A/N: It's my own fault for making myself sad and listening to this stupid, brilliant song but it's just too perfect to not write a fic about. I usually don't write song fics, but this was just begging to be written.

Set during the time when Cas was working for Crowley and little bit AU I guess. And of course, I cannot write a Supernatural fic without it being Destiel. It's like impossible.

Summary: Dean knows there's something off about Cas. Whether it's the way he's been acting or the way he's answering Dean's prayers less and less every day, he knows something is up. If only the angel would say something about it.

Say something

I'm giving up on you

It was the perhaps the fifth time that Cas has flown off without so much as answering a single one of Dean's questions. He was beginning to get angry with the angel, wondering why all the secrecy and why all the lies if whatever he was up to would result in something good. If Cas had a trick up his sleeve that would somehow stop Raphael, then Sam and Dean deserved to know about it, if only to help in any way they could. But no, Castiel insisted that he had it under control, that he could handle it and there was no need for worry.

Cas asked Dean to trust him, and he does, really he does. But it's getting harder and harder when the angel stops answering his prayers like he used to. Before, it would be a simple matter of saying:

"Castiel, who art in Heaven, I pray he get his feathery ass down here,"

And Cas would come as always, standing uncomfortably close to Dean's side with a muttered, "Hello Dean," in that gravelly voice of his. Now all he gets is silence. No flutter of wings to signal Cas' sudden appearance, no voice startling him out of nowhere, nothing. He would never admit it to anyone, but sometimes he would drop the joking act and actually pray, plead, for Cas to come see him. Because he was acting strangely as of late and Dean just wanted answers to what seemed to be unanswerable questions in his friend's bright blue eyes.

I'll be the one if you want me to

Anywhere I would have followed you

The thing is, whatever secrets Castiel might be hiding, whatever mess he's managed to get himself into this time, Dean would have gladly helped. He would have provided assistance in anyway possible if it meant easing the burden on his friend. Every time he shows up, which isn't very often anyway, he looks as though the fate of the world rests solely in his hands. And despite being an angel of the Lord, Dean knows that even angels have their limits. Cas has asked Dean to trust him, yet he has given no sign that he returns the favor. As much as Dean wants to believe Castiel trusts him implicitly, there's just no solid proof. Perhaps being a millennium old being ruins the ability to bestow complete trust in another, but Dean had though that maybe they, maybe he, would have been the exception, selfish as it sounds.

Even when the others suspect Cas of not telling them everything, he still holds on to his belief that Cas knows what he's doing. After all, he trusts Cas, with everything. He had flown into Hell to save him, to raise his soul from perdition, and for that Dean will forever be in his debt. He owes it to him to at least have a little faith when things get rough.

And I am feeling so small

It was over my head

I know nothing at all

What finally shatters Dean's trust in Castiel - and perhaps shatter is too strong a word as Dean still refuses to believe it even when the proof is right in front of him - is an innocent comment about Superman. Just a simple, brief mention of him that suspiciously sounds exactly like what Bobby had said earlier. And in that moment, Dean knows. He knows that Cas has been listening in on them, keeping himself cloaked from their view, deliberately not appearing when Dean prays to him, and the knowledge hurts. It hurts that Cas has been deceiving them all this time. It hurts to see that same expression of betrayal reflected back on the angel's face when they surround him with holy fire. And most of all, it hurts that even after they know about what he's been doing, Cas still doesn't trust them enough to tell them what he's been up to for the past who-knows-how-long.

And when Cas finally tells them that he's in it with Crowley to crack open Purgatory and swallow up a million nuclear reactors to defeat Raphael, it hurts like a knife to his chest. Or perhaps it would be more fitting in this case for it to be in his back, because Cas working with the King of Hell is the worst kind of betrayal.

While Sam and Bobby continue to interrogate Cas, Dean sits there, numb and wondering how on earth this came to be. This whole thing with the angels and Crowley and Purgatory is too much. They're in way over their heads here, Cas too, and he has no idea what to do. Cas' plan to absorb millions of monster souls like some sort of celestial sponge is definitely not the way to go, but the angel seems determined to see it through to the end, convinced that he's right.

He thinks that maybe winning this is impossible. Up against an archangel no less, with wings made of lightning, it's preposterous to think that any of them stand a ghost of a chance. And here Cas is, trying so hard to help when all it's doing is making everything ten times worse. He wants to tell Cas that his idea is ridiculous, that eating up all those souls can't result in anything remotely good, that if it all goes wrong - and it will, whether it's from Crowley's interference or from Cas' vessel exploding from the overwhelming power inside it - he'll lose him. Underneath it all, all the lies and the arguments and explanations, that's the only thing Dean is truly afraid of.

And I will stumble and fall

I'm still learning to love

Just starting to crawl

There has to be another way. Dean refuses to believe that this is the only option. He's not going to lose Cas no matter what and that's a fact. The angel assures them that he can handle it and he has it all under control, but Dean can see the uncertainty and apprehension that plagues his features.

He can do this. He can still get through to Cas in time to save him from his own undoing. And if there's anyone to blame for Cas' willingness to use himself as a meat suit for a bunch of monster souls and probably die in the process, it's him and Sam. He doesn't regret the choices he and his brother have made, but it's influenced his angel in ways he didn't know could happen to heavenly beings. Cas is like them, determined to succeed even if it means his own destruction.

Reluctant as they are, he convinces Sam and Bobby to wait outside while he talks to Cas. He pleads with Cas, just to listen and hear him out. He tells him that it doesn't have to be this way. And Cas argues that this is the only way. Dean tries, he tries and tries to provide a sound enough argument to Cas that opening up Purgatory isn't the answer, that it will only cause more harm than good, but Cas is having none of it. Castiel tells him that if he doesn't do this, war could break out in Heaven, that he needs to end it before it begins. Without their Father to turn to for guidance, the angels are lost, confused and angry, the archangels scrambling for power and aquiring followers in their wake. It's to restore order, to become powerful enough to stop the fighting; Castiel has to do this.

Dean refrains from telling him that his brothers and sisters, and God to boot, are all douchebags anyway and they can all just suck it up and deal, but he knows that it will get him nowhere. Especially with Cas who still regards Heaven as his home, and even though Dean believes wholeheartedly that all of Cas' family are generally not good despite being angels, he understands why Cas is doing this. He understands, but that doesn't mean that he's going to let Cas become some power-crazed God figure to stop it. Cas may tell him that won't happen but Dean says that they can't know for sure and he isn't willing to risk losing someone he cares deeply about for a last ditch effort that may or may not work, not to mention that Cas is getting all his information from a demon.

Say something I'm giving up on you

I'm sorry that I couldn't get to you

Despite all his pleading and his most convincing, charming smile, Cas still manages to escape the ring of holy fire and successfuly block out any attempt at contact from Dean. Stupid, he thinks to himself, that there was only one thing he needed to do and he had failed. All he'd had to do was to get through to Cas, to get him to see that going power-mad wasn't the answer. He wonders how tightly Crowley has Cas wrapped around his finger.

For whatever reason, Cas has some deal with Crowley that Sam and Dean are not to be targeted by demons. Of course, not everyone gets the memo and occasionally the angel appears to rescue him and then disappears as quickly as he came, off to reprimand Crowley and keep his minions in line. Usually, in that short time that he can see Cas again, he manages a hello before he flits off again, leaving Dean alone surrounded by dead vessels.

And I will swallow my pride

You're the one that I love

And I'm saying goodbye

Once, just once, he manages to get Cas to stay, but he'll never admit it's because he begged him. When he has his full attention, he lets it all out in an attempt to convince the angel not to do this. He doesn't bother telling Cas that it's a bad idea. It'll only result in Cas assuring him otherwise and leaving. Instead, he tells him that if he's going to do this, then he better swear to come out of it okay. Cas seems taken aback by Dean's sudden change of heart, eyes narrowing in suspicion and wondering what the hunter is playing at. But then Dean turns his angel's world upside down by finally admitting what he hasn't even been able to admit to himself for the past year, perhaps longer.

Dean's declaration has Cas frozen to the spot and for a moment, he wonders if he's said the wrong thing, revealed too much of his own heart. Because if Cas has gone dark side like Sam and Bobby continue to believe then it can only lead to disappointment and heartbreak.

However the expression on Castiel's face is not one of horror, or plotting. There is shock and maybe even slight disbelief, but a smile slowly rises to the surface, one that has Dean's heart flipping in his chest because he hasn't seen it in what seems like forever.

He unfreezes and just for a second he's back to the old Cas, not understanding humans like they're the funniest creatures he's ever encountered and looking like a confused pup with the way he'd tilt his head to the side. Clearly he hadn't expected Dean's outburst to affect him so, but the more time he spends with the hunters, the more receptive he's become to emotions. Cas leaves with a promise that, no matter what happens, he will come out of this unscathed.

Say something

I'm giving up on you