A/N: Wow, thank you everyone for the enthusiastic responses and for the workable criticisms! I hope I can live up to the hype...

Anyway, this is the first chapter of Part 2, and I really hope you'll stick with me on this one. This part is the thing that started the whole story, and I've got it planned all the way through to the end, so... Go team reviewers? Keep me honest?

Disclaimer: I still don't own anything related to Supernatural.

...

Dean,

If you're reading this, my plan actually worked. You won't be seeing me for another nine months, and I'm sure Lisa has already explained the particulars to you. I can only hope you don't hate me.

I know I should have talked to you about this, but I was terrified you would say no. And, Dean, you're always telling me I should look out for myself and make my own choices. So this is me looking out for myself.

Not many people get the chance to start over again, but I just might get to. I'm still an angel, and I can still Fall—the big Fall, not like the falling I've been doing since the day I met you. I can become a human, but that means starting over from the very beginning.

If I did this, I have only one shot, one lifetime, to get it right. And I'll need someone there to teach me. That's where you come in.

I know this is a lot to ask of you, and I wouldn't ask you if I didn't think you could do it. But Dean, I'm not going to remember anything. I'll need you to tell me stories of Castiel the angel. Don't just tell me the good parts, either. Tell me all the mistakes I made—once you think I'm old enough to handle it, of course—and tell me the truth about what's out there.

That's another thing. Dean, I meant it when I said I wanted to be a hunter. It's the only thing I can think to do to help people, to atone for what I did. And don't tell me you don't want to put me through that. Don't say you're not putting me through that life. I can just picture your face. You'll get upset and tell me that you're not going to ruin this brand new life of mine. Thing is, Dean, I'm not sure if just living a good life is going to be enough to save me from Hell. I need something more. I need to be a hero—I need to be like you.

So I'm sorry for getting Lisa and Ben involved in this, but I had to be sure you would stick around once I stopped being an angel. It had to be you. You have to be the one to get me through this life. You're the only one I trust to do it right.

I hope I can help, though. I hear parents say that they wish they had an instruction manual for raising children, so I left you my best approximation of one here. It'll be different raising a fallen angel. I've given you as many warnings as I could, but I'm sure you'll be able to figure most of it out on your own.

I'll see you in a few months. And, if we do this right, I'll also see you in Heaven when this is all over.

~Castiel

…..

Dean paced outside the room. Ben was sitting out there with him, and Sam was on the way; he had been driving all night. Sam was supposed to be there, but early labor . . . .

He wasn't ready for this. He so was not ready for this.

He hadn't ever asked for a family; he had known he could never have one. He hadn't been there when Ben was born; he had just sort of jumped into semi-fatherhood without getting through the hard parts. He'd changed a diaper and put a baby to bed before, but that had been, what, one day?

"Dean, would you relax?" Ben said, but he was grinning ear to ear.

It hadn't been easy these last nine months. He'd fought hard to keep Ben and Lisa out. He tried every plan he could come up with. He thought maybe he'd just check in. It would be like it was before, when he called if he was close, but he promised himself he would never come if he was down, if he was dangerous, and especially not if he was drunk.

But the more pregnant she got, the harder it was to leave, especially the closer the due date approached. There was a little baby angel in there, and he couldn't just leave Cas. So he established a home base. He moved back in, stayed in Texas and drove from Lisa's place to wherever he was needed on a job. And he tried to ignore the fact that Ben was researching on his own, that Ben could salt the doors and windows, that Ben knew (at least in theory) how to kill anything that came their way.

Thing was, he wasn't as needed anymore. There were monsters, sure, but no demons. No plots to take over the world. And there was still a price on his head, and that sure kept him on his toes, but the monsters had learned not to get close to his family. The ones that tried were scattered in pieces across the entire state of Texas.

Benny had moved in, too, just to help out (Ben had taken to calling him "Uncle Benny," and Benny just ate it up. He was already planning the kid's Christmas presents). Benny liked the area, and he'd been looking for a place to settle in. He figured if he was going to be branded as a friend of the Winchesters for the rest of his life, he might as well embrace it. They made a good team; Benny looked out for the family for the nights—full-time when Dean was on a hunting trip—and Dean kept a steady watch during the day. Nothing was going to happen to Lisa or Ben. He was not going to make the same mistake twice.

And Cas had helped. The instruction manual was more than just a guide to raising an angel baby; it was like Cas's hunting journal. In the "Pregnancy" section, he had listed all the things that might go wrong with not only the physical pregnancy but the supernatural dangers Crowley might send their way. There were spells, summonings, chants, curses, talismans, everything Cas could think of.

The door opened, and a nurse poked her head out. She found Dean and crossed the waiting room. "Are you Dean Winchester?"

He nodded. It was weird; he had never been this scared before.

"You can go in now."

It was ridiculous how nervous he was. He slipped inside, and there she was, lying there so covered in sweat that she just glowed. She looked perfect, happy. She was smiling down at a little bundle in her arms.

He came around the side of the bed to look at him. Little baby Cas. Dean couldn't help beaming at him. He even had a little tuft of black hair on the top of his head. (Cas admitted to him that he had saved just an ounce of energy for one last miracle—a transfusion of Jimmy Novak DNA; he'd gotten used to looking that way.)

"He's amazing," he said. He reached down and squeezed Lisa's shoulder. "You did good, Lis."

She looked tired when she glanced up at him and put her hand over his. "Next time a friend of yours asks me a favor, remind me to say no."

Ben poked his head in through the door next. He grinned when he saw Dean and Lisa holding hands, but his smile got even bigger when he saw baby Cas. "Hey, that's him?" he asked, leaning down. "Can I hold him?" He looked up at the nurses for confirmation. They nodded.

"Watch his head," Dean said. (He couldn't believe he had actually said that out loud.)

But he shouldn't have worried. Ben was great with Cas. He cradled Cas into the nook of his arm, looking down at him with a face Dean had seen before. It was the face of a proud big brother. "Just you wait, Cas," he said. (Cas just stared up at him with wide eyes, almost unblinking, like he was just trying to take everything in at once.) "Just you wait until I get to take you on your first hunting trip. Or when I teach you to drive the Impala."

"Hey, wait a sec—"

"Right, cuz Cas is the only one who gets to be a hunter." Ben rolled his eyes. They had this argument before, and Dean lost. It was hard to keep telling Ben that he couldn't be a hunter when Cas had asked him to raise him in the life, and Ben was irreversibly part of that life now, too. "Give me some credit, Dean. I'll be a good big brother. I've got a good example." He looked back down at Cas and bounced him around. "You'll be my Sammy. Sound fun?"

Cas just stared at him with big, wide, blue eyes. Freakin' adorable.

"Do you want to hold him?" Ben asked.

Dean faltered. Of course he did. Of course he wanted to hold him. He was going to be taking care of this kid for the rest of his life.

But this was Cas. This was the angel who got him through everything these past few years, who saved his life and taught him more about being human than even he had realized. And now he was someone different, and holding Cas in his arms, changing his diapers—that would be like admitting that the old Cas was gone.

But he couldn't stop it as Ben handed him over, and Dean took the little bundle in his arms. "Hey," he said quietly, and he was surprised when his voice stopped in his throat. "Hey there, kiddo. Welcome back to the world."

Baby Cas looked up at him with those same big eyes, but this time, something lit up behind those eyes. He made some gurgly noises—Dean could only hope they were happy gurgly noises—and closed his eyes, turning his face towards Dean to snuggle in closer. Even as a baby, Cas felt safe with Dean.

Dean almost cried—he really did. Yep, this was the same old Cas. Still curious, still trusting. "Hey, Cas. You ready for this?"

Cas was falling asleep now, so he probably didn't care what Dean said.

"He likes you," Ben observed.

"Of course he does!" Dean tried not to sound so offended; he knew Ben meant well. But this was Cas; how could he not like Dean?

Cas was asleep by the time Dean handed him back to Lisa, and the nurses ushered them out of the room, insisting that both mother and baby needed their rest. But when they emerged, Ben and Dean were grinning so broadly that Sam—who had by now reached the waiting room—actually had to stop and laugh at them both.

"How's he holding up?" Sam asked, but he was talking to Ben. Ever since Cas shoved them into being a family, Sam had become the uncle Dean never knew he wanted to be. He and Ben were already masters at playing pranks on Dean, and they were officially his least favorite team.

"You should have seen him," Ben laughed. "You'd have thought he was the one going into labor, the way he was driving the Impala."

"I bet he started humming Metallica?"

Ben laughed again. "Yeah, he said it keeps him calm."

"Ridiculous, isn't he?"

Dean rolled his eyes. "Okay, you two. Cut it out."

Sam looked up at his big brother and grinned. "Hey, Dean," he said.

"Heya Sammy. Glad you could make it." He was at his brother's side in two strides, wrapping his arms around Sam's overlarge frame. Since Lisa's announcement, they had seen less and less of each other as Sam went searching for a way to get rid of Crowley—and, by extension, Crowley's contract on the Winchesters—and he had been hunting on his own in the meantime.

"You look awful," Sam said.

"I could say the same to you," Dean shot back. "Did you just crawl up out of the sewers?"

"I did try to shower before I came here." Sam looked embarrassed, so Dean didn't press him for more details.

"Hey, Sam," Ben said, tugging at Sam's sleeve. "What were you hunting this time?"

Sam glanced over at his brother for confirmation. Ben loved to hear hunting stories, and he was always begging Sam to take him along for the ride one of these days. (Dean wouldn't hear of it. If anyone was taking Ben, it would be Dean, and it would be an easy hunt. Ben was still going to go to at least apply to colleges, too, but Ben had made Dean swear that, when he turned eighteen, he would let Ben choose what he wanted to do with the rest of his life.)

Dean sighed one of his "I suppose you can if you have to" sighs, and Sam grinned, taking Ben under one massive arm and leading him aside to tell him about the ghouls in Massachusetts.