I do not own Star Trek 2009 or Supernatural.

This pretty much fits anywhere into the series anytime (most likely a good chunk of time) after The Tamir Incident.

"Ready to go?"

"Indeed. After you."

Sam Winchester strolled out into the cool night air, tasting the tang of motor oil, alcohol and human sweat on the shallow breeze.

Spock fell into step beside him, both scanning the dark and dangerous street with calm professionalism.

He and his companion were dressed in scruffy leather, metal and rough cotton, stained and worn. Sam's barely regulation-length hair was scrubbed messily every which way and Spock's impeccably sharp cut had been spiked on end with heavy-duty gel. Anyone who saw his ears where they were headed would assume the Vulcan was Romulan, especially when confronted by a well-practiced, intense glare. Heavy metal clip-on earrings rang musically from Spock's green-tinted ears as Sam rolled his shoulders under a battered leather jacket with metal-plated shoulders. Big, old-fashioned steel-toed boots thudded against pock-marked asphalt as steam from the sewers rushed around the two tall figures in a stench of rotting sewage.

They were going on an anthropological research mission to an underground fighting ring run by the local planet's gangs.

This was what Sam and Spock did on their night off.

If the captains knew, they'd throw an epic, supernova fit.

Clearly what they didn't know couldn't hurt them. Plus Jim and Dean would want to come and those two, they always stuck out in a crowd and that just ruined any cultural observations. If the two scientists wanted to observe native-stranger relations, all they had to do was transport down to the surface of any given planet and watch their captains in action. Native-native interaction without knowledge of third-party observation required a little more subtlety than either Jim or Dean were willing to give. Especially for hours on end.

So instead Sam and Spock wandered aimlessly (as aimlessly as one could with a goal-oriented Vulcan) off the ship, chattering (as well as one could with a stoic Vulcan) about advanced light physics in ways guaranteed to make both Jim and Dean keel over in boredom.

Then they snuck out and Sam had to quash the impression that he was acting like a sixteen year old slipping away to try his first beer.

He shook himself.

They could look after themselves. They were adults.

And this was fun.

Their first foray into the more violent side of humanity had come some eight months earlier. Now whenever they had the chance, they went out, which amounted to about once every joint shore leave.

Spock was considering writing a paper on the socio-cultural examination of violence in leaders as represented by humans (arguably one of the weaker aggressive species), Klingons (stronger but not as inventive) and several other fascinating examples.

This underworld was so very different from everything Vulcan that it was like a colossal slap in the face every time he went below. Sam Winchester's solid, dependable personality became a lifeline for Spock, who wanted to understand emotions, needed to understand every aspect of something that rippled right down to the very core of humanity. Spock needed to comprehend this phenomenon that his cultural upbringing had addressed only in the most restricted, rudimentary forms.

Not that Spock would ever write this down, but Sam Winchester was a part of this self-imposed learning process. Sam's curiosity drove him down to the dregs of an often terrifically violent galaxy but even in the deepest, nastiest brawl, even when other races three times his size backed away from the terrifying persistence of an angry Winchester, Sam never lost his intrinsic wholesomeness.

Jim and Dean had it too, but it was far better hidden.

Spock wanted to find that same uniquely human wholesomeness in himself.

Spock was a great partner. Dean was the best brother a guy could ask for but he had no interest in the anthropological ramifications of violence as expressed as a political strength (essentially represented by the king of the hill example).

Spock did. He was also trustworthy, observant, shrewd and sensible (read: not stupid) about reading and reacting to new situations. The only thing Sam had to watch for was Spock's occasional slips out of "emotional badass character" and back towards the curious, detached observing scientist.

And hell, the half-Vulcan fought like no one Sam had ever seen except maybe Jim and Dean. Even then, he had the physical advantage over the captains (didn't mean he'd win, but Spock definitely didn't lose either).

He was good company too. Sam didn't have to worry about offending Spock with his intelligence. Whenever Sam got overly excited, he would bring out big words and expansive gestures in an attempt to communicate his genuine enthusiasm for the subject, usually some scientific breakthrough. Other scientists were intimidated or baffled and few non-scientists wanted to listen to a detailed discussion of a micro-fungi found only on starships.

Dean would listen most of the time but it wasn't out of real interest (more like Sam thinks this is fascinating so I will too until Sam stops talking), which made Sam happy but still wasn't quite what he was looking for.

Spock on the other hand, always had a genuine interest in Sam's findings.

Including the first expedition into violent night life.

Tonight they were casing a new joint where apparently a group of Klingons were holding court. Klingons were of particular interest – the only race more arrogantly sure of their place in the universe were the Romulans and they never moved in large groups like Klingons.

Slipping in the back door, Sam led the way through throbbing masses, sweat and shouting and a thumping bass pulsing through the crowd all combining to create a unique environment. Violence bred here, slipping around the hearts and minds of men, human and otherwise, to fester and spurt out in brief flashes of pain and blood in the fighting cage.

The first time they had come Spock could only stay for an hour or so. The emotional overload was too much. It had shocked him profoundly – a visceral manifestation of all negative emotions in one place.

It disgusted him, repelled him. Spock understood now what the humans meant when they said 'it made their skin crawl' – a creeping, cold, prickling sensation all over his skin, telling him in no uncertain terms how intrinsically wrong such a place was.

But the encounter had given him great insight into the mentality of the individuals they sometimes had to pursue and bring to justice. Turning away from the ugliness in the world did not seem logical at all. To ignore something and stay away from it on principle as his Vulcan instructors had ordered when he first expressed an interest in studying emotion ran counter to everything Spock's scientific, curious mind demanded.

Sam Winchester understood the need to know. He had made a very good point after that first night – they may never understand exactly why people chose such self-destructive actions but they could at least understand the discernable facts pertaining to the environment.

Sam had also said that they would stop making these trips after twelve months. "Gaze too long into the abyss," he had remarked, "and the abyss stares into you." At the time Spock had agreed to the time limit but had not understood the logic behind the declaration.

He did now, his sensitive nose rebelling against the reek of sweat, booze, drugs and cigarette smoke. This world would suck you in and eventually even the staunchest individual would be lost. They were reaching into fire to gain knowledge but eventually the risk would grow to outweigh the goal.

Carefully observing his surroundings, Spock noted the usual substance dealers, the pimps selling women, the professional fighters and the amateurs who would most likely end up dead within a few rounds.

The Klingons were easily spotted. Just about everyone in the joint gave them a clear berth and Spock carefully noted their pack formation. He nudged Sam and they got to work, watching closely.

They were just about ready to leave when the warehouse doors slammed open with a bang and gust of relatively fresh air.

Two tall, curious undercover Starfleet heads poked out of the crowd. "What's going on?" Sam asked. Spock shrugged. He found it a fascinating motion, oddly liberating in its ambivalent free motion and used it quite a bit undercover, to Sam's unending amusement. Spock refused to use it in front of Jim and Sam understood – Jim would never let him live it down and the fact that Jim didn't know was a sly, secret source of amusement for Spock whenever Jim was a little frustrated with his Vulcan first officer.

"Shit Spock, they've got a kid, a human" Sam hissed, peering over the crowd. "He can't be more than nine."

Spock glanced over at the ring. "It appears they are preparing a new form of entertainment.

By most species' standards, the boy was beautiful – long, dark curly hair, big wide green eyes, a cherubic face only slightly marred by purpled bruising. Judging from the roar around the arena, the kid was the night's main prize.

Even from their dark corner, Sam and Spock could see great fat tears trembling in the child's eyes as he tried not to cower. "Damn it," Sam growled and started pushing through the crowd.

Spock trailed along in the Winchester freight train's wake, reflecting that for all Sam's supposed logic and level headedness there were times when he and his brother were distinctly alike. Not that Spock disagreed with Sam's actions, on the contrary, but the Vulcan was acutely aware that there were only two of them in a volatile, dangerous situation.

Sam was big enough to push his way to the front. When the announcer called for a challenger to the heavy-weight Danubian champion, Sam's fist shot up unerringly in the sudden silence. No one really wanted to fight a Danubian except for the seemingly crazy human who hauled his 6'4 bulk up the chain link fence and vaulted into the cage. The roof slammed shut over him, Klingons clamping it down as they laughed at the foolish human.

Had Spock been any less a Vulcan, he would have sighed in resignation. Instead, he simply parked himself at the edge of the cage facing out, watching his partner's back with a wary glare.

Sam grinned fiercely at D'keel the Danubian Destroyer, who was already eyeing the boy with something that repulsed decent people. "Human die," D'keel rumbled, turning his focus to his opponent and Sam banged his leather-gloved fists together in challenge.

Danubians were slow but stupidly strong. If Sam got caught, the whole fight would be over in less than a second. Their heavy gravity world meant that their bulk was ridiculously large and their skeletal frame strong. There would be no quick neck twisting here, no shattered skulls. It would most likely be a bloody conclusion, since while most Danubians scorned weapons, Sam had no such qualms and the best way to put down a Danubian was to take out his brain via his eye.

'Course, D'keel didn't need to know Sam was armed.

All he had to know was that an idiot human thought he could go toe to toe with the champion and win.

The roar of the crowd around him brought Sam back to reality. If they wanted to get the kid out unmolested, Sam had to make this a good fight, one that was showy and scrappy. He crouched down into a practical stance as his opponent lumbered across the arena. Sam took the opportunity to slam two hands over the Danubian's ears with punishing force, skipping out of range in an instant.

Shaking his head dizzily, D'keel regrouped, plodding slowly after his lighter tormentor.

Spock admired what glimpses of the fight he could catch out of the corner of his eye. Sam displayed a thorough understanding of what it meant to fight a larger opponent, probably using all the tactics Sam had experienced used against himself as the biggest person in a fight. The crowd agreed with Spock's assessment, judging from the approving roars. They liked to see an underdog win.

And Sam Winchester was absolutely ruthless, fearless. When the first bell rang, he was already feeling the bruising impacts resulting from continually striking an opponent far harder than he was, but D'keel was suffering from several kidney shots, ringing ears, disorientation and several splits in his eyebrows, causing thick blue-purple blood to spill constantly into his eyes.

"Are you well?" Spock asked, not taking his eyes from the crowd.

Sam was busy catching his breath. "Yep," he replied shortly, waving off the Klingon offering him ale. "I'll finish it next round. Anything longer and I'll be suffering broken bones."

"That is a prudent course of action."

"Thanks." Sam pushed himself to his feet with a grunt, shaking out his shoulders.

Then Sam kinda found himself wishing they'd brought Dean after all. D'keel had picked up a very large, wicked looking ball and chain, to the booing of the crowd, who loved a brutally bare-handed kill most of all. Judging from the expert flicks of the wrist, the Danubian knew exactly how to use the deadly, effective weapon.

And all Sam carried was his durasteel K-bar knife and a few smaller blades.

"Advice?" he called over his shoulder.

"Either engage from extreme long-range or extreme short. Anything less will be disastrous."

"Right," Sam muttered, taking a look over at the terrified kid. Extreme short or long, no middle ground. Good thing Sam was fond of knife-fights and had studied that particular discipline in a very high degree of detail. His expertise showed as he danced around the long chain, using fences and floors to pinwheel about like a bouncy ball until D'keel lost patience and paused for a brief second too long to gain extra speed.

Sam slammed the K-bar down into the rubber mat, pinning the spiked chain to the floor and scraping his knuckles badly. As D'keel took a two-handed stance to yank the knife out, Sam's smaller blade whizzed across the distance and into D'keel's left eye. With a roar of pain, the Danubian dropped his chain and clapped two hands to his left eye. Darting in close, Sam took out his second biggest knife and buried it to the hilt in D'keel's right eye.

The Danubian dropped like a stone and silence fell over the arena.

The fight had ended in three seconds' worth of time.

Grunting, Sam yanked his K-bar knife out of the floor and sheathed it again before stalking over to the terrified kid. Hauling him up by the bicep, Sam motioned to the roof.

The Klingon leader grinned nastily, shaking his head and waving another heavy-weight fighter forward until Spock reached into the small gap between bar and chain link, ripping the mesh back easily to a hushed mutter of the crowd. The war-like Vulcan sent the crowd tripping back several paces with a withering gaze as Sam pulled the boy out of the arena and propped the kid on his hip.

The poor boy was shaking like a leaf but Sam couldn't let anything other than a rock-solid expression of possessive triumph crack his face.

Spock covered their retreat the entire way, a 'tattooed' hand covering the hilt of a wickedly long knife.

Once outside, Spock held out his arms. "Give me the child. We must run." Sam groaned but didn't argue. The kid didn't complain, clearly terrified out of his wits and Sam was beginning to feel the fight in his bones.

Spock set a nearly unbearable pace for the tired Winchester but the growls and roars from the dive behind them fuelled their escape. Slipping in and out of alleys, up and over rooftops, they moved down through the dirtiest slums until their arrival at the closest tiny little Starfleet security outpost.

Neither Spock nor Sam had brought ID and they didn't have time to go back to their hotel. The planet would soon be crawling with Klingons. So Sam hit the button for the little self-destruct packet that held all their IDs back at the hotel and broke into the station with rather disturbingly graceful ease, slipping kid and Spock past the dozing security guard.

Punching the Enterprise's transport code into the computer, Sam fidgeted, feeling more and more like a kid caught with the cookie jar. Bobby was over with Scotty tonight. The captains and everyone else were on the planet. And Bones was on duty. They might be able to slink their way through this one with minimal explanation.

"Whit in the blue blazes are ye doing callin' me from the boondocks on a shore leave night, Spock?" Scotty bawled through the communicator and Sam hastily hit the volume slider as the guard snorted loudly in his sleep.

"It's Sam and Spock, Scotty and we need an emergency beam-up for three."

"Aye?" the Scotsman asked, puzzled, but the pad warmed up and the two adventurers were very happy to see the Enterprise's spick and span silver transporter room inside of a heartbeat.

"What the hell kind of science expo was you two at? What are you wearing? Spock, are those earrings?" Bobby demanded irritably as Sam winced and sat down on the transporter pad. "Damn boy, you look like you went ten rounds with an angry Danubian."

"It was two rounds actually and the kid's going to need some help," Sam tried to deflect. Clearly someone had called Bones, because the doctor blew into the transporter room like an ill-omened, sharp-edged wind.

"Sam Winchester," McCoy snapped as he gently palpitated a very swollen Winchester hand, "what on earth have you been doing to yourself?"

"We believed it necessary to relieve this boy from his unfortunate situation as a sexual slave and the safest, most expedient manner of extraction was for Sam to win a fight against D'keel the Danubian Destroyer, thus gaining credibility in the eyes of this planet's underworld. Obviously we were successful." Spock paused when Sam sent him a pleading "shut up!" look.

"You did what?" Bones squawked in an undignified manner, re-examining bone with interest. Sam shrugged and tried to pull his hand away before quailing and desisting under the doctor's jaundiced eye.

"Ye went two rounds with D'keel and won?" Scotty seemed more than a little shell-shocked at the idea.

"It wasn't a big deal, look at the cute kid, he needs help!" Sam smiled as winningly as he could, knowing the chain-link shaped bruise all down his face and neck would most likely help his cause in looking very earnest.

McCoy seemed to be building up immunity regardless because he didn't even break stride, waving Chapel forward to take the kid. Bobby's hand started slipping towards his communicator and Sam glared. "Don't you dare. Not until I'm put back together. He'll hover like a mother hen. I'm fine Bobby, just a little banged up."

"Concussion," McCoy muttered, "five broken bones in one hand, four in another, a fractured foot, strained ribs, never mind fine Sam, how the hell are you still moving?"

Bobby hit the comm.

Sam groaned.

Dean didn't know whether to kill his brother, slap him on the back or just pound his head off the wall.

He settled for calmly listening to the whole story, agreeing with Sam's actions and then demanding at the top of his leathery lungs for Bobby to let him either skin the entire underworld alive or ground his brother to the Impala for the next century.

Bobby told him to get his head out of his ass and stop acting like an idjit.

Kirk thought the whole thing great fun (except for the child-slaves part), especially when Scotty circulated pictures of Spock dressed like a badass complete with earrings and biker boots. Then he thought about the sheer number of enemies surrounding two solitary Starfleet officers in a hostile environment and joined Dean in bawling out both Spock and Sam.

The very irritated captains were given permission by the Admiralty to clean out the fighting rings and did so with brutal efficiency and alacrity, finding and freeing at least a hundred and twenty more children.

Sam deliberately did not ask any of the children their names. He was afraid he'd never let them go if he did. Uhura, Chekov and Ash understood, banding together in the Coalition for the Protection of Soft Hearts, dashing about at top efficiency behind the scenes to give Castiel, Bobby, Jo and Sulu more time to play with the kids.

Dean thought them idiots but didn't push.

It took Chapel a week to convince the rescued child that they weren't going to return him to that world and even longer to put him back on the road to recovery. Dropping all the children off at a star base especially equipped to deal with severely traumatized children was difficult but necessary. Given the trouble either ship could end up in on any given week, former child sex-slaves wouldn't find much quiet or stability within the kind, well-intentioned crews who had done their best to help the kids have something approaching fun while staying on the starships

Needless to say, after the whole mess had been cleaned up, Sam and Spock were not allowed shore-leave together again unless they took their captains along.

Sam and Spock thought this very unreasonable given the amount of trouble Jim and Dean got into on a regular basis.

The captains didn't care much what their idiot first officers thought.