Author's Note: And here it is, the third and final installment to the story that was never meant to be more than a oneshot in the first place. I do believe the conclusion is fitting, and I hope you all do, as well!

Part III: Choice

They found Mrs Hudson hovering just outside the door, leaning one shoulder against the wall and wringing her hands in front of her, an expression of distress adding further wrinkles to her already-lined features. It was obvious that she had heard most, if not everything, that had transpired, and the thought was causing her no little measure of anxiety. Mycroft let out a soft breath and willed himself to pause his stride; it was likely, after all, that the woman would have to cope with many more nights like this one, especially if Doctor Watson happened to be absent, and for that, if nothing else, he owed her at least a word or two of reassurance, however paltry.

"I presume you have at least a vague notion of the current situation, Mrs Hudson," he said, looking squarely down at her, and if his voice was rather frosty, he hardly thought anyone could blame him for that.

She nodded, twisting her fingers together as though she were trying to knot them into rope. "He's in a bad way, isn't he?" she asked softly, with a betraying glance toward the doorway, where John, thorough man that he was, had remained to keep a careful vigil until someone else could take his place.

"To put it delicately, yes."

Mycroft hesitated and closed his eyes for a brief moment, but he had had far too much experience in the handling of fragile conversations to even think of putting off further explanations. Sherlock really did drive him to it. He lifted his chin slightly.

"If you weren't already aware, Mrs Hudson, I feel obliged to inform you that my brother has an unsavoury dependence on certain substances, narcotics in particular. While you may have noticed that nicotine is his drug of choice, there have been and likely will be times in the future when this is not enough, in which case, cocaine and morphine appear to be his greatest preferences. I take it you are in complete agreement when I say the latter two are to be avoided or prevented if at all possible."

She let out a soft noise of dismay, bringing one clenched hand up to her mouth and looking alternately between Mycroft and John as though waiting for a contradiction from one of them. "Oh, I know he used to smoke – nasty habit, I won't even allow it in here most times – and then he puts those things, those patches, on his arms a lot these days – says it helps him think – and I don't – "

"Well," Mycroft said, cutting her off, "this is rather more serious than that, isn't it?"

It was a rhetorical question; he gave her no chance to respond, but turned his head back to John and gave the doctor a short, crisp nod. "If you wouldn't mind, Doctor Watson" – and he gestured pointedly in the direction of the sitting room. "Mrs Hudson will keep an eye on him until we're finished."

All the same, he did not miss the hesitation with which John complied, the way his hand stuck to the doorway as long as possible before falling with visible reluctance back to his side. He did not want to leave Sherlock. Understandable, to some extent, but at the moment, what Mycroft had to say was far more important than anything the doctor could possibly hope to accomplish by staying in Sherlock's immediate vicinity. With so many people up against him, the danger was past – for now.

Doctor Watson put a gentle hand on Mrs Hudson's shoulder as he turned away, murmuring a soft "Thanks" before she scuttled quietly into Sherlock's bedroom. Mycroft said nothing until they had reached the sitting room again, but found to his surprise that when he did open his mouth to begin, John had already made the first strike.

"No one told me about this. Bothered, even."

His voice was unexpectedly cold, and not for the first time, Mycroft found himself wondering how far the unknown depths of this man extended. He prided himself on his ability to read an individual at a glance, but John Watson seemed to defy definition.

"Surely you had your suspicions," he responded evenly, folding his hands neatly behind his back. "Sherlock can be terribly unsubtle about some things, and I'm afraid this is one of them. Well, you're a doctor. You know the signs."

"Maybe," John conceded flatly, in a harsh, unfriendly manner that was hardly a concession at all, "but there haven't been any, not recent ones. He hasn't done anything – hasn't even smoked – just the nicotine patches when he's on a case."

Mycroft considered for a moment before answering slowly, "It has been... quite a while. I had foolishly begun to hope that he had made a change for the better, and that any warning I might give you would be, shall we say, pre-emptive in the extreme." He breathed a low sigh, focussing carefully on the rug beneath his feet before flicking a sincerely apologetic glance upward. "You have my apologies for that, Doctor. An error in judgement, on my part."

"Damn right," John muttered.

The doctor folded his arms over his chest and stared steadily, almost disconcertingly, at Mycroft for rather a long time, in a way that suggested he would very much like to kick the elder Holmes out of the flat right there and then and was only refraining from doing so because there was information he needed to know. Mycroft kept his composure, and waited.

"So." John's tone had hardly changed at all. "What's going on, then? How bad is it? How often does it happen – and what the hell do you expect me to do about it?"

"Beginning with your last question, I think you know perfectly well what you have to do about it." Mycroft's voice became suddenly sharper, more insistent, though he was beginning to doubt that an air of authority would have anything less than a detrimental effect on the much-needed cooperation of John Watson. Soldier he might be, but ordinary he was not; that much Mycroft had discovered during their first meeting. "Tonight," he went on, "you have to watch him, you have to stay with him; and from now on, Doctor Watson, you have to be aware that certain extremes will push Sherlock past the point of his own discipline, and when that happens, you have to be ready to act accordingly. My brother is a man of volatile temperament, as you've already had occasion to notice, and he is very much a danger to himself in these cases."

"Yeah, really? Never would've guessed."

"I would advise you not to waste your scorn on me, Doctor," Mycroft told him sharply, with the uncomfortable feeling that underneath the exterior he had spent so many painstaking years polishing, he was not nearly as immune as he would have liked to the subtle stirrings of guilt and disappointment. "Whether or not I deserve it isn't really the issue at hand."

Doctor Watson's mouth had compressed to a thin, hard line, and despite the soft orange light of the lamps in the flat, the shadows under his eyes seemed even more pronounced than ever. "Answer the rest of my questions, then," he said quietly.

"It's difficult to say. For all his logic and his carefully-calculated solutions to life's more obscure problems, my brother is hardly a machine." Mycroft rubbed two fingers over his temple in a futile attempt to relieve the headache that was building there. "It's not always easy to tell how certain – incidents – will affect him; failure, of course, is the most likely."

"You mean like today. At the bridge."

Mycroft nodded. "Sherlock is in constant need of mental stimulus. When he can't get it, or when it is cut off too soon, too suddenly, he resorts to more artificial methods to make up the difference."

"And when he's solved something too late – "

"Exactly."

They stood there in uncomfortable silence for nearly a minute, each, Mycroft presumed, occupied with his own dark thoughts. There was very little he could do to try to soften the blow, but he seriously doubted whether blunting such an inevitable if unpleasant reality might not have the opposite effect, in the end. He wasn't about to risk testing that theory.

"You know," John remarked quietly after a long interval, "the way you explain all that, it just sounds like he's doing it because – because he can't stand to be proven wrong. Like he doesn't want to admit it, so he just doesn't – "

But already Mycroft was shaking his head. "It's far more complex than that, I'm afraid, and nothing I care to delve too much into at the moment. But I think you'll come to see it, in your own time." He turned, paused, and then looked slowly around again to fix the doctor with a pointed, searching glance.

"Always assuming, of course, that you choose to stay. You are under no contract, Doctor Watson. No contract except your own."

He spoke the literal truth, in what he meant to be fair warning, for he knew through painful personal experience that Sherlock was no easy man to live with, even drugs aside. It took a man of a certain character to merely put up with him – someone like Inspector Lestrade – and someone with something even more, something strong and oddly intangible, to take any step further than that.

One month later, when a Chinese smuggling ring seeped into the open in search of a jade hairpin, John Watson was still there.

A month and a half later, when the man known as James Moriarty began his deadly game with the brilliant detective Sherlock Holmes, John Watson was still there.

And ten months later, on a very dark and aching Christmas night, when Sherlock Holmes returned to his flat with the smoke of one cigarette still burning in his lungs and a pale, haunted look he only managed to partially conceal flickering in his eyes, John Watson was still there.

"You have to stay with him, John."

And John Watson stayed.

Thank you! Thank you so much to all those who have favourited, followed, and especially to those who have reviewed (of course, you still have one more to do! ) I've enjoyed writing this very much indeed. Any final and/or overall comments you could leave would just make my day or night or whenever I happen to get them. :)

In a shameless bit of prompting, I would also encourage any and all of you lovely readers out there to take a look at a post-Reichenbach, multi-chapter story that I'm currently working on in collaboration with the ever-brilliant Setep Ka Tawy. It is "Returning to Tomorrow", and can be found on Setep's profile. Heavily plot-based, the story deals with not only Sherlock's return (which is, I assure you, probably not quite as you've read it before) but with an intricate scheme devised by someone we all know rather well. Please take a look, if you've a mind!

Again, your thoughts on this piece have meant so much to me, and thank you for being wonderful readers!