Dean Winchester hated landings. Not only because all the credit went to the pilot plotting a course rather than the guys in charge of maintaining the ship and ensuring no one on board died a horrible death should the engines overload or the shields fail, but because despite his protests the ship's shields would almost inevitably get turned off on landing to consume energy. Space ships were designed for space, not for regular flight; they weren't designed for sand or mud or rain, and if anyone bothered to take a look at the comparative costs of repair work after a standard landing to the costs of keeping a shield running they would agree.

Dean was unfortunately familiar with having his voice of reason ignored. Half the reason he'd asked for assignment to the Impala was so he could keep an eye on Sam, make sure his studies into alien diseases didn't end with his contracting any of them.

The other half, admittedly, was the ship herself.

The Impala was a beauty; a little old, yes, and the main reason she'd been equipped for exploration rather than left in the Milky Way system for commercial work was because she was unfashionably angular in design. Curveless she might be, but any engineer who knew their stuff salivated at the thought of her. They couldn't help it; she was a natural born survivor and yes, she was expensive to maintain and temperamental with it, but she'd yet to lose anyone on board through any fault of her own. Dean planned on keeping that slate clean.

.

Their current mission suited that goal nicely; yes, the planet had its own share of wars going on, but at least these guys were pre-nuclear. Hell, pre-explosions in general, which Dean approved of thoroughly though he did sometimes wonder why they'd yet to find an alien civilisation that didn't either function as a single-mind entity or have spent the major part of its history at war. Some were at peace or mostly at peace these days, but the records so far showed the longest peaceful period enjoyed by any race they'd come across to date was nine millennia - impressive, sure, but a tad depressing in the infinite scheme of things.

The dominant two on this particular planet didn't seem to mind being observed, likely because the guys and girls taking notes and snapping photos gave off that whole herbivore vibe by running for it whenever the creatures under observation tried to approach them. Andy and Sarah in particular leant that theory legitimacy by being vegetarian.

There was also the fact that the winged guys in the forest seemed to have a real, real hate-on for the desert lot. A 12th century crusade sort of hate-on. Either way, it meant alien darts stayed aimed at alien flesh instead of his baby, and Dean couldn't honestly claim to be interested in interspecies politics beyond whether or not it was likely to incur damage to the Impala or any of the occupants with sense enough to stay on board.

.

Dean liked to think he could be forgiven his reacting less than positively to the news that a member of the winged forest brigade was going to become one of those occupants.

Of course, he didn't get any say - it was for the Captain and anyone with medical qualifications beyond first aid to decide who got to come on board and who didn't - but while Dean had been helping keep the ship's air filters from cooking there had been 'an incident'. Said 'incident' happened to involve a forest alien giving Sarah a near-fatal leg piercing, thankfully by arrow rather than poison-tipped dart, and refusing to leave even after carrying her back to the ship. Dean appreciated the sentiment, but as far as he was concerned letting it on board was overkill.

After muttering something to the effect of "don't let me say 'I told you so'" Dean opted to wipe his hands clean and sulk in the engineering bay. He might not like letting any of the apprentices on board touch the ship's equipment, but truth be told he knew full well they could do their jobs, and sulking was more effective if you could force the people you were sulking at to come to you.

.

Dean should have known things would take a turn for the ridiculous once his brother got involved. The research scientists on board, a few botanists aside, had their heads screwed on; they kept their guest under observation, took samples when they needed them, and kept it sedated.

Sam, on the other hand, had always been a sucker for hopeless cases. Sarah too, and when she wasn't taking advantage of her injury to make insinuations about Sam's bedside manner she was happy to show their guest how she was healing up. Dean might have expected Sam to be a bit pissier about having his girlfriend flash her thigh to an alien every other day, but no, everyone seemed quite content to enjoy their alien love-in and completely ignore Dean's own misgivings about the situation.

Even more annoying was how bunking with the ship's doctor didn't get him any inside gossip on their guest. Sam would just wander in, flick through a few images and reports on his digipad, occasionally say "Huh", and then lock everything down before Dean could take a look.

Hell, the closest he got to an answer out of Sam was "Actually, they - wait, what? No! It's - patient confidentiality, Dean!"

Trying the "It's an alien, dude," argument on Sam would have been an exercise in failure even before the laws about all conscious beings, intelligent or otherwise, came into effect. Hell, Dean would probably get an earful about "We're the aliens here" for his trouble. Didn't stop Sam eating meat though, the hypocrite.

.

Dean was a man who enjoyed his music. Not necessarily anyone else's music - generally speaking if it didn't have at least one guitar in it, electric or otherwise, he wasn't touching it - but there were classics for a reason. Sam thought it hilarious that Dean's mind was stuck in the twenty-first century or earlier, but Sam listened to modern power ballads and had all the taste of a fourteen year old girl.

It was more than a little disconcerting that his first meeting with their resident alien involved walking into the cargo bay to pick up his CD player and speakers before the thieving bastards he called apprentices could do any damage to the antiques - sure, it was a good sign that they could appreciate the music, but you were meant to ask before borrowing something like that - and finding it growling away to Rammstein.

"Hey," Dean said, part wanting to run and yell for the scientists to pick up their stray, but mostly finding curiosity kicking in and wanting to know why in particular their guest liked Rammstein.

And, judging by the shriek and series of agitated twitters it let out before pressing the skip button, it really didn't like Led Zeppelin.

Metallica seemed okay though.

"Hey," Dean repeated, closer now and keeping his eyes firmly on the alien's face given the medical room gown had ridden up while it was squatting and Dean didn't want to think too closely about what he'd seen beyond how it implied his friend here was either male or both. That was the main problem with aliens - they looked alien. It'd be nice if once in a while they ran into Vulcans or Romulans or whatever people once thought aliens might look like but no, real aliens liked to look all too much like amoebas or the offspring of elephants and chimpanzees. Castiel's race at least had the bonus of easily identifiable faces and torsos.

They were also apparently capable of working out how to use the skip button. Huh. "You like rock music too, then?"

The alien finally seemed to register Dean then, standing up and standing up some more - Dean didn't really trust anything organic that was taller than him, Sam included, six foot two being more than tall enough for any intelligent creature - before holding out his hand. "Cassssstiel," he said with apparent difficulty, and Dean winced. Any poor bastard given a barely pronounceable name by Anna, the ship's communications officer and part-time chaplain, deserved sympathy.

"Hi Cas. Name's Dean."

"Namesssdean -"

"No, just - Dean. Dean," he repeated, kicking himself. When he'd been assigned to the Indefatigable six years back they'd tried to give him diplomacy lessons, but his tutor's migraines claimed victory and he'd been put back to working instead of talking inside three weeks.

"Dean," Castiel repeated, thin lips pursed. "Dean."

"Yeah, glad we got that cleared up," Dean said before shaking Castiel's hand and letting it go. "Look, this is great and all but I should be getting back to work -"

"Work," Castiel said, narrowing all four eyes before he turned his head and spat on the floor.

"Gotta say, I agree," Dean replied, looking around before dragging a bench over given chairs weren't going to do Castiel's wings any favours. "Wait here."

Castiel nodded, staring all the while Dean opened up the main ventilation grid and pulled out the filter, sitting it on top of the same table as the CD-player. Technically the filter didn't need cleaning out for another week, but at least it meant he looked busy if anyone intended on checking in.

Castiel didn't like Muse or Ozzy either, but Iron Butterfly passed muster.

.

Apparently getting to have something resembling a conversation about real music was a bigger delight than Dean had consciously thought, given how pissed he felt when what had been a surprisingly pleasant afternoon ended up interrupted by Castiel gripping Dean's shoulder and arm with both right hands and standing up to face two irritated scientists and one anxious guard.

"Castiel," Zack cautioned. "What did we agree?"

"No red," Castiel replied, and Dean smirked despite himself; the cargo bay did have a nice big red 'no unauthorised entry' sign emblazoned on every door, so Castiel's wandering on in was far from innocent.

"It's cool guys, he's with me."

"Under whose authority?"

"Your ass," Dean replied, picking at the clumps of grease and lint stuck under his fingernails. "He's not bothering anyone down here."

"He's bothering us. We're already behind schedule, so if you don't mind -" Zack had the whole middle management with an inferiority complex impression nailed.

Dean sneered but knew better than to push his luck while the guard was there; the newbies and a few of the sadistic veterans could get trigger-happy if pushed. "Hey, Cas?"

The alien released Dean's arm, looked down at him with the saddest eyes Dean had seen outside of Sam pulling the puppy dog trick, grunted quietly.

"No red." The wink probably went by without notice but he hoped the tone didn't.

Dean couldn't be sure Castiel had picked up on any other human subtleties yet, but the alien was smart enough to start learning a language his throat wasn't made for and to work out what play, pause and skip did on a CD player. He might be a realist by nature but he also liked optimism when and where he could get it.

.

Dean knew full well there was nothing he could do about Castiel's situation himself, but there were definite advantages to having the ear of the ship's doctor. Waiting for Sam to finish his shift would have been a bitch even without his brain trying to fill in the blanks as to why Sam looked so blissfully happy on returning from checking up on his still bedridden, still thigh-injured girlfriend, but it was a small sacrifice to make for a good cause.

"So," Dean said, casually, "I hear Zack's got a schedule now."

"Doesn't surprise me," Sam replied, checking out his reflection in the mirror and grinning like an idiot. Dean hoped to God he'd never looked that dopey back when Cassie had been his supervisor. "Zack bitches if his check-ups overrun, doesn't surprise me he's uptight about everything else. I'm scared if I ever have to give him a rectal examination it'll break my fingers."

"Jesus Christ!" Yes, Sam's words had been somewhat muffled by toothbrush and toothpaste but it didn't change the fact they were also traumatising. "Give a guy some warning!"

Sam grinned in a way that suggested he knew exactly what effect his declaration was likely to have on Dean. "You brought him up."

"I mean Castiel, smartass. Zack's got a schedule based around him."

That wiped the smile off Sam's face. "Who said that?"

"Zack did," Dean replied, trying to look mostly disinterested. "Ran into him and Castiel. He bitched - and I quote - 'We're already behind schedule'."

"Right," Sam said, jaw tightening before he resumed brushing his teeth.

Dean could have pushed for a reaction then and there, but if he'd learned anything over the last two years bunking with Sam it was that his brother's temper worked to best effect if left on a slow burn. Dean wasn't much of a bleeding hearts liberal but he knew Zack well enough to know anyone with two brain cells to rub together - Michael aside, but only because he had the patience to cope with Zack and the power to override him, and even then that didn't count given Mike was back on Earth - didn't deserve to be stuck with the bastard.

.

The next morning went by smoothly enough except for Castiel having apparently gone missing overnight. Dean didn't mind; it took the smugness off Zack's face when he had the miserable luck of bumping into him on his coffee break, and nothing had been stolen or damaged.

Pity Castiel didn't think to tell anyone he was still on board, because Dean could have done without the heart attack of turning on his CD player and hearing twittering coming from inside the engineering bay.

"Son of a bitch!"

"Dean," came a reply from above him. "Hello, Dean."

"Hi, Cas," Dean replied, turning around with every intention of rolling his eyes but laughing out loud instead on finding Castiel clinging upside down to the main water pipe. "Get down from there."

"Why?"

Okay, now he had the right to roll his eyes. "Because."

"Why becaussse?"

Dean hit skip, back to Led Zeppelin, and waited. Two angry spits and an annoyed squawk that sounded too much like "Feep!" for Dean to take it seriously, then Castiel gave up, flew down while still covering his ears with one set of hands and pressed skip again.

"Fuck," Castiel said, lowering his hands, and Dean had rarely been more envious of extra limbs. Whoever designed two hands for two ears needed their engineering degree revoked.

"Yes," Dean agreed. "You're gonna get me in trouble."

"Don't," Castiel said, gripping Dean's arm, teeth bared but - well, Dean's survival instinct was pretty strong, but whatever was in Castiel's eyes didn't look much like anger.

"Don't what?"

"Trouble," Castiel replied. "Zack sssay I am trouble." Castiel's eyes narrowed. "Fuck Zack."

Dean nodded, both in agreement with Castiel and in agreement with his own decision to get Sam involved. Zack's being a dick could cost more than a few understudies leaving due to conflicts of personality, it could get their guest to give humans a very, very bad report card on going home. "No one likes Zack. He's a douche."

"Good," Castiel replied, before patting Dean on the head. "No one likesss Zack. I like you."

"Thanks."

"You're welcome," Castiel said, sounding thoroughly pleased with himself at getting the pronunciation right. Dean couldn't blame him; Castiel already knew more English than Dean knew Chinese after five years of trying it at school. "Make secret," Castiel added, patting Dean on the shoulder as if he were doing him a favour before letting go and skipping ahead to Iron Butterfly again.

At some times Dean could be a bit slow, but others he was sharp as a tack; his stomach twisted as he grabbed Castiel's lower right hand by the wrist. "Who taught you 'secret'?"

"Andy," Castiel replied, pulling his hand free before flying back up. Dean had to repress a shudder for a second; walking and flying with four arms was fine, but crawling with four arms looked all too much like scuttling.

He had to say, it was a hell of a relief to hear any name not involved with Castiel's study as the source of 'secret', but Dean would be damned before he'd just let that word slide.

.

The funny thing about Andy was that everyone liked him. Everyone. No exceptions - even utter dicks like Zack or people who got pissed off at the drop of a hat like Vick from security liked Andy. He was laid back and inoffensive and mellow, and generally just always felt like that one friend of a friend you always meant to get to know better but kept forgetting to.

He was also very, very, very fond of sampling anything rumoured to encourage being laid back and inoffensive and mellow. Dean had long suspected half the reason alien botanists were stereotyped as highly pleasant was due to their sampling of samples, and Andy was proof of that theory.

"Yeah," Andy said with an easy grin. "You got me. I've been hiding Cas from Zack, slap on the handcuffs. Totally worth it though, did you see Zack's face?"

Dean exhaled, breathing easily again. "Dude, I'm not gonna tell. I just wanted to check it wasn't anything weird."

"Hiding an alien isn't weird?"

"Well, yeah, but -"

"It's cool, Dean, it's cool," Andy said, rolling a strip of paper between his fingers absent-mindedly. "Figure someone's given him the human bad touch spiel already. Aliens, man."

.

Between the botanists, engineering, and the crew's general dislike of Zack being almost as universal as its fondness for Andy, keeping Castiel hidden was kind of easy all things considered he was a six foot six, six-limbed - or eight, if you counted the wings, nine if you counted the tail too - beastie.

Who, appropriately, liked "Number of the Beast".

Sam had started full on fuming as soon as he'd heard about Castiel showing distress at the idea of being around Zack, which basically meant as soon as the Captain was finished with his own explorations of the desert they could see to Zack getting a verbal spanking. The damned sandstorms cut off any communication the magnetic fields hadn't already distorted, meaning they were basically stuck waiting for the weather to improve or hoping and praying he stuck to the three week expedition originally planned. Dean had to be thankful that at least this Captain wasn't one of the drama queens, so "three week expedition" actually meant three week expedition rather than six week holiday or two days visiting the locals then running before the nukes hit.

All in all Castiel was pretty well covered, and therefore there was no real reason for Dean's stomach to continue feeling unsettled.

.

It wasn't that Dean didn't have friends. He knew Sam who knew Sarah who knew Andy who knew everyone - it was just that all his friends were like that. Friends of friends, or friends of friends of his brother. He'd never really picked up a friend of his own, they'd just come as attachments. Girlfriends were something else, but Dean had never handled break-ups well so they didn't really count.

It was weird to trust an alien with his music collection more than he trusted any human, but for whatever reason Castiel had decided he trusted Dean and it seemed rude not to return the favour. Castiel didn't exactly conform to human social norms and it bypassed a lot of the bullshit Dean had never really taken to personally; stranger still, Castiel seemed to treat half his conversations with Dean as if he was humouring Dean by responding, not the other way around.

There was also the whole personal space issue; Castiel's kind, general knowledge told it, lived in close-knit communities and as a result were touchy-feely by nature. Castiel was no exception, though he normally limited himself to shoulder and arm touching, and seemed as protective of his wings as - well, any other creature with wings. It was a pleasant sort of surprise when Castiel overrode any remaining rules about touching and not touching with a hug.

Dean didn't really know why giving Castiel a picture book he'd questionably acquired from the nursery warranted a hug, but it was really quite pleasant once he'd got past the initial panic of having six foot six of scarily strong alien wrapping itself around him. The four arms thing actually made the hug extra awesome - kind of like a group hug without coordination issues or embarrassment.

It also meant learning his first bit of alienese, because Castiel was insistent on saying "Thank you" in his own language and twittering away angrily until Dean copied him. Luckily, it seemed the high pitched tweets and twitters were largely reserved for commands and annoyance - general conversation, "Thank you" included, was limited to guttural growling and far less of a strain on human vocal chords.

Also explained why Castiel was so fond of Rammstein, though Dean had no plans to point out what Castiel might think of as a complimentary sound likely meant something closer to "I want to have sex with you and eat your kidneys". That said, maybe in Castiel's culture that was a compliment - Dean wasn't exactly well read on their mating habits.

.

As far as Dean had been concerned since he hit fifteen there were only three languages worth learning; English, bad English, and the language of love. It was something of a surprise to find that while his vocal chords attempted to snap if he tried any of the higher pitched words in Castiel's language, Dean was quite adept at picking up the growls. All that singing in the shower had come in handy after all - and it was with a decidedly smug grin that Dean corrected Sam when referring to the forest aliens with "Actually, they prefer the term 'Anli'."

Not that he was any expert - he was about as handy with Castiel's language as Castiel was with mechanics - but it was neat to be picking up a few choice phrases including a nickname for Zack that Dean suspected translated roughly to flaccid-dicked ass-weevil. The constant threat of a slap upside the head if he got the pronunciation wrong was a good motivator; kind of a pity his language teachers at school hadn't been allowed to use physical violence, though he suspected Mrs Shaw had considered it more than once.

.

That unsettled twist in Dean's stomach was an utter bitch when it made its reason for existing known. It wasn't that Dean didn't want Sarah to get better - just that her walking around on crutches meant Castiel had no reason to stay. He'd kind of got comfortable thinking he'd have Castiel around for a while yet, and selfish as it was, he'd liked the idea. Castiel blatantly liked him more than the other humans on the ship, even if it was in part for the music, and there wasn't really anyone else Dean knew who appreciated the vocals on In a Gadda da Vida the same way he and Castiel did, albeit for different reasons.

After the mess with Zack, Dean had figured Castiel's leaving would be a sneaky thing; it was a bit weird to hear instead that Sarah and the botanists had planned a goodbye party. There was cake. Most likely add water-and-dried-egg packet mix cake, but still cake.

Castiel didn't even eat cake. Anli taste buds couldn't detect sugar.

Maybe it was douchey to invite himself along but Hell, he'd been the one keeping Castiel entertained through this for the most part and given Sam was the one to tell him about it that totally counted as permission. Sarah didn't seem to mind although a few of the other guests were wary of letting Dean near the cake, leading Dean to suspect that it wasn't just a sugar high people were getting out of it.

Dean didn't do goodbyes, so it was a little annoying to find himself in the middle of one. Castiel had been doing plenty of handshaking, the four arms thing coming in really handy for multitasking, but he was far from content to let Dean get away with the same.

"Dean," Castiel said, arms wrapped tight around Dean's chest and shoulders. "I like you." A pause, then, "Come with me."

Dean swallowed, clenched his fists until his palms hurt from his nails digging into his palms. "I have to stay on board, Cas. I can't eat your food, y'know?"

Castiel sighed, long and hard. "Yes. I'll missss you."

"Same here, Cas," Dean agreed, hugging back. "Sucks to be me."

If anyone other than Andy had tapped Castiel on the shoulder to ask, "Am I interrupting something?" they would probably have earned a punch for their troubles, but there wasn't one soul on any planet who could hurt Andy; besides, it was Castiel's goodbye party, not Castiel-and-Dean's.

Didn't stop Dean from going back to the engineering bay to sulk, though.

There weren't any unexpected visitors this time.

.

Dean knew full well he was just as insufferable doing things he enjoyed as he was doing things he disliked. It was his way, so he was hardly surprised to find he was far from the man of the moment once the return path to Earth was set. Besides, the advantage of flight was the complete removal of boredom - general maintenance still had its place, yes, but keeping an eye on engine temperatures, air levels and external damage was a lot more exciting when you didn't have anywhere to safely dock at for seven hours in all directions.

That and the fact hearing about Zack's lecture off the Captain from Sam had given him a warm glow of grim satisfaction for a good few hours were sure signs that things were on their way back to normal; Dean just needed to ensure everyone got back home safe and sound, collect his pay for the mission, figure out if he wanted to stay assigned to the Impala, and get on with the next job.

.

The combined advantage and disadvantage of having a brother you actually liked was that they tended to know you a fair bit better than you knew yourself. Admittedly the reverse was also true, and Dean knew more about Sam's weird habits and idiosyncrasies than anyone else did, but getting caught off guard was always discomforting.

Eleven in the morning wasn't technically early, but after a long, hard night of too much alcohol and too few women Dean figured some grumpiness was fully warranted when answering the phone. "S'up," Sam greeted, all those years of schooling put to good use.

"Hey," Dean replied, returning the favour and switching the monitor on; only a handful of people on the planet deserved to suffer Dean's patented morning scowl, and Sam was one of them. "What're you ringing for?"

"Nothing," Sam said, fighting off a grin that clearly meant 'something'. If this was a prank or Sam calling just to share his joy over getting laid Dean was going to kill him the next time they met up. Slowly. "Just thought you'd like to know, Andy's samples attracted a lot of interest. They're thinking of starting a botanical expedition, though the desert was a bust."

"Woohoo," Dean deadpanned, not really feeling the enthusiasm he probably should all things considered Andy was a friend. It wasn't really his fault, the happy hormones needed at least another hour to kick in. "Go team Andy."

"And," Sam continued, undeterred, "They've asked for an engineer. To keep the air filters and temperature controls in order."

Dean straightened at that, gut twisting, not entirely believing what he was hearing and that he was apparently lame enough to be excited about it. "Seriously?"

"Seriously," Sam replied with a smirk. "Not that you'd be interested in applying." Sam tapped the screen, dragged an email onto it for Dean to pull up, the application form already half filled in.

"You son of a bitch," Dean said, grinning. "Pretty unsubtle way to keep me out of your hair."

"You're a jerk when you're not getting laid, you know?" Sam replied before picking up his coffee and looking over at something that seemed to warrant more attention than his conversation with Dean. Lucky bastard probably did have Sarah waiting for him. "Don't tell me how that works with Cas, though, I could do without a first hand account."

"Woah! Hey, Cas and me, we're not -"

"Whatever, Dean," Sam interrupted, reaching to hang up. "Have fun."

.

It might have taken two interviews, an aptitude test, a practical test and two months out in the middle of a forest bored out of his mind because the research team had chosen their equipment well and maintenance only took three or four hours' work a day, but their small base did finally attract attention.

Castiel showed up the very next day, startling the newbies who'd never seen an Anli up this close, startling them more by knowing basic, if broken, English.

"Forgot to tell you something," Dean grunted, trying to speak despite the arms crushing his chest and waist in a hug.

Castiel made a bird-like croon, ignorant of or uncaring of Dean's statement.

"Zeppelin rules. You have no taste."

.

The End