Sherlock opened his eyes and found himself in a concrete room, with metal girders and a large metal door in front of him. He frowned this is not where he intended to go, in fact he didn't recognize this room in his mind palace at all.

"That's because it's not your mind palace."

Sherlock spun at the voice. Mycroft stood behind him looking quite smug.

"What is this?" asked Sherlock.

"This?" Mycroft looked around, "Looks like a bunker."

"Yes, I got that reinforced concrete walls, and wrought iron door. Standard bunker, but this specific image isn't from my mind."

"Because currently we are not in your mind," said Mycroft.

"How am I not in my own mind?" asked Sherlock.

"Think Sherlock, what were you doing?"

"John fell asleep watching TV, and I've been trying to figure out what I missed in the Dryfus case, and also…oh," said Sherlock with drawing comprehension.

"Yes, oh," said Mycroft smirking, "you also were performing an experiment with the powdered dream root, you put some in your tea."

"I'm dreaming, I'm having a lucid dream, fascinating," said Sherlock looking around, "That doesn't explain this, I have no memories of this place."

"But lucid dreaming wasn't you goal when you drank the tea was it?"

"No," said Sherlock, "John watches the appalling show about demons, and magic and they mentioned the root. I did the research and ordered some online."

"In the TV show what does it do?" asked Mycroft.

"It allows you to share dreams, but that's nonsense," said Sherlock.

"Is it?" asked Mycroft turning to look at the door which had cracked open to allow a sliver of light to spill into the dim room. "Is that why you had John drink first? That way when you drank it you were drinking some of John. You wanted to see inside his head, well here you go."

Sherlock walked through the open door and out the flap of a tent. The desert sun beat down on him, the compound was in complete chaos. Shells came down at random intervals, people were running crying, screaming. The injured were being laid out on stretchers on the floor being checked and rechecked by triage doctors and nurses moving them on to the treatment tents nearby.

"Orderly!"

Sherlock turned at the sound of a familiar voice. John stood at the entrance to one of the tents, he looked exhausted dressed in fatigues with his sleeves rolled up, he stripped off bloody gloves and grabbed a new pair from a box on the table. A private ran up to him and John pointed at a prone figure in the tent a sheet pulled up over the top.

"He's gone," said John, "take him out and I'll call for the next one." The private nodded and he and another man went into the tent. John walked into the crowd of wounded kneeling periodically to check vitals and give words of comfort. He spoke in hushed tones to the nurses giving directions and orders as he went. Sherlock followed behind him, fascinated by this calm, competent side to his friend, and doctor. John knelt down by a man and lifted the bandage on his chest.

"You shouldn't be here," he said, looking Sherlock directly in the eye.

"I'm not even sure where we are," said Sherlock.

"Camp Bastion, this is a bad day," he said, "Normally we can get them inside, but…this was a bad day." John looked down at the man he was treating. "I'll operate on him for four hours, but I won't save him, he's lost too much blood and the volume of casualties today means a delay in treatment." He stopped and looked back at Sherlock, "Why are you here? Normally I don't see you until…" The world shifted. They were at the swimming pool. Sherlock saw John and himself standing there.

"Sherlock!" John screamed as a shot rang out and Sherlock watched himself get shot, the sniper round pierce his flesh. John dived and they both went head first into the pool. That's not how it happened thought Sherlock, then the world exploded.

Sherlock gasped for air as he broke through the surface of the water. He looked around he was outside, it was dark, a small boy's head bobbed a few feet to his left and a little boat drifted ahead of him.

"I'm tired," called the boy.

"Come on now Johnny, you can do it, got to be strong," A man balanced precariously on the prow of the small boat, he was holding a bottle and looking down on the boy, John, Sherlock realized, John when he was a small boy. "Go get the bottle and we'll go back to shore okay?" The man screwed the lid back on the bottle and tossed it a good fifty feet from the boat. Little Johnny turned to swim for it. A few seconds later the outboard motor on the boat started up and the boat sped away.

"Wait! Stop!" The boy tried to yell to wave his arms in the water, but he's using all his effort to keep himself afloat. But the boat disappeared into the darkness and silence fell on the boy bobbing in the waves.

"I survived." Sherlock looked around and saw John, adult John sitting on a pontoon raft that hadn't been there before. Sherlock climbed up and sat beside him. "I swam to shore, it was only about a mile, but I was tiny, skinny and tired from playing fetch with Harry's one and only boyfriend. Jake the charmer. I ended up in hospital with dehydration and exhaustion. That was the first time I thought about taking up medicine," said John smiling a little. He looked at Sherlock. "You don't normally cameo down here," he said.

"Down here?" asked Sherlock.

"Childhood stuff," John shrugged, "Everyone has demons Sherlock. Sometimes you cameo in Afghanistan, wounded solider, over eager rookie running off into trouble…those events and you are fairly closely linked so it makes sense in my mind. But down here is where I don't want you rooting around…Why are you here?"

"I may be dreaming," said Sherlock.

"I'm definitely dreaming, the Dryfus case, drowning victims. It doesn't take Freud to figure that one out. It's terrifying drowning. I don't want to be here," said John standing up. They were on the street outside Bart's.

"No, no, no," said John putting his head down. Trying not to look up. Sherlock looked around another John was standing in the road looking up at the building he could hear the phone conversation.

"It's what people do…don't they leave a note."

"You bastard!" cried John advancing on Sherlock from the other side of the street. "You made me watch! You made me watch you die!" The thud and the scream happen behind them in fading distance as John furious and devastated grabbed Sherlock by the lapels and shook him hard. "How could you do that?" asked John quiet now his head on Sherlock's shoulder, "Somethings can't be unseen."

Sherlock stood alone in a long corridor of the bunker, doors every few feet. They had viewing holes and he opened some as he passed. One had a little girl covered in blood reaching out, another contained a desert road and few scattered body parts, there was one that held Sherlock's gravestone, one where a woman sat on a couch vomiting into a bucket, she paused to look up.

"What like you're so fucking perfect?"

There are operations, and disfigured faces, and vast desert battle grounds behind those doors. Each more horrific and terrifying than the last. John stood at the end of the corridor.

"You don't belong down here," he said.

"I'm behind some of these doors," said Sherlock.

"No, not you, just some things I need to keep down here," said John, "Not everyone can delete things at will."

They walk through the door at the end of the hall. They're in an elevator car, the old fashioned kind with the caged front. Sherlock is surprised to find they're not on the bottom level.

"What's at the bottom?" asked Sherlock turning to John. He was surprised to see a child older than the boy in the lake but not by much. He was wearing a stretched out T-shirt splattered with blood. He had a split lip, and a black-eye.

"There are monsters down there," said the boy, "don't go down there Sherlock, please."

"But this is what you came to see, isn't it?" Mycroft stood by the lift control and hit the button. "You want to know how John became the man he is. The best friend of Sherlock Holmes can't really be a good man. Can he?"

"Sherlock please, I don't want to go down there. If you go I have to go, and I don't want to go. Please." It was John, older, younger, solider, doctor, friend all speaking at once.

They were going down. The next floor held a bunch of soldiers running over a field in a fire fight. The light went out and there were people injured people reaching through the grate. Bloody, burned, and broken reaching for them.

"Help us! Help us!" they cried.

There was a single gunshot in the darkness and silence. John slid down the wall to the floor covering his face with his hands. Sherlock dove through Mycroft and slammed on the emergency stop. The car jolted to a halt. He hit the button for the ground floor and turned to John, but he was alone again.

The lift stopped on Baker St. a few doors down from 221. The upstairs windows were open and smoke was billowing out. Sherlock covered in soot with his hair at odd angles sat on the curb in front with John beside him.

"The reaction was much more energetic than I anticipated," said Sherlock blinking in the light.

John burst out laughing.

"No!" Mycroft slammed the button for the basement and the lift dropped so fast it threw Sherlock to the floor. The lights flickered and finally went out, the lift dropped faster into the darkness. Sherlock could hear John's childhood self crying quietly in the corner. An emergency light glowed orange as the car shook to a halt at the very bottom.

John looked up at him with tears staining his cheeks.

"Please Sherlock," he said and faded away.

The grate slid open and Mycroft vanished. A single bare light bulb hung from the darkness and a small wooden table sat in the pool of light. Sherlock stepped forward.

John stepped out of the darkness, well it looked like John, but it wasn't any John that Sherlock knew, he seemed to flicker between wearing an army uniform, and John's typical civilian clothes. Regardless of the outfit, the one constant was that John's hands were covered in blood. They weren't just red, like they were stained, they were dripping like he'd just dropped his hands into a pool of the stuff. It didn't seem to be wearing off either, his hands remained constantly shiny and wet with blood.

Sherlock couldn't move, couldn't speak, John just smiled at him. The army version took off his helmet and put it on the table, bloody handprints smeared grotesquely on the sandy brown material and in a blink his civilian form was shrugging out of his coat and laying it over back of a chair, the lining now stained red, with smudges on civilian John's cream colored jumper. He sat down and looked at Sherlock expectantly.

He leaned back with his hands folded in across his chest. Sherlock flinched as the blood pooled and dripped down his front, flickering from army jacket to jumper randomly, the drips remained the same running down his front.

"They warned me," said John a little smile playing on his face, "about you. They said you were killer waiting to happen."

"They were correct," said Sherlock with mild grimace.

"You did that because of me," said John.

"I did it because he deserved to die."

"Lot's of people deserve to die, Moriarty deserved to die, but you didn't kill him when you had the chance, chances," said John. "It's what he wanted from you all along you know? I did that to you much better than he could have, because you didn't even realize that's what I was doing."

"You're talking nonsense," said Sherlock.

"I killed for you in the first few hours of knowing you," said John, "I'm the killer that made murder socially acceptable action for you. I made killing an option, because for me it is an option. Both as a solider and a doctor death is always an option."

Sherlock frowned, "That seems counter intuitive to me."

"Not for me," said John examining his blood soaked fingernails, "I've had the best programming available to make me into a killer," he paused, "that's not completely right, the programming wouldn't have worked if I hadn't been here to embrace it."

"And what are you?" asked Sherlock.

"I'm the part of John who is a killer, I'm that little voice in your head that says, things would be so much easier if that person weren't there anymore."

"Everyone has that voice," said Sherlock.

"Not everyone is given a set of rules and shown how to let the voice free without letting it take control," John smiled his eyes lit up almost gleefully, "You've given me the most opportunities to come up from the depths you know, the insight of a killer is very useful when hunting one."

"John isn't a killer," said Sherlock.

"Pretty high body count for a blogger then," said John grinning. "He almost let me loose once, a couple of years ago. It was glorious, I smelled the blood and knew it would be a fantastic hunt, but alas it was not meant to be."

"What happened?" asked Sherlock.

"Mycroft," John sneered, "he's afraid of me you know."

"Mycroft isn't afraid of anything," said Sherlock.

"He's afraid of losing you," said John, "and when he stepped in before I'd even got my head of steam, I knew that you were alive and there would be no hunt for vengeance that day."

"What did Mycroft do?" asked Sherlock.

"He threw me into a private hospital on a 72 hour hold," said John.

"Why would that tell you I was alive?" asked Sherlock.

"If Mycroft had really thought you were dead, he wouldn't have had me sectioned he'd have given me a gun and an expense account." Sherlock couldn't deny the truth of this so he stayed quiet for a moment.

"You knew then that I was alive, why didn't you come find me?"

"I was mad at you," said John his eyes turned dark, "you went to so much trouble to leave me behind. I don't go where I'm not wanted Sherlock. I figured you were done with me and set my sights on other things."

"But that's not true," said Sherlock, "Everyone said you mourned me for months, you barely left the flat for a year before moving out."

"That wasn't me," said John drawing doodles in the blood that had dripped on to the table, "I'm the part of John who would have gone with you, would have reveled in the bloodshed and torn a bloody hole in the earth to seek vengeance for you. But you weren't dead and you didn't need me, or want me," he shrugged, "So I laid back, John doesn't need his killer always just below the surface and I'd seen enough action to sate me for a while."

"Did the rest of John know I was alive?" asked Sherlock.

"I'm sure other parts put the pieces together eventually," said John, "I mean I don't think he consciously knew as a fact, but I know that other parts of him felt the incongruence and understood."

"I don't understand," said Sherlock.

"There's a difference between perceiving something and knowing it in the right part of your brain that makes it something you can act on," said John. "Even if he'd really known he would have still mourned you, mourned the friendship you abandoned, mourned the life he'd finally settled into. I know I mourned the outlet you gave me in this civilian life I'd suddenly been thrust into. I mean all those years being honed into a weapon and to suddenly be sheathed in a woolly jumper and shoved into the back closet you've no idea how mad that made me."

"You survived the two years I was dead without an outlet," said Sherlock.

"Well actually there's a funny story about that…" John grinned, but his voice was fading.

"Sherlock," a voice called out of the darkness, "Sherlock," it was Mrs. Hudson she was in the flat, "Oh Sherlock wake up you've got a visitor."

Sherlock jerked awake, he'd gone under and fallen sideways on the couch. John was blinking at him blearily from his chair have apparently woken up at the same time.

"God," he said, "I was more tired than I thought, what time is it?" John glanced at the clock. "I need to get home to Mary." He saw the young man presumably the client step in the door. "Do you want me to stay?"

"I always value your input," said Sherlock, "but I understand if you need to get home."

John checked his phone clearly tempted to stay.

"I'll text Mary and let her know I'll be late and not to wait up," said John.

Sherlock smirked and turned his attention back to the young man. He gestured him to a chair.

"Please come in, I believe you have a problem in your garden," he said.

The boy began to talk and Sherlock deduced his issues quickly before turning his gaze back to John. His friend had so much more buried in his depths than could be imagined. Could he have simply been dreaming? Or had he really taken a journey into his friend's mind and glimpsed the darkness he held hidden there? John finished texting and stood up. He went into the kitchen and started to making tea, but after a few minutes Sherlock noticed the tap was still running, John was just stood there with his hands in the water.

"John," he called, "never mind the tea it was the housekeeper, she keeps killing the family pets because she can't stand the mess they make." John snapped out of his fugue and turned the tap off he slowly dried his hands on a tea towel and returned to the living room as Sherlock showed out the young man.

"In that case I think I will head out then," he said.

"Are you okay?" asked Sherlock.

"It's nothing," said John, "bad dreams that's all. Par for the course I'm afraid." He grimaced and looked around vaguely for his jacket.

"Your old room is made up," said Sherlock.

"What?" said John.

"You already told Mary not to wait up, you're obviously exhausted you should stay here and start out fresh in the morning," said Sherlock.

"I don't know," said John wavering.

"I'll make the tea, you go sit down," said Sherlock.

"You'll make tea?" said John incredulously.

"I am perfectly capable of making tea," said Sherlock affronted.

"Fine," said John yawning, "I probably won't get a cab at this hour anyway." Sherlock walked into the kitchen and started filling the kettle at the sink. "Maybe I'll just go on to bed," said John.

"You won't sleep now," said Sherlock, "if you were just having a nightmare, you're too tense. Have a few sips of tea and relax." John nodded and sat down he rubbed his hands over his face and blinked trying to wake himself up a bit more. "Here," said Sherlock shoving a mug under John's nose.

"That was fast," said John taking the mug.

"Do you want to talk about it?" asked Sherlock.

"What?" asked John, "the tea?"

"Your nightmare," said Sherlock.

"It's nothing new," said John, sipping his tea, "I'd rather just left it alone."

"You think its a weakness," said Sherlock, "but it just proves to me how much of a good man you are."

"Sherlock," said John uncomfortable.

"I know," said Sherlock, "just relax and go to sleep." He leaned forward to catch John's cup before it dropped and John slumped asleep in his seat.

Sherlock took a swig from his own cup and soon he had to lie down on the sofa before finally losing consciousness.

John blinked at the bright light streaming in through the windows above him. It reflected off the polished marble floors and the gilt trim of the doors that surrounded him.

"What the hell?" said John.

"Welcome," said Sherlock, "to my mind palace."