Dean and Sam were soulmates. Not entirely unheard of in siblings, but very rare. They might know love, but they were bonded tightly to each other first and foremost. They would never have a soulmate bond with a lover, destined to be bound in an entirely different way. After Mary passed, John kept their bond quiet, taught the boys to do the same. There was enough danger from the outside due to their bouncing from place to place, no need to give schoolyard bullies with little understanding further ammunition. As the years wore on, the boys rarely spoke of it at all. When they died though, neither was surprised to find out they shared a heaven.
Years had passed since that day, they'd stopped the apocalypse more than once, fought off demons and angels alike. They'd even reconciled God and His sister. They'd fallen away from each other more than once, but always they'd come back. They had a home now. They still hunted, though most of the big bads had been put down, little things like when they'd started.
Cas and Dean had gone off together on a hunt. Simple salt and burn, only a small way from the bunker. A ghost had begun terrorizing a young family. Dean could have handled it alone, but Cas insisted on tagging along.
"Are you certain this is the right grave?" Cas tossed the shovel up out of the hole he'd dug and grabbed the lighter fluid from Dean. "Aren't spirits a little more lively right before they're burned?"
As if on cue, a figure blinked into existence right in front of Dean. He had only a second to pull up his shotgun before he was thrown into a gravestone. His skull connected with the granite and stars popped in his vision. "Cas!" He struggled to right himself, to get to Cas before the spirit could hurt him, but Cas was faster and the ghost went up in flames.
In seconds, Cas was out of the hole and at Dean's side. He had little of his angel mojo left, but he was still faster and stronger than any human could hope to be. "Dean!" He pulled Dean into a seated position and felt at his head. "Are you hurt?"
"No. I think I'm ok. Good job torching that bitch." He smiled up at Cas, but something was wrong. He rubbed at the back of his head, feeling for blood or bruise. A small goose egg was rising up in his hair, but nothing memorable. So why did those blue eyes he knew so well look so faded? "Cas?"
"Dean? What's wrong?" He sounded worried.
"I think I hit my head harder than I thought." Cas pulled him to his feet and he looked around. The world seemed to be fading somehow, all the color draining slowly to shades of grey. His face paled and he felt as if a vice was cranking down on his lungs and heart. He looked to Cas, eyes wild with panic and breaths coming faster. "Sam. We have to get to Sam, now." Cas didn't hesitate, and they both ran for the car, leaving tools and open grave behind.
Dean still remembered the day he first saw colors for real.
He bounced on his toes, tight with excitement and anticipation. "Soon?" He asked again.
Auntie Missouri laughed and patted his head. "Soon baby. Listen hard, is that your daddy's car I hear?"
Dean listened with all his might, eyes closed and head tilted to the side. There. The distinct rumble of a '67 Chevy Impala filled the night. He ran to the front door of their house, Auntie Missouri laughing as she followed. He stood at the door, once again bouncing, waiting anxiously for Dad to open the door.
It took longer than he wanted, but soon the door opened and Mom slipped inside. She looked tired, but she was smiling. Right behind her came Dad, a bundle in his arms and a bag on his shoulder. Dean let out a little squeal. He heard Mom talking with Auntie Missouri. Had he been good? Did he eat? All the questions Mom always asked his caregiver. Dad crouched down. "Dean," his voice was quiet and gentle, "are you ready to meet your new brother?" Dean nodded and got as close as he could. "Meet your brother, Sam."
He barely registered Mom watching, barely took note of anything at all. As soon as green eyes met hazel the world turned to color. "He's beautiful." Dean sighed.
He felt a hand on his shoulder and looked up at Auntie Missouri, tears were in her eyes. "You two boys will have a stronger connection than any brothers I've known." She whispered to him. Mom and Dad had funny looks on their faces. "You take good care of your brother Dean Winchester."
Dean looked back at the boy in Dad's arms. "Don't worry Sammy. I'm going to take the best care of you. Promise."
The Impala roared through the night; Dean's foot hard on the gas. He would apologize to his baby later, make it right. Now though, now he was pushing her harder than he'd pushed her in years. Desperation fueled by the slowly failing colors of the world around him. Cas was beside him, one hand holding tight to the seat and the other clamped to Dean's thigh. It was a reassuring weight that only just kept him on this side of panic. "We'll get there Dean." He whispered in a continuing litany. "He'll be ok." It was almost a prayer on his angel's lips. Please Sammy, I'm coming. Hold on. Were his constant thoughts, tripping over themselves as he pushed the car to her limits and beyond.
They pulled up to the bunker only 20 minutes from when the colors had started to fade, colors linked to Sammy, to his soulmate. He barely had her in park, wrenching the keys from the ignition, when he leapt from her and bolted for the steal door that should be closed but wasn't. Oh god, oh god, oh god, went his internal monologue. His feet hit the stairs and he hardly touched them as he ran into the bunker. He could hear Cas behind him, crashing through just as recklessly, just as desperate.
The library was a mess, books everywhere and tables overturned. He searched frantically for Sam. "There Dean!" Cas pointed out the blood trail that lead out of the library and to the hall with their rooms. Together they followed it.
They rounded the corner that led to their rooms, and there he was. The only bit of color left in Dean's world was crumpled against the wall. He was shirtless, only wearing a pair of sleep pants, and angry red wounds covered his chest. Blood poured from them, bright red against his pale flesh. Dean slid to a stop on his knees next to his brother. "Oh god, oh god. Sammy!"
"D'n?" Sammy slurred, voice weak and lips coated with blood that was slowly changing from red to shades of grey. Hazel eyes searched, unseeing. Dean reached for his brother's face, smoothing hair back from his forehead. Sammy's eyes finally found Dean's; a smile curled the edge of his mouth. "Dean." He coughed weakly and blood spattered Dean's shirt. As if from far away, Dean could feel Cas' hand on his shoulder.
"Hang on Sammy. Just hang on. We're here. I've got you." Dean searched the wounds on his chest, trying to asses the damage, looking for a place to help. The hand on his shoulder tightened and he looked up into once-blue eyes. "Help him Cas. Please."
Cas looked between the brothers, searching, desperate. "I'm barely even an angel anymore Dean. I-" the angel shuddered and bowed his head, "I can't heal him."
"No!" Dean pulled Sammy to his chest, holding him like years before, like when he'd lost him the very first time. It would always hurt like this, like something had a grip on his heart and was squeezing. He couldn't live without his brother. He turned wild eyes on his angel. "I need him Cas. There's no me without him. Help me."
Cas looked up then, once-blue eyes filled with tears. "I can't Dean. There isn't enough of my grace left for this. I would burn through all of what's left to save him. You know I would. I would do anything for Sam, just as you-" Suddenly he cut off. His eyes widened and a look passed over his face that Dean knew well. Cas had an idea. An idea that was crazy, that would cost something. He waited for the angel to explain, but no warning was given except a curt "brace yourself", and then his hand was plunging into Dean's chest from the back.
Dean howled in pain, white hot agony filled him and his vision blanked out for a moment. He held tightly to his brother, the other piece of his soul, his world. When the pain stopped he saw the glow as it faded from Cas' eyes. Sam coughed against him and then his arms were tight around him. Cas crumpled to the floor, sagging and barely conscious.
"Cas?" Dean pulled Sammy away from himself as he reached for Cas. "Sam?" He pulled his brother back, torn between the two. Sam pulled back.
"I'm ok Dean. I'm ok. Is Cas?" He struggled out of Dean's arms and both brothers reached for Cas. Gently, they pulled the angel into a hug.
"Cas! You did it! You saved him/me!" They said together. Cas blinked owlishly. His skin was pale and he looked exhausted, but he was ok. He hugged the brothers tightly and they sat on the floor together for a long moment before Dean was brought back to the present.
"What attacked you Sam? Is it still in the bunker?" He held tight to the two most important things in his world and looked around, body held taut and ready to fight.
"It's gone Dean. Took off fast like it was spooked, out the front door. I was trying to get to my cell, left it in my room. You ran in just minutes after it left me, probably just missed passing it."
Dean shook his head and pulled Cas and Sam tighter to himself. It didn't matter. Another something to hunt. It would pay, whatever it was. They would hunt it down and destroy it, like they always did. Right now though the danger was passed. Right now he would simply hold tight to the two pieces of his soul, one of which he nearly lost. It didn't matter, because Dean Winchester's world was in color.