AN: Well, I banged this fic out in about half an hour while listening to Half a Heart by One Direction. Driving people to tears with fanfiction oddly pleases me xD I do not own Supernatural or Half a Heart by One Direction.

When Sam Winchester finally left his room in the bunker to head for the library after a restless night of no sleep, he passed Dean's room. Normally, this was just a routine route, and Dean would be under the blankets, fast asleep. But this very early morning - 2 to be exact - Dean wasn't. Sam could hear soft shuffling noises coming from the room. He shrugged it off, ignoring them, and was about to carry on to the library when he heard Dean's voice. It was low, quiet, and he seemed almost to be... crying. Sam frowned, looking confused. He moved silently across the floor, hovering a few inches from Dean's door, which was cracked open so Sam could see the darkness and the back of a shape hunched over the bed. "Please, Cas," the figure said. His head was down, and Sam suddenly realized what he was doing.

He was praying.

"Please, Cas, God, I miss you so much. Please... Just... Please come back. Please. Come back. For me? Please, Cas, I... I love you." Dean's voice cracked and Sam took a step back. He felt like he was intruding into something private, but something held him to the room. He felt somehow tied to it. He listened still, as Dean finished his prayers, like a child before bedtime.

"Please come back for me, Cas. I need you, buddy. I love you. Okay, there, I said it. You aren't just a star to me. You're my whole damn sky." Dean must know, Sam thought, that Cas couldn't hear him... "I miss you." He voice cracked again, and his head tilted up. He was looking at the ceiling, as far as Sam could tell. As if trying to see through it to the stars... To the heavens...

"Amen."

Dean knelt, hunched in that position for a minute, and silent, like a ghost, Sam watched through the crack in the door. Then, Dean got up slowly. He lifted something from the ground with him, and Sam realized the awkward, dark shape was a jacket. The jacket Cas had left behind when he left the bunker.

Slowly, Sam turned. Equally slow, he made his way to the library, his mind swimming. As soon as he arrived and entered, he dropped to his knees in front of one of the bookshelves. He raised his hands and folded them. Winchesters didn't pray, but a certain angel had brought them both to it. "Please, Cas..." Sam began quietly. "I don't know if you can hear me, I don't think you can, but... Dean, he really misses you. He loves you, man. Please just..." He stumbled over his words, not knowing how to voice his plea. "Please, Cas, just... Just come home."

The sky didn't look the same, Dean decided.

He didn't know what it was about it, but it looked different. When Cas was there, for a while, a short day, everything seemed brighter; the sky a wonderful blue. Not just one shade, either. Blues of every colour and hue were thrown into the mix, swirling together to make a beautiful pattern with the clouds. Colours and wonderful scenes that Cas had taught him to see. But once Cas had left, it looked, just... different. Darker. He missed Cas.

The beautiful colours that Dean had seen in just a normal sky were back to their dull, pale, blue.

Only half a blue sky. Kinda there, but not quite.

Dean left like that, without Cas, he was missing something. Like... Like... He didn't know how to explain it. Like he was missing something he had taken for granted. Like... Walking around with only one shoe.

Like he was a puzzle piece, the corner, the solid, the also there, and Cas was the piece across the top that fit into his side perfectly, no pulling, pushing, or bending require. He felt like half a man without Cas.

It felt like there was some sort of arrow in his chest. There was this awful, stabbing pain in his heart when he looked up and didn't see Castiel longing around in the living room, watching Disney Channel. He felt like there was half an arrow in his chest when he accidentally made 3 cups of coffee and 20 minutes later, there would be an ice-cold cup on the coffee table.

He missed all the stupid little things he and Cas would do together normally - Dean trying to teach Cas to make burgers, watching the porn channel, trying to occupy him, trying to teach him how to do normal human things, watching the old Chuck Norris reruns at 3 in the morning, teaching him to drive, just sitting next to each other. Not having to do anything.

He felt like half a heart without Cas.

Cas sat, his legs dangling off the edge of the dock, his arms crossed and resting on his knees. He'd seen someone, a car... And it was black. For a moment, when shining second, he'd thought it was the Impala. The 1967 Chevy Impala, which you'd never see without Dean Winchester in the front seat. He missed Dean, so he'd delusioned himself into thinking that the black '09 Impala was the '67, Dean's baby.

It wasn't.

He'd stayed, though, down by the river. It reminded him of Dean, for some reason. He didn't know why, but his hands folded themselves as he looked up at the sky. The light blue eyes blinked, and he started to pray.

"Dean... I miss you, Dean." Dean could not hear him, Cas knew for sure, so he didn't know why he was doing this. But he was. He was praying, to a man who did not believe in God. "I miss you, so much, Dean. I just want to be beside you again."

The wind picked up, but it remained a pleasant breeze. Through his line of sight, a dark black bird flew overhead. The tide lapped gently at the land, where the river meet solid ground. Cas swallowed. "I really, really miss you, Dean. I love you."

The dark-coloured bird honked, as if it had heard Cas' pleas. It even switched directions, flying instead upward. As if to take his words to God. As if to deliver his prayers to the man who could make could on them. But all Cas really wanted to do right now was talk to Dean.

"Dean... I just... I know you can't hear me... I don't even know why I'm doing this but... But I love you. I love you, so, so much Dean, and I need you beside me."

"The sky doesn't look the same without you, Dean. I don't... I still see them, the way I have seen the colours before, the way I first saw them, but they are duller without you, Dean. All the swirls, the colours, the beautiful patterns of this stupid, wonderful world... they just don't look the same. Like half a blue sky. Kinda there, but not quite."

I feel like I'm missing something with you here beside me, Dean. Like I'm missing something I've always had like... Like a shoe. Without you, Dean, I feel like I'm just walking around, stumbling around, in only one shoe."

I feel like half a man without you. It feels horrible, Dean. It feels like there's this... half an arrow in my chest, plunging into my heart every time I see a man in a leather jacket and he isn't you and a black car and it isn't yours and hearing Metallica blaring from someone's house or on the radio and it isn't you playing it. It hurts, Dean. I just want you."

I miss all the things we used to do together. I miss the TV watching, the hamburger making, the coffee, the 'culturing' me and making me listen to your favorite music and teaching me how to drive and, Dean, I even miss the fights, all of them. Every single one."

I feel like half a heart without you."

Dean, Cas' old jacket in his hands, stood in the middle of the living room, in front of the coffee table where two ice-cold mugs sat.

"I try to... I try to get you out of my head, Cas, but I can't. Truth is, Cas..."

Cas was still looking up at the sky, his hands folded. A fluffy white cloud lazily drifted across the sky. He opened his mouth, paused, and then spoke again. "I'm lost without you, Dean. I don't just want you, Dean, I need you."

"Cas, buddy, I love you. And since you left... Every day... I've been waking up to..."

"Ever since I left you, Dean, I don't know why I did. I love you. I love you. I love you. And every day, I've been waking up to..."