Disclaimer: I don't own BBC Sherlock or any of the characters, nor do I make any profit from writing this. Just too inspired by the show that I had to borrow them.

Sherlock takes on a new case where a local BDSM club are involved in human trafficking, with the club specialising in the sale, torture and eventual murder of submissives.

John isn't surprised in the slightest when he hears that Sherlock agreed to take the case, but when they go to the club under the guise of a dom/sub relationship, John is surprised by how well Sherlock takes on the role of the dominant male.

And how much he begins to like it.

Part One

It really shouldn't have been that big a deal, or so John had thought when Sherlock texted him to request his assistance with a new case and to come back to the flat as soon as he'd finished his shift at the clinic, but he later admitted to himself that anything involving Sherlock was a big deal and therefore he should have been prepared for anything and surprised by nothing.

His shift ended early, as it happened, so when he reached 221B and jogged up the stairs, the last thing he expected to see was Sherlock Holmes in his best outfit; a Spencer-Hart (as usual) but with a tight-fitting black shirt instead of the white John was accustomed to seeing on his flatmate, again with the topmost buttons undone, with the whole outfit emphasizing the paleness of Sherlock's skin and the smooth flawlessness of it. Not that this was unusual. Sherlock had a habit of making even the grubbiest outfit look fantastic, such was man's character with his self-confidence and well-deserved ego, but that wasn't the detail that made John pause in the entrance to the living room with a complete loss of what to say.

The man himself was sitting in his chair, one leg crossed over the other as normal … with his riding crop draped over his knees.

"Ah, John," Sherlock said, looking completely unfazed at John's somewhat surprised expression. John found he couldn't tear his eyes away from where Sherlock's fingers were on the crop, one hand holding the base while the other slowly slid the tips of Sherlock's fingers up the length of it before sliding them back down in what John was sure was just a check for damage or wear. Yes, that must be it. "The clinic let you go early. Good."

"Err… Case?" John asked, swallowing around a dry throat.

Sherlock pushed himself to his feet with all the fluid grace that only a member of the Holmes family could possess, holding his riding crop down by his side as he pulled out his mobile. "Lestrade texted me. The body of a twenty-two year old Caucasian male was found down by the docks at half past two today. I've just returned from examining the body at the scene."

"Right…" John said, still looking at Sherlock's riding crop. "So why do you have your riding crop with you?"

Sherlock looked up at John from his mobile, his mouth quirking into a sort of half smirk. "It turns out Lestrade wasn't joking when he thought I would find this one interesting." He looked back down at his mobile and clicked some buttons before turning it around to show John what he'd pulled up, and John found himself blinking at some images several times before he realised they were close up shots of a very naked man's abused backside. "These are some pictures I took of the body whilst I was there," Sherlock went on to explain. "Underneath the strikes of the flogger there are fading bruise marks; you can see them there along the small of the back, the buttocks and thighs." He took the mobile back from John and locked the screen before putting it back inside the pocket of his suit jacket.

John still didn't understand what this had to do with Sherlock's riding crop, and the other man must have deduced it because he rolled his eyes with an air of impatience. "The bruises were made two days ago, but the flogging marks were made just before his death by a man who didn't know what he was doing with the flogger, or, more likely, didn't care how he was striking the victim. Yet the bruises have been placed on the body with deliberate care; it's possible the man was a submissive because there is clear evidence of aftercare on the bruises and he wouldn't have been able to look after them himself without some sort of assistance.

"Lestrade has already texted me the details of the man they're interviewing; a Dom called Jeffrey Burkenright. He reported a missing person to the police shortly after the bruises were inflicted, probably because they had played a scene before parting company, and it was afterwards that the man was kidnapped. It's obvious the Dom didn't kill the victim though; the flogger strikes are all wrong compared to the bruising."

John wasn't the least bit surprised when his brain faltered over Sherlock's use of the word 'Dom', 'submissive', and 'flogger', his words catching in his throat when he went to ask a question because it turned out he didn't know what he wanted to ask. "Ok… So why do you have your crop again?"

Sherlock looked at John as if seeing him for the first time, his confusion darting across his face. "Oh, didn't I mention it? We're going to the BDSM club where the man was last seen by his Dom before he disappeared. But it's not just any BDSM club, John. It's a gentleman's club!" The last was said with a gleam in Sherlock's eye and that half-smirk again, showing just how amusing the detective was finding the whole ruddy fiasco.

"Of course we are," John replied, rolling his eyes and wandering towards the kitchen to make himself a much needed cup of strong tea.

As he was pulling a cup of the cupboard and went to find the sugar, he couldn't stop himself from startling again when he realised Sherlock was directly behind him. "Jeez! Sherlock!" John gasped, turning around to face the other man. "Honestly, one of these days I'm going to buy you a bloody collar with a bell on it!"

Sherlock cocked his head to one side, intrigued. "Why would you want to do that?"

"So I can hear it when you're coming!" John said before turning back to finish his tea. He flicked the switch on the kettle and went to retrieve the milk while he waited for it to boil; and felt his irritation rise when he heard the switch being put back into the 'off' position and the faint 'chink' of the cup being put away. "Sherlock, what are you doing?"

Sherlock didn't answer immediately, instead taking John's arm by the crook of his elbow and guiding him to the stairs which would take them up to John's room. "No time for tea," Sherlock was saying as they were walking, before gently ushering John up the stairs. "Your outfit for the club has been laid out on your bed."

"Oh, so you're dressing me now?" John said, a hint of sarcasm dripping from his voice, but Sherlock didn't so much as flinch.

"Well the club is the five star hotel of the BDSM world, or so I've been led to believe," Sherlock drawled. "We can't go there looking any less than our best, can we."

John didn't have an anything to say to that and couldn't find the energy in him to say no when this was the nicest way Sherlock had ever asked him for anything (even if he was actually being told what to do), and obediently trudged up the stairs to get dressed. Although he couldn't resist sticking his middle finger up behind him because he just knew that Sherlock was watching him.

The sound of Sherlock's laugh rang in John's ears for a long time after he'd shut his bedroom door.

oOo

Twenty minutes later, John found himself sat in the passenger seat of a rented Aston Martin, the DB9, in a gleaming charcoal colour that had looked simply stunning when the hire car employee dropped the car off outside their flat. His face had broken out into a wide smile, having never considered the fact that looking their 'best' also meant having the best on offer as well.

And Sherlock hadn't been kidding when he said that they needed to look fantastic; on John's bed, Sherlock had laid out a suit that John had never seen before, with the suit itself coloured a lovely dove-grey with a pale blue shirt and light grey shoes which were a shade darker then the colour of the material. When John had slipped it over his shoulders, the clothing had clung to his frame in all the right places and that made him feel great about himself because, if he was being honest, he hadn't quite managed to keep his trim figure from his army days and the new outfit made him feel more confident. It was difficult not to though, especially since it was obvious that there had been no spared expense; the suit had been especially tailor-made to John's specifications, and it had left John wondering when Sherlock had gotten his measurements before he realised that Sherlock had barged in on him more than once in the bathroom when he'd been completely naked. After the Irene Adler case, John was no longer surprised at how Sherlock managed it.

Sherlock must have noticed that it was no trouble at all for John to leave the flat when the car arrived, undeniably excited about getting the chance to drive an Aston and feeling like he'd woken up on Christmas morning. And more than a little put out when he realised he wouldn't be driving it.

"It's not proper, John," Sherlock had said, but that hadn't explained anything to him and he sorely wanted some answers.

"What do you mean 'proper'?" he asked, trying very hard not to act like the two year old he was pretty sure he'd been when he found out he wasn't driving the car.

Sherlock glanced at him from the road for a split second, the look no less powerful for only having half of Sherlock's focus on him. "Another thing I forgot to mention. It isn't proper behaviour for a Dom to be driven around by their sub. Upsets the power dynamics too much, or so they would have us believe. Imbeciles."

John felt his mouth drop open with Sherlock's words, feeling a chill up his spine although the car's air-con had been adjusted to a steady twenty-two degrees centigrade to combat the cold December air. "Excuse me?"

Sherlock stopped the car at a red light, pulling the handbrake up and putting the car into neutral before turning his head to John. "We need to have assigned roles to be able to infiltrate the club," he said slowly, as though he were speaking to a child. "They're not going to let us in the door if we don't have the roles planned beforehand. I need to be the dominant partner in the relationship because I need to question the people there and I wouldn't be able to do that as a submissive. It would draw too much attention."

"And you didn't think to tell me this before you decided to take us to a BDSM club?" John asked. He could feel his temper rising, his left hand completely steady because of the rising tension within the vehicle. "Tell me, Sherlock, does this mean that I'm going to be spread-eagled over a barrel before the night is out, or is that just the warm-up?"

Sherlock scoffed, resuming his driving again when the lights turned green. "Don't be ridiculous," he said, turning down another road and pulling into a car park that looked like it was for private use. "As your Dom, I will have a responsibility to ensure that you are kept safe and happy throughout the course of the evening. It does work both ways, of course. You will need to respond to any order I give you without question, but be assured, John, that I will not ask you to do anything that is outside your comfort zone."

"Not that this entire evening isn't out of my comfort zone," John grumbled, staring out the side window of the car in favour over glaring daggers into the side of the detective's head. "And I suppose it hasn't escaped your attention that I am one hundred percent straight, meaning that I have absolutely no interest whatsoever in pretending to be your sexual partner? Submissive or not?"

"As I said before, John, I won't make you do anything outside of your comfort zone. I need you to trust me."

Otherwise this won't work was the unspoken part of that sentence, but the words flowed through John's mind as loudly as though Sherlock had spoken them. "So what do you need me to do? How are we going to stop them kidnapping the submissives?"

It was as good an acceptance as Sherlock knew he was ever going to get from John, so he didn't hesitate in giving him all the details necessary before they prepared to enter the club.

oOo

Sherlock was a man of his word, John was relieved to see, so by the time they'd reached the club and made their way inside, John only had to endure a few leering looks from the Doms who were undoubtedly single, with the eyes being more appreciative from the Doms who were already in relationships and had their subs kneeling down beside them.

When they walked through the front entrance to the building, John could safely say that it wasn't anything like what he'd been expecting for an establishment that catered to the elite of the BDSM class. Rather than people being kept behind bars having pain inflicted upon them, or finding individuals swinging from the ceiling in harnesses, he found that the atmosphere was more civilised than he'd initially given them credit for. Sherlock hadn't overdressed them in the slightest, considering almost every person John saw had some sort of suit on or was dressed in a smart-casual way, and the people themselves were smiling, conversing in small groups and around what Sherlock described as 'art'. In other words, submissive men and women who were bound or gagged (or both) in various different ways in several states of undress, all straining to be admired by their Masters and the Dominants that also viewed them.

Although the colour was just what he expected; almost everything John could see was a shade of red or completely black. He guessed some things were more traditional than others and colour was no exception, with the owners of the club going as far as polishing the wood of the bar to a shade more reminiscent of the black cherry so it matched the rest of the décor, rather than the pale oak that the wood would have been originally (or so he was reliably informed by Sherlock).

As they proceeded to a corner of the very large room, John had to keep reminding himself to keep his eyes averted from any people that they passed, playing the role of the passive, obedient sub the way Sherlock had told him to, and having to rely on Sherlock's sense of direction with only one of Sherlock's hands on the small of his back to guide him. The club itself wasn't busy; it was still early, just gone six in the evening, but that didn't mean it was deserted, and already the noises of the room began to filter their way through the fog in John's head. The sounds were coming from the centre of the room specifically, the place where a small stage had been set up, and, before John had averted his eyes, he'd seen a young woman being tied up by a much older man to a large wooden 'X', a man who seemed to have the single-minded intent in showing off his prize.

Though his methods of showing her off certainly weren't ways that John would have considered treating any partners that he'd had previously.

The rhythmic sounds of bare flesh being paddled seemed much louder now, with every other snap of the leather-covered item being accompanied by the cry of the woman enduring it. No, 'enduring' was the wrong word, John decided when he'd been given permission by Sherlock to look at the stage. 'Enjoying' was far more apt a word to describe the look the woman had on her face, although it was streaked with black tears from where her mascara had run and the cheeks of her arse were a bright red, making John wince with every strike even though the woman was begging her Dom for more by the end of it.

In short, the whole experience had left John feeling rather out of his depth, but when he risked a glance at Sherlock, the other man looked as composed as ever, completely unflustered by the activity going on around them.

"It's always nice to see new faces," John heard another man say, and saw it when the person's shoes came into his line of sight. "Is this your man?" The question had been directed at Sherlock.

John felt Sherlock's hand sweep across his back to his opposite shoulder, placing his fingers where the other man would be able to see them. "Can there be any doubt?" Sherlock said, leaning close so that when he spoke John could feel the breath coming from Sherlock's mouth against the nape of his neck. He struggled not to shiver with the sensation of it, but had the niggling thought that that was the exact reaction Sherlock was going for. What better way to show a man's submissive nature than to have him physically tremble at the sound of his Dom's voice in his ear?

It's just an act, it's just an act.' John repeated the lines over and over in his head while he gave himself permission to respond to Sherlock's voice, his frame trembling slightly under Sherlock's fingers, and felt more than saw Sherlock smile in response.

"Hmmm, yes," the other Dom said with his appreciation evident from his tone. "Very nice. He knows the sound of his Master's voice."

"Yes. He does." Sherlock sounded totally assured of that fact, despite it being a blatant lie, but the confidence Sherlock was displaying was enough to convince the other Dom of their relationship together.

"Is this your first time to a social event?" the man asked Sherlock, his own sub coming by to kneel at his Master's feet and giving John a small smile when they made brief eye contact before he dutifully lowered his eyes to the floor. John kept half an ear open so he would hear when Sherlock gave him a command, but while he was being ignored he decided to pay closer attention to the only other submissive he'd seen up close since they arrived.

The submissive was a young man with the kind of look that you would see on a surfer in the States; the expensive cut on his blond hair and faint tan on his body made him look more mature than he actually was, for he couldn't have been older than twenty-five, but his demeanour was so meek and pleasant to watch that John found himself wondering how he could have found such a state of mind while being dominated by another man. Obviously, it could just be that he was gay and enjoyed the attention that his Dom showered him with, but from looking at him John guessed that there was something more, but for the life of him he couldn't pinpoint exactly what it was.

"May I take a look at him?" The other Dom's voice rang sharp in his ears, and John fought to remain still and calm while Sherlock seemed to take forever in answering.

"I'm afraid he's not quite ready for showing off," Sherlock replied, rubbing his fingers into John's shoulder in what was meant to be a soothing gesture as the detective automatically picked up the signals of John's feelings towards being handled by another Dom. "We're both relatively new to this game, you see. There are some areas which we're still under the process of discovering about each other and I need to know how he reacts in every way until I can show him at his best."

The Dom chuckled. "Of course. It would be a shame to see him at any less than his full potential. Perhaps, when you are both ready, you would be willing to share your relationship with the people here? It would be marvellous to watch." Before Sherlock could respond to the other man's suggestion, the Dom carried on speaking. "In fact, my boy here is due to have a private showing in one of the smaller booths of this club. I'm sure it would please him greatly to show your man a thing or two of how it's done. You said it yourself, you're both relatively new to this lifestyle. Maybe some of the things he can show you will make the transitions easier."

John felt Sherlock's fingers slide from his shoulder to underneath his chin, tilting his head up marginally until he could see Sherlock's eyes. The intimate touch to his jaw was threatening to become too much for him, having only ever done the move himself with a woman he was intimate with, but somehow he kept it together. 'Remember the case. Remember the lives you'll be saving.'

"Well, John? What do you think? Would you like to see them do a show for us?" Sherlock's voice was deceptively curious, but when John looked at the other man's eyes, he could see that Sherlock was giving him the opportunity to back out from it. He said he didn't want to put John in any situation that he couldn't handle and he meant it. Yet, at the same time, John could see it in Sherlock's eyes that this could be the make or break that they'd been searching for since they arrived. They needed to find out everything they could about this club while they were here, the private rooms being no exception, and it seemed that invites were very rare. They wouldn't get this opportunity again.

Something inside of John steeled itself, and in the calmest voice he could muster, he said his first words of the evening. "Yes, Sherlock."

To be continued

A/N: Thank you to the people who have reviewed and faved this work! :-)

I humbly dedicate this chapter to Puggle, who has stuck with me through the writer's block and the long waits between the parts in my stories and whose words have always made me smile on even the darkest of days! *Hugs*

In answer to my guest review - I heartily concur, and this fic is my way of rectifying that problem. I hope you enjoyed it!