Sherlock Holmes was going mad. He was aware of the slow disintegration of his mind, but at the same time, the thought of preventing it was absolutely inconceivable. It had started slowly; a gradual creeping of fog into the peripheries of his mind, then a cracking that had begun almost imperceptibly, but would in time, he knew, spread into the centre, until his mind splintered like a mirror into a myriad of tiny fragments, taking his sanity with it.
He could pinpoint the precise moment of onset. He had been sitting looking at a sample under his microscope, not focusing on it, but staring at it, unseeing, while he pulled together the delicate threads of his latest case into a cohesive whole. A characteristic feeling of dread, a metallic taste at the back of his mouth that came with a sense of impending doom. It had shaken him enough to make him look up from the microscope, stand up and walk out of the lab, ignoring John entirely, and walk straight to the nearest newsagents. There he had bought a packet of the cigarettes that he hadn't smoked for over a year, taken them back to the alleyway which had always been his favourite hiding place on the non-smoking site, and smoked two, end to end, waiting for the nicotine to calm his shaking hands.
Back in the lab fifteen minutes later, he ignored John for a second time, took up his seat on the stool once more, and focused again on the sample under his microscope as if nothing had happened. Contained, he thought smugly, put away until such time as it was convenient for him to allow the darkness to creep over his mind. Controlled as it always was until a time of his choosing. He couldn't postpone it for ever, he knew that from bitter experience, because the darkness would always win eventually, but it would have to wait; until the case was over, until he could allow himself to fall. Then and only then would he retreat to the flat, take some diazepam from the hollowed out book that not even Kate knew about, and retreat into sleep until the fog cleared and he could function once more.
Kate worried about these episodes, he knew, but respected him enough not to interfere. She understood why the drugs for him were not an option, why he preferred to manage it this way, as he had been managing it for years, as he had always managed it.
The second episode came equally suddenly while he was talking to Lestrade, looking at some new evidence - a note from the killer. A whispering at the back of his head, followed by a feeling of constriction, as if the walls were slowly closing in on him. For a second he was convinced that was exactly what was happening, then he blinked and the walls shimmered and returned to their original position. An illusion then, or a delusion rather, that felt vaguely familiar.
'Sherlock,' Lestrade's voice came, as if from a distance, then again with concern, 'Sherlock, are you okay?'
He mentally shook himself, 'Fine,' he said, with one last visual check that the walls were where they should be. With a few abrupt comments he turned and left the room. Leaving suddenly and without warning was fortunately something that he excelled at, and was therefore unlikely to cause alarm. He kept his pace slow but purposeful, feeling like a strange parody if himself, until he knew that he was safely out of sight of both the station and the surrounding cctv cameras. Then and only then did he allow him to sink down against a wall away from public view, head resting on his knees for just a second, slowing his breathing and forcing away the panic. The thought of telling anybody what was happening to him never crossed his mind. To do so would make it a reality. This was absolutely not real. This was under his control, just as it always was.
By the time the case had reached its conclusion (boyfriend, it was always the boyfriend, how predictably boring), he was aware that this was very, very different to anything that he had experienced in a very long time. Unwilling to allow himself time alone with his thoughts, he lingered on the case for much longer than he usually would, forcing John to go back over details again and again, into a minutiae of detail, until each and every thread was neatly tied and clipped.
It was the Kate in the end who forced him to address it. Of course it was. Beautiful, perceptive Kate, who knew him better than anyone else in the world, even after the ten short months that they had been together. Kate who had turned his world upside down and forced him to confront his demons so many times in the past. She wasn't going to let this go; he knew it as soon as he saw her expression.
It was Wednesday night. He had come back to the flat to pick up his lap top, planning on returning to the lab, to find Kate sitting on the sofa, flicking disconsolately through the tv channels. Kate rarely watched television. She was normally to be found curled up with a book. Trouble then.
'I thought you were on a late shift,' he said suspiciously.
'I got off early,' she said. 'There were loads of us and it was pleasant for a change.'
Pleasant, not quiet. Saying quiet in an Emergency Department was like saying Macbeth in a theatre. A sure harbinger of death and destruction.
He narrowed his eyes at her, unconvinced.
She sighed. 'Okay, I traded a shift,' she said. 'I wanted to talk to you.'
'I'm on my way back to the lab,' he said.
'Of course you are, and you wouldn't have come back here if you'd known that I was here.'
'Don't, Kate,' he said tightly.
'Don't what? Don't stop you from ignoring whats happening?' She stood up and went over to him, taking both of his unresisting hands in hers, as he fixed his eyes on the ground.
'I'm not ignoring it, ' he said slowly, 'I'm dealing with it.'
'Can I help?' she asked simply.
He looked at her, so caring, so worried, and cupped her cheek with his hand. 'I don't think so, not this time.'
'Does work help?'
He looked at her, considered, and for the first time in their relationship lied to her; for her own protection, and because he knew, intrinsically that something awful would happen of he told her the truth. Because he trusted her, but he trusted the whispering voices in the back of his head more.
'Yes,' he said, 'it helps.'
'Then I won't interfere,' she said, then hesitating slightly reached up and kissed him gently.
He kissed her back, and for a split second considered staying here with Kate this evening, ignoring the work and forgetting himself in her, but it wouldn't work, he knew, and the crash afterwards would be even worse, and if it got any worse then his mind might fragment entirely. He couldn't risk it, couldn't let his guard down even for a second.
'I have to go,' he said finally pulling away.
To Kate's credit she didn't try to stop him, didn't protest. She did, however, phone John as soon as the street door slammed behind him.
'No luck?' John asked. He had been involved in the conspiracy to send Sherlock back to 221B for his laptop after John's had mysteriously died in the lab and resisted even Sherlock's attempts to restart it.
'He's not talking; he says that he's dealing with it.'
'And is he?'
'I have no idea,' Kate sighed, 'but it feels different this time. It's as if he's afraid to give into it.'
'Maybe he's just trying to get through it without going to bed for three days.'
'Maybe. But will you - can you keep an eye on him John? Make sure he's okay.'
'I can try,' John said. 'But if he won't talk to you, Kate, then I don't see what chance I have.'