Let Go

When Castiel finally found him, he feared he was already too late.

The man stood alone in a wasteland of death and destruction. The ground was strewn with bodies that had been hacked and slashed apart. The earth was stained red with the blood of the slain.

No demon had survived the massacre. Every last one of them had perished in one man's war against Hell. Even Abbadon lay dead at his feet.

It was over, then. Hell wasn't closed, it was empty. The world was that little bit safer. They had victory at last.

But at what cost?

Each of those demons had been possessing an innocent human. When they died, their vessels died also. How many fathers, mothers, brothers, children, had lost their lives here today?

Many of the souls in Hell had not yet mutated into monsters. But they had been purged with the rest.

Every war had casualties, Castiel knew. Collateral damage was unfortunate, but unavoidable. He grieved for those who had perished, but believed they were going on to a better place.

His true concern was for Dean.

The last man standing on Hell's final battlefield, he looked more lost and alone than Castiel had ever seen him.

Nothing left to fight, nothing left to kill.

Everything had been building up to this moment, and now there was nothing.

All he had was a Blade in his hand, and a Mark branded into his skin.

He was covered in blood that was not his own, and he was shaking.

Castiel approached cautiously.

"Dean."

Dead eyes stared sightlessly past him.

Black eyes.

"Dean."

The shaking stopped. One by one, every muscle in Dean's body tensed with anticipation. Every fibre of his being exuded the raw, unadulterated power of a man born and trained and unafraid to kill.

Black eyes fixed on the intruder, and a feral grin began to curve his lips.

The Mark glowed.

"I am not here to fight you, Dean."

A flicker of uncertainty.

This close, Castiel could see the white-knuckled grip Dean had on the handle of his weapon. Every moment of contact was pumping poison into his veins.

"I'm here to help you."

Dean stared at him without recognition or comprehension. He was already so far gone.

Castiel wondered if Dean even knew his own name.

"Dean… If you had only talked to me sooner, I could have told you about Cain and the deal he made with Lucifer. I could have warned you about the Mark and what it would do to you. I could have stopped you before you ever laid a hand on the First Blade. I could have prevented this."

But that was exactly why Dean hadn't told him. He held no value for his own life unless he was using it to save other people. Hunting wasn't just a job for him, it was his life. His purpose. He would sacrifice everything for the cause. He would even forfeit his own soul.

He thought everything was his responsibility. He believed he was the one who had to fix it all.

Even if Castiel had been given the chance to warn him, Dean wouldn't have listened.

He would have said killing Abbadon was worth it.

But seeing Dean now, so far from the man who had laughed at an angel in a brothel, Castiel felt that the cost was too high.

They were losing Dean. They were losing the man who loved pie, the man who sang off key, the man who treated his car like a beloved child, the man who held onto hope when there was none, the man who pushed through the pain, the man who never gave up on family, the man who always strove to do what was right, the man who did everything out of love. The Righteous Man with the most beautiful soul Castiel had ever seen.

The Mark was corrupting him. Polluting his goodness, burning away everything that made him who he was. Leaving nothing but a killer in his place.

"Dean? Tell me there is still some part of you in there. Tell me I am not too late."

Dean did not answer, but he had not made an attempt to kill Cas either. If he were truly lost, there would be no differentiating between friend and foe. He would not have stopped when the demons were dead. He would have gone on to find more flesh to sink his blade into.

Castiel chose to have hope.

"Listen to me very carefully, Dean. You need to let go of the First Blade."

Dean took a hasty step back, the blade coming up defensively.

"I am not going to hurt you," Castiel soothed. "Just let the blade go, just for a moment. Prove to yourself that you can."

Dean looked down at the jagged bone clutched so tightly in his hand. "Mine. Birthright."

The Winchester brothers, descended from the bloodline of Cain and Abel. To suit their own purposes, the angels believed it was Dean's destiny to become Michael's vessel and kill Lucifer. But maybe every road in Dean's life led here. Maybe he was always going to follow in Cain's footsteps.

Castiel knew where this path would take him.

Killing one's own brother. Castiel would never believe Dean was capable of killing Sam, but, in light of Sam's death wish, all of a sudden it became an alarming possibility. If Dean did it, if he sent Sam's soul to Heaven – to the eternal peace Sam was ready to embrace – the transformation would be complete. Dean would be a full-blooded demon. He would be a Knight of Hell, the first of a new order. He would raise a new generation of demon, and in a few millennia demons would once again terrorise the Earth.

"The Blade has served its purpose, Dean. You killed Abbadon, you destroyed the demons, and you vanquished Hell. Your job here is done. You can let go now."

Dean's gaze fell on the Knight lying dead at his feet. "I… killed the bitch."

"Yes, you did. It's over, Dean."

Dean shook his head. "I need… I need…"

"That is the Blade talking. Its thirst for blood will never be sated, no matter how many you kill. You need to put it down. Trust me, those urges will fade. Just let go."

Dean looked at the Blade, then turned helpless eyes on the angel. "I can't."

"Then let me help you."

Dean wavered.

Castiel took a step forward.

Dean went from docile to hostile in an instant, his Blade slashing towards the angel with deadly intent.

Supernatural reflexes saved his life. He vanished from the physical plane, allowing the blade to pass through where he had been standing a split-second before, then reappeared a moment later. Before the hunter could come around for a second attack, Castiel caught Dean's wrists.

"Stop! You don't want to do this Dean. You don't want to hurt me."

Dean struggled in his grip, but Castiel held firm.

"Let go, Dean. Drop the Blade before you do something you will regret."

Dean snarled, gnashing his teeth at him, bucking and kicking and twisting for all he was worth. Castiel drew on every ounce of strength and Grace he had to hold the almost-demon at bay.

"Calm down, Dean. I am not the one hurting you. It is the First Blade. It is poisoning you. You have to let it go!"

"No!"

Dean jerked one hand free and slammed a fist into Castiel's jaw. Cas recoiled but didn't dare release the wrist he now held in a death grip. If Dean regained use of his right arm, Castiel would be dead before he hit the ground.

"Dean-"

The fist flew again, cracking violently across his nose. Blood spurted everywhere. Dean punched him again. And again.

But Castiel wouldn't let go.

"Fight it, Dean! I know you can fight it! You are stronger than this!"

He could feel skin splitting, bones crunching, internal blood vessels bursting, but he would not relent. Not for his own sake. Castiel did not fear death. He feared what his death would do to Dean when he came back to himself. If he ever came back to himself.

He thought about Cain, and what it had taken to convince the Father of Murder to put down his Blade.

Collette.

How had Cain phrased it? She loved me unconditionally.

And if loving Dean when he was covered in blood, when his eyes were black, when he was trying to beat Castiel to death with his bare hands wasn't unconditional love, nothing was.

But for Dean Winchester, one word was even more powerful than love. Love was frightening, taboo, weakness. Feelings of love were never admitted out loud. But Dean's first priority, his primary motivator, the most important thing in his life was-

"Family, Dean. You said that we were family."

Dean froze.

Stared at him, wide-eyed, as though seeing him properly for the first time.

"C-Cas?"

"It is me, Dean. I'm right here."

"Cas?"

"I'm here, Dean. I'm here, and I'm not going anywhere. I promise."

Dean began to tremble. "C-Cas- I didn't- I couldn't-"

Guessing the cause of Dean's distress, Castiel drew on his Grace to heal his injuries. "I am fine, Dean. But I am worried about you."

"I-"

"You're not okay, Dean. You need to let go of the Blade."

Dean's eyes fixed on the weapon in his hand. A look of intense concentration spread across his face. His entire arm shook. One finger peeled away-

"I can't!" he gasped, reflexively tightening his grip on the blade as though it was a lifeline. "I can't. I'm not strong enough."

Castiel had heard those words before. "Yes you are, Dean," he said quietly. "I believe in you. You can do this. You can let it go."

He tried again, straining to release the blade. But, as if in retaliation, the Mark on his arm burned an angry red, and he sagged in Castiel's grip. "No," he panted. "I can't. I need it. It is a part of me now."

"This Blade is keeping you away from your family, Dean! You know you can't go anywhere near Sam with that bloodlust pumping through your veins. You hurt me. You'll hurt him. You'll hurt innocent people, and I know you don't want that. You have to let go!"

"But-"

"Drop it, Dean!"

Dean gasped, his hand springing open of its own accord. The Blade fell to the ground with a dull thud.

Without hesitation Castiel snatched up the cursed weapon and vanished with it, taking it back where it belonged – the bottom of the deepest ocean. He made sure it was buried deep, and then dumped two hundred tonnes of rock on top of it to be certain.

When he returned, Dean was in a crumpled heap on the ground, sobbing hoarsely.

Castiel's heart wrenched. He knelt down beside his hunter and gently tilted his chin up. "Dean…"

The eyes that looked up at him were no longer the soulless black of a demon. They were green, but awash with tears. "Cas? You- you came back?"

Castiel smiled a little. He had finally learned the human custom for emotional reunions – he wrapped his arms around Dean and pulled him in close, embracing him tightly.

He whispered a single word in Dean's ear. "Always."

ooOOoo

A/N: There it is, folks. Cas saves Dean, just like he always has and always will. I am considering continuing this with Cas helping Dean through withdrawal… thoughts? Thanks for reading, I hope you enjoyed! Remember reviews are love :)