A/N: Just a quick missing scene. Mycroft was a bit weird in this episode, so I wanted to sort of explore what's going on in his head. Not sure how well I managed but it was amusing to write anyway.

Watching the interrogation, he systematically divests himself of all emotion.

It's something he's been able to do since childhood - to simply turn off that part of himself which feels, remove the weakness of his lamentable human condition. A condition which, one might be tempted to argue, led him to sitting in this dim little torture chamber in the first place. Because there really isn't a reason he needs to be here.

Others could have gone in his stead, surely. Risking someone so important as Mycroft Holmes on a lowly infiltration-and-extraction mission? Absurd. It's been years since he's involved himself so directly with his work. And furthermore, back when he'd been low enough in the pecking order to feasibly be sent on these sorts of trips, he'd always had something of a reputation for finding ways to manipulate his peers into completing the missions for him. Because he is not, never has been, and never will be a spy. He controls spies. Uses them like the political tools they are. His pawns.

Here he sits now, though. A lowly pawn. Answering to none but himself, certainly, but there's still no denying the fact that he's disguised in a foreign uniform, carefully analysing the spoken words of the interrogator for grammatical patterns he may have missed in his hasty refresher course on Serbian hours earlier, having broken into a military installation for the express purpose of... well.

Not rescuing. Clearly not. Because that would imply there's someone in the world Mycroft deems worthy of being saved. Extraction, then, of a valuable human asset. Nothing more. Sherlock Holmes is, whether he likes to admit it or not, an incredibly effective spy. A useful resource, one which should be preserved for the good of the nation. But then of course he is, isn't he? Because he's related to genius, the flesh and blood of Mycroft Holmes.

... because he's Mycroft's baby brother.

A pang of something far too much like emotion flits through Mycroft's consciousness and he quickly smothers it. Sherlock grunts in pain, kicked hard in the stomach. The young man weakly spits a gob of blood onto the rough-hewn floor, coughing. Internal injury, perhaps. Or simply a bitten tongue. Crimson glints in a small puddle on the stones below their feet.

Mycroft regards the display dispassionately - he really has no other choice but to remain stoic, of course. Must maintain his cover. Before him the interrogator shouts, questions, snarls. Sherlock doesn't answer. He won't, obviously. Far too high a pain tolerance. Likely ensconced himself deep within his own head by now, as he's always been wont to do in times of stress, so it's probable he's not even feeling any of this. A faint twinge of pride, then worry, before Mycroft once again cuts off his mind's ability to process emotion. Doesn't care.

The interrogator begins to get annoyed, however, and takes up a short length of pipe. Hm. Well, that could be problematic. Mycroft leans back casually in his seat and weighs his options - what's the worst he'll do? A broken arm? Cracked ribs? No chance of going for the head, they're still in need of information. Paranoid, these lot. Wanting to know what Sherlock was doing here, what knowledge he found, whom he told it to. So they won't kill him. Incapacitate him, though... yes. Bound to happen.

He'll allow three broken bones, Mycroft decides, before he steps in. Elsewise he runs too much risk of breaking cover. There's always the chance of the Serbian taking too close a look at their faces, after all - noticing similarities. Granted, Mycroft and Sherlock have never been exceptionally similar in the physical sense, but they do nonetheless share certain qualities. Habits, bearings, accents. Not worth the risk.

Mercifully (mercy, no, just less hassle later on - he doesn't care) the pipe doesn't find a use, as Sherlock's taken it upon himself to worm his own way out of the mess. Why he took so long to do so Mycroft has no idea - playing up the drama? Perhaps having a fit of masochism? Whatever the cause it sparks a vague flame of irritation in Mycroft's chest. The daft child could have done this ages ago and saved the both of them several minutes of tedium. (Several minutes of torture. But then he's unaffected by such things, so it's no matter. Annoying, that's all.)

His Serbian's doubtless appalling, rushed as he was to re-learn the blasted language, but Mycroft plays it up regardless. No one will question him on his speech patterns, considering the rank of uniform he's stolen. And in any case the interrogator's far too distracted now to notice. Love affair, apparently. Good eye. He hadn't caught enough of a look at the man's outerwear before he'd stripped to shirtsleeves, hadn't spotted all the signs, but Sherlock's been in this room far longer. (How much longer, before Mycroft had arrived, and how many blows?) He's had more chance to observe and piece together facts.

Mycroft does what little he must to keep the deduction going. Just a few words, doesn't take much, and soon enough the two of them are alone.

He's not entirely sure at this point whether Sherlock's even recognised him. By his voice, surely? But then they've never spoken Serbian within earshot of each other. It hardly matters anyway, he supposes. They've got guards within paces of this room, out in the hall, on the other side of rough stone barriers. Close enough to overhear. The act must go on.

Mindful of the window in the door he lifts himself casually from his seat, keeps his body language smoothly languid, taunting, looming over the prisoner. Sherlock's hair is filthy, badly in need of a trim. Usually never lets it get this long. Mycroft doesn't think about the length in terms of time, nor of the severity of events which would keep one out of reach of a barber. He grabs the dark curls in a painfully tight fist instead and drags his brother's head up to hear the words whispered in his ear.

"Sorry, but the holiday is over." He hesitates a microsecond. A tad sentimental, really, but... "Brother, dear."

Necessary to make the distinction - Sherlock may not know it's him, even now. It's impossible to tell how far off in his own head the idiot's wandered, isn't it? Could be too busy reciting chemical equations to himself to have identified his sibling. Teasing inflection to his voice, then, as Mycroft straightens up. Just to be sure Sherlock's caught on to the situation. Certainly not trying to lighten the mood of an otherwise grim reality. He'd never be so frivolous.

"Oh, dear." Sherlock mumbles around a smile. The information about London's terror threat doesn't seem to have fazed him much. Woozy, perhaps. Well he has just been beaten to within an inch of his life. Finally the man lifts his head a bit, smirks up at Mycroft with a squint for the harsh light. "And here I thought you'd just come to rescue me."

Mycroft sniffs in distaste (blood dripping down the boy's chin, a thin rivulet from his nose, ugh, disgusting) and darts a quick glance back towards the door. No one on guard duty besides the impotent youngster with the too-loud headphones. The rest of the unit assume their prisoner's in safe hands with a mysterious high-ranking guard they've never met nor spoken to. Imbeciles, the lot of them.

"We have approximately fifteen minutes before the guard is relieved of his station. In that time I will unchain you, replace the handcuffs you were brought in with, and escort you out of this room. We will maintain our charade throughout. Do you understand?"

Best keep things as linear as possible. Sherlock's still grinning like a giddy child, after all. Who knows, he may have finally succeeded in knocking himself silly during that foot chase earlier. Had one of the soldiers butted him in the skull with a rifle stock to shut him up? Seems a likely cause for that swelling bruise on his temple.

"Handcuffs? Not very brotherly of you," the boy mutters with a low snicker. Mycroft rolls his eyes as he fishes a small key out of the pocket of his stolen coat. Yes, definitely had a few screws knocked loose - well, no matter. He's always suspected his brother of being insane. Hardly a surprise to be proven right.

The heavy cuffs of the chains pop open freely and Sherlock doesn't even try to keep himself upright, just collapses to the floor with a groan and a mumble that sounds suspiciously like an insult. Mycroft ignores it, reaches down and drags his little brother to his feet. He snaps on the set of steel handcuffs over red-raw wrists and doesn't dwell on the smears of blood staining his gloves.

"What'd they send you for?" Sherlock asks as soon as he's found his precarious balance under Mycroft's grip. "Run out of disposable cannon fodder? Or perhaps you're disposable now, hm? Lost some standing, brother dear? Just a pawn like all the rest of us, what tragedy befalls kings."

"If you continue to insist on rambling incoherently I will not hesitate to make use of a gag," Mycroft informs his erstwhile prisoner in an annoyed monotone. For god's sake, child, this is no time to act like a fool. Sherlock just sniggers rather drunkenly as they make their way to the door of the interrogation chamber.

"Incoherently?" Sherlock snorts, lets his head lean sideways onto Mycroft's shoulder as they walk down the hall. Mycroft waves a signal to the guard as they pass, shrugging Sherlock off as he does so - all is well, he's simply returning the inmate to his cell. Back to your station, peon.

"You should hear your Serbian if you want incoherence," Sherlock continues airily. "Utter tripe."

"Kindly shut up," Mycroft bites out through a tightly-clenched jaw. They really can't afford to have one of the guards overhear them speaking fluent English together. Won't help to switch to Serbian, either, owing to their mutual non-native accents. Not for the first time since embarking on this absurd little foray he finds himself starkly reminded of why he absolutely loathes field missions. There's nothing here he can count under his control - all one can hope for is to keep a vigilant eye on the halls they pass, ready to take action if needed. He drags his belligerent little brother along behind him, refuses to care if he stumbles. Keep up the act. From a distance they need to seem legitimately at odds.

Not much of a stretch, that.

"You shut up," Sherlock counters petulantly, giving the arm in Mycroft's firm grip a half-hearted tug. Regardless of his whingeing tone he does, in fact, fall silent. Mycroft isn't entirely sure if that's down to his orders or the simple fact that the younger man's currently exhausted and in pain. He chooses to believe it's the former. Healthier for the ego, isn't it? Labouring under the delusion that Sherlock may have actually listened to him for once.

Every checkpoint as they travel through the base seems to taunt Mycroft's formidable predictive abilities with all the ways this ridiculous excursion could go wrong. A guard missing his shift, the interrogator returning, some off-duty soldier strolling past. Every scenario more troublesome than the last. But, as is always the case when he plans things so meticulously, the mission goes off without a hitch. Within minutes he's prising open the seldom-used back entrance to the small stone bunker, shoving his brother through ahead of him into the dark chill of night, striding confidently through the blacked-out shadow of a disabled floodlight path.

"Now what, off on a family hike?" Sherlock grumbles as Mycroft unlocks one side of the handcuffs. He leaves the other end securely fastened, ready to snap back on should they be confronted on their way to the waiting truck ahead.

"Yes, seemed a lovely evening for a bracing jaunt. Doubtless you could use the fresh air." Despite the bland quip of his tone Mycroft remains on high alert as they tread across dimly-lit concrete. Sherlock trails after him - close enough to resume his role of escorted prisoner in the event of an altercation, but far enough away to make it obvious he's not completely thrilled with the idea of being swept out of danger by his big brother.

"Could have nicked me a shirt, at least," he mumbles in irritation. Wordlessly Mycroft strips off the pilfered uniform greatcoat and holds it out towards his companion. The night isn't particularly frigid and they're scant metres from the vehicle anyway, so the loss of warmth doesn't bother him.

Sherlock looks like he might decline for a split-second. Quickly, however, he accepts the offering. Shirtless, barefoot, middle of the night... even Sherlock's not committed enough to his petulant act to refuse a wool coat in such conditions. He bundles it tightly around himself and stands silently shivering as Mycroft exchanges a few clipped words with the double-agent in the driver's seat.

"Paid off or flown in?" Sherlock asks once they're both settled in the back seat. Mycroft would have preferred to sit up front, but they'll be less likely to be taken to task over proof of identity in the rear seats. Straightening the lapels of Sherlock's coat (to make him seem more like an off-duty guard should they be stopped - certainly not because the daft child's turned the collar up again in a bid to make himself look ridiculous) and making a passing attempt at nudging his brother into doing something about his atrociously-tangled hair, Mycroft frowns.

"I should think that would be obvious."

To be honest it worries him a bit that Sherlock doesn't know. Should have been able to see the answer in the man's clothes, his hair, the stubble on his chin. Had he not taken the time to observe? But Sherlock always observes. Can't help it, in fact. So why the lapse...?

The exhaustion, perhaps? His injuries...? Internal bleeding, even? How hard had he been struck?

"I'm fine, christ's sake. Stop giving me that look," Sherlock snaps suddenly, rolling his eyes. Mycroft quickly forces his features to smooth back into a neutral mask and leans back in his seat, picture of composed elegance. He hadn't been concerned, of course. Sherlock's simply reading too far into facial expressions. Terrible habit of his.

They're questioned briefly by a guard at the compound's entrance, but their forged paperwork does the job it was made for and they're soon through to the open road. Airport's several kilometres away, a private jet and much-needed change of clothes just shy of an hour's drive off. Sherlock's leant his head on the window beside him and appears halfway to falling asleep, still bundled up in the oversized coat. Mycroft keeps his gaze trained ahead. Far more important to have his eyes on the road, watch for any looming threats their driver may miss.

There are none.

With absolutely no trouble whatsoever they arrive safely at the runway. Mycroft unceremoniously wakes his brother by grabbing his arm and yanking him out the truck (eliciting a stream of grumbled swearing, and of course that's not comforting, not in the least - definitely hadn't been exactly what Mycroft had hoped to hear, the predictable reaction of Sherlock unwillingly roused from slumber) and leads him to the waiting plane.

Once they're safely in the air Mycroft excuses himself to change his clothes. Out of this ridiculous uniform and into something more befitting his station. He returns to the cabin in a semi-casual pinstripe suit, feeling much more himself, and takes brief mental stock of a successfully completed mission. Primary asset recovered. No major incidents. Hadn't jeopardised his cover. Everything went, for lack of a better term, swimmingly.

As he resettles himself on his side of the aisle his eyes stray towards his brother.

Sherlock sits curled up like a child in the plush fabric of his seat, fast asleep. The man's hair hangs limp and tangled, shadowing his face, and filthy trousers have speckled the cushion beneath him with dirt and tiny flakes of dried blood. Despite everything, he looks... peaceful.

Mycroft wonders vaguely when his little brother last felt safe enough to sleep.

Glancing away, he looks instead out the window beside him.

A break in the clouds... dawn shines through.

Without meaning to, he smiles.