Previously on Supernatural...

For one brief, glorious moment, Baby's body shone like some sort of flaming beacon. Then the arcs retracted, her glowing skin winked out, and she dropped onto the scarred, blackened, broken concrete floor with an anticlimactic thump.

After using so much power protecting the Winchesters from the ritual's magical fallout, Castiel had barely enough energy to transport Sam and Dean back to the motel. He warded the small room from angels and demons alike, healed the worst of the brothers' injuries, and then went back to the warehouse to get Baby. He couldn't run the risk of disrupting whatever the ritual had done to her, so he physically carried her six miles back to the room. Once all his charges were in one room, Castiel settled in to regain his strength and wait.

After twelve hours with no change, he figured it was safe to step out for a quick supply run. He returned two hours later to find Baby sitting outside the motel room, freshly showered and wearing her tattered leather jacket over clean clothes. "Hey Cas," she said softly, her silver eyes watching the clouds above with childlike fascination.

"Hello Baby." Castiel sat beside her, setting down the six-pack, sandwiches, and container of pie he'd bought. "You haven't changed back," he quietly observed. "Did the spell - "

"No." She sounded...resigned. And tired. Very, very tired. "It's not holding."

"I see." He turned his gaze skyward as well. "How much longer do you have?"

"Maybe sunset, if I'm careful."

"Should I wake - "

"No!" Baby cupped her belly, wincing from her forceful objection. "No, don't wake them. It won't make this any easier for any of us." She forced a smile as she looked into his eyes. "Will you...will you promise to do something for me?"

"Of course," he replied. "What?"

"I'll tell you when I come back." She stood up shakily and slowly made her way down the sidewalk. Castiel could see how difficult even that movement was for the Impala. He watched her go until she turned the corner, then re-entered the motel room to check on the Winchesters.

She returned an hour before sunset. Her internal injuries were clearly worsening, judging from her labored breathing and the black smoke that now continuously poured from her mouth like a dragon's breath. Instead of entering the room, Baby lingered at the doorway and beckoned for Castiel to join her. He shuffled outside, and together they sat on the concrete step in front of the motel room. For several minutes they said nothing, not even looking at each other, watching the sun slowly descend towards the horizon and paint the western sky with beautiful shades of purple and red and orange.

It was halfway beneath the lip of the earth when Castiel finally broke the silence. "What did you want me to do?"

"You're doing it." She reached over and slipped her hand into his. "I - I just don't want to be alone at the end."

Unsure of how to respond, but fully aware of how much his presence was needed, Castiel said nothing. He merely nodded and squeezed her hand gently, turning his eyes to watch the sun set. When her head tilted to rest on his shoulder as the last rays of daylight vanished, still he said nothing. Even when her human body faded away and the Impala reappeared in the parking spot, Castiel said nothing. He merely stayed outside, with her, all night.

He had promised, after all.

Watching his brother tinker on the Impala from the door, Sam sighed. Dean had spent every waking minute since yesterday morning under Baby's hood with a wrench and screwdriver. He wouldn't even let Sam help with the repairs, only stopping to catch fifteen-minute naps and harass the local garages for the parts needed to rebuild Baby's engine. He'd said that after all she'd been through, Baby deserved the extra time for him to fix her up right.

But Sam knew it was because he was hoping...praying...that fixing Baby would let her change back.

"Hey." He was jolted out of his thoughts by Dean's curt tone. The older Winchester wiped his hands on a greasy rag. "She's up and running. I'm gonna catch a shower and then we can blow this one-horse town." The disappointment was clear in his eyes, like someone had shattered his favorite toy in front of him and he couldn't put it back together.

"Dean - " Sam began, but Dean pushed past and limped into the bathroom for a shower. Blowing out another sigh, Sam let his eyes return to Baby's patched frame. He could still remember waking up the previous morning, stepping out into the weak morning light and seeing Baby parked in her space, looking like she'd been driven through a firefight during a road rally. He'd looked back to see Dean leaning against the doorway for support, green eyes focused on the bullet-ridden car for a full minute, before he'd limped out and rested a hand on her hood. He'd mumbled something too softly to be heard, then turned around and gotten dressed and started the long process of fixing her.

"Can't you see he's hurting, Baby?" If there was any chance that her soul had survived being ripped out and stuffed back into her body, maybe she could hear him. "Do something," Sam whispered to the car. "Please. Anything." When nothing happened, he shook his head. What was I thinking? We're never that lucky.

He was packing their duffel bags twenty minutes later when a familiar flapping sound preceded the words, "She's still there."

Sam whirled around to see the trenchcoat-clad angel suddenly standing in the doorway, looking out at the Impala. "She's okay?" he confirmed.

"She's resting now, like a tree slumbering in winter." Castiel never took his eyes off the car. "Her soul has been badly damaged, but is intact."

"Then why hasn't she changed back?"

"The spell that allowed her to transform is no more. She could not even if she wanted to."

"But if there is a way..." Sam couldn't help the hope in his voice. After everything that had happened in his life, you'd think he'd have learned by now to not hope for the impossible. But impossible things happened with alarming frequency around the Winchesters, and he felt it was time for Fate to give them a break. "Could she?"

Castiel shrugged uncertainly. "I do not know. Perhaps one day, she could." He stepped outside, but when Sam rushed after him, Castiel was already gone. He shook his head and heaved an exasperated sigh. Thanks a lot, Cas.

"Excuse me." A man suddenly walked up to the door and pulled out a clipboard. "Is there a Dean Winchester here?"

Immediately cautious, Sam's eyes narrowed. "Why?"

"Delivery from Picture Perfect Photos." The messenger held out a thick manila envelope. "A girl came by two days ago and placed an order for rush delivery. Said her boyfriend was leaving town today, and she wanted to make sure he got it before pulling out."

Thanking the messenger, Sam took the envelope and examined it. He had no idea why a girl would send pictures to Dean, since he'd made no effort to get to know anyone in Valence. The only girl they'd known at all was... "Was her name Paula?"

The man consulted his clipboard. "Yeah. Paula Campbell." He nodded a farewell and headed off, leaving Sam with his mouth agape in shock.

"Sam?" He looked up to see his brother standing in the bathroom threshold, clad in jeans with a damp towel hanging around his shoulders from the shower he'd just stepped out of. When his eyes landed on the envelope, he couldn't fake any interest when he asked, "What is it?"

"It's for you." Sam held out the envelope and added, "It's from Baby."

Sudden energy flared to life in Dean's eyes, and he quickly crossed the room and took the envelope from his brother. With a quick flick of his knife he sliced open the envelope and extracted a single glossy photo. Sam grabbed a folded piece of paper as it fluttered out and opened it carefully. Seeing it addressed to Dean, he handed the paper to his brother and said, "Take your time. I'll put the bags in the trunk and wait for you."

Dean heard Sam speaking, heard him grab their bags and leave the room, but he didn't really hear him. Tucking the photo behind the letter, he flipped open the single typed sheet and sat on the bed to read.

To Dean -

By the time you get this, I'll be back to myself again. I'm sorry for not waking you up before I change back, but I knew it'd only hurt us both. Now you can fix me up good as new. Couldn't do that with my meatsuit, could ya?

What happened to me is not your fault. I'm a Winchester after all, and we've a long family history of heroically sacrificing ourselves for each other. I did what I did knowing that I was going to save you, so that you and Sammy could live to hunt another day.

Remember, I'm not really gone. I'm always with you and Sammy, every mile we head down the highway or some back-country road, every hotel and motel you pull into, every moment we have the sky above our heads and the asphalt in front, behind and beneath us. I'm right there with you two, just like I always have been. Just like I always will be.

These past few days, I've had the chance to experience so many amazing things. I've left you something to remember them as I will - as the best time of my life.

I will always love you both.

Baby

A tear slipped from his eye and plopped onto the paper. Dean quickly swiped the liquid off before it smudged the ink, then folded the letter and carefully put it in his pocket. The back of the photograph had the words For my Dean, remember to smile clearly written beside a date he recognized as the day before yesterday's. Flipping it over, he stared like a blind man suddenly granted sight.

The photographer had obviously caught Baby after she'd raked her hair back from her face, judging by how her hand was resting on her neck and her hair was slightly ruffled. The smile she had was a soft and secret thing, but with an edge that gave her expression a hint of spunk. Her eyes sparkled like polished silver and held such a look of love that made his heart clench.

Dean kept his eyes on the photo as he headed out to join Sam. His brother looked over as he slid behind the wheel. "You good?"

"Yeah." Dean slipped the photo into his sun visor and gripped the wheel tightly with both hands. Reading her letter had given Dean some sort of closure. And like Baby had pointed out, it wasn't as if she was really gone. She was still here with them, and she always would be. And now, he had something to remember her by. "Yeah, I'm good."

"You sure?"

"Yeah." His smile reappeared as he put the key in the ignition. "How about you, Baby? Ready to go?" When Baby's engine turned over and rumbled to life, he chuckled in relief. "All right. Let's go home."

Smiling as well, Sam switched the radio on to let music filter through the speakers.

Ooh, the wheel in the sky keeps on turnin'
I don't know where I'll be tomorrow
Wheel in the sky keeps on turnin'
Whooa, my my my my my...for tomorrow

And...ROLL CREDITS!

Thank you all for sticking around! I'm thinking of writing a sequal to this, but I'm not entirely sure yet. If you want to input ideas, send a PM or review!

But review anyway! I'd love to know what you thought of this!