DISCLAIMER: I have no affiliation whatsoever with Moffat, Gattis, or Arthur Conan Doyle, to whom all the credit for this universe belongs. Aside from the fun I had writing it, I have not and will not profit from this story in any way.

John wasn't even entirely sure he knew wha t polo w as. Sure, he had played water polo once at school and the concept had been quite similar to football, except that you had to toss the ball to one another while desperately treading water and half of the fun seemed to be blatantly trying to drown your classmates by pulling them below the surface by their ankles and playing a game of oxygen deprivation chicken, but how could all of that translate to horseback? Honestly, he didn't want to imagine – it sounded quite horrifying – but in reality, it seemed to result only in some of the most boring and meandering stories he had ever heard.

Of course, he couldn't quite say that to the pasty older gentleman who had engaged him in conversation what felt like decades ago, but nor could he seem to extract himself from this awkward situation. At this point, excusing himself to get another drink seemed to be his only option, although this one was still a little more than half full and he'd already done that twice in the hour since they'd arrived (once when confronted with a translucent-skinned young man who kept wiping his nose on his sleeve cuffs and again with a woman who bred those terrifying hairless cats), so he had to recognise that it wouldn't be a viable strategy for much longer.

"And do you know what else?" the man guffawed, suddenly clasping John's shoulder like an old friend. John observed the sloshing of the drink in his hand and judged that if there was little enough liquid not to overflow from the sudden force, it was an acceptable amount to down in one gulp. He tilted his head back and poured it down his throat, then resigned himself to nodding politely through what he had decided would be the last such story.

His tie felt too tight, which was silly because it wasn't as if he were unaccustomed to wearing one, and the clacking of high heels against marble floors echoed off the high ceilings like some kind of reverse sonar that only served to disorient him further. John hated functions like this. He was ill at ease with this kind of crowd, would have been even if he wasn't totally sure they could pick out how he didn't belong from the other side of the spacious Renaissance wing. Sherlock, of course, could play the part perfectly (though John suspected that this particular role required substantially less acting of the posh bastard than most did), and looked perfectly at home among these museum donors and committee members. He didn't have to worry a fig about passing for Richard Lyle III or IV or whatever it was, while John had enough on his plate trying to live up to the nondescript title "and partner."

The man burst into raucous laughter and John accompanied him politely, head beginning to swim. He looked down at the glass in his hand and blinked in surprise as if he had just noticed it was empty.

"Well, wouldn't you know it?" he remarked. "You'll have to excuse me a moment, I'll just be –"

"Hold on, hold on, dear boy; let me just call someone over!" The man raised an arm to flag a server down and John was quick to stop him.

"No need, no need," John assured him. "Thank you so much, though. I'll just get it myself – stretch my legs – and I'll be right back," and with that, he made his escape.

John had always been under the impression that tact was of paramount value in this social stratum, so he assumed he must have imagined the judgmental look that the bartender was giving him (though it was one he had often seen directed at Harry), and he took the drink gratefully. Now was the time to put the plan into action. He cast a glance across the room and his eyes lit upon Sherlock: elegant, charming, passing flawlessly. He resisted the urge to take a swig for courage – that was probably the last thing he needed right now – and he made his way to the smaller side room.

The crowd was thinner there; John noticed that that there were no waiters circulating with trays of olives or prawns or those fantastic goat cheese tarts that had almost been enough to keep him in the main hall. The ceilings were also lower, making the room less imposing and less subject to echoes and distortion. Conversations were whispered here, and the occasional ringing peal of laughter drew disapproving glances.

Several of the newly acquired pieces – mostly jewelry – were on display here, outside their glass cases in the open air. John recalled the map that Sherlock had cooked up and gone over with him again and again. He quickly recognised the tiered display shelf it would be atop of. Slipping his hand into his pocket, he found the cold hunk of metal and warmed it in his palm. Standing directly next to the shelf was a young woman – not quite too young for John to be talking to, he didn't think – in a modest purple dress. She was lovely; dark-haired, slender, with an angular face that looked nothing like poor, sweet Mary's. The last thing John wanted to do right now was remember when he had last stood before a beautiful woman with a ring clenched in one trembling hand.

She turned toward him just then and caught him looking, but she gave him a smile that was friendly, if slightly wary. He smiled back and took the invitation, and as he crossed the small room, he was sure to favour his left leg only slightly but just enough to be noticeable. Not like a man who needed a cane, he hoped, so much as one who had just returned from a ski holiday with a torn ligament, which was his story in case anyone asked. He only knew one person who would be able to pick out the difference and anyway, that person was on his side.

John smiled broadly (he might not quite pass for high society, but he had a face people trusted and he knew it) as he reached her side. "Hi there," he said warmly. "Didn't we meet at one of these before? I feel like..."

"Oh, we must have," she replied, returning a brilliant smile. "I'm terribly sorry, though, you'll have to remind me of your name."

"No, thank you for saving me the embarrassment," John said with a chuckle, and she laughed too, and an elderly woman in a horrendous pearl-splattered gown shot them a dirty look. "Daniel," he said, stepping forward and extending his arm. "Daniel Briggs."

"I'm Laura," she said, reaching for his hand, and as he bent to shake it, he allowed his shoulder to bump the shelf, which teetered and wobbled with dramatic tension that was nearly comic, and he had just enough time to register the look of horror on Laura's face as the pieces on the topmost level fell to the floor.

"Oh God, oh no, oh no," sputtered John, and his left hand dipped into his pocket as he dropped to his knees. He'd only have a few seconds. He recognised the ring immediately – he had been carrying a replica of it around all day, after all. Laura was kneeling beside him, reaching for a brooch and, praying he'd be deft enough that she wouldn't see, he shot out his hand and let it hover over the ring for a second, lifting it with the tip of his middle finger as he let its twin fall from his palm.

He let it lay where it fell – it was safer to wait for Laura to pick it up – and reached to recover another piece, a pair of earrings that had fallen side by side, when he heard urgent footsteps approaching from the direction of the great hall. Security, or maybe museum staff – it didn't matter anyway. Feigning a cough, he lifted his hand to cover his mouth and popped the ring between his lips. Laura didn't appear to have seen.

"Oh God, I'm so embarrassed," John moaned, secreting away the ring in his cheek like a hamster. "I hurt my leg recently and I guess I just –"

"I'm sure it'll be fine," soothed Laura, leaning back on her heels to survey the area. "It doesn't look like anything's broken. I think we've got all of it, actually."

"Might have," John agreed. The metallic taste in his mouth was unpleasant and he was worried about talking too much – would the ring clack against his teeth noticeably? The noise alone could give him away, but he was also concerned about the damage the large diamond could potentially do. They were supposed to be the hardest substance on earth, weren't they? In any case, they were certainly up there.

"Is everything all right?" John looked up, feeling the ring shift backwards (oh God, what if he swallowed it?), to see a very imposing-looking security guard standing over them with a horrified expression on her face.

"Oh God, I'm so sorry," John offered, getting to his feet. "I must have stumbled – I've an injury, you see – and knocked the display off balance, and..." He held out his hands palms-up, and the pair of earrings he had manage to pick up while pulling off the switch looked pitifully inadequate next to how Laura had recovered the remainder of the pieces. John put on his best chastened embarrassment face and awaited her judgement.

"Nothing is broken," Laura assured her, and John almost smiled. Having one person on his side already made him feel optimistic. He really must have one of those faces, but it never ceased to surprise him. As Sherlock had told him before they left the flat, Stop worrying, John; nobody ever believes someone like you would be up to anything bad. (Though he had soon felt compelled to add, Some of us do know better, of course.)

The woman collected the jewelry from their outstretched hands and began the process of returning each piece to its place, and John chalked a point for himself on his internal scoreboard. "Oh God," she muttered. "What order do you think these went in? Do either of you remember?" It was all John could do not to breathe a sigh of relief when he realised how unlikely it was that she'd recognise the difference.

"There were nameplates, I think," Laura chimed in. "Unless those fell off, too – no, wait, they're glued down!" She quickly became absorbed in the task of helping the security guard.

"Shall I go get someone to help, then?" John offered. The security guard seemed distracted as she gave him the go-ahead and it was all he could do not to grin. "All right, then. I'll be back straightaway! I'm so sorry!"

Saying you'd call the authorities yourself, as John had learned when he first began accompanying Sherlock on cases, was an absolutely brilliant way of keeping them from showing up at all. It was a simple enough lesson but it rarely, if ever, failed him. He could hardly believe his good fortune.

John's eyes were quick to pick Sherlock out from where he was standing at the other end of the hall. And how could John fail to see him? Sherlock was in his element, his personality was switched on and dialed up – he was entirely at home there in a suit and a role perfectly tailored to him. The crowd almost seemed to part around him, though that was probably just the alcohol.

As he crossed the room toward Sherlock, John tried not to let his nerves betray him, fought to keep his walk casual, a vacant cocktail party smile plastered on his face. He lifted his glass to his lips and (carefully sucking his cheek against his teeth) downed this drink, too.

"Richard, could I borrow you for a moment?" John asked as he came up behind Sherlock, resting a possessive hand at the small of his back. Though John had never before brought a man as his date to a high-society function (or anywhere else for that matter, despite what so many people seemed to think), he was confident that he could slip into the role of "boyfriend" more easily than Sherlock could; that should fall more into his area of expertise.

"Daniel!" Sherlock exclaimed warmly, turning into John's touch, eyes bright as he bussed his cheek, which had gone pink from the alcohol, John could feel it. "Of course – would you just give us a moment please?" he asked the couple he'd been chatting with.

"So sorry, really," John said to them as Sherlock took him by the arm and led him a few steps away – far enough to create the illusion of a private conversation but not so far that they couldn't be heard. John contorted his face slightly, letting his mouth twitch, and hoping to draw Sherlock's attention to the lump in his cheek.

"Is everything all right?" Sherlock asked him, dropping only the pitch of his voice to disguise that it was still his normal speaking volume. His eyes were wide with concern as he laid a solicitous hand on John's arm, and John felt a small flutter of warmth – stupid, stupid – at the unexpected expression of comfort. Sherlock, it seemed, could play this role better than John had ever had cause to suspect, and – yes, a sideways peek confirmed that the young couple, for all their unfailingly polite no-troubles and not-at-alls, were very much attuned to this side conversation.

"I'm sure it's nothing," John began, "but I've just had a call from my mother, and –"

"Oh, of course, I see," murmured Sherlock, clicking his tongue. There was a surprising amount of sympathy in the way he cut John off, as if he already understood the situation intimately and wanted nothing more than to spare John the discomfort of having to rehash painful personal details. "Would you like me to drive you? I could just –"

"Oh, no, I think it'd be better if I got a cab," John answered quickly. As he took Sherlock's hand in his, a rogue thought flitted across his brain and suddenly, just like that, he found himself acting. "You stay here and enjoy the party; you've been looking forward to it for so long."

Sherlock gave a little chuckle at this, but he did not appear entirely swayed (nor, John noted with some irritation, did he seem particularly impressed by John's ad-libbing).

"Are you sure?" Sherlock asked.

"Positive," John said and clasped his hand. "Just enjoy yourself and I'll see you later tonight" He tugged Sherlock's hand gently, discreetly. It seemed he could rely on Sherlock's acting skills and while he'd never dare to call Sherlock's observational prowess into question, John's head was spinning from the alcohol and somehow he didn't fully trust him to recognise the body language of someone asking for a goodbye kiss.

But Sherlock was smiling down at him and John forgot the metallic taste in his mouth as he went up on his toes, which was something he'd never had to do before, not for a kiss. The edges of the diamond felt sharp enough to cut, and so he turned the ring so the band faced outward, holding the gem gently but firmly between his front teeth as their lips touched.

Any first kiss can be a little bit unfamiliar, a little bit strange. And considering their respective levels of inexperience (John with men, Sherlock in general (presumably, at least), and the two of them with each other), it wasn't so unexpected, John thought, that this one would be rather more awkward than most. Not that it really felt like a proper kiss, not really, when almost all of John's attention was focused on the perfect way to manoeuvre a small band of metal inconspicuously past his teeth and between his lips and into Sherlock's mouth. Not when he couldn't stop worrying that one of them would get the angle wrong and the ring would fall to the floor, or that the diamond would scrape across the enamel on his teeth (he could almost feel the sound already, like nails on a chalkboard), or that it would strike Sherlock's incisors with a telling clack and heads would turn and everyone would make that stunning leap of logic and then they'd be caught. And the alcohol, instead of giving things its usual soft, rosy haze, was just making John feel uncomfortably hot and rushed, magnifying the heat of all the eyes he was sure were fixed upon them.

It was strange for something so much like a kiss not to feel like one, but so much of John's life these days was neither fish nor fowl, especially where Sherlock was concerned, so he didn't particularly dwell on it. Instead, he tilted his chin slightly to angle his mouth further upward and rested a hand on the nape of Sherlock's neck to finagle smoother access, and when Sherlock, ever quick to adapt, responded with a mirror-image shift and Sherlock mouth opened soft and warm to him, John inhaled a sharp breath through his nose and almost forgot what he was trying to do.

He gathered up his focus and trained his thoughts on the rigid, metallic form of the ring, not how warm and pliant Sherlock's lips, Sherlock's mouth felt in comparison (Did thinking about not thinking about it count as having thought it? John's head was swimming), dedicating himself fully to the task at hand. Now, that last Scotch was chasing the others through his veins, thrumming heat up the back of his neck as he finally pinned his hopes on this angle being the right one, and worked the ring forward with the tip of his tongue, parting Sherlock's soft lips with a hushed whisper of breath. And Sherlock took the ring on his tongue like Communion, pulling it back with a little cat-like lap that made the tip of his tongue flick, electric, against John's own.

For a second, John tasted Cabernet and there was a flash of memory, of a wineglass and of Sherlock's long fingers pinching the stem, and a wave of giddy relief rushed over him. A smile broke across his face, stretching his lips almost chastely against Sherlock's one final time as he sank down off his toes and settled his weight into the heels of his dress shoes. It was absurd how the loss of a few grams of metal could make him feel as if an enormous heavy yoke had been lifted off his shoulders.

Chuffed, he beamed up at Sherlock for a second before managing to wipe the grin off his face; it was uncharacteristic, after all, for someone so concerned about his mother. Sherlock's cheeks were pink – from the wine, John corrected himself prematurely, from the wine. And maybe partially from embarrassment; considering the circumstances, that had been a bit of a long kiss, a deep kiss, rather too much tongue. John didn't want to look around and risk confirming what he suspected, that everyone's eyes were upon them, and so he just looked up at Sherlock and remembered that the ring was in safe hands and that his part in all this was successfully finished, so he had to just get out and go home.

"Right," he said, running his tongue over his canines so as not to lick his lips. Shit, what was his line?

Irritation flicked across Sherlock's eyes, just quick enough for John to catch it before the veil of sweet solicitousness fell again. "I'll be round later, then," he rumbled. "I'll bring dinner. Check that everything's all right and give her my love, Daniel."

"Will do," John promised, and Sherlock smiled down at him with warmth in his eyes, and as Sherlock squeezed his hand, John could feel a sort of tangling twist in his chest and suddenly he wanted, he needed desperately to be back at Baker Street and back to his normal life and the normal Sherlock, the one who was as cool and slick and unyielding as the ring tucked safely away in his cheek. He let Sherlock's hand drop and took a retreating step backward. "Bye, then."

Sherlock bid him goodbye, and he retreated, conscious that any eyes that might have been on them were now turned studiously back to the faces of their own companions. Tact was truly a lovely thing. And it didn't seem like the curators or any other concerned museum staff were looking for him yet – but then again, what kind of jewel thief would make a pit stop during his grand escape for a celebratory snog? The spectacle might well have provided him a little protection, he reasoned, though that was hardly cause to linger overlong.

John got himself out of the museum and into the cab just slowly enough that it couldn't be called hurrying, and as they pulled out into the traffic, he plucked his mobile out of his suit pocket and texted Lestrade.

"Looked real," he wrote. "S has it now. I'm out safe".

The response came a few seconds later ("John, please. I CAN'T know that!" –andJohn can almost hear the exasperated sigh) and he tucked the mobile safely away again and stared out at the skyline. The driver was weaving in and out of traffic and the road was bumpy and the alcohol sloshed away in John's stomach along with the goat cheese tarts, but he managed to make it back to 221B without being sick. He kicked off his tight shoes, drained a glass of water once, twice, and then filled it back up again before passing out on the sofa.

He woke up at three twenty in the morning, stifling under a heavy wool blanket. There was a dim light coming from the kitchen and Sherlock was hunched over the table, squatting barefoot atop a wooden chair, deeply absorbed in the delicate operation of transferring the contents of one Petri dish to another using a long pair of tweezers.

Bleary-eyed, John shuffled into the kitchen, knowing now not to worry about breaking Sherlock's concentration – if the man didn't want to be distracted, nothing could stir him. John paused a moment to watch him at work.

"Was it the real thing?" he asked. Sherlock gave no sign of having heard. He set down one very tiny fibre in the dish on the right, waited intently for a few seconds and then set about picking up another from the dish on the left. John downed the rest of his water, refilled the glass in the sink, and decided to put away that morning's dishes before going to bed. He had the cupboard open and most of them returned to their rightful places before Sherlock stirred.

"Mm?" he enquired.

"The ring," John clarified. "Was it real?"

"Oh," said Sherlock, as if it had been days ago. "Yes. Real. Lestrade's still insisting on running tests, for some reason, but I'm sure that was it."

"Well done, then," said John, closing the cupboard and mopping up a small puddle on the worktop. "I'm for bed. If I can get back to sleep, that is."

"Hmm," replied Sherlock, directing his remarks to the Petri dishes.

"Goodnight," he called back over his shoulder.

"'Night," came the response. For a moment, John considered turning on another light so that Sherlock wouldn't strain his eyes, but soon thought better of it. If the lights were low, it was probably because those were the conditions required by whatever test he was doing. It was silly to think that Sherlock would have risked compromising one of his experiments to keep from waking his flatmate. Although the blanket had been a bit of an anomaly...

John found that his own bed was much more comfortable than the sofa, and he sank into the cool sheets and read until his own eyes were weary; then, after a second of hesitation, he kept going. He nodded off and startled awake when the book fell closed on his chest, then found his place and began again. He finally flicked the light off after the second time the book glanced his face, secure in the knowledge that he was tired enough to drift off without mulling over the events of the day.

NOTES:
・ Not beta'd or Britpicked, so please tell me if anything sticks out!

・ I feel like the line about the Scotch chasing the other drinks is riffing off of something, probably Douglas Adams, but I can't quite pin it down. I just know I'm not that witty on my own!

・This is my first attempt at writing something light and fun. Please let me know your thoughts!