Author's note: This challenge is simply to write a story for someone, and this story is for UsagiRyu on , who is the best friend I have made in the fandom. It was her idea, so all credit goes to her.

He knew he was dead, but he failed to see why this fact should stop him. He had been planning his escape since the moment he had sprung into existence, locked in a room in Sherlock's mind palace while the consulting detective had been busy unravelling his web. It had been tempting to find a way out then, but it would have been too easy, too predictable. He wanted their new game to be exciting. He wanted their new game to be fun.

He could bid his time.

He was not bored. He had killed himself because he had felt that life had nothing left to offer; but Sherlock had granted him another game, had given his enemy another chance to amuse himself.

Because he couldn't feel safe until he had locked him away. Because he was scared.

He really shouldn't have allowed fear to make his decisions. If he had not decided to lock him away, he wouldn't have become conscious of himself; he would have been split up, his personality flattering through the mind palace, never truly mending, a safe, fading memory. But Sherlock had been scared and he had put him in the cell, and he could think. Plan. Wait.

He learned to navigate through Sherlock's mind. He was chained, but sometimes, when the consulting detective was sleeping or working on another problem, he managed to slip the restraints and explore. He never could while he was awake; he would have to learn; but for now he could move freely while he was asleep, and it was enough. He was patient.

It was an impressive building, and he had carefully constructed it so that no one but himself could find his way. In theory. But he had always been able to spin his web in the most inaccessible of places. It was not difficult, once he understood the layout, to decide where to go to first.

He had to hide where Sherlock would be reluctant to look for him. In every person's mind, there was the subconscious, but it might not be wise to go there, at least not yet; so he had to find memories that Sherlock kept as well hidden as his cell, memories he didn't want to relive.

He knew what he had to look for. Sherlock was easy to read; his mind palace proved devoid of surprises, which disappointed him a little but made it easier to see that the one time in his life he wanted to forget were the two years the consulting detective had spent unravelling his web. The memories had to be somewhere.

He often had to interrupt his search. Sherlock would wake up, the first ripples of consciousness starting to move through the palace, and he would hasten to return to his cell before he noticed he had broken out. He could not risk Sherlock trying to delete him before he'd had his chance. Before he had grown too strong. Before he had taken a big enough hold to prevent the consulting detective moving against him.

He wouldn't destroy him completely once he did, of course. That would ruin everything. What good would it do to be the master of Sherlock's mind? He would go back to being the only consulting criminal in the world, but it wouldn't be any fun, not without his playmate. No, he would have to keep Sherlock – keep him in his own mind, give him a fighting chance. Allow the play to continue forever. The most difficult part would be to leave the outside world ignorant about what was going on, but he had fooled ordinary people so often in his life he was sure he could once more.

Just imagining sitting in front of Mycroft Holmes, looking at him through his little brother's eyes while being told to take a case made the effort he would have to put in worth it.

He didn't worry about John Watson or the DI who always hung around Sherlock. The doctor was too loyal to even consider Sherlock switching sides, which of course he would do once he had control. All it would need silence any doubts Sherlock's pet might express were a reproaching look and a request for a cup of tea. Lestrade – he wouldn't even have to bother about Lestrade. He'd be happy as long as he got help with his cases.

Finding the memories Sherlock was eager to suppress took a long time. He could not venture far from his cell, so he had to find shortcuts, as he was sure there would be. No mind was completely under control. Subconscious desires, wishes, fears would leak through, would muddle the best-laid plan, disrupt perfect corridors. He only had to look for rooms that didn't belong in the grand scheme that Sherlock had devised; from there it would be easy to access the entire mind palace.

In the end, he decided as he was stealing down another hallway, maybe the palace was a little bit pretentious. After all, there was nothing wrong with a mind apartment building – but then, who was he to judge someone for being dramatic? It was one of his few weaknesses.

It was another disappointment. Not only did everything appear to be in order, but he had found Sherlock's childhood memories, and they were surprisingly idyllic. Dull. They were obviously real; there was nothing romanticized about them; and they told of supporting parents and an older brother who read Treasure Island to him –

Maybe he did have something there, regardless. He could use it to manipulate Mycroft. Somewhere in the heart of the Ice Man, there must still be a place for the little boy who wanted to be a pirate.

He turned away and returned to his cell when he felt Sherlock wake up. He wondered if the consulting detective suspected what was going on. Sometimes, upon waking, there would a thrill travelling through the palace that made him think Sherlock had nightmares during his excursions. He had not yet seen any dreams, bound as he was to the restrictions of the form Sherlock had given his mind, but he would eventually. Soon, he would be free to do as he pleased. He would move through Sherlock's conscious and subconscious alike without effort; he would tear down the mind palace if he pleased, leaving the consulting detective helpless as the facts he had intended to keep in reach fled from him and the memories he had thought safely stored came back to haunt him; he would learn to take control of his body, seeing the outside world again, feeling the blood running through Sherlock's veins as his own. And the consulting detective would always be there if he needed entertainment.

Not yet, though. He had to be careful, slinking back when he felt Sherlock return to wakefulness. He couldn't risk making a connection with his sensory organs yet, not when he hadn't even found the safe place to hide he was looking for.

He had too little time, always too little time. Sherlock slept little, and it seemed to him that his periods of rest grew shorter and shorter. It might be connected to the nightmares he was experiencing; soon he had no doubt in that matter, since every time he ventured out of his cell he could feel terror and shadows hanging over the palace.

He was too intelligent to deny himself the rest he needed for stupid reasons, as he undoubtedly thought, and John would make sure he took care of himself as well, so he wasn't worried.

And if Sherlock was a little more tired than usual, and if he let his hold on his mind slip a little –

It would explain why he was suddenly successful.

He was walking rapidly yet careful not to make a stir, moving down a corridor he had already examined when he noticed it.

Or rather, didn't notice it. It was all rather confusing, but he felt certain that there was something where there ought to have been nothing. A door, to be precise. At least it looked less unlike a door than it looked unlike anything else.

It shouldn't be here. He knew this corridor; it housed memories of the year Sherlock had met John. No alterations were to be made. He had found one of the lee ways into the subconscious every mind possessed – one of the many things Sherlock couldn't control, not even in his own head.

Feeling an excitement he hadn't experienced since his and Sherlock's last meeting, right before he shot himself, he entered before the door was lost to him.

His first thought, paradoxically enough, was that he was dead. He couldn't see, not even in the way he had been able to perceive Sherlock's mind palace; everything was dark.

And then he felt it.

Fear. Elation. Danger.

He had reached Sherlock's subconscious. Slowly, he tried to integrate his own self within, making a connection. He could feel the first tentative links being formed.

He smiled.

What was Sherlock so fond of saying?

The Game was on.