He'd known it for some time now. It started when his feathers started falling out.

He hadn't told Dean. He hadn't told anyone. It was just something that was inevitable, at this point, and there was no stopping it. Logic told him that it didn't matter if people knew or not. He'd still be dying either way.

Emotions told him differently.

He was, undeniably, human - at least a little bit. Enough to know better than to keep a secret. But then, when he thought about telling Dean, he couldn't. He'd open his mouth and no sound would come out.

He almost told Dean once, but Dean was intent on asking him for another favour first.

But now there wasn't much time left. He didn't intend on telling Dean, but he wanted to say goodbye.

He used the remnants of his power to teleport to Bobby's house. Slumped over, he straightened his posture and walked to the living room, where Dean was sitting.

Dean looked up and half-jumped. "Jesus, Cas. I thought we talked about this."

Castiel swallowed.

Dean looked back down at the newspaper he'd been reading. After a moment, he looked back up. "Well?"

Castiel blinked. "W...what?" he stammered, pale.

"Well you aren't just swinging by to shoot the breeze, are you chatty Cathy?" Dean asked sarcastically.

Who was Cathy?

Castiel closed his eyes. More of Dean's stupid, hostile banter. He didn't want it to be like this. It didn't have to be like this.

Dean frowned slightly. "Hey, you OK?"

Castiel used a hand to lean on a bookshelf and opened his eyes. No. No, he wasn't "OK". He was dying. He was...this was it.

"Yes," he said.

Dean was silent.

"Dean," Castiel continued, hesitating. He didn't know what to say. "I want to give you something."

"What, another 'gift from God'?" Dean scoffed. "Not interested."

Castiel closed his eyes again. "No," he said simply. He stepped forward, stumbling a bit. Dean stood up uneasily and put a hand on his shoulder, steadying him.

Castiel put a hand in his trenchcoat and pulled out a vial. Inside was a silvery-white, glowing substance. Dean stared.

"It's my grace," Castiel said roughly.

Dean's eyes widened. "Cas, what the fuck?"

"I won't need it anymore."

"What? Cas-"

Castiel gripped Dean's shoulder, placing his hand where he knew the handprint scar was.

"That way, I'll always be with you."

Dean gripped Castiel tighter, trying to hold him up. He was yelling a stream of expletives, mixed with questions and calls for help as Cas sank down onto his knees.

Castiel didn't understand what was happening anymore. He could hardly see straight, but he suddenly found his eyes lost in Dean's own green ones. He felt a strange sensation in his face.

He smiled for the first and last time.