That's it. I've had it up to here with the 21st fecking century. I'm done with it, do you understand? This culture of perpetual, never-ending connection, twenty-four-seven availability, to hell with it. I'm going to an island with no reception.

Here I stand, doing my honest best to play a wonderful finale scene at a public swimming pool of all bloody places – and in case you're interested, I'm finding that particular bathos rather difficult to stomach – here I am about to get blown to bits with my own bomb and my phone rings.

I'm going to an island. I'm going to an island with no reception and then I'm going to make a little raft out of a coconut and send my mobile away from me on the tide so it'll drown and become nothing more than a distracting alien artefact for a very confused angler fish.

Could have sworn I put the bloody thing on silent...

But let's accentuate the positive – at least I remembered to change my ringtone already. He doesn't appreciate it, yet. If he wasn't looking at me down the length of a gun, he'd probably be laughing. I wouldn't mind if he did. So long as he remembers it. And later, when it all makes sense, when it's real and true and all put out in front of him, he'll get it.

Stayin' alive. That's me and you, my old mucker, for tonight at least.

Someday you'll know what I mean by that.

But my phone's still ringing and anyway, the moment between us is pretty much shattered. Shattered, and the pieces cast about the ground and stamped on until they are but a fine crystalline powder. So what's the harm? Who knows; maybe it'll be something interesting. And maybe hell will freeze and pigs will fly in formation over it shoot red, white and blue smoke out of their arses, because everything interesting in the world, until just a second ago, was happening at the side of a public swimming pool. Very likely I'll end up having whoever's on the other end of the line killed. And the moment is gone, so what's the harm?

"Do you mind if I get that?"

The good doctor gets a look on his face like he's going to leap upon me and murder me with his bare hands, just as soon as he figures out what the hell is going on. Bless his heart. It's these everyman types, you know, these pedestrian sorts. He just doesn't understand. And nobody will ever be able to explain it to him.

Holmes, though, Holmes understands the absurdity of the moment. Gestures with the gun, "Oh no, please." Then adds, with what I assume to be the public-schoolboy equivalent to menace, "You've got the rest of your life."

I find that very aggravating. Not the threat, you understand. I'm used to threats. I don't mind threats, and especially not from him. And it's a good threat too. That's what's aggravating. He's really not pulling it off.

Whoever's on this phone doesn't know yet that they are being slowly tortured to death. There's some little comfort in that.

"Hello?"

"Is that Jim Moriarty?" No, love, you just called that man's number and were mysteriously patched through to another irritated-sounding Irishman. He's a sheep farmer, living in New Zealand, his name's Kevin, lovely fella…

But this idiot question comes in a cultured, self-possessed voice. A woman's voice, which through tone and timbre and not a single one of her stupid words tells of intelligence, of breeding, of a sound business mind. So I don't hang up, right away.

"Yes, of course it is; what do you want?" Holmes is glaring. I wish he wouldn't. I did ask, after all, if he minded, and now he's going to stand there glaring at me down his bloody useless little gun, making me feel rude, like a prick, like one of those wankers that tries to have a full-blown conversation on the Tube when they know the reception's going to be patchy and… Sorry, I mouth over.

Fine, he hisses back. He doesn't mean it.

This isn't really how I had envisioned our first real denouement. I've let him down, now that I'm thinking about it. Let us both down. But the voice on the line is still talking, and I have to listen. It helps, very slightly, to turn away from Holmes. And she's going on, and on, this posh bint, whoever she is, all the pussy-footing and the double-talk that people seem to believe is so essential and then, finally, she comes to the point. That key point they always have. It's the sentence they blurt out when I get sick of listening to them and myself or an associate swiftly produces a knife to place to their throat. It's the line she really should have opened with.

It goes straight to my heart. Before I've even thought or understood the implications, "Say that again! Say that again and know that if you're lying, I will find you, and I will skin you."

I don't know what Holmes and Pawn Johnny are doing anymore. Very likely they're hardly reacting at all, and only waiting to see if there's an opportunity for them in this. An opportunity.

Oh yes. Opportunity is definitely the word of the moment. An opportunity. A golden, glorious opportunity.

That voice on the line, that woman who just took out a golden key and opened out the pearly gates of heaven to piss down light on me, and Holmes, and all the undeserving little lice that get between, she is calmly obedient, and repeats, "I can give you their hearts."

She doesn't need to explain. Questions like 'who?' are not for people like me to ask. To have gotten this far, to have even gotten my number, she knows who. And it's that word 'their', that plural, that makes her so wonderfully important.

Out of a moment gone to shite, roses are suddenly blooming.

She tries to go on then. "Wait," and I put her on hold. She requires my full attention now. Demands it. And I no longer need this paltry excuse for a parlour scene. I'll see dear old Lanky-legs there again, and soon, and it'll be much, much more fun than this.

He doesn't mind me taking these first few steps forward. Watson does. We're looking at murder again, I think. Me, getting barrelled into the pool, stranglehold, all very dramatic. And my mobile full of chlorinated water with that woman on the far end suddenly unreachable. He better not even try it. I'm hoping if he starts to get up, Moran'll do something about it. Anyway, I step forward too close to that lovingly crafted Semtex waistcoat and Holmes readjusts his grip on his weapon. Nothing happens. Really he should be shot, coming that close to pulling the trigger. Don't get me wrong, I'm glad he's not dead, but it means Moran is hesitating, is off his game. I've put him off too, it seems.

That bloody bomb… People don't understand the work that goes into that. Not to mention the expense. And all the hassle of kidnapping Watson, getting him fitted up. I won't say it wasn't a laugh, one for the Christmas video, but… looking down at it now, it just seems like such a waste. I'm not sure if it's Holmes I'm talking to, or that poor, sad-looking empty jacket; "Sorry… Wrong day to die."

"Get a better offer, did you?"

No, Sherlock, darling, love, sweetie, angel-drawers, we're not doing the 'absurd moment' bit anymore. We've moved on now. I'm trying to be genuine with you. Show a little bloody appreciation. You're looking at the only other person on earth who could ever feasibly treat you like an equal. Show a little fecking appreciation, s'il vous plait.

"You'll be hearing from me, Sherlock." Because if he's not going to be civil, I'm not going to be civil. Even when I turn my back again, he doesn't lower the gun. It's very clear that I'm leaving this time, and he still feels the need to see me out of the room. That's offensive, isn't it? I'm not the only one alive who would find that offensive? Wouldn't you be offended? I'm trusting him not to use it and all he can do is stand there like he's considering it anyway.

It makes me a little vicious, I'm afraid, with my new and most valuable contact. As I take her off hold, I'm overcome with a burning need to make sure she knows exactly where we both stand. "If you have what you say you have, I will make you rich. If you don't, I'll make you into shoes."

Pushing through the door, I snap my fingers. Not just so Moran will know to bail out for real this time, but to break the spell. To make him lower that bloody gun. To make Watson get up from worming around on the floor like a scared child. And, if I'm totally honest, to switch myself off too. Take the adrenaline down a notch, slow the heartbeat. Get ready, not to die or to be matched, but to do business.

"I wouldn't have called you," she says, "Unless I was sure." She says that with distaste. Threats, it seems, don't wash over her as they do me. She's not offended, not angry… she's disappointed in me, that I'm so weak as to have to make threats. I like it. It's brutal, but I like it. "It's what you want, isn't it? Both the Holmes brothers, totally, absolutely. Their still-beating hearts."

"Now how would you know that?"

"Isn't that what you want?"

"It is," I admit to her, candidly. "It is very much what I want. You wouldn't play around with what I want, would you?"

"No."

"That would be unwise." I say it lightly, as though teasing.

And she, teasing right back, "Oh, I'm sure." She's laughing. Not so you'd know it, not so it becomes a problem between us, but just a little edge on her voice, laughing at me asserting myself, my silly little alpha-status play.

I don't mean for there to be a pause. Somehow one manages to happen.

She breaks it, "This is where you tell me to name my price, Mr Moriarty."

Ah, now, that's a bit much, dear. A man could get annoyed, being spoken to like that. "Is it now… Extortionate, I'll bet."

"Not at all. The country will pay me what I'm owed."

Oh, there are so many questions there. You could go blind with all the questions on that one. Talk about your loaded statements. But it's unprofessional to just fire a barrage at her, so I pick the most prurient, the one which applies to me, the only one that really matters, "Then what exactly do you want from me?"

"Expertise. You help me get what I want out of dear old Britannia, and in the process, you get your own hearts desire." That's 'hearts'. A simple plural. No possessive apostrophe. My hearts, desired. How very clever, how very classy. Elegant.

"What do I call you?"

With triumph, and relief; "Adler. Irene Adler. Where can I find you?"

"Don't be so forward. I'll find you, Ms Adler."

And with this, I am breaking into night air. I use the sound of the door and the change of atmosphere to hang up on her with a little style, a little grace. Moran is already waiting with the cab. I jump in the back, sit on the seat behind the empty passenger, so we can talk and I still look like a fare.

"What happened there?" is how he greets me, and with such utter incomprehension you'd think I'd sprouted wings and a tail in there and flown out via a fiery portal.

"You heard the detective," I tell him. "Better offer."

And as much as my heart breaks, for dragging my dear aforementioned detective all the way out to this arbitrary place and then denying him the satisfaction of a proper climax, like the worst kind of pricktease, I settle a little, there in the cab. It doesn't sting so much. Because I know, when we meet again, when it all comes together all over again, it'll be ten times better. Neither of us will be walking away next time. This, tonight, let's just call this a dress rehearsal.

A better offer? Sherlock, you great daft sod you, you have no idea…

[For HayleyC. I was too much of a coward to PM and thank Hayley properly, after my little hiatus. This is the best I can do]

I always felt like Belgravia would be the most interesting episode to write the 'other side' of - the Moriarty angle. I wrote this as a one-shot but I could see it continuing, maybe. I don't deserve it, after all this time, but if anybody has any thoughts or feelings, feel free as ever to let me know.

Hearts,

Sal.