In 10.09 "The Things We Left Behind," Castiel explains to Claire that a human soul can only inhabit a body as long as it maintains "a certain structural integrity." However, despite having been disintegrated by Raphael at the end of Season 4, we know Jimmy is still in there during Season 5. So rather than write that off as a continuity error, I came up with this.

Chained to a Comet

I once told those Winchester boys that being possessed by an angel was kind of like being chained to a comet. It's all light and power and force and inevitability, and all you can do is hold on as you're dragged along for the ride. It's blinding, it's paralyzing. But I learned pretty soon that if I focused, I could get a pretty good sense of what was going on, what Castiel was doing while he wore my body like a suit.

Of course, I learned almost as quickly that most of the time, I didn't really want to know. So I just kind of retreated into a corner of my own mind and let the angel do his thing.

I couldn't shut everything out entirely, though. So when I overheard something about an archangel, I was curious—and when I realized Castiel was actually afraid, I figured I ought to pay attention.

But no sooner did I poke my head out, so to speak, than everything became a blaze of light. And when my vision cleared… it was like waking up. I found myself in what looked like it might be somebody's living room, except it was covered in blood. Blood, and little chunks of—well, you get the idea. And I was me, alone, in full control.

And then I realized that the blood and… stuff… splattered all over the place was… also me.

Before that could sink in, though, I became aware of someone else in the room with me. A woman, keeping a respectful distance and smiling tenderly but insistently. "Hello, Jimmy," she said.

"Who are you?" I asked—more like demanded. "Where's Castiel?"

"Castiel is gone," she said, as if speaking to a child. "The archangel smote and killed him." She stared me directly in the eye. "And you."

I took a deep breath and forced myself to look around. "Yeah. I gathered." I swallowed hard. "So, are you an angel, too? What happens now?"

She laughed gently. "I'm not an angel, Jimmy. I'm a Reaper. And I'm here to take you home."

My breath caught in my throat. "Home? You mean…"

"I can't normally tell souls where I'm taking them," said the Reaper, "but you were an angel's vessel. You died in the service of Heaven. And so I'm allowed to tell you: that's where you're going."

Somewhat to my surprise, that wasn't as cheerful a thought as I'd always assumed it would be. All I could think about was my family. "What about Claire?" I asked. "And Amelia?"

The Reaper nodded sympathetically. "They will mourn, and they will move on. You needn't worry about them anymore. They loved you and you loved them, and now it's time to let them go."

Oh, it was hard. It was really hard, to not insist that I be allowed to say goodbye. But I knew it wouldn't make a difference. Finally, I said, "Okay."

She took my hand, and everything faded away.

I was surrounded by white light. It wasn't hard and burning like the wrath of the archangel; this time it was soft, peaceful, even comforting. And there was a Voice.

It wasn't something I could hear, per se. There weren't words as such. But I had the distinct impression of someone saying, "It isn't time. There is still work to do."

And then, just like that, I was back. Whole, alive, massively confused… and riding shotgun to an equally baffled Castiel.

Honestly, at first I wasn't sure I hadn't just dreamed the whole thing. Castiel assured me, though, that we had indeed died, and he suspected God Himself had resurrected us. To help the Winchesters stop the Apocalypse.

I know. Trust me, spend enough time around those guys, and your definition of "crazy" gets all kinds of screwed up.

So I let Castiel take the wheel again, and if I thought the previous year was weird, well, the next one was completely bananas. I kept a closer eye on what was happening this time, so by the time Michael and Lucifer—yep, that Michael and Lucifer—squared off in Stull Cemetery, I thought I was ready for whatever would happen next.

Then Castiel had to go and get involved. (Have you ever heard an angel try to swear, by the way? It's hilarious.) He's got a major soft spot for the Winchesters, you see, and Lucifer was possessing one of them—Sam. So Cas was trying to keep the fight from happening in the first place. And… it got us killed. Again.

Well, there was nothing I could do about it, so I didn't bother arguing with the Reaper. Just shook my head and went into the light.

What happened next made me want to scream.

The Voice—God?—wanted to send us back. Again.

So I shouted as loud as I could. "Wait!"

And nothing happened. The Voice went silent. And the light didn't fade.

God was listening.

"What do you need me for?" I asked.

It was Castiel who answered, back from the dead once again. "I need a vessel if I am to continue my mission. Finding another could be difficult, especially since I presume you would object to my asking Claire."

"You leave my little girl alone!" I growled. "Look, you need a body? Take mine. I'm done with it. But do you really need me along for the ride?"

Castiel fell silent. I don't think the idea had occurred to him.

I addressed the Voice this time. "Can't I stay here? Haven't I earned a rest?"

There was a long pause, then Castiel said, "Are you certain this is what you want?"

"Yes," I answered. "Just… look out for Claire and Amelia, all right? Keep them safe. You promised me once, and I'm still holding you to it."

"I'll… do my best," he said quietly.

So that's how I ended up here. Castiel is down there on Earth somewhere, probably helping Sam and Dean save it for the umpteenth time. And I… I'm free. And I've been waiting for you.

I've missed you so much, Amelia. But we're home now.