to exist,' breaking my concentration. Damn it! Instantly my thoughts travelled to Dean as I remembered the smug look on Metatron's face as he explained how he singlehandedly killed Dean. If I used the last of my grace to save him, maybe then I would be forgiven for my sins. Perhaps I deserved to die. After all, I was the one who allowed myself to be caught in Metatron's web of lies and allowed his manipulation to weave its way around me. It was I who caused my brothers and sisters to fall. To be stranded on Earth for possibly all eternity. I had felt their pain, confusion and vulnerability. How could I ever expect others to truly find it in their hearts to forgive me? When I couldn't even forgive myself? If my last act on Earth meant I could resurrect my dear friend; the man, who had taught me so much about humanity and had opened my eyes to a new way of life. A way of life that thrived upon free will. Then I would die happy. At the very least with a clear conscience. Ripping up the rule book, reflecting back on it now, may have been another risky decision that I undertook too lightly. After all it led to Heaven's chaos. It probably eventually led to Metatron believing as I once foolishly did that he could become a substitute God. A hero as he so boldly put it. However, surely everyone deserved free will? Humans and angels should all be stood on equal footing. Why should one race be superior to the other? Only one thought stood firmly in place in my curious mind and that was Dean needed to live.

Sighing, I tried to rein in my spinning thoughts. I usually allowed my mind to drift off on tangents. Either I contemplated something too deeply or I barely gave it a second thought. This must have been my problem. Dean did not deserve to die. His only mistake was accepting the mark of Cain and in fact that was not his even his real mistake. He just never fully understood the consequences of that hellish mark. Dean's desire to kill Abbadon was too powerful for him to resist. Once the end was in sight there was no stopping the Winchesters. No entity on this Earth could ever stop a Winchester. Growling softly I came to a conclusion. Over the years I had learnt that Dean and Sam were dependent on one another, despite all the nasty exchanges that they frequently shared they could not live without each other. It would be like having a peanut butter and jelly sandwich without the jelly; it just would not be the same. I could not allow Sam to be on his own without anyone left in this empty, wide world. Either I somehow restored my grace and saved Dean or I truly repented for my sins and used the last of my strength to save Dean and died in the process. Once again raising him from the possible threat of perdition. Even though I wanted to believe that Dean's soul would be spared and sent to Heaven. Suddenly, the pit of my stomach knotted. It felt like a heavy stone had become lodged in my gut. What if Sam had already tried to change fate and save Dean himself? "Please Sam don't sacrifice yourself again in your brother's name" I murmured to myself as I flew down to Earth. As I continued to descend a thought penetrated my concentration. A fear that had until then remained elusive to me. Could Sam and Dean, after all of the events they had endured, really afford to no longer have me by their side?

As I landed inside the bunker my senses all started screaming at me sending tiny alarms around my body. Instinctively I drew my angel blade. Something was amiss. The atmosphere felt malevolent. Heavy with fear and desperation; most likely from Sam, mixed with sulphur and excitement; Crowley! Flecks of ember reached my eyes as I walked with steely determination towards the room where I could sense the King of Hell was dwelling. More like the King of Kilts. Quickly a small smile played on my lips as I reached for the door knob. Dean would have been proud of that joke. However, the smile vanished as quickly as it had emerged and I breezed into the room with a feeling of dread. Crowley turned to face me with his flashing smile and infuriating charm:

"Hello angel wings! What took you so long? I thought you would be one of the very first to meet the new and improved Dean Winchester." The arrogant king held a smug expression across his face as I met it with a deadly serious glare.

"What do you mean by? New and improved," Crowley simply continued to smile and made a graceful, sweeping gesture with his hand indicating I should approach Dean's bed. Tentatively I began to move forward and immediately I saw that infernal blade still gripped in his supposedly cold, dead hand. A mixture of anxiety and anger clutched at my gut forcing it to twist into unfathomable shapes. Reaching the edge of his bed I softly whispered, "Dean?"

Dean began to move causing the bed sheets underneath him to rustle. Opening his eyes, it took all of my composure to not roar out in anguish. Dean's vibrant green eyes ceased to be present. In their place were soulless black orbs that possessed sinister white flecks. He was a demon and I feared he was a mere shell of the man he used to be. Locking my eyes on to his I found no words could even begin to express how I felt. Sickness rose in my throat and I could not bear to look at Dean anymore. Turning away I focused my gaze on Crowley. That smug son of a bitch. "What have you done to him?" I demanded as I pointed my angel blade towards him.

"Easy there tiger before I try out my new pet. Luckily for you Deano here is still shall we say adjusting to his new form. It is quite a rollercoaster for the senses when you are stripped off all of your humanity." Crowley said calmly as I listened in stony silence, my patience decreasing as each word passed from that serpent's lips. I cursed the day he ever gave his soul away to a demon.

"That doesn't answer my question, Crowley". An ounce of irritation crept into my voice making his eyes light up.

"It's so sweet Cas. Seeing you so riled up about your dear lover. Unfortunately you won't be able to save him with a kiss. Don't look so concerned. I assure you I did nothing to him. It is the beauty of the mark. That is all." In that moment my anger consumed me and I lunged at Crowley. Grabbing him by the collar I slammed him against the bedroom wall.

"Get over yourself and tell me what you did or the mark did to convert Dean into a demon!" I growled as Crowley's expression turned from one of being mocking to one of slight agitation.

"Take it easy there Cas. You don't want the last precious drops of your grace to burn out by wasting it on me do you?" Crowley said quietly. I believe Sam would have called this psychological but as soon as Crowley had spoken those words my strength seemed to be sapped away by some invisible force. Releasing him I resorted to holding my blade under his neck. "Fine. You want to know the truth? I told Dean a little bedtime story. A little myth shall we say about the mark and how it managed to resurrect Cain. You see as you have pointed out in the past you and Dean share a profound bond, correct? Well, it appears the mark of Cain also shares a profound bond with Dean." Crowley explained with annoying enthusiasm.

"I don't understand what you mean?" I responded to Crowley his complex way of explaining things eating away the last of my currently, emotionally charged brain cells.

"Basically the mark does not want to let go of its current owner" Crowley pointed out bluntly, clearly sighing at my 'lack of intelligence'. Ironically I was satisfied with this answer. Not that it did not shock me and make my spine shiver, but I assume you will understand what I am trying to say. Lowering my blade, I headed for the door as Crowley passed me and sat down on the chair next to Dean's bed. His dark eyes fixed on Dean's pale face, his skin tone only just beginning to seep back into his rugged features. Glancing over my shoulder I absorbed every detail of Dean that I could. Desperately trying to not make eye-contact with those merciless eyes. Hoping to somehow preserve his memory just in case I would never see him again. My stolen grace was slowly dwindling and I could only guess that I had only a matter of months left to live. Unless I was able to be salvaged by some kind of miracle.

Miracles. Ha! What a joke. After all of the things I had witnessed I no longer believed in miracles. As I walked into the main living room of the spacious bunker, I opened my wings and prepared for flight. However, a deep voice with a gentle lilt beckoned me and forced me to remain stationary.

"Castiel is that you?" Sam called out from the shadows and I sighed gesturing to him to come forward.

"Hello Sam. I was just passing by. I am truly sorry about Dean. You must feel awful." I began to speak to Sam softly however he interrupted me with an explosive rage,

"I am not giving up. Dean is going to live! No matter what the cost. I will not lose him. If only Crowley…" I raised my hand to signal Sam to stop as I realised there was no point in allowing himself to get worked up over what had happened.

"I know Sam, Crowley's intervention is not ideal, but Dean is alive. I guess that is the only thing we can truly be thankful for." I attempted to soothe Sam to the best of my abilities using my increased understanding of human emotions due to my own experiences of when I was a human.

"What? Deans. Alive," Sam asked his voice laced with shock and disbelief. Before I could elaborate Sam interjected "You mentioned Crowley. What the hell has this got to do with Crowley? I have been trying to summon that dick for ages!" It was in that moment that I realised I had made a terrible mistake. Sam was oblivious to the dark truth that his dear older brother no longer existed in this world. He was trapped inside his own body. As a demon. A very powerful demon that was still in touch with the mark of Cain.

"Sam. I am. Dean. He is not the same. He," Sam ignored me as he began to move determinedly across the living room. However, I flew in front of him and firmly shoved him away.

"What the hell is wrong with you Cas? Get out of my way! I need to see my brother!" Tears of frustration brimmed in Sam's eyes and I knew the pain he must be feeling. However, I knew I must remain strong for both of the brothers' sakes.

"No Sam you must listen to me. I cannot let you see your brother." I began to address Sam sternly, who pouted childishly and attempted to lash out at me. In response I grabbed his arm and threw it away as he tried to grab my torso.

"Why the hell not Castiel? If Dean's alive then surely everything is going to be alright?" I had to admit even I was taken aback by Sam's naivety. It must have been his grief talking.

"Sam your brother is a demon." I explained hurriedly praying that he would see sense and not attempt to bolt past me to meet the dastardly truth in the eye. No one should ever have to witness a loved one imprisoned as a demon. Especially when their family member as in Sam's case was the only one left in this entire, lonely planet.

"What? Dean's. A demon!" Sam gasped in horror and I noticed his legs turned shaky so I motioned he should take a sit on the couch. Obliging Sam sat down heavily and placed his head into his large palms. His body began to rack violently as huge sobs engulfed him. All of the events of the last couple of months must have been flooding back to him all at once. Awkwardly I placed a hand on his muscular shoulder. In that moment I conceded I would remain by Sam's side as long as I was able to. Silently, I offered a prayer to anything or anyone that might have been listening to allow my stolen grace to not disperse before I had had the chance to save Dean.

"Do not worry Sam. I promise we will find a way to fix. I mean save your brother" I said gently as Sam mumbled something in response. I could only assume it was a thank you or he was venting his anger by linking my name with blasphemous words. Looking up at the ceiling and to no one in particular I asked internally 'When would the Winchester's ever be granted peace?'.

Thank you for reading. Please feel free to review. Any positive or negative criticisms are accepted.