The case had been going on for 10 days now. It was too long. The clues were there but Sherlock couldn't read them. He lay prone on the sofa, his mind going over and over the details, stepping through the crime scenes, in minutia. But he couldn't see. With a moan, he screwed his eyes shut, brought his knees up to his chest and rolled to face the back of the sofa, trapped in his mind.

John frowned as he looked at Sherlock from his chair. The awkward position he had contorted himself into must be painful. The sofa wasn't big enough for his long bones to fit easily, and John was worried about the man. He had never seen him so stumped before on a case, and they both knew that time was running out to solve this one. Lives were in danger, John thought, and huffed. Lives were always in danger when Sherlock Holmes was involved in a case... usually John's.

With a sigh, he got up. "I'll make us a cuppa, shall I?" He said to Sherlock's back. Knowing the detective was unlikely to have heard him, and was even more unlikely to respond, he headed straight for the kitchen. The familiar tasks involved in making the tea soothed him. For once there were no random body parts stored in the fridge, so even getting the milk out wasn't the 'adventure' it was usually. He idly looked round to see what food there was for dinner. Nothing, as usual, it being Sherlock's turn to shop. John smiled to himself in frustration at his brilliant, but clueless flatmate. He was the cleverest man John had ever met, and yet Sherlock was incapable of the simplest of tasks such as remembering to buy milk on his way home. Takeaway again tonight then.

Some hours later the tea was untouched and John had yet to see a sign of movement from Sherlock. Placing yet another steaming mug on the table, John gently touched Sherlock's shoulder. "tea's on the table Sherlock" he said quietly, not wanting to intrude on the detective's thought process "I'm off to bed, see you in the morning". Sherlock didn't acknowledge him, and John took his cup upstairs with him, with the intention of spending some time reviewing his latest blog entry before sleep. He knew he couldn't help Sherlock when he withdrew into himself like this. The best thing he could do was sleep and keep himself well and ready to do whatever Sherlock wanted him to do tomorrow. "Probably something dangerous, possibly illegal, definitely exciting" he said to himself with a wry smile. He might protest that Sherlock had him racing around following in his wake just so he had someone to show off to, but John loved it really, and would always be grateful to Sherlock for bringing so much colour back into his life. Even if that colour was frequently blood-red.

oOo oOo oOo

It was 4am when John woke. He could hear faint sounds of movement from downstairs which he assumed meant Sherlock had finally found a new insight into the case. With a sigh and a look of longing at the warm cosy bed he was giving up, he got up, pulling a dressing gown on as he walked out of his room. There was no point delaying it - he had tried that when he'd first moved into 221b Baker Street and Sherlock had tended to burst through his bedroom door and talk at him while pacing round the room. Given the choice John preferred to be in the living room for those lectures. He felt decidedly uneasy with the detective in his bedroom, and his jaw tightened as he remembered the last time and how Sherlock had woken him abruptly from a very interesting dream, and how the great detective had been very lucky John had scrambled enough sleep-dulled wits together to hide the evidence of his arousal before Sherlock had noticed it.

With his eyes half shut and his mind still asleep he shuffled into the bathroom. Sherlock tended towards extended monologues when he got going after days of silence, it was best to pee first. He opened the door, to be met with a gasp. His eyes widened in shock at what he saw. He had unintentionally caught Sherlock in the act of doing something very, very bad.

oOo oOo oOo

Sherlock jumped to his feet, a guilty expression flashing across his face before he managed to control his emotions. "What do you think you are doing bursting in here?" he asked haughtily.

"Don't even think about trying that one on me" snapped John, now fully awake. "And you'd better come up with an explanation damn quickly for why you are standing here with a knife in your hand, and blood dripping down your arms. Preferably one that doesn't make me want to throttle you for being so goddamn stupid" The end of the sentence came out in almost a snarl as John fought to control himself while looking at the scene in front of him. He had walked into the bathroom to find Sherlock sitting on the floor with his shirt off, the knife against his arm, in the process of cutting himself.

"I..." Sherlock faltered, and looked down, suddenly lost. John relaxed slightly, unclenching his fists, and reached out, took the knife from his flatmate and dropped it into the pocket of his dressing gown. Taking Sherlock's hands, he pulled the taller man to him so he could inspect the damage done. Without conscious effort he had slipped into Doctor mode - clinical and assessing. Not the first time, he noted, twisting Sherlock's arm to see the silvery scars underneath the new cuts. Absently he wondered how often, and how he had managed to miss this happening under his nose. He avoided looking at Sherlock's face, not wanting to know what he might see there. Guilt maybe, perhaps defiance. Shame? John wanted to focus on the wounds first.

He walked Sherlock into the living room, a hand still around the younger man's wrist. With a gentle push he seated him on one of the dining chairs. With a quick glance at Sherlock's face, to show him the half-smile on his lips, he allowed himself to meet his friend's eyes for a second before sternly saying "stay". He knew he couldn't moderate his tone enough to keep it neutral right now and remove the anger he was feeling, but Sherlock could read him if he gave him eye contact, and would know the anger came from concern.

Walking away he quickly gathered the first aid box and some other supplies. He returned to Sherlock, who hadn't moved. With his daytime clinic Doctor's un-judgmental facial expression in place, John sat on a chair opposite and started work. The familiar tasks of cleaning the cuts and bandaging allowed him to settle his mind. He was aware of Sherlock's eyes watching his fingers with fascination as they disinfected and inspected. Now John could see the damage himself he calmed down. There had been a lot of blood but the cuts were relatively shallow. No serious harm done.

"Why?" he asked quietly, all the while focussing on his hands tending to Sherlock's arm.

"I, uh," Sherlock stalled. "You're the doctor, you tell me".

John looked up at Sherlock, saw the confused look on his face - the mix of emotions flitting across it, and took pity on him. "You hurt yourself." He said simply, "because you can't let go. Because you are trying to solve an impossible case and you haven't eaten or slept in days. You are at the end of your tolerance and something had to give, and this was the way out. You knew the endorphin rush would feel good, and it was the work of seconds to achieve a 'hit'. Close?" he asked.

Sherlock nodded. "It was this or calling my dealer" he admitted.

John couldn't help a slight hiss of disapproval at that. He hated the idea of the brilliant Sherlock slicing into his own flesh, but he despised the thought of seeing him high as a kite, lost to everyone.

"You can't keep doing this, you know?" he said in a gentle voice, looking up at Sherlock.

Sherlock could see the worry and concern on his friend's face, and the touch of suppressed anger underpinning it all. He shuddered slightly. John was his closest friend - his only friend, and he wouldn't like it if Sherlock told him what he saw in the doctor some days - the darkness. Sherlock knew that John thought he had it tightly under wraps, but at times like this, when he was caught unprepared, it came closer to the surface. Sherlock was fascinated by it, by the paradox of the mild-mannered man who shared his life, and this creature of snarling rage and ferocity he kept chained up inside of him. Idly Sherlock wondered how one would go about releasing that, and then soberingly decided he would really rather not have it directed at him. He wasn't sure he would survive it.

Slightly dazed, Sherlock realised John was looking at him expectantly, waiting for an answer. "Not tonight, no" he hazarded.

John nodded, satisfied with that for the time being. "Will you try and sleep for me please?" he asked. "I know every minute is important on this case, but you need to take care of yourself." He gently helped Sherlock to rise from the chair, and led him back to the sofa to lie down. Covering him with a blanket, he waited until the detective shut his eyes, then on impulse reached down and kissed the top of his head. Sherlock's eyes flew open in surprise, and he watched as John smiled down at him. "we'll talk when this case is over," he promised. "Just keep yourself alive and healthy for me until then please". The detective nodded slowly, once, then closed his eyes again as his thoughts went back to the case, tuning out the sounds of John slowly making his way back up the stairs to his bed.

oOo oOo oOo

Two days later, and the case was closed. Sherlock's mind had finally found what it was searching for in the clues, and had made the link which led the police back to the kidnapper. In celebration John had dragged his friend out to Angelo's for dinner, and had even managed to get him to order some food and take a couple of mouthfuls. The wine John was drinking had loosened his tongue, and the two were having a good time, laughing about the ridiculous chase they had ended up in on the previous day, which had resulted in them hiding in a rubbish bin full of rotting cabbages for what had felt like hours.

"I haven't forgotten" said John, suddenly becoming serious. "About the other night, in the bathroom. You and I need to work out a way of stopping that happening again, because I'll be damned if I want to patch you up like that again."

"What do you suggest?" asked Sherlock, intrigued despite himself. He knew John wouldn't insult his intelligence by offering a textbook solution.

"I don't know yet" John admitted, "but I'm working on some ideas." And the conversation moved on to happier things as he prompted Sherlock into eagerly recounting the number of basic mistakes Anderson had made at the last crime scene.

They were quiet on the walk home, each of them lost in their own thoughts. When they reached the front door John stepped up to unlock it, then turned suddenly to look at Sherlock. His eyes were full of concern, but Sherlock noted a gleam of something else in them too. Was it excitement? Anticipation? Lust even? In the orange glow of the street light, Sherlock couldn't be sure, and before he knew it that look had gone, his eyes had dropped, and John was back to being John.

Nothing more was said that night, but the next morning John passed Sherlock a cup of tea and told him in far too casual a voice, which made Sherlock's senses prick with interest, "next time you feel like that, promise me you'll come to me first, okay? I want to help, and I have an idea for an experiment we can try. And if I can't make it better for you, you can do whatever you need to do - cutting, drugs, whatever - and I won't stand in your way."

Sherlock looked at him with interest, noting that John was deliberately avoiding eye contact. Something to hide then. Something he didn't want Sherlock to know just yet. How intriguing!

"I promise" Sherlock agreed readily. He thought the trade off of being subjected to John's proposed experiment was well worth it if he got to find out one of the good doctor's secrets. And John had agreed to allow him his preferred release otherwise. He really didn't have anything to lose.