Bet your window's rolled down and your hair's pulled back

And I bet you got no idea you're going way too fast

Cas could close his eyes and picture the scene perfectly. He could see the way the Impala would be rolling down the highway, the window rolled down so Dean could embrace the cold night. He could picture the way the wind would rush into the car, blowing back Dean's hair. He could see, clearly, the way Dean's hands would rest across the steering wheel – almost lazily, as if he weren't thinking about driving anymore.

And he probably wasn't.

Castiel knew Dean – probably more than Dean would ever like to admit, because for some reason, Dean didn't like people to know him – and he knew that Dean would much rather speed down the highway (and he did mean speed; how had the Winchester boys lived for so long when they drove like that?) than think. Dean would rather speed down the highway than face reality.

Cas wished Dean would face reality. He knew it would be better for his friend – for the man he had come to care so deeply about – if he could just open his eyes and see the world. Dean saw darkness, and often times, that was all Dean could see. But there was so much more than darkness to the world; there was so much more than negativity on this wonderful earth that his father had created.

But, Cas had to admit, sometimes Dean had a point. Sometimes the darkness could be all consuming.

You're trying not to think about what went wrong

Trying not to stop 'til you get where you goin'

Cas wondered, for a brief moment, if Dean was thinking about their last moments together, before he scoffed at himself. Yes, Dean was thinking about it – it had not gone exactly to plan, and Cas knew that Dean would blame himself. He'd only wished that he'd had time to explain his own plan to Dean. Cas couldn't leave purgatory with his friend – not because he was an angel, but because Cas couldn't let himself go.

Cas had no right to return to Earth. He had to stay in purgatory because he owed a debt to the world. He had to pay his dues back to himself.

He just hadn't known how to tell Dean. He had come to accept that, from the time he had met Dean through the years to present day, he had come to love the man. He loved him like family – more than family, in some ways, he supposed. And family didn't hurt one another; that's why he didn't tell Dean. He knew that his decision would hurt, and hadn't known how to say the words.

But now that he had time to think – in purgatory, all he had was time, to think and to fight monsters – he had decided that he hadn't made the right decision.

He knew that Dean would be in the Impala, Sam next to him, but his mind would be stuck in purgatory. Dean had a tendency to blame himself for everything, and it would be the same with purgatory, trying to think about what he could have done differently in order to get Cas out safe as well.

Cas wished he wouldn't – though he knew that it was pointless. Dean would go on blaming himself and pretending he wasn't doing so; pretending that he was fine, that he was moving on, and that nothing was wrong. Dean should actually move on – accept that Cas had chosen purgatory, and gone on to what Dean did best: slay monsters.

Cas was glad that Dean never realized that he was a monster.

You're trying to stay awake so I bet you turn on the radio

And the song goes

Cas could remember one of the few times he had travelled with the Winchesters in the Impala. It had been a dark night – as all nights were – and he could feel exhaustion overcoming his vessel. Though Cas himself never felt the need to sleep, the vessel often felt tired – something Cas always ignored until it went away. And, even if he had felt any inclination to sleep, he doubted he would be able to.

Dean had turned up the radio so loud Cas could feel vibrations in the back seat. He found himself placing his hands flat against the seat to feel the vibrations against his skin. It was an odd sensation, but Cas found himself enjoying it.

Dean was also carelessly singing along with the radio – rather off tune, if Cas were to give an opinion – but Cas also found himself enjoying the singing. It was, really, the only time he had felt completely comfortable in an automobile – even if Sam's occasional snores did grate his nerves a little.

"Dean," Cas ventured as an advertisement came on the radio.

"Yeah, Cas?" Dean met his eyes in the rearview mirror. "What's up? Need to pee?"

"What? No." Cas shook his head. "What was that song?"

Dean just grinned. "That's my favourite."

I can't live without you, I can't live without you, baby

I can't live without you, I can't live without you, baby, baby

Cas was always in control. He was in control of himself and of his surroundings. He knew what was going on. He made his own decisions. He was independent – even in heaven, surrounded by his family, he had always been a freethinker. Being a free thinker had been what had landed him with the Winchesters in the first place. In the beginning, they had been a necessity; he needed to use them and they could use him.

It was a … business deal, of sorts. Both sides could benefit. Yet somewhere along the way (Cas couldn't pinpoint exactly when), it had stopped being a business deal. Somewhere along the way, Sam and Dean Winchester had become his family and he had come to love them.

It had been the only thing that had made him second-guess staying in purgatory. If he stayed here and paid for his sins, he would never see his family again. And what happened then? What would he do without his family?

The highway won't hold you tonight

The highway don't know you're alive

The highway don't care if you're all alone

But I do, I do.

Dean Winchester didn't dare close his eyes – didn't dare blink. Here he was, on yet another unforgiving strip of pavement, like the thousands of others he'd travelled before, with Sam sleeping in the passenger seat, his favourite song playing on the radio, Baby's engine purring as it always did, but something was wrong.

It was a typical scene – one Dean would have defined his life as. Once upon a time, it had only been junk food wrappers, weapons in the trunk, and a call to Bobby if Sam-the-encyclopedia fell through.

One day, a new, completely unexpected element had been added to his life – the life he reveled in; the life that, though it had caused more pain and heartache than any man should have to experience, was the life he wouldn't have dreamed of trading for anything else.

And that new element had been a self-righteous, pain-in-this-ass, wouldn't-have-known-a-damned-joke-if-it-had-bit-hi s-nose-off angel. Castiel (what a pretentious name; just like the pretentious ass butt) had angered Dean to no end – still did, matter of fact. But the difference was that it wasn't Castiel, it was Cas. Somehow, that made all of the difference in the world.

In the end, it hadn't even mattered.

No matter how far Dean stretched; no matter how hard he worked to keep his family happy, alive, and together, he always failed. He always let down the ones who were counting on him. Cas had been counting on Dean to get him out of purgatory. Dean had been counting on himself to get Cas out of purgatory. But he hadn't. Cas was rotting in that hell hole and Dean was never going to see him again.

He was never going to see Cas again – no one was.

Dean was grieving. He knew Sam was grieving too, but Sam was in denial. Sam didn't know the finality of purgatory; Sam didn't know of Dean's failure either.

But apart from Sam, and perhaps a few in heaven, no one noticed that Cas was gone. No one noticed that the world was literally missing an angel.

A pain-in-the-ass angel who deserved a hell of a lot better than Dean Winchester.

The highway won't dry your tears

The highway don't need you here

The highway don't care if you're coming home

But I do, I do.

Dean glanced at Sam. His brother had his face jammed against the window of the Impala, breath steaming against the glass. Sam was down for the count – understandable, as it was approaching four A.M. He envied Sam's ability to sleep. Dean couldn't sleep, not anymore.

He used to be able to before his mother died, before his father lost his mind, and before monsters became real. Now, sleep just served as a way to remind him of all that he had lost throughout the years and all of the people he had managed to fail.

The latest of which was Cas. Because of Dean, Cas would never return to Earth. Cas would never again sit in the back of the Impala, saying how angel travel was faster, and complaining about the volume of the radio. Cas would never again question him about the strange little lines painted on the black top, what they meant, and how fascinating it was that humans had managed to survive for so long.

"Dammit Cas," Dean muttered to himself, feeling tears begin to prick at his exhausted lids.

Dammit Cas. Dammit Cas, why couldn't you have grabbed my hand? Dammit Cas, why couldn't I have been better, stretched a little further, for you?

Dean hit the heel of his hand across the steering wheel, attempting to let out some of his frustrations. He laid his foot heavily across the gas, attempting to leave memories and thoughts behind – though Dean knew better. He couldn't just leave everything behind; he had been trying to leave the vast majority of his past behind for such a long time now. He knew that it wouldn't work. He knew that he would be haunted by the absence of Cas into the afterlife.

"Dammit Cas," Dean whispered, as though his angel friend could hear him. "I'm so sorry."

I bet you got a dead cell phone in your shotgun seat

Cas, though he had never had an affinity for human artifacts, found himself longing for a cell phone. He had hated using the things, preferring to simply travel to talk to the person face-to-face. When he had used cell phones, they had left him utterly confused, though Sam and Dean had taken great amusement in his helplessness.

Now, Cas wished he had a cell phone. He doubted he would be able to make a call from purgatory, but if he could just hold the object in his hand, push the buttons as Dean had impatiently taught him and bring up the … contact list. He'd had dozens of numbers in that contact list, all patiently programmed by Sam, though he'd really only had a few people to call – he'd had multiple alternate numbers for Sam and Dean.

If he had his cell phone in his hand right now, he would call every single number in that phone, waiting to hear a gruff "speak" from Dean or a "hello?" from Sam.

Then he had to wonder if he would get an answer at all. The Winchesters picked up new numbers more than any other human being and they hardly ever thought to charge their alternate cell phones – something that had more to do with the fact that they never had enough outlets in their seedy motel rooms to charge all of their phones than it did carelessness.

But Cas knew, that even if their cell phone had been dead when he called, he would get a call back the instant they saw his name. Dead cell phones – dead anything or not – they loved him too.

Yeah, I bet you're bending God's ear talking 'bout me.

Dean wondered what Cas would say to him, or about him, right now. Cas was the type of guy who forgave – the total opposite of Dean, who held onto grudges and pain.

Dean knew what Cas would do if they were face to face again – Cas would tell him that it wasn't his fault; Dean did all that he could; Dean shouldn't blame himself.

Dean, though, had to wonder what Cas didn't say aloud. In the deepest parts of his mind, as Cas prayed to his absent Father, what did Cas say? Would Cas ever curse him – say he wished that Dean were just a little bit better and had kept his word more often? Did he wish that Dean had been a little stronger; a little faster?

Dean doubted it. Cas was too good for that. It was something he had often picked on the angel for, but something he had, secretly, admired. Dean had spent his life surrounded by bad. To be so close to something so good was foreign, but, at the same time, intoxicating.

He knew that if Cas was talking to God about him, or even thinking about him, Cas would be thinking good things; things Dean didn't deserve to have thought about him. The only good quality Dean Winchester had was that when he loved people, he would protect them to the ends of the Earth. Cas, though, had never seemed to figure that out. Cas had seen goodness in him, even where Dean had never been able to see it.

If Cas were praying about Dean right now, Cas would be saying: keep Dean safe; don't let him dwell on this; let him live his life.

Cas was a selfless prick like that.

You're trying not to let the first tear fall out

Would Dean cry over him?

It was an errant thought. Cas thought it was a ridiculous question to pose – Dean Winchester didn't cry and he certainly didn't cry over angels that had decided to stay in purgatory; angels that had lied to him by omission.

That, however, didn't mean that Cas didn't shed a single tear – a product of sorrow overwhelming his vessel, he was sure – over what he had lost.

Trying not to think about turning around

Why the hell should he continue on, down the road, to some nowhere town with some routine monster to save some routine people who would never know he had done so? Why couldn't Dean just turn around, find his way back into purgatory (he was Dean f'ing Winchester and if he wanted a way into hell, goddammit, he'd find it) and get Cas out. The situation would be the same – purgatory wouldn't want his humanity there and would try to purge him.

Except this time he would have his angel with him.

Dean chewed on his lip and honestly thought about pulling the Impala into a U-turn, speeding off, and getting right down to business. But the logical side of him (he liked to call it the Sam side because it was this nagging voice in his head that sounded eerily like his little brother) reminded him that even if he were going to break into purgatory, he would have no way of doing so.

Maybe it would be better to do some under the table research – under the table as far as Sam was aware; Dean couldn't have his brother knowing about how he had failed Cas – and go back into purgatory with a plan. It sounded unlike Dean and his usual let's-bust-in-the-door-and-then-go-from-there attitude, but Dean wasn't as reckless as he once was. Contrary to popular belief, Sam wasn't the only Winchester who knew how to think.

Dean would gather a plan and then he would go back for Cas. Despite his aversion to have a plan, he had already let Cas down. His rescue, when it happened, would go perfectly. He would make sure of it.

You're trying not to get lost in the sound but that song is always on

So you sing along

Cas found himself humming. Perhaps a dangerous thing to be doing in purgatory, but for so long all he had heard were growls and threats from things coming to attack him. A bit of music was just what he needed in this moment and he was not going to deny himself this.

So Cas wandered, and he hummed. It wasn't until he had stopped humming – after attracting the attention of a vampire – that he realized he'd been humming Dean's favourite song.

I can't live without you, I can't live without you, baby

I can't live without I can't live without you baby, oh baby

"Stop looking at me like that, Sam," Dean growled as he closed the trunk to the Impala.

"Like what?" Sam asked innocently.

"Like you're worried about me."

"I am worried about you," Sam pointed out, leaning against the roof of the car. "Do you want me to drive?"

"No."

"You could sleep," Sam suggested.

"I don't need sleep," Dean grunted, dropping into the driver's seat.

Sam sighed before folding himself into the passenger seat. "You aren't yourself," he said as Dean gunned it for the highway.

"I'm who I've always been."

"You're angry."

"I'm always angry," Dean countered.

"Is this about Cas?"

Dean's eyes tightened with pain, but he didn't dignify Sam's question with an answer.

"You can talk to me you know," Sam pushed.

"There's nothing to talk about!" Dean flipped on the radio. "Get some sleep, Sammy."

Sam sighed again, but knew there was no arguing with Dean. He made himself comfortable in the seat, hoped that Dean would soon confide in him, and drifted off.

The highway won't hold you tonight

The highway don't know you're alive

The highway don't care if you're all alone

But I do, I do.

"Look at this," a nameless demon taunted, "A defenseless angel trapped in purgatory."

Cas knew he wasn't defenseless. He wondered how long it would take the demon to know the same thing.

The demon sneered, but Cas remained expressionless. Let the demon expend her energy on the offensive. As long as Cas was good on the defensive, he would be all right. He didn't need to waste energy in attacking first. He just needed to get the right blow in.

The demon lunged for him. Cas overestimated her height and missed his shot; he ended up clipping her in the collarbone while she tore down his neck. Cas felt his vessel's blood – hot and sticky against his neck, pouring down the collar of his coat.

The demon grinned, prancing away from their brief, battle's embrace. She stretched onto her toes before going for his neck again. Cas knew better this time and aimed his weapon in the right place. He turned away from the battle ground, continuing on into the depths of purgatory, feeling more alone than he ever had before.

Once, he had been used to loneliness. He had been used to feeling like an outcast – a rebellious angel, no longer welcome in heaven and an angel on earth, untrusted by humans. Though he knew he had to adjust to loneliness again, Cas didn't know if he could.

Though he would spend an eternity alone in purgatory, he would also have an eternity to remember what togetherness felt like. When he had left his family in heaven, he had missed them, but he had never quite felt lonely. That was, simply, because he hadn't learned how to embrace emotions – how to properly feel – until he was placed in a human vessel that felt deeply and he was confronted by humans that made him feel deeply.

He had an eternity to remember everything.

He also had an eternity to hypothesize about what was happening on Earth. And Cas knew, though exact time keeping was an impossibility in hell, that someday the day would come when he would have to hypothesize that Sam and Dean were dead like so many other humans before them.

Cas was, slightly, glad that he would never have to experience that. He would be able to convince himself that someday hadn't happened yet, and that Sam and Dean were just fine.

The highway won't dry your tears

The highway don't need you here

The highway don't care if you're coming home

But I do, I do.

"Look, man, I have to be blunt."

"Great," Dean rolled his eyes. He finished scrubbing monster blood off his hands and shut off the tap. "Can we pack up first? 'Cause I really want to get out of here before people find the corpse."

"Ah…good point," Sam conceded throwing errant clothes into a suitcase and grabbing scattered guns from around the hotel room. "Besides, talking in the car will be better."

Dean raised his eyebrows, hefting a bag over his shoulder. "Oh yeah? Why's that?"

"Because then you can't run away," Sam said with a sarcastic smile, gesturing for his older brother to walk out the door first.

"Heh," Dean retorted, pulling a childish face.

He sauntered to the Impala, throwing his bag into the trunk and waiting for Sam to do the same. Once everything was secure, he closed the trunk and found his way behind the wheel. He waited, rather apprehensively, for Sam to start talking. He had a feeling that Sam wanted to talk about purgatory – and by extension, Cas – something Dean had been closed mouthed about for months. He hadn't found a way back into purgatory yet to perform his rescue, but he was getting close and he didn't want Sam to find out about the plan and stop him from going back.

"Dean, I'm worried about you."

Dean didn't answer until he was merging onto the highway. Usually he preferred back roads, avoiding rush hour traffic – and there were no burger joints conveniently located along the side of the highway – but he thought that focusing on the traffic would be better than focusing on this conversation.

Sam tapped his foot impatiently, aware that Dean was avoiding him as much as he could in the closed confines of the car. "Dean?"

"You know, I think we've had this conversation before. I'm fine, Sammy. Don't worry about me."

"I'm your brother. That's kinda what I do. And, yeah, I've been worried about you ever since you came back from purgatory and told me Cas had died."

Died. Dean felt his throat close up at the lie. No, Cas wasn't dead, but he might as well be. Cut off from everything, battling monsters for eternity … Dean had doomed his friend to a fate worse than death.

"And I know it must have been an awful thing to see, but, Dean, please. Stop brooding."

"It's not brooding." Dean snapped.

"Fine, mourning, whatever. I miss him too, miss him like hell. But damn, Dean. We've lost people before. This isn't your fault."

Oh, but it was his fault. He had doomed Cas to purgatory, just like before him, he had doomed Jo to die. Dean hurt everyone who cared about him.

And he knew that once he brought Cas back home, he would have to say his goodbyes – Dean couldn't continue to hurt Cas.

I can't live without you, I can't live without you, baby

I can't live without I can't live without you, baby, oh baby

One moment, Cas was in purgatory still trying to come to terms with that fact, even though he had consciously made the decision to stay. The next moment, Cas was back on Earth. He was not sure how. He was not sure why. Yet he found himself not caring about the particulars. It didn't matter why he was back on Earth, it only mattered that he was.

And now he had some people to find.

He closed his eyes and willed himself to Dean, like he had so many times in the past. He felt himself flicker and he opened his eyes. For a brief moment, he was on a different road, the Impala speeding past him. He saw Dean and Sam fly by for a brief second – saw Dean's incredulous eyes flash up to the rearview mirror as though to see if it were really him – before Cas felt himself being pulled away from that road.

He was back to where he had started, panting. He felt weak: his time in purgatory must have done a harsh number on his body. His powers weren't fully there.

Never mind; he would just have to keep trying.

The highway don't care

The highway don't care

The highway don't care

But I do, I do.

Dean fought to keep his jaw from dropping. He fought to keep from slamming on the brakes. He fought to keep himself under control.

Because that couldn't have been Cas casually walking along the side the road in the middle of nowhere. It just couldn't have been. If Cas were back, he wouldn't be travelling along a road like a homeless man. He would come back to Dean.

Unless … unless Dean had been wrong.

Unless Cas hadn't forgiven him.

No, Dean told himself, that wasn't Cas.

That had been the first sign of Dean Winchester completely losing his mind.

He was just glad Sam hadn't noticed … yet.

So, Dean drove on and tried not think of the Cas-mirage tromping along as the Impala soared on by. He tried not think of Cas in hell. And he tried not think of the justice in the fact that it was Cas haunting him now.

I can't live without you, I can't live without you, baby

I can't live without I can't live without you, baby, oh baby

This time when Cas closed his eyes and willed himself to Dean, he didn't find himself staring at Dean through a mirror (though that had been heart-wrenching and confusing). He knew, as he travelled this time, that he would finally come face to face again with Dean and Sam.

He would finally return to his family.

I can't live without you, I can't live without you, baby

I don't own anything recognizable. Thanks to my beta: bethanyyerinn. The song is Highway Don't Care by Tim McGraw and Taylor Swift.

~TLL~