A/N: This is my first (completed) multi-chapter fic. I'm pretty excited! Let me know what you think :)

Lost Without You

Chapter One

A fierce battle raged within him.

Independent thought and free will grappled with centuries lived in unquestioning obedience to the orders of Heaven. His desire to help the humans fought against the drive to complete his objective. The deep-seated trust he had in two stalwart hunters struggled against the instinct to eliminate any threat to the Angel tablet. Belief in the Winchesters combated the blind faith he had been taught to have in his superiors. Emotions battered against the cold, ruthless nature of a Hammer of God.

And a frantic pulse of Dean, Dean, Dean, DEAN thundered through his veins, trying desperately to drown out the order shrieking in his head to kill him, Castiel, kill him now!

Months of brainwashing had conditioned Castiel to obey. Years of friendship screamed at him not to. The opposing wills were slashing, clawing, tearing at each other, ripping him apart.

The agonising pain brought on by doubt, confusion, hesitation and disobedience could only be relieved by the brutal collision of his fist with flesh and bone, and even then only for a moment. He kept pounding mercilessly as he felt bones shatter, skin split and blood gush over his knuckles. A flailing, fighting limb was snapped as easily as a toothpick, twisted and held tight to restrain his victim. The man was pinned, trapped, helpless.

But Castiel couldn't deliver the killing blow. Not with green eyes staring up at him from a face battered, bruised and barely recognisable, filled with the hurt of betrayal, fearful and pleading. He knew those eyes.

Dean.

Naomi sensed his hesitation, tried to drag his attention back to the task she had assigned him. Bring me the tablet!

Dean, his mind repeated stubbornly. Dean, Dean, Dean.

Kill him!

De-

KILL HIM!

He wasn't strong enough to fight it. He could feel his resistance crumbling, stone walls of courage and will tumbling to dust and ruin. Under Naomi's training and tutelage he had already killed Dean over and over and over; what was once more?

He stood towering over the human, powerful like he had not been since he surrendered the souls from Purgatory. If he did this, he would be welcomed back to Heaven as a hero. He just had to squash this one little ant. One ant. It was nothing. Dean was nothing.

"Cas. Cas." It was a tortured wheeze, choked with blood. "I know you're in there. I know you can hear me."

His words were meaningless. Castiel held the blade poised, ready to end this man's existence once and for all.

"Cas, it's me." His unbroken arm was raised in supplication, reaching for him, pleading.

Castiel was stoic, unmoved. He knew what had to be done.

"We're family."

He almost wavered, but he knew the human was just trying to manipulate him. The angels were his family. He was doing this for them.

"We need you."

Emotion jolted in his chest. No – but… the angels needed him more. Didn't they?

"…I need you."

The world stopped. The noise stopped. The chaos and confusion and doubt and madness – it all stopped.

In that moment, there was only Cas and Dean and three words that meant everything.

I need you.

Something roared to life within him, burning through the haze in his mind and the veil Naomi had drawn over his eyes.

He saw Dean, really saw him.

The Righteous Man who had sacrificed everything for his brother. The human who had almost lost his humanity in the pit. The broken soul immersed in darkness that had cowered from the light but then embraced salvation when it was offered. The damaged body Castiel had made whole. The wounded hunter who never gave up the fight. The man who had shown him the difference between right and wrong and taught him to screw destiny in favour of forging his own path.

Dean was the one who helped Castiel pick up the pieces after he Fell. Dean gave him hope and purpose and someone to believe in. Dean made him feel like he belonged. Dean laughed at his lack of social skills, but patiently showed him how to navigate the strange complexities of the human world. Dean kept him accountable for his actions, pulling him back from the brink time and again. When he screwed up so badly that he thought there could be no redemption, Dean forgave him. Dean searched for him in Purgatory even after Castiel had abandoned him. Dean tried his best to save him, even when he didn't want to be saved. He always tried to save him.

Somehow, everything Castiel needed was personified in this one man. He depended on Dean like no other, and Dean bore that burden without reluctance or complaint. It meant a great deal to him, and Castiel was beyond grateful.

But for Dean to admit that he needed Castiel as well… that meant everything.

"Cas."

Three letters. One syllable. Castiel's nickname, given to him by Dean as a token of friendship and a symbol of camaraderie.

It broke the dam.

His grip slackened. The sword fell, clattering on the stone floor.

There might have been a glimmer of relief in Dean's eyes but, as adrenaline receded and as he pulled his injured arm away, it was swiftly overwhelmed by raw agony. Dean curled in on himself with a moan, bloodied and broken by Castiel's own hand.

Castiel couldn't bear to look at him, to see what he had done.

In his desperation to be distracted from the pain he had caused, he became aware of a strange thudding sound, reverberating in his head. There was a drum beat nearby. It called to him.

Instinctively, Castiel looked to the tablet. No longer the objective of his Heaven-ordained mission, it was all the more captivating. Reaching for it was only natural. Touching it swept away the last vestiges of Naomi's mind control in a flood of white light, leaving Castiel free at last.

The knowledge brought him no comfort. If anything, the guilt weighed heavier.

He could feel that he was expected to protect the tablet, but all he could think about was the man kneeling before him. Though Dean teetered on the precipice of unconsciousness, he wouldn't let go. He was still wary of Castiel's intentions. Still afraid.

Castiel had nearly killed him.

He needed to make this right.

He reached out to heal the injuries he had inflicted –

Only for Dean's head to be jerked out of his reach, baring his throat to the sharp blade of an Angel sword.

"Naomi!" Castiel gasped. She had materialised behind Dean and seized him within the blink of an eye, too fast for Castiel to do anything to stop her.

"You disobedient child," Naomi snarled, yanking on a fistful of Dean's hair to crane his neck back further. He made a choked sound and tried to reach up with his good hand to break her hold, but she dug the tip of the sword in deeper, drawing blood. Her attention was all on Castiel, though, cold eyes boring into his. "Why do you never do as you are told?"

"Let him go."

"No. It is clear that this pathetic human is the only way to get through to you." She dragged the blade lightly across Dean's throat, a thin line of blood spilling in its wake.

Terror shot through him. People were fragile – Dean was fragile. One deep slash would kill him, and Naomi had enough power to make sure his death was permanent. "Stop!" he begged. "Don't hurt him!"

"You have already done that, Castiel. And I will finish the job, unless-"

"Unless what?" In his desperation to save Dean, he was willing to offer anything.

"Unless you hand over the tablet. Right now."

Startled, Castiel looked down at the stone he still had cradled to his chest. He had almost forgotten about it, but now the steady drum beat grew louder in his mind, urging him to protect the tablet at all costs.

His gaze was dragged inexorably back to Dean. Green eyes were begging Castiel – not to save him, he realised, but to keep the tablet from falling into Heaven's hands.

Castiel was torn.

"Castiel!" Naomi snapped. "The tablet. Now."

"A-a-ah, sweetheart," a voice drawled. Crowley appeared in the doorway, dragging a bloodied Sam into the room by his hair and dumping him unceremoniously on the floor. The demon dusted his hands and flashed a charming grin. "You're not the only one with a bargaining chip, Naomi dearest."

"Crowley," Naomi sneered. Dean strained to see what was going on and Naomi yanked his head back harder in punishment. He grunted with pain but she ignored him. "You risk much by coming here, demon."

"Actually, I think I'm pretty safe. There is an army of demons swarming into this building as we speak. Besides, you've got your hands full with that one."

"The tablet is ours!"

"Well now, that's up to our little nerd angel. What do you say, Castiel?" Crowley said. "I'll trade you the Moose for the tablet."

"Sam?" At the mention of his brother Dean resumed his frantic struggles against Naomi's hold, scratching up his neck further in the process. Blood dripped liberally from his wounds, but the jugular had not been severed. Yet. Dean seemed heedless of the danger. "Sam! Sammy, answer me!"

Sam groaned, stirring faintly. Crowley pressed a boot down on his neck, pinning him to the floor. "Down, boy," he smirked. "Don't fret, Squirrel, I haven't hurt him. Much."

"You bastard! Let my brother go, or so help me-"

Crowley tsked, shaking his head. "Dean, Dean, Dean. You are hardly in a position to be making threats. I am afraid this one isn't up to you. This is all on your boyfriend. So what'll it be, Castiel?"

Castiel looked helplessly between the two brothers. His responsibility to the tablet demanded that he vanish now, abandoning the Winchesters to their fate. Dean's love for his brother demanded that he trade the tablet for Sam. His duty to Heaven demanded that he keep the tablet from falling into enemy hands. His fear for Earth's future if the angels gained even more power demanded he take the tablet as far away from Heaven's reach as possible.

But his heart…

"Tick tock, Castiel," Crowley taunted. "You have ten seconds before I break Sammy's neck."

"Cas, please," Dean begged. "My brother-"

"No, Castiel! If Crowley gets the tablet he will destroy all of us. Give it to me."

"If you do that, Sam dies. 8 seconds."

"If you don't, Dean dies!"

"Let them go!"

"5 seconds."

"You cannot betray Heaven again. Too many of your brethren have already died by your hand, Castiel! Give me the tablet and you may yet redeem yourself!"

"No, Cas. Save Sam. Please. You owe me that much. Don't let the bastard kill my baby brother. Please."

"2 seconds."

"Cas!"

There was raw desperation in Dean's voice. Castiel knew that Dean had lived his entire life protecting his brother. All he had worked for, all he wanted was for Sam to be safe and happy. He would give anything. He would die for him.

Dean was right. Castiel owed him. And he would do anything, anything for Dean.

Decision made, Castiel moved to pass the tablet to Crowley.

"I'll kill him, Castiel!" Naomi screeched. Her eyes were wild. Mad. She wasn't bluffing.

Even as Crowley stretched out a hand to grasp the stone, the muscles in Naomi's arm bunched, preparing for the killing thrust through Dean's chin up into his skull.

Dean was going to die.

In that instant, all reason and logic fled.

Castiel flung the tablet at Naomi, forcing her to drop the sword in order to catch it. Not pausing to hear Crowley's roar of fury or to see Naomi's expression of triumph, Castiel lurched forward and slapped his palm firmly against Dean's forehead.

"Cas-"

Angel and human vanished.

ooOOoo