Author's Note: Extremely mild trigger warnings again, although there is nothing that wasn't already covered in the last chapter.

Welcome to the world of extremely depressed and guilty Castiel.

I do not own Supernatural.

May 2

ONE MONTH LATER

Castiel was aware of two changes. First, he was aware that Lucifer once more had complete control. For three weeks, Lucifer had gone in and out of consciousness… but now he appeared to be back, and even more upset than usual.

The second change was that Castiel could feel his father. God. For the first time in his long life, Castiel felt the undeniable presence of the nearness of his father's light. It was wonderful to feel, a fantastic reassurance. It was the first time since Lucifer had taken over his vessel nearly four months ago that Castiel felt a sense of happiness, a sense of hope. He hadn't felt Ember's presence or the Demon Blood Bond for nearly a month now, by his estimate… and God was somehow back.

And suddenly, Lucifer was once again pushed to the back of his mind. This time, however, unlike the other times, Castiel realized that Lucifer had willingly relinquished control.

When Castiel looked around, he saw his father, for the first time. It was Heaven to look upon him, and his light was pure warmth. "Father," Castiel said reverently.

"My son," said God, and he was smiling. Then he said, "Someone wants to talk to you."

Castiel could already feel Ember's nearness, just on the other side of the door. His heart swooped with guilt, and something else.

"Ember," he said immediately, opening the door. He felt when he looked at her as though he was starved for her. He had been so worried…

His guilt felt like a punch to the gut, stronger now than ever before. He couldn't believe she could even stand to look at him. What he had done to her was unforgiveable. "I'm so sorry," he said heavily. "I had no idea. I tried-…"

"Cas, I'm sorry," she said, and he could tell she was holding back tears. "I never should've said any of those things when you were just-…"

He was horrified. She was sorry? But she had nothing to be sorry for… "You were a demon," he insisted. "Because of me. I should've checked, I should've thought…"

"Cas, it's not your fault," she insisted again. "How are you?"

Castiel looked at his feet. He wished he could kiss her, wished he could be with her, wished he could comfort her. But he'd done quite enough already. He couldn't even bear to look at her anymore. "I'm doing what I can, to save the world."

Ember's eyes began to fill with tears, and she reached for him, but he shrank back. He couldn't stand to think about what he had done to her. And it didn't matter, because he could already feel Lucifer nudging him gently, asking for the reigns. It would be fine, now… his father was here. "I'm sorry, Ember," Castiel said one last time. Then he relinquished control, this time painlessly.

~ANGELS WILL FALL~

While his father was around, Lucifer was somewhat more lenient regarding allowing Castiel to see what was happening. Ember, Dean, Sam, Crowley, Rowena, Charlie, his Father, and Lucifer were slowly going about recruiting everyone they could for the final fight against Amara.

Lucifer's job was to recruit the angels in Heaven, however Heaven was less than happy to see him. "I came here to ask a good-faith favor of you folks, but as you are clearly less than kindly disposed, perhaps you'll, uh, lend an ear to my very own Jiminy Cricket," Lucifer told them, ushering Castiel forward.

It was the first time Castiel had been in Heaven since he had broken out Metatron. "Hello, brothers. Sisters," he said warily.

"Castiel?" asked Caraheal.

"It's me," he said.

"Do you think we see any daylight between you and the Adversary?" snapped Achobald.

"I understand," said Castiel, guilt clawing at him like cold hands. "But Lucifer and the Winchesters have found our father. But he needs our help to fight Amara. I have seen him myself." Castiel understood why Lucifer had asked him to come forward. Lucifer had a reputation for being "The Deceiver," "The Lord of Lies." Castiel had a reputation for loving humans too much, for having too much tolerance, and for being impulsive and disobedient - but he also had a reputation for being honorable and a kind Commander.

"Let's hear it from Him," snapped Achobald.

"In good time," said Castiel. "Do I have your support?"

"I can't even look at you, Castiel. You have befouled yourself with the Deceiver."

"You know, every second that I've spent subordinating myself to Lucifer, it's been a torment," said Castiel honestly. "It's destroying me. It's burning through my vessel. But through me, he and God, they will defeat the Darkness. That's my role in this fight. It's God's fight. You can play a part in that fight too, if you join me."

And they did.

May 3

The big fight with Amara was over.

They had lost.

The witches, demons, angels, Lucifer, and God had all fought her, and they had all lost.

But at least Lucifer was gone, blown out – or, dare he hope, killed – by Amara.

It was the first time Castiel had been himself in months. Now there would be people who would want him to answer for his time as Lucifer. Dean and Sam would want to know why he made the decision to allow Lucifer to possess him, and what he planned to do if Lucifer hadn't been killed in the battle against Amara.

And Ember… At least with Dean's Demon Bond, the two of them had been equal in power. They'd each had free will. But the demon bond with Lucifer… how had such a thing even happened? Surely she must blame him! He should have known, should have thought about the possibility. He'd known Lucifer created the demons. He should've known Lucifer would know how to pervert an angel and create a blood bond… He would never forget, as long as he lived, the sight of her black eyes. "Stop holding back! You did this to me, again, at least enjoy it! We can be together again… sort of…"

He had closed the door on their relationship when he thought he was dying, but as soon as both of them realized that he wasn't dying, it felt as though the door had somehow opened again. As much as he had tried to avoid her after their kiss, he had secretly hoped that somehow, miraculously, she still loved him. She had been with Dean at the time, but perhaps someday she would have made a different choice, a choice that would have allowed them to be together, if the fates aligned. Now, though, after everything that had happened between them, the door was closed forever. He had caused her nothing but pain, and what little apology he had been able to give her would never make up for the damage he had caused.

All things considered, it occurred to Castiel that he was almost, almost relieved it was the end of the world.

~ANGELS WILL FALL~

"How are you doing?" Dean asked from his seat in the front of the Impala. "You good? I mean, you know, the whole Lucifer thing."

Castiel was far from "good." He wondered if there was enough liquor in the liquor store they were headed toward for an angel to get drunk. It was the end of the world, after all, which meant that he wouldn't have to worry about the hangover.

"I was just... so stupid," he said.

"No, no, no. It wasn't stupid. You were right. You were right to let Lucifer ride shotgun.

Me and Sam wouldn't have done that," said Dean.

"Well, it didn't work," said Castiel. "And Ember-…"

"Will be fine," Dean finished. "There was no way of knowing about the Demon Blood Bond."

Castiel's head whipped around. "Do you know what happened?" he asked imploringly. "How-…"

"Crowley told Ember that the Demon Blood Bond was only called a Demon Blood Bond because angels are too pompous and stuck up to use that method of conversion," said Dean casually.

Of course. Finally, it clunked into place. Just as he had been too short-sighed to realize that Ember's demon attraction issues applied to both demons and angels, he had been too short-sighed to realize that angels could form blood bonds as well. He had, yet again, fallen ill to the elitism that plagued angels, the elitism that had ultimately been the downfall of angels like Raphael and Michael.

He was so stupid – and Ember had paid the price.

"Cas, there was no way you could've known," Dean said. "I know you would never have hurt her. But Lucifer…it was our best shot, and you stepped up," Dean continued.

"I was just trying to help," Castiel said miserably.

"Well, and you do help, Cas."

"You know, I—…"

"You're the best friend we've ever had," Dean interrupted. "You know that?"

Castiel looked at him in shock. "You're not… angry with me?"

"We've both done a bunch of stupid shit," Dean said, shaking his head. "But at the end of the day, nobody's ever been there for me like you, and Sam, and Ember. You're our brother, Cas. I want you to know that."

"Thank you," Castiel said, touched. He felt somehow that this meant far more to him than when he referred to another angel as "brother" or "sister."

Dean's cell phone rang. "Yo," he said, answering it. "All right. We're on our way."

"Sam's got something," Dean said, hanging up the phone. Castiel heard the tires screech as Dean turned around the Impala to head back to the bunker.

~ANGELS WILL FALL~

They had a plan. God had said that Amara's weakness was light, which made sense, really. They were going to end her. They had everything they would need, theoretically. Billie the Reaper had even shown up, and provided thousands of souls, which had been harnessed into a bomb.

"So what now?" asked Castiel, after shooting Ember another furtive glance. Neither of them had tried to speak to the other yet, but Castiel could feel her eyes on him when his back was turned. Likewise, his eyes were drawn to her each time she was looking somewhere else.

"Well, now we have the bomb, so we just have to find Amara," said Sam.

"I can track her," said his father. "She's not warded anymore. Why would she be? She won."

"Okay, so?" asked Dean.

Castiel didn't want to say what he was thinking, but he had to. "We need somebody to get close to her, someone with a … personal connection," he said finally.

"Dean, no," said Ember, and Castiel felt jealously flare up within him as well as a rising panic.

But they all knew it had to be Dean. The connection forged by the Mark of Cain would cause Amara to allow Dean to get closer than any of the others. Rowena and Crowley were raising their eyebrow at Dean, waiting for his answer. Ember was looking horrified but resolute. Even Sam swallowed hard.

~ANGELS WILL FALL~

Before he died, Dean had one request: to go to the grave of Mary Winchester, his dead mother.

Castiel was the first to say good-bye, and he caught Dean in a hug. "I could go with you," he offered.

Dean looked at Ember, just briefly, and Castiel followed his gaze. When they made eye contact, however, Castiel looked away once more. "No, no, no," Dean said. "No, I gotta do this alone."

"Cas… she loves you," Dean whispered, leaning in closer. "Take care of her." Castiel's eyebrows furrowed together in shock, but he recovered quickly. He glanced at Ember once more, and nodded, wishing that this was even a possibility.

"Thank you for everything," Dean said to Castiel, louder this time.

Then Dean turned and addressed the group. "Okay, look. I want a big funeral," he said. "All right? I'm talking epic. Okay? Open bar, choir, Sabbath cover band, and Gary Busey reading the eulogy."

"Done," said Sam, while Ember nodded. Tears were streaming down her face.

"And for my ashes, I like it here," Dean continued, looking near to tears. "Yeah. You know, as far as eternal resting places go."

He moved closer to Ember, nodding at her. "Ember," he said, and reached to hug her, but she kissed him fiercely instead.

Dean pulled back, surprised. "I'm sorry for everything, Dean," she said. "I'm sorry it didn't work out like we'd wanted. But I love you…"

"I love you too," he whispered into her ear. "I always have, and… I always will, even if that love is different now. I'm sorry I couldn't be better, couldn't be everything you wanted."

"Dean…" she said, but he shushed her with another soft kiss.

Castiel's stomach clenched with jealousy, even though he was ashamed of feeling this way. They hadn't touched nearly as much as they used to when they'd gotten back together, and Castiel had appreciated this. He looked away, feeling like an intruder on this most private of moments between lovers.

Dean reached into his pocket, then, and took out the keys to the Impala. He hesitated for a moment, as if collecting himself, and walked over to Sam. Sam shook his head, with tears in his eyes. The two men talked softly for a moment, then hugged. This hug lasted longer than either of the other two goodbyes - a hug between brothers.

Finally, Dean let go, and already he seemed miles away. He gave one last determined look at the group. "Let's do this," he said.

Chuck snapped his fingers, and Dean was gone.

~ANGELS WILL FALL~

Somehow, the six of them – Sam, Ember, Castiel, Rowena, Crowley, and his father – had found their way to a bar called "The Lazy Shag." The bar was closed, but Crowley had opened it anyway. It seemed fitting, somehow, here at the end of all things.

Crowley and Rowena were sitting at the bar companionably, taking lazy drinks. Sam was speaking in hushed voices with God in the corner. With horror, Castiel realized that Ember was approaching him, for the first time since Lucifer had left his vessel.

It was just as he thought – she was looking at him differently. Once she had been his best friend's girlfriend. Then she was his girlfriend, and afterward there had still been something between them, whether it was a hope, or a wish… Now, she looked at him with trepidation, and there was terror in her eyes. He could tell she had steeled herself before even approaching him.

"Ember, I'm so, so, so sorry," he told her. "I never thought there could be a demon bond between us, and it never even occurred to me that Lucifer would pervert-…"

"Cas, you told me that already," Ember said, calmly. "And I already told you, it's not your fault." She swallowed hard. "Look, if we survive this… I think I'm gonna take a break from the whole hunting thing. You know, with Dean gone, and all, I think it's just best if I sort of… lied low and took some time to heal."

It was just as he'd thought. Ember never wanted to see him again. "It's not your fault," she said again, seeing the upset look on his face. "And I don't blame you, or anything like that. It's just… I think I need some… space. You know, a quiet life. For awhile."

Castiel understood. It was better this way. His presence had only made things difficult for Ember and Dean as a couple, ever since Castiel had been with her. And now Dean was probably going to die, and he had saddled Ember with a horrible blood bond… it was probably better this way. He felt a horrible weight settle in his stomach.

Suddenly, Sam cried, "Chuck!"

God had disappeared.

A few minutes later, the sun returned to the sky, and they knew it was over.

Dean had done it! The world was saved.

And Dean was gone. And Ember never wanted to see him again.