Disclaimer: I don't own SPN.

So this was meant to be prompt 66 of Moments but I just had to turn it into a one shot because I love this song so much and I needed to do it justice! I strongly advise listening to Demons by Imagine Dragons while listening to this because this follows the structure of the song and draws so much from it and you won't fully feel the emotion of this fic unless you do listen to it.

Also, this one shot is dedicated to one of my best friends, who is the main reason I love Imagine Dragons and therefore this song so much. Thanks so much, theotherarchangel, (who can be found on AO3), aka Luci! :)

"Just how bad is it, Dean?" Cas said. Dean looked down at the pulsating Mark of Cain on his arm.

"It's fine," he said shortly. He couldn't tell Cas the truth! He couldn't tell him how the Mark was making him crave blood and violence and destruction and how he dreamed of killing everybody he loved every other night! He couldn't do that to his friend! But he couldn't hide from the raging beast inside him no matter what he did!

-D-

While hugging Cas, Dean averted his gaze. He normally loved staring deep into the angel's eyes but he knew that if Cas could take one look into his eyes, he'd see just how dark Dean was inside and want to help. And Dean couldn't do that to Cas. Cas didn't deserve to see just where Dean's inner demons hid, not after everything he'd done for Dean!

-D-

Dean was used to everybody expecting him to fail. Because that was what he was: a failure to everybody around him. Every single person he couldn't save weighed heavily on him and it wasn't uncommon to sometimes have nightmares in which he was accused of all of their deaths. If only he'd been faster! Aimed better! Figured out what monster it was in time to save that kid!

Sure, everyone professed how much they loved Dean. They called him the best hunter in the world and said that he was someone to be proud of. But when the curtain came down, Dean saw what they really thought. He was nothing but a no-good failure whose only achievement in life was messing up the world time and time again. Selling his soul to bring Sam back…kick-starting the Apocalypse downstairs…failing to stop Cas from going Godstiel…getting his ass sent to Purgatory…shoving an angel up Sam's ass and getting Kevin killed…trusting Crowley and getting the Mark of Cain…the list went on. Dean knew that everyone was just waiting for him to fail and as soon as he did, they immediately pointed out just how he'd messed up and how much of a screw-up he was.

And they were right.

-D-

"I don't wanna let you down, Cas," Dean shrugged, "but you know I'm going straight back downstairs when I die."

The look Cas gave him was absolutely terrifying.

"And why," the angel seethed, "pray tell, is that so?"

"Are you serious?" Dean gave a hollow laugh. "So you haven't seen all the crap I've done over the past few years? I've broken pretty much every one of God's holy rules or whatever and I've killed so many people and screwed up so much and you still think I'm going upstairs?"

"You're not going to Hell because I won't let you," Cas said firmly. "Even if I have to march downstairs and raise you from Perdition again, I will, despite being a sorry excuse for an angel. Because you deserve better, Dean! You deserve so much better than so many other people!"

Dean stared at the angel, stunned. He didn't deserve this sort of love and support! He was just a broken, flawed, sorry excuse of a human being whose only purpose was to protect Sam – and he'd even failed at that! Three times! What sort of brother let their little sibling get stabbed in front of their very eyes, then jump into Hell and then sacrifice themselves to shut the gates of Hell?

"Is this about the Mark, Dean?" Cas' face softened. "Is it getting to you? I know that it is difficult to control –"

"No," Dean interrupted. "It's not the Mark, Cas. I'm fine."

Of course that was a lie. And Dean didn't want to have to hide the truth from Cas. But he was doing it for his angel! Cas didn't need someone as dark and flawed and broken as him! Hell, he was the poster boy for the seven deadly sins alone!

Cas looked disbelieving but still stepped forward and wrapped his arms tightly around Dean. Dean stiffened immediately but slowly and surely relaxed and cautiously put his arms around Cas, as though one careless touch would break and shatter the angel.

Why did Cas even stick around anymore, when all Dean did was break stuff?

-D-

Was Dean ever going to be truly free from his demons? They were woven so deeply in his soul, were such a massive part of him, and there was no way that he could ever shake them, no matter how hard he tried. He was just fated to carry this baggage around, unable to shove it away or shake it off.

Dean knew that he needed to let Cas go. Cas may have been a warrior of God but that was precisely why he needed to leave Dean and never look back. Dean was just dragging him down! Thanks to Dean, the angel had lost his home, his family and even his grace! If Dean hadn't corrupted him then, years later, Cas would never have even met Metatron and been tricked into casting the angels from Heaven!

But Dean was selfish. He couldn't let Cas go no matter how much he tried. He needed to have Cas with him! Because one look into Cas' eyes and Dean immediately felt hopeful. One glance at those deep blue eyes, shining with the pure love the angel felt for him, and Dean was immediately hooked on him again, needing that next fix of Cas to keep him sane and stop him from going off the deep end. But it was for those reasons that Dean needed to let him go! He had to save that little bit of light still in Cas' eyes; the tiny bit of bright hope that he still possessed! But why couldn't he let Cas go?

Because he was in love with him.

-D-

The realisation hits Dean like a tonne of bricks as he wakes up, gasping and panting. Shaking his head to force the dreams and memories to the back of his mind, Dean swings his legs over the side of his bed and hurries out of the room. He knows just what he has to do.

He finds Cas in the main area of the bunker, frowning down at a book. Dean takes one quick glance at the evil symbol on his arm and then strides towards Cas before he can change his mind.

"Dean," Cas says in greeting, looking around and giving him an exhausted smile. Dean is suddenly hit with a wave of longing – a deep desire to hug his angel, hold him tight and never let go. Because Cas is his rock; his anchor; the only point of light in the dark dump of the world around him. He also feels an intense need to kiss Cas. He needs to cover the angel's lips with his own and feel and caress every little bit of him. He has to hear Cas shouting his name in hoarse ecstasy. He needs to wrap Cas in post-sex cuddles and give him little kisses and laugh as he strokes the angel's hair and protect him from the darkness outside and just love him!

Because Dean is in love with Cas. He realises that now.

"Cas." Dean sits down next to Cas, who immediately gives him his undivided attention. "Look, man…I dunno how I'm gonna go saying this but you need to hear it."

"I'm listening, Dean."

Dean takes a deep breath. This is it. He's going to take the plunge and tell Cas just how he feels.

"You know that I'm pretty messed up," he begins slowly. "I've got so many demons it's not funny. And I'm not talking about the ugly-ass smoke ones. And you…you…"

Dean curses to himself. Why is this so hard?

"I can't escape 'em, Cas," he says desperately. His voice is low, rough and just broken. "I've tried for years…but they never let go. I can't get rid of them. But…"

He rubs the Mark of Cain. Cas immediately notices this motion.

"It's bad, Cas," he finally admits. "It's really bad. I don't know how long I can resist it. I dunno how long I can hold out before I give in and start killing everyone. Because – because I dream about it every night. Every night, I dream about hurting and killing everyone…even you and Sam. And you know I'd never do that if I could help it."

"I know." Cas takes Dean's hand. "You are an amazing man, Dean. I know that you would never hurt us voluntarily. And I know that you can fight this because you are more than just the Righteous Man. You are Dean Winchester and I believe in you."

Dean's breath hitches. What the hell had he done to deserve such a beautiful angel?

"You're wrong, Cas." He sounds close to tears. But he's Dean Winchester! He won't cry! "I just can't escape 'em. And I've tried to keep you out of it 'cause you don't deserve that burden. But maybe…maybe you can show me how to fight 'em. You're the only one who can help me, Cas. I – I need you."

'I love you.'

The raw emotion and love in Cas' face staggers and overwhelms Dean and he momentarily forgets to breathe.

"Of course I will help you, Dean." Cas gently caresses his cheek and Dean leans into the touch. "I will always help you. You need only ask."

Dean blinks rapidly.

"I don't deserve you, Cas," he mumbles, looking down. "You don't need me dragging you down. I just –"

Before Dean can say any more, Cas cups his face with two hands, leans over and firmly presses his lips against Dean's. Dean's mind immediately short-circuits as electricity shoots to his brain and crackles around his body and all he can do is grip handfuls of Cas' dark hair and clutch them tightly as he reciprocates. It's better than kissing all the random women he hooks up with. It's better than kissing Cassie. And it's definitely better than kissing Lisa.

In this moment, Dean wishes that he wasn't human just so that he wouldn't have to pull back and take a breath. But the minute he has enough oxygen to satisfy his body's needs, Cas pulls him back in for another kiss that Dean eagerly returns. Why hadn't he told Cas about his feelings before? How could he have forbidden himself from ever having this?

It doesn't feel like nearly long enough before Dean needs to breathe again. However, instead of kissing Dean for a third time, Cas pulls back and takes one of Dean's hands while gently stroking his cheek.

"Don't you ever say that you are unworthy of any love, Dean," the angel says firmly. "I've loved you ever since I first laid a hand on you to raise you from Hell and I fell for you in every way."

Dean gapes.

"That long?" he says disbelievingly. Cas smiles and nods and quickly kisses him again.

"I always believed myself unworthy of your love," he says.

"Don't say that, Cas," Dean sighs, rubbing at his eyes. "I'm bad for you. I screw everything up and everyone's not afraid to tell me that. And I've got so much crap on my shoulders and so much blood on my hands and I'm nothing but a broken waste of space –"

"Stop," Cas growls, his hand momentarily tightening around Dean's face. "Don't ever talk like that, Dean. You are not a failure and I will never, ever call you that. And I also carry a massive weight on my shoulders, not to mention that my hands are swimming in blood. I've killed so many, Dean, and not just during the millennia I was Heaven's soldier. I massacred Raphael's followers when I believed myself to be God. I murdered two of my friends – Rachel and Balthazar – and I very nearly killed you in Lucifer's crypt. And all of the innocent humans caught in the bloodshed between Heaven's factions are on my hands because I was the one gullible enough to believe Metatron's lies. Does that make me any less worthy of your love, Dean?"

"No! Hell no!" Dean says immediately. "But that's not the same!"

"Isn't it?" Cas challenges. "We are both equally guilty, Dean. We are both drenched in blood. And I am nowhere near as innocent as you believe me to be. I don't need you to feel as though you must protect me. I am perfectly capable of taking care of myself and sharing the enormous burden upon your shoulders."

He gives Dean a long, slow, burning kiss.

"I love you, Dean," he says. "And I want to be there for you but you must ask for my help or I cannot give it to you. Will you allow me to help you, Dean?"

Dean looks deep into Cas' eyes, trying to both project and conceal the demons hidden deep inside. He knows that he needs Cas' help to even begin to deal with all of the crap inside him but he doesn't want to let the angel get close and then end up hurting him. Cas seems to know what he is thinking because he shifts his chair as closely opposite to Dean's as possible before leaning over and embracing Dean. Dean can feel Cas pouring every little scrap of love he feels into the love and the enormity of this amount staggers him, making him take a deep breath and clutch Cas like a lifeline.

"Please," he said. "Please. I need your help. I need you, Cas. I – I love you."

Cas pulls back to survey Dean before his face breaks into the biggest smile that Dean has ever seen. The fact that he is responsible for this fills Dean with the warmest, happiest sense of pride he has felt in a long time and he can't help but grab Cas' hair again and kiss him passionately, trying to show Cas just how much he loves him as Cas just did to him and ignoring the dark words swirling around in his head.

'Don't get too close,
It's dark inside,
It's where my demons hide,
It's where my demons hide.'

And just like that, for that brief moment, Dean's demons disappear.