"Sherlock! Sherlock?"

The voice echoes, muffled by distance, vibrating off stone walls. He's at the bottom of a well, Sherlock thinks.

No, not a well. An oubliette. Fitting.

"Jesus. Jesus, Sherlock - what have they done to you?"

Under the sting of panic, the voice has a soothing note of affection. Sherlock closes his eyes, savouring the warmth of it, the familiar resonance. John

"Sherlock, look at me please."

Sherlock looks but he can only see stone walls and a tiny point of light very far above him. Too far.

He's warm here. It's quiet. They can't reach him. It's for the best.

"I'm calling an ambulance. They'll be able to - Sherlock, you'll be better very soon, I swear. You're safe now."

Safe. Sherlock rolls the idea around in his mind. Imagines it as a glass marble he can roll across the floor, admiring the points of light it casts on the walls, the inner blue-hazel shine.

When Sherlock had constructed his mind palace, many years ago, he'd hesitated at the thought of this particular addition. He'd stood for a long while in the basement dungeons of his mind, contemplating the portion of earthen floor that he'd earmarked for construction.

Assassins and spies sometimes carry cyanide pills as an insurance policy. However well trained they are to withstand high levels of pain every person has their breaking point. If one is imprisoned, tortured, if things become too much, if you come too close to breaking… well, there is always an exit strategy.

Sherlock doesn't carry cyanide. It is too imprecise a failsafe from his point of view, too easily taken away or lost or consumed by accident. He'd had a better idea. When there is no longer hope, and no escape from pain his oubliette is there for him: a dark well deep inside his mind palace in which Sherlock can exist. All sensory input is chocked off by stone walls, thought, need and memory muffled by the darkness.

The oubliette only has one small flaw: there's no way out.

"They're all dead, you know. The men who did this to you. It wasn't me - Mycroft's men. I wish it had been me."

There's a silence in which Sherlock lifts the marble to his mouth, presses it absentmindedly to his lips. He thinks it tastes a little of gunpowder residue, a little like milky tea.

"Sherlock," John's voice is raw. Vocal chords tightened, tensed, Sherlock speculates. Emotion. Sentiment.

"Sherlock, if you can hear me, please blink. I won't ask you to say anything just please, please..."

Hearing John's voice fade into strained silence is painful. John is clearly unhappy, and Sherlock doesn't want that. It defeats the object.

Sherlock blinks, as vigorously as he can manage.

"It's OK," John says, in a dull voice. "It's not your fault. I know you're in there. I know you'll come back eventually. When you're ready."

There is a short silence and then John's voice sounds again, clearer and louder as if he'd moved closer to Sherlock.

"I just - I just wanted you to know. They can't hurt you anymore. They're gone."

Sherlock touches his pocket, and isn't surprised to find another marble. It is smaller than the other one, wine red. When Sherlock holds it up to his eye everything around him looks blood drenched.

Sherlock carefully places the marble on the floor next to his other marble. They sit on the ground, twinkling like jewels in the dirt.

It was after the swimming pool, Jim Moriarty's mocking voice and John's foolish bid to sacrifice himself that Sherlock finally decided to build his oubliette. Ever since he'd been a child Sherlock had had secrets, small pieces of knowledge he'd held close to his chest, before locking them up the Treasury Wing of his Mind Palace. They'd been precious to him, but not so precious that he could imagine living the rest of his life in a dark hole just to keep them safe.

It wasn't until the pool, John's steady burning defiance, and Sherlock, run that Sherlock realised he had something he couldn't lose.

They mustn't hurt John.

Sherlock has quite a collection of marbles now. He lays them out around him on the floor, placing them in intricate patterns, arranging and unarranging them, remembering the things John has said. The yellow one, that was when John told him about having tea with Mrs Hudson, how much they'd both missed him. How the flat was too quiet and tidy without him. The white one was for the bloody buggering snow which had shut down all the tubes and buses and meant that John had had to trudge three miles across the city just to see Sherlock. The lime green one was for John's new job at the clinic, and the powder blue one was for him losing it. He hadn't said why, but Sherlock knew. John still spent far too much time at Sherlock's side. Obvious.

Sherlock's favourite marbles he always keeps close to him, cradled in his palm. The deep shimmering purple from when John had told him that he was the best and cleverest man he knew. The red marble from when John wanted to kill for him. The hazel-blue that is exactly the colour of John's eyes.

One day, John arrives angry. He doesn't say anything but Sherlock can hear him breathing.

"Mycroft showed me his report," John bites out at last. "The reason they tortured you. It was me. Wasn't it? They wanted to take me too."

Sherlock sighs, looking down at the floor, now completely covered with marbles. He'd hoped John wouldn't find out.

"Why didn't you just tell them?" John hisses. "I'm a soldier, I could have handled it. How could you - how could you - fucking."

There's a silence in which Sherlock can't breathe. When John speaks again his voice is low, dangerous.

"I need you to stop this, Sherlock. Just stop this. How do you expect me to stand it, watching you just sit there all day, staring and drooling? I know you're in there. I can't - I can't do this anymore. I just can't." There is a hitched breath. "If you don't look at me, actually look... I'll leave. I'll go away and I'll never come back."

Sherlock balls his fists. Closes his eyes and opens them again as hard as he can. The only thing he can see is wall.

And then he hears the sound of a door closing. Sherlock sits slowly back down on his pile of marbles, his chest constricting. When he opens his clenched fist he finds another marble inside, lead coloured, and curiously heavy. He lets it fall through his fingers onto the floor.

"I'm sorry," John's voice, unusually hoarse, sounds unexpectedly in the darkened well. Sherlock starts, scattering cascades of marbles. He hadn't expected John to return.

"I don't know what got into me. I've been out of my mind recently. What little mind I have, I suppose you'd say."

There's a silence, and a sound suspiciously like a sniff.

"I wouldn't ever leave. Not for real. You know that? I promise you. I won't leave you alone."

The marble in Sherlock's hand is huge, as big as his fist, glittering and clear as a diamond. I won't leave you.

"I've spoken to the Doctors. There really isn't anything more they can do for you here and I - I think it would be good for both of us, if you came back with me. To Baker Street. I'll get carer's allowance, that should keep us in beans - and Mycroft will stump up some money for the rent."

There is a pause.

"I'd like - I'd really like to have you back with me again. Living close. I'm not a nurse, obviously, but I think I could do a decent job. Is - is that what you want, Sherlock?"

There's a long pause.

"Stare blankly into the distance if you agree." John says.

In his dark prison Sherlock rolls his eyes.

"Good," John says quietly. "That's settled then."

The new marble is lovely: midnight blue and glittering with stars.

The pile of marbles has grown so deep now, Sherlock can't wade through them anymore and is forced to sit on them, like a bird on very colourful nest. When he looks up he notices the light at the top of the oubliette has grown wider and brighter.

"You know what bothers me?" John says conversationally one day. Sherlock stops rolling the marbles between his fingers to listen.

"I never told you. I should have told you. Another mouthful of soup, that's right."

One advantage of being in the oubliette, Sherlock thinks, is that at least he isn't aware of John's attempts to force food down his throat. No doubt under John's unrestrained care his body will become as fat as Mycroft's.

"I suppose I thought you knew," John says. "I thought we could take it as read. Maybe you did. I wish I'd told you though. I wish I could be sure that wherever you are you knew."

Knew what? Sherlock thinks. He stands up, suddenly afraid he'll miss the next words John says, craning towards the entrance to the oubliette a few feet above. He can feel a cool breeze from above brushing over his face,

Knew what, John?

"I was a coward then," John says. "I didn't want to admit it. Not the sort of thing men like me do, go around telling their mates that they love them."

There's a silence during which Sherlock holds his breath.

"I do, you know. More than I'd thought I could love a friend. More than anyone I've ever dated. Hell, maybe even more than my own family -" John cuts himself short. Takes a breath. "I didn't know. I didn't know one person could mean so much."

When Sherlock takes his hand out of his pockets, it isn't a marble he finds but gold coins, a waterfall of them, filling his pockets and then falling out, lining the floor beneath him.

Sherlock is very close to the top of this oubliette now. Ever since John had said he loved him the marbles had come thicker and faster, dozens of them streaming through his fingers at no more than a word from John, lining the floor, bringing it higher and higher.

Sherlock is afraid sometimes of what might happen when he finally gets out. What might be out there, waiting for him. The darkness here is so soft, so warm and enveloping. On the other hand, Sherlock will get to see John's face again. That is worth almost any danger. Sherlock hugs the blue-brown marble close to his chest and waits.

"Happy birthday, Sherlock," John says, as he enters the darkened room. He can never tell if Sherlock has really slept, or whether he has just lain there all night staring into the dark. He switches on the light.

"Mrs Hudson made chocolate fudge cake, so you know, someone loves you. And I've got some old case files from Lestrade, I'll read them to you after breakfast. Looks like there's a locked room murder here, that ought to be good value."

Since Sherlock had been hurt, John has got into the habit of talking all the time, voicing all the passing thoughts in his head as if talking twice as much would make up for Sherlock's lack of conversation. If he could, John imagined Sherlock would be in a spitting fury at the inanity of it all. Maybe he is somewhere deep inside. John hopes so. When he thinks about the alternative he feels more deeply lonely than he ever has in his life before.

Carefully, John lifts Sherlock out of bed, placing him in his wheelchair. As ever Sherlock simply stares straight ahead, not the faintest flicker of anything in his eyes to show he knows what is happening.

John straightens Sherlock's pyjama collar. He'll need a wash later, but breakfast first. John tries not to think about the nasty burn he can see, marring the white line of Sherlock's throat. Seeing the scars of what those bastards did to him still makes John sick sometimes, anger like a flash of white heat exploding in his belly.

Not now. It's Sherlock's birthday, and John owes it to him to make it as pleasant as humanly possible. He reaches out a hand to brush back the curl that is falling into Sherlock's eyes.

"Hey," he says. "I miss you, you know."

There is a small noise from Sherlock, a soft huff of breath. John bends over him, alarmed.


To John's surprise, Sherlock's eyes begin to move from the fixed point in the distance towards John. Hardly daring to believe what he is seeing, John puts out a hand to hold Sherlock's wrist. Pulse even, steady.

"Sherlock?" John asks again.

Sherlock's lips twitch spasmodically twice, before he finally manages to open them.

"John," he says, his voice sounds like the creaking of a rusted hinge, dry and corroded due to lack of use.

John's grin is so wide he thinks it might crack his face in half.

"Welcome back."

A/N: This was written for the following prompt:

Initially Sherlock fled into his mind palace to escape the horrors of what they were doing to him, but now he's lost and can't find his way back out, even though he can hear John and knows its safe now.