A/N: So sorry I took so long in writing this one – I didn't want to be clichéd, and disappoint myself! As a result, this chapter is particularly long. It is un-beta'd, so I would be glad of constructive criticism :)

Warnings: As for previous chapters, except additionally, mention of suicidal thoughts.

xxRegretteRienxx

Sherlock lay in bed listening to John move about the flat. There was light swearing as he visited the bathroom, preceded by a strange, choked sound that Sherlock couldn't quite identify without being able to see John's face. It was part frustration, part laughter, but that second element didn't make sense, given John's current mood, so Sherlock dismissed the flawed conclusion.

John inevitably then proceeded to the kitchen, bypassing the bedroom without so much as a glance in. Sherlock waited until he heard the kettle switch on – John would be slightly preoccupied – and then meandered downstairs himself, not bothering to dress. He perched on the armchair and steepled his hands as he continued his efforts to kickstart his brain.

His drug kit was still laid out on the coffee table, he noticed, with a small, self-deprecating huff.

John hadn't seen him come into the living room, but now he turned around with the mug of tea in one hand, and a couple of biscuits in the other. He didn't seem surprised at Sherlock's sudden materialisation, but the groan of exasperation he emitted upon seeing Sherlock had distinctly less of a note of fondness in it than usual.

Sherlock refrained from quirking an eyebrow in response to John's curious behaviour; cautious that excessive analysis would further antagonise the doctor.

"Couldn't be bothered to get dressed?" John asked rhetorically, predictably taking a seat furthest away from Sherlock, from the drugs, from the near-empty bottle of vodka.

Sherlock eyed the vodka warily. He should have just given it away when Mycroft had presented it to him in that ridiculous gift hamper a few months ago in reward for solving yet another of the British government's tedious cases. Why they couldn't run effective screening of their staff was beyond him. But he'd solved the case and been given...this. He wanted to smash the bottle, hurl it out the window, break something, but that truly wouldn't solve anything, and would undoubtedly make a loud noise, which Sherlock didn't think he could handle at the moment.

"You're not dressed, either," he pointed out, unhelpfully.

John sighed. "At least I'm clothed, Sherlock." he replied, not even looking in Sherlock's direction.

Interesting. Aside from any other hang-ups, John never had any qualms about seeing another person's body, except in deference to the others' sense of decorum, and since Sherlock had none of this, and John knew it, there was therefore something else, something different in John's perception of nudity. This led Sherlock again to conclude that whatever had upset John last night was of a sexual nature.

"Go on, then," John sighed. "What have you managed to deduce so far? Have you figured out why I could possibly have any problems with your wonderful, flawless self?" There was a distinct undertone of anger in John's words, but Sherlock took the fact that he was still in the flat, still even talking to him, as a good sign.

Best to tread carefully, though.

"I took some cocaine last night," Sherlock began, knowing that pointing out the obvious would be perceived as less invasive – it was ridiculous how people attached emotional significance to Sherlock's observations, but nonetheless.

"How very clever of you," John responded, and Sherlock knew that he wasn't just being sardonic about Sherlock's observational skills, but also his decision to imbibe in the chemicals again, despite John's repeated advisements against the habit.

"And drank a significant amount of alcohol." Sherlock continued, not acknowledging John's comment.

"Better and better," John declared. "And what does a combination of cocaine and alcohol do to the human anatomy?" he was being patronising now, and it unnerved Sherlock.

He had to find out what had happened to instigate this behaviour in John. John wasn't bitter, John wasn't needlessly violent, John wasn't uncomfortable and stand-offish when Sherlock decided to go around the flat in the nude – although, he did often recommend clothing during the cooler months, an expression of concern which, in itself, served to warm Sherlock up.

"Poor judgement," Sherlock began to list the symptoms that he was perfectly aware of, "heightened energy, lowered inhibitions, greater tendency toward violent acts or sexual activity," the stiffening of John's posture did not go unnoticed, "increased pulse rate, respiration, perspiration...and complete disregard of others, in favour of meeting their own desires."

John snorted, in a 'you can say that again' manner. "Bravo." he said dispassionately. "What else can you deduce?"

Sherlock's eyes narrowed. "You weren't home until late last night," he noted. "No dinner plates here, or in the kitchen, so you ate out. I...can't remember whether you had a shift at the clinic yesterday," Sherlock said, not meaning for the admission to be so plaintive.

John's eyes darted over, but he disguised his concern efficiently, behind a veil of anger. "Serves you bloody right," he muttered. "Maybe you should continue with the vodka and cocaine cocktails. See how much you can lord it over us mere mortals when you start needing assistance to tie your own shoelaces."

John's words struck Sherlock hard. He feared dementia, feared the loss of dignity, of independence, the slow diminishment of awareness until people couldn't stop the expressions of pity taking over their faces every time they saw you, or thought about you. He didn't want to be reduced to that, couldn't imagine himself so confined.

He struggled to subdue the emotional response, and searched his mind – what clothes had John left in the bedroom? That would say whether he'd been socialising or working...but his memory failed him.

"I was working." John relented, finally.

"Thank you." Sherlock responded in a vehement whisper of relief.

"Working late, so you came in, and saw me with my kit everywhere...I would have wanted you to entertain me, but you would have been uninterested, possibly a combined interest in getting yourself some rest as well as trying to ensure that I hadn't taken too much – "

– I hadn't, he refrained from saying; John was unbudgeable on the matter of how safe Sherlock's supply was, or how careful Sherlock was in measuring out doses. John didn't want to hear Sherlock's arguments about the natives of Southern America using coca for years – all of that sort of paled in comparison to the experience of hordes of junkies that filled the clinic every week. Well, maybe 'hordes' was an overstatement, Sherlock conceded, but the amount that John complained about these patients certainly gave the impression of an endless stream. And 'junkies'. Who came up with that ridiculous name? Sherlock was not a junkie. An addict, certainly, but the product Sherlock used was far from being 'junk'.

Sherlock looked up suddenly; he'd been lost in his thoughts a little too long, and John hadn't said anything either.

"So you took me to bed?" Sherlock prodded, and John nodded slowly, rubbing his forehead with a pained expression.

"Please tell me what I did," Sherlock was practically begging now. He had never gone so long without knowledge. It was agonising.

John sighed, but didn't elaborate.

"I have no data!" Sherlock shouted, unable to cope with the foreign state anymore.

John glared at him and stomped out of the room.

Sherlock dashed after him before realising what he was doing, and plucked at John's sleeve.

John shook him off abruptly. "Fuck off, Sherlock."

They burst back into the bedroom, and Sherlock stamped his foot in frustration, not even caring that he hadn't done that particular temperamental gesture in years. John's movements around the flat were mirroring how very little their conversation was progressing.

The bedroom was providing Sherlock with more evidence, however, and he could now see the full cup of coffee gone cold on the chest of drawers, the pair of John's work trousers on the floor, distinctly rumpled in a manner not merely consistent with being discarded on the floor. Too many creases around the crotch. Additionally, they were stained from ejaculate.

John hated the feeling of ejaculate in his trousers. Sherlock knew this. Therefore, he avoided sexual interaction with John in circumstances where this result was liable to occur – even when he greatly desired sexual interaction in such circumstances.

Well, usually.

Mostly.

Sometimes.

He tried, damn it! It wasn't his fault if he was particularly excitable of late – he didn't usually have anyone around who was willing, interested, and interesting.

John was like a rare, endangered breed, and Sherlock didn't want him to vanish. If that meant a few insignificant sacrifices, then so be it. It was the big sacrifices that really challenged him.

"Did I...touch you last night, John?" he asked hesitantly, not wanting to know the answer, but needing to ask anyway. He had an impulse to block his ears against John's reply, to put on a childish display of avoidance, but a stronger will caused him to lift his gaze to John's face. If he'd done something horrible, he had to find out.

John's face was bitter, unrecognisably ugly, and he continued fidgeting angrily around the room, purportedly getting clothes together for the day, but most inefficiently, most disorganisedly.

"What a very technical term, Sherlock. You see that on police reports all the time, don't you? 'Victim was touched by the attacker, before being murdered.' Yes you did touch me last night. And then you jerked me off against my express wishes, and then you decided it would be funny to imitate me when I came!" John slammed a drawer shut, causing Sherlock to jump. "You betrayed my trust on so many levels last night, I can't even begin to think of forgiving you!"

Sherlock quelled the knot of guilt, and murmured the best, worst, and only excuse he could think of. "It wasn't me. I would never do that to you. It was the drugs."

It sounded weak, even to himself, but what he wanted John to understand was that he would never do it while sober. He would never do it deliberately. He needed John to realise just how highly he regarded him.

"Oh, for fuck's sake, Sherlock!" John exclaimed, with zero tolerance for such a blatant dodge of responsibility. "Then the drugs have to go! I don't want to share my bed with them! I want to share my bed, and my days, and my life, with you!"

It wasn't the first declaration of love and commitment John had made in regards to their relationship, but it took Sherlock by surprise anyway. John still wanted to be with him, despite his gigantically monumental and numerous fuck-ups.

"You want me to go to rehab." he concluded with a slightly mournful tone to his words.

"Yes, Sherlock." John agreed. "You don't need the drugs, and I don't want them. Our life would be just vastly improved without them. I think rehab would be a fantastic idea."

Sherlock sat on the edge of the bed; agitated by the information about the prceding night, and anxiously debating between the horrors associated with rehab (which hadn't worked during his previous visits in his youth), and with John leaving, respectively.

"I don't think I can do it." he confessed, and hated himself for sounding so pathetic.

"If you don't do it, you won't be allowed to work on any cases anymore." John explained, stern, but not cruel.

"I know." Sherlock whispered.

"If you don't do it, I'll tell Mycroft that you're using again." John persisted.

"I know." Sherlock repeated. It didn't scare him. It was the punishment he expected, he associated with his habit.

"If you don't do it," John was whispering as well, now, and knelt in front of Sherlock, gently taking his hands and looking him in the eye with a steady gaze. "I will leave. And probably you'll figure out where I am, and probably you'll follow me if I continually move house. But I won't love you with the drugs, Sherlock. I won't be able to. Now which life do you think you can live?"

Sherlock bit his lip and looked down. He couldn't deal with either situation. If he took the therapy, he'd be isolated in a cold, bland, clinic, surrounded by idiotic, plastically friendly and concerned healthcare workers who he hated. He'd be kept away from John, away from his real life, bored, and in horrible pain. And Mycroft would judge him. He always did.

On the other hand, if John left, he wouldn't be able to continue. He might as well kill himself. Take a blissful overdose and vanish out of existence. Escape. But that, too, was no solution, as his actions would undoubtedly cause John pain. People always did mourn the dead, no matter how nasty the deceased had been in life. And John took it hard when a stranger died. How would he respond when it was someone he cared about?

Sherlock couldn't do that to him. He was torn and trapped.

"Sherlock?" John pried gently, using his thumb to sweep away the tears Sherlock hadn't realised he'd shed.

Sherlock grabbed his hands desperately. "I don't want to be away from you," he declared passionately, and kissed John's hard-working hands in a bid for forgiveness.

"Then go to rehab," John repeated, patiently.

"I'll still be away from you!" Sherlock cried. "I'll be all alone and bored and I'll hate it and rehab doesn't even work properly!"

He was shouting, raving, and terrified, because he knew that this meant that John would leave him.

"You've been to rehab before?" John asked, surprised. Of course he hadn't known. He wasn't naturally inclined to the deductive reasoning that Sherlock was, after all.

Sherlock nodded mutely.

"Well, it'll be different now. I'll look after you on your weekends at home. That's got to be healthier than going back to the Holmes residence after a week of therapy!" John chuckled, attempting to finally lighten the mood.

"Weekends at home?" Sherlock asked, sure he'd misheard.

"They didn't have that treatment program when you went before?" John mentally re-allocated the age Sherlock must have been during his first attendance of rehab, but made no comment. "It's been found that contact with loved ones, as long as there is no opportunity to obtain drugs again, can increase the effectiveness of therapy." he explained.

Sherlock rubbed his nose furiously on his wrist, and cleared his throat. "I...wasn't aware of that program." he admitted in a shaky voice. "What else can I do?"

John tried not to think of how horrendous the rehab experience would have been for a much, much younger Sherlock being locked away for months on end with no decent contact with his loved ones – not so much meaning his family, as his various brain stimuli. He climbed onto the bed, and leant Sherlock against his shoulder. "I can visit you during the week during visiting hours, you can call me or I can call you on the room phone, you can have any books you like, and you can have your violin." He stroked Sherlock's bicep gently while listing these features, and the detective seemed to be somewhat calmed.

"Can I take my experiments with me?" Sherlock asked, a more-familiar tone of curiosity returned to his voice.

"No, Sherlock. Of course not!" John couldn't help an affectionate burst of laughter, but Sherlock huffed at the response.

"How tedious."

"But you'll go?" John needed to know for sure.

The silence before Sherlock's answer was endless, and John wished he'd sat in a position where he could see his expression. Not that that would probably help – the man was infinitely talented at disguising his emotions.

Finally, the words that John needed to hear were voiced.

"Yes, John. I'm sorry."

-END-