The fear grew stronger. Despite Sherlock's best efforts, he found himself making excuses not to go to bed. It wasn't noticeable to John because he had always slept less than average and he took care that his appearance stayed normal – he'd had enough of his suspicious looks when the nightmares had first started – but his situation became more and more frustrating as time went on.

He could not work on cases properly if he was scared the whole time. He could not verify facts if he could not go to his mind palace without noticing that it had become a dark and strange place. He did not know how. It was his mind. The building he had constructed. He had known every corner since he was a child. He should have noticed the changes sooner; it felt like everything had changed in a second, but that wasn't possible. Even if he was losing his mind, it didn't happen from one moment to the other. His mind palace must have been infested long before he had noticed any change. He blamed himself. He should have paid more attention. His mind was his most delicate instrument, but he had allowed himself to be distracted by experiments, cases, friends, to be swept away by comforting familiarity, and he was paying the price for it. If he told John, if he told anyone, he would soon be forced to see a doctor; if Mycroft was not already making preparations. His brother would be the first to notice the changes in him, he was sure. He always had been.

Being examined, his mind being torn apart in the attempt to explain what was wrong with it – the thought was more than he could bear. He would conquer the fear because he had to.

Sadly, this decision didn't help when Greg noticed his trembling hands at a crime scene. They were always trembling now, and the feeling that someone was standing behind him had become a frequent companion. He didn't even turn around anymore, so that he was surprised when the DI's voice ran out.

"Are you alright?"

He turned and found Greg frowning at him. His gaze was fixed on Sherlock's hands.

The DI had dismissed John's worry about Sherlock two or three months ago because he had seen nothing to worry about, but he had studied his friend closer since then and had noticed that he seemed distracted at time. He couldn't expect him to be the same he had been when he had disappeared, of course; but he had never seen that look on his face, and he had seen many. He didn't claim to be Sherlock's best friend, or even being regarded as a friend by him, but he knew him better than most. And John had been right. Something was wrong.

He should have known better than to ask Sherlock if he was alright, but it was the first thing that came to mind when he saw his hands shaking, hands that he had watched steadily filling acid in different containers and examining bodies; even when John had been in danger, his hands had never shaken.

As soon as the words came out of his mouth, he expected the dismissive answer "Of course" and he was not disappointed. Sherlock then told him his deductions and all but ran out of the crime scene, John at his heels.

He wasn't even given the luxury of wondering whether he had imagined that Sherlock's hands were shaking when he caught Donovan's eyes across the room and saw that she was worried.

He would have to speak to John again.

Sherlock was furious, but he tried not to let it show as he waved down a cab. He was not angry at Greg; he was angry at himself. He should not allow irrational feelings to rule him.

"Swift exit" John commented as they sat in the cab, and he simply replied, "The case was boring".

It hadn't been, not really, but he wouldn't tell John. He would tell him about it once he had dealt with it. Maybe.

He spent the next few hours experimenting before retiring long after John had gone to his room. He needed the rest, even if he didn't want to sleep.

He dreamed of his mind palace. Until then, his dreams had been of faraway or not-existing places; but this was his mind palace, how it looked now; and he felt instinctively that he looked like he always did when he was walking through the hallways, as he had when he had first started working with Greg and realized the potential that lay in all the information he had collected.

The fear seized him suddenly and unexplainably, and he was running before he had decided to do so. Something was after him. He didn't know how he knew, but something was after him.

He saw a door he had never seen before but simply threw it open and fell into darkness.

It took him a moment to understand that he was in his subconscious, but he felt better. He only had to wish for a light for it to appear, and he sat down near the darkness, determined to find out what was wrong.

He felt someone moved and looked in a face that he had thought he'd never see again.

The thread of fear was not easy to follow. It ran through Sherlock's subconscious and conscious at the same time, and if he had ever been prone to despair, he might have. But he had always loved a challenge, so he happily kept following and losing the thread. He had no idea how Sherlock's true self materialize – or well, whatever he was supposed to call it – or if Sherlock even had an identity like himself.

He might not have. He had been created, recreated as he had been in life, to be locked away; everything in this palace was Sherlock's creation. But there had to be a source of each personality; there had to a place from which it sprang. And so he followed the fear, one of the first instincts of children. He had always appreciated it, instead of fighting it like Sherlock would undoubtedly have.

There had to be a solution. There had to be.

The thread he had been following felt different than the fear that permeated the mind palace all the time now. He had wreaked enough havoc with the nightmares to learn the difference. Sherlock was asleep; he had soon learned that it was easier to follow his feelings when he was. When he was conscious, he suppressed them. He couldn't when he was asleep and his subconscious took over.

There the fear was again. Without caring for caution as he had until this moment, he dashed forward through several floors and finally found another entrance into the subconscious he hadn't known about. They would appear occasionally; he was certain that it could not be controlled, neither by him nor by the consulting detective. While he had grown better at navigating in the darkness and had grown considerably stronger, he would have preferred not to have to dive in when he was so close, when he needed all his strength to focus on Sherlock instead of trying to keep himself together. Also, he had no idea what form Sherlock's conscious would take in the darkness. Maybe none at all.

But that would mean he couldn't win, and a game without the chance of winning was just like one without the chance of losing – none at all. And that would not do.

But he was following the fear, and he hoped – he had to –

There was a light. For the first time, there was light in the dark of the subconscious. It surprised him. Why would there be light?

It occurred to him immediately that of course Sherlock – if he was strong enough, if he was focused enough – would want a source of light to feel safe. If some part of him had fled into his subconscious. He delighted in the irony that this might well have happened as an unconscious defence mechanism. It was certainly clever enough for Sherlock for once.

He gently floated – he could not describe the sensation better – towards the light. The fear was still there, but he couldn't see anyone –

No. There was someone cowering at the edge of the shadows. So typical Sherlock, not to allow himself comfort when it was most needed.

He smiled and moved forward. The shape hadn't moved. As he came closer, it became clearer.

It was Sherlock, but a different version of him. He looked younger. Vulnerable. It was no wonder that he had cracked under the strain and run away.

He wondered if he would know him. Maybe this was a younger version, body and mind, one who had not yet gone through everything the consulting detective had.

He would gladly tell him who he was. What he could do.

But when he walked into the light, he saw immediately that Sherlock recognized him.

He grinned.

"You didn't think I'd stayed chained up when there are games to play?" he inquired, grinning.