A/N: This is my first ever Destiel ficlet. I was listening to the song by Phil Collins and it just moved me that this is so Castiel and Dean. I hope you like it. Lyrics are in italics. Just a long drabble perhaps. :)

How can I just let you walk away
Just let you leave without a trace
When I stand here taking every breath with you

You're the only one who really knew me at all

Castiel watched in silent pain as Dean turned and walked away; Chuck snapping his fingers and sending him to the garden to face Amara, face his death, and hopefully save the universe one last time. He should have stopped him. He should have screamed, "Stop! I love you. Don't leave me!", but he couldn't. That's not what Dean wanted. It was never what Dean had wanted. But it was all Cas ever wanted, ever needed, ever thought about: it was all Dean. Every moment of his time on Earth, every breath he took since taking Jimmy's vessel was for Dean. Always. From the second his hand gripped Dean's shoulder and raised him from Hell he knew: there was nothing else for him but this man. This being, this soul that touched Castiel's in a way nothing else had ever done before. He defied Heaven and Hell and braved Purgatory for this man. He went against everything, turned his entire world around for him, and for what? An occasional slap on the back or the random smile? Cas didn't ask for much, he asked for nothing actually; but would it be so much to ask for Dean to admit it to him? Just once, just once tell him that he loved Cas too.

How can you just walk away from me
When all I can do is watch you leave

'Cause we've shared the laughter and the pain
And even shared the tears

And now here he was, saying goodbye forever to the one human he'd always needed; the one person in all of creation that could make Castiel happy. After everything, didn't Cas deserve this? Didn't he deserve Dean's love? Why was his existence so fraught with pain and strife that the simple act of making Dean Winchester smile was enough to propel him through the next adventure? Was this his role cast eons ago by his absent father? To be the guardian, the watcher, the protector of the man he loved, but to never have that love returned? That was fine. If that's what was meant to be, that was fine; he could accept that. But how could he just turn away and watch Dean walk to his death without a word between them?

Sure Dean had tried to talk to him in the car earlier; but it wasn't enough. Something had stopped him from saying what he truly meant. "You're always there. You're the best friend we've ever had. You're our brother, Cas," Dean had said. Castiel had let him talk; let him say what he thought Cas needed to hear. And it was nice to hear that, it was. But to throw Sam into it, and to say 'friend' and 'brother' when he really meant 'love': that tore at Castiel; it ripped him apart more than if Dean hadn't said a word.

They'd fought wars together, fought monsters and even one another, and always it came back to Dean and Cas: The Angel and the Hunter. And still Dean couldn't admit it to himself or to anyone. The fact that his love would forever go unrequited was something Castiel dealt with every day. He knew their love would never come to life; but it still hurt him. Still killed him slowly every time Dean's emerald eyes fell upon Cas's lips and lingered there, but his hands wouldn't move. Still broke him inside every time Dean touched him or hugged him, but never gave more; called him family, but never lover.

So take a look at me now
Oh there's just an empty space
And there's nothing left here to remind me
Just the memory of your face…

And you coming back to me is against all odds
And that's what I've got to face

Castiel knew this was it. Dean was going to die, and that would be the end. There was no coming back from this one; no one could bring him back, and by the look in Dean's eyes as he left, he didn't want to be brought back. This was the final task for the weary hunter. The final sacrifice after a life full of pain and anger and hurt; this was it.
Cas let himself be lead out of the cemetery to the pub. He sat and stared at nothing, his heart was empty without Dean. All his Grace and power and love were pointless without Dean Winchester in his life.

I wish I could just make you turn around
Turn around and see me cry
There's so much I need to say to you
So many reasons why

And what should he have said? Castiel replayed those last moments over and over. He should have demanded Dean pull the car over and look at him, really look at him. As he said goodbye, he should have screamed and beat his fist at him, begging him not to leave; not to take on this burden. He should have grabbed him and pressed his lips against Dean's, should have shown him what he felt, because after all these years the looks weren't doing it, the tiny smiles and jokes meant nothing; he should have shown him how he felt. Shown him the tears were for Dean only; he was for Dean only.

Take a look at me now
'Cause there's just an empty space
But to wait for you is
All I can do, and that's what I've got to face

It was stupid and selfish to think like this, Castiel knew that. If Dean could give up everything for everyone, Cas could let him go. He could let him be the hero and die with purpose. And Cas was too much of a coward to go with him; to defy Dean's wishes and stand with him at the end, hold his hand so he wasn't alone. All he could do now was wait. Wait and pray and hope that Dean could fix this; that he could save the world. Wait until he could see him again in Heaven; wait until he had the courage to go to him and hold him and kiss him and tell him everything.

Take a good look at me now
'Cause I'll still be standing here
And you coming back to me is against all odds
That's the chance I've got to take

And when the sun returned to normal he knew. He knew Dean was dead. He was sure he would feel it when his soul left the Earth, but he was too distracted by his grief to think about it. He stayed with Sam. Sam would need him now, and Dean would want him to look after him. He and Sam could grieve together; find some solace in their pain together.

He should have seen the woman standing in the Bunker when they entered, he should have been vigilant and protected Sam, warned him; but all his thoughts were on Dean. When he saw the blood drip down from her hand he knew what was about to happen and he braced himself for the blast. But it was OK; the pain of being ripped back to Heaven by the sigil was nothing compared to the pain he'd endured watching Dean Winchester walk away from him for the last time.

So take a look at me now…