Euston station. Night time, but the place is brightly lit and still very busy. Among a number of other travellers, John is walking across the greenish-black flagstones of the concourse, his overnight bag and a small plastic bag from a sandwich shop in one hand. He heads towards the departures board and scans it for his train. He finds the 8:35 to Carlisle. A notice in bright red letters blinking underneath the destination and the departure time reads "DELAYED - 30 mins". John sighs in annoyance and gets out his phone.

221b Baker Street. The living room. Sherlock is still in his armchair, flicking through a book on his lap, his mind obviously on other things. After a moment, he throws the book down onto the coffee table. The book lands on top of the newspaper that Mycroft left there earlier, covering most of the headline and the picture underneath it so that only "12 Dea- - -rth Leeds" can still be read. The book on top is entitled "The Dynamics of Combustion". Sherlock gets up from his chair and starts pacing, now randomly picking up objects from the dining table and dropping them again without looking at them, now gazing out of the window into the night. Outside, it has started to rain. There is a sheen of drizzle on the window, slightly blurring the view of the street below. It appears to be deserted.

Euston station. John has found himself a seat somewhere and has unpacked his sandwiches. He's got started on one of them, but his eyes are on the phone in his other hand, shaking his head as he – probably not for the first time - hits a speed dial but gets no answer. A tannoy announcement rings out through the concourse.

FEMALE COMPUTER VOICE: Ladies and gentlemen, your attention please. The 8:35 Virgin service to Carlisle, calling at Warrington Bank Quay, Wigan, Preston, Lancaster, Penrith North Lakes and Carlisle, is currently running approximately 60 minutes late. We apologise for any inconvenience.

John glances up again at the departures board. The notice underneath his train now blinks "DELAYED - 60 mins". He rolls his eyes.

221b Baker Street. The living room. Sherlock is still prowling around the room like a caged animal. The third time he passes the dining table, he stops, squats down and picks up his violin case that has been stowed under it. He lifts it onto the table, opens the lid and takes out the instrument and bow. He tunes very roughly, and launches into what may be the opening bars of the violin part of the Dies Irae from Mozart's Requiem, or maybe just something of his own. As suddenly, he breaks off again, lowering the violin and the bow until his arms hang limply at his sides, staring at the carpet. Then he turns, replaces the bow and runs his free hand pensively along the plushy dark green lining of the case. He hesitates for a moment, then digs two fingers into a gap between the fabric and the casing where the lining is beginning to peel off, and fishes out a miniature white paper envelope, about the size of a large stamp. He pockets it, carefully replaces the violin in the case and closes the lid with a snap.

Euston Station. John is pacing back and forth in his corner of the concourse, his phone at his ear.

JOHN (under his breath): Come on, Harry, pick it up.

He turns, and the departures board comes into his view again. He glances at it, then does a double take. The red "DELAYED - 60 mins" notice has been replaced again. It now reads "CANCELLED". John lowers his phone and groans in frustration. A moment later, another tannoy announcement comes on.

FEMALE COMPUTER VOICE: Ladies and gentlemen, your attention please. The delayed 8:35 Virgin service to Carlisle, calling at Warrington Bank Quay, Wigan, Preston, Lancaster, Penrith North Lakes and Carlisle, has been cancelled due to extensive damage to overhead lines caused by severe weather throughout Cumbria and Lancashire. We apologise for any inconvenience.

221b Baker Street. Sherlock's bedroom. Muted light from the lamp on the bedside cabinet between the bed and the open door. Sherlock has taken off his dressing-gown and his shoes and is sitting cross-legged on his bed. In front of him on top of the sheets there is a small tray. On it is the paper envelope we saw earlier, now unfolded to reveal its contents – a little mound of white powder. Next to it on the tray are a tablespoon, a cigarette lighter, a syringe and a needle, the latter two still in their transparent packages, an antiseptic spray, and a rolled-up bright blue tourniquet. All the equipment is scrupulously clean and arranged with rigorous geometrical precision. It looks more like an alignment of surgical instruments in an operating theatre, or like the set-up for a scientific experiment, than like what it really is. Sherlock contemplates the arrangement for a moment with his chin resting on his folded hands. Then, without hurry, he picks up the spoon and the lighter.

Euston station. John is standing at the information desk on the concourse, talking to the uniformed man sitting behind it. The man types some data into his computer, checks the results on the screen and shakes his head regretfully. John nods resignedly, picks up his bag, turns and walks towards the station exit.

221b Baker Street. Sherlock's bedroom. In close-up, we see Sherlock's fingers open the package with the needle, take it out, pick up the already unpacked syringe from the tray and attach the needle to it. His movements are very controlled, very systematic, relentless in their calm efficiency.

Inside the back of a cab. John is being driven through the rainy London night. He's looking out of the car window without really seeing anything, lost in thought. Suddenly his phone rings. He digs it out of his pocket and checks the caller ID.

JOHN (taking the call): Harry, for God's sake! I've been trying to get through to you for hours. Listen – (He breaks off, instead listening himself. After a pause, impatiently) Yes, I know, I know. Listen, I can't make it tonight, my train's been cancelled and there's none til tomorrow, if then. (Another silence as he listens to the reply.) No, heavy weather up north, apparently. Lines damaged. That sort of thing. (Another silence. Then John frowns in utter confusion.) What do you mean, not a breath of air where you are?

221b Baker Street. Sherlock's bedroom. Sherlock, on his bed, unbuttons the left cuff of his shirt and rolls up the sleeve as far as it will go. He picks up the blue tourniquet, winds it around his bare upper arm and pulls it tight.

Inside the cab. John, having finished his phone call, is looking out of the window again, his brow furrowed, but now clearly paying attention to where he's going. After a short moment of streetlights flashing past, he leans forward towards the driver.

JOHN: Right, this is it.

The cab slows down and stops at the kerb.

221b Baker Street. Sherlock's bedroom. A close-up of the syringe being loaded with a yellowish-brown liquid. Then the hand that holds the syringe tilts it upright. Behind it, Sherlock's face comes into focus, his brows knit, critically checking the level. He hesitates for the shortest of moments, then lowers his hand towards his left forearm, which he has braced on his knee. The point of the needle is inches away from his skin when -

JOHN (off-screen, from the direction of the open door, in a voice of imperturbable calm): You're not going to do that with me standing here and looking on, are you?

Sherlock freezes, his hand with the syringe suspended in mid-air.

SHERLOCK: But you're not here, John. You're on your train to Carlisle.

We cut to John, who stands in the doorway, still in his jacket, a moist sheen of rain covering his shoulders and his hair, looking down at his friend with an expression that is hard to read. There is no shock in it, in fact little surprise, and certainly no trace of pity. After a moment, Sherlock un-freezes, exhales audibly, lowers his hand, carefully holding the syringe upright so it won't drip, and looks up to meet John's gaze with a strange mixture of defiance and resignation on his face. John crosses his arms and nods towards Sherlock's hand.

JOHN (slowly, choosing his words with care): So. What exactly is it that you find in there that you can't find anywhere else?

SHERLOCK (disdainfully): Don't make it sound like a love affair, John. (He contemplates the syringe in his hand, turning it this way and that.) It's a means to an end. Nothing more. A shortcut.

JOHN (calmly): A shortcut to what?

Sherlock shrugs.

SHERLOCK: Taking my mind off things.

John nods in mock-understanding.

JOHN: Oh, of course. Yes. I see.

He walks over to the bed and sits down at its end, on the very edge of the mattress, then leans forward, capturing Sherlock's gaze and holding it unflinchingly for close on half a minute. When he speaks, his voice is low but resolute, almost stern.

JOHN: You give me one reason, one compelling, irrefutable, unchallengeable reason why you need to do this, and I promise you, I will walk away and let you.

SHERLOCK (with a wry smile): You're very sure of your case.

JOHN (standing his ground): Are you?

With a sigh, Sherlock puts the syringe down on the tray in front of him and folds his hands in his lap. He seems to be looking inward, a range of expressions passing across his face, from cynical to wistful, from wistful to pained, and hence, after a moment of an intense struggle that shows nowhere but in his eyes, to absolutely bleak. John is watching him from his place at the foot of the bed. He waits until Sherlock's face is entirely still again, then straightens up.

JOHN: Alright. Sorry, I win.

He leans across, reaches up to Sherlock's left arm, loosens the tourniquet, lets it slide it down to Sherlock's wrist as if to take it off, then quick as lightning slips the loop over Sherlock's right hand as well and - not exactly gently - jerks it tight again, effectively tying Sherlock's hands together.

JOHN: Now excuse me for a moment. I need to flush something down the loo.

He picks up the tray, gets up from the bed and without a single backward glance walks off into the bathroom.

221b Baker Street. The bathroom, brightly lit. John drops the tray and everything on it into the washbasin with a clatter. He picks up the syringe and breaks off the needle with an expert twist. His movements are precise but a little jerky, his anger showing through. He rolls the needle into a thick wad of toilet paper and bins it. Next, he empties the contents of the syringe into the toilet bowl and flushes them down, then pulls the syringe apart and twists the plastic pieces in his fingers, too, until they are useless. They, the opened packages and the cigarette lighter join the needle in the bin. With the spoon in his hand, John hesitates, but then turns it over and looks at the underside, where it is blackened with soot. John grimaces in disgust and throws it into the bin, too. Then he turns the tap on and begins to wash his hands, rubbing them vigorously together.

221b Baker Street. Sherlock's bedroom. Sherlock is still sitting on his bed, now with his back against the bed-head and the back of his head against the wall above it, his legs drawn up and his arms on his knees. His hands are still tied together with the blue strap of the tourniquet, and his eyes are closed. There is a sound of approaching footsteps, and Sherlock turns his head and opens his eyes just as John reappears in the doorway. There is a moment of silence while they look at each other. John is standing very still, his arms hanging at his sides. In Sherlock's face, the eyes are the only things that seem alive, beautifully desperate and desperately beautiful.

SHERLOCK (tonelessly): So, what now?

JOHN (squaring his shoulders): Now? Now you can lie down and sleep.

Sherlock doesn't move.

JOHN: C'mon. I'm waiting.

Sherlock holds out his bound hands to him in a wordless plea.

JOHN (coolly): I don't think so.

Sherlock gives him an exasperated look, then without another word slumps down on his side and curls up, facing away from John. John sighs, then sits down on the bed, his shoulders against the bed-head, crosses his ankles and settles down to his watch.

221b Baker Street. Sherlock's bedroom. Grey morning light filtering in through the blinds. Seen from above, Sherlock and John are lying next to each other on the bed. Sherlock is still curled up on his side. He seems to be deeply and peacefully asleep, the strap of the tourniquet still in a loose circle around his wrists. John, on the other side of the bed, is on his back, also still in last night's clothes, one hand behind his head, the other extended towards his friend, almost but not quite touching. His eyes are closed, too. After a moment, the silence in the room is broken by the muted beep of a text alert on a phone. John opens his eyes, blinks a couple of times, then rolls over and takes his phone out of his jacket on the floor by the bed. He hits a button and frowns blearily, trying to focus on the message that has appeared on the screen. It reads:

John – thank you for your cooperation. Trains to the north-west will return to schedule at 8:00 a. m. Should he still be asleep, please check his sock drawer, the binding of the Thai Cuisine cookbook on the top shelf in the kitchen and the lining of his violin case before you leave. Mycroft

John runs his hand over his face and shakes his head in disbelief.

On the other side of the bed, in close-up, eyes still tightly shut, Sherlock smiles a wry little smile.

THE END

October 2014