(Chapter reposted because FF is being a bit silly.)

CW: suicidal ideation, blood, disturbing imagery.

Sherlock stands at the bottom of the stairs, braced between the wall and the railing, the slam of John's door filling the hallway. The crash of something hard and heavy against the door slaps Sherlock in the face, and he jumps, involuntarily reaching up to touch the thin, silver scar on his cheek from John's punch so long ago. John's sobs pour from the flat, his raw, wicked screams searing Sherlock down to his bones. He stares at his trembling fingers and rubs them together, feeling the faint echo of smeared blood on his skin.

Slowly, he picks up John's cane and jacket, then creaks up the stairs to John's flat. Sherlock kneels at the threshold and leans against it, laying John's things on the floor beside him. He runs his hand over the old door, its rough, wood grain. A splinter catches on his finger, and he presses it deep into his skin until it disappears. He stills his breath, listening to John's soft cries on the other side, the rustle of his clothes. Closing his eyes, he focuses on John's ragged breathing, counting the passing minutes by his own heartbeats. He reaches 1,050 pulses when John speaks one word, wrangled from the bottom of his throat. "Why?"

"It was necessary."

"Necessary." John's brittle laugh is thick with splinters. "Why'd you do it?"

"Moriarty. He was dead. I had to kill him, but there was still more. His whole web. I couldn't let them have you. Us. If Moriarty were dead, his network would stop at nothing to eliminate us. I couldn't let them hurt you."

"No. You did a perfectly good job of doing that yourself. How did you do it? I saw you there, I saw..." John's voice breaks thick and wet. "I saw you die. I watched you fall. Your hands...your eyes...they were..."

"I was dead. Almost. For a moment. Those wounds were real. I have the scars to prove it. I didn't think I would survive it."

"So. Did you decide to lie to me when you went up to meet Moriarty, or was it later? Just so I know when you decided not to trust me anymore."

"I didn't...I thought." Opening his eyes, he skims his hands over the wood again, blood beading up from his finger, streaking across the surface. "If you were out of the way, if I were alone, it would be easier. And then I fell, and I knew Moriarty was dead, but the rest of them were still out there. And I couldn't let them lie."

"And you had to run off alone." John laughs again, the sound as hollow as the cheap door between them. "You and your massive intellect."

"It wasn't that. I needed...I couldn't." Sherlock tears at his hair, trying to pull the right words from his scalp. "I needed to do this by myself." He mutters to himself. "You wouldn't understand this, I knew you wouldn't understand."

"Then try to explain it to me. You're the great consulting detective, you can surely explain it to an idiot like me."

Sherlock flinches as if struck again. "You're not an idiot."

"Then what am I? Nothing, apparently, since you did this to me. You couldn't even tell me—"

"You are everything to me."

"I can't believe that. Not after everything you just said." John's voice is hard as flint. "You don't lie to someone for three bloody years and make them think you're dead and hold onto your ashes every night and wish they'd fallen off the roof with you."

"I'm sorry."

"God, Sherlock... This isn't like putting a head in the fridge, or what you did at Baskerville. You think sorry's going to make up for what you did? Three years, Sherlock! Do you know what this did to me? Do you have any idea?"

Sherlock hears John's voice crack, the slide of his hands over skin and stone. Sherlock curls his long body in on itself, clutching the collar of John's green jacket in his hands, worrying the edge. "I don't know. Not all of it. But I'd like to know. Mycroft showed me pictures."

"Mycroft? What...?"

"He showed me pictures of you. The way you...changed."

"Wait...what? Mycroft knew?"

Sherlock swallows down a thick knot in his throat. "Yes. He helped me. He had the resources I needed. My recovery, changing the records, the funeral, the hunt."

"Mycroft." John's voice burns, the name growled out with bared teeth. "He...that bastard. So. Who's in your urn?"

"I don't know. Nothing human though. He assured me of that."

John harumphs. "I guess I should be grateful to him then, for tending to me so very well. I thought I was as trustworthy as your brother. I guess not."

"He had what I needed."

"And you didn't need me?"

"Of course I needed you." Sherlock's lungs start to throb, his heart bruised and pulled towards the man on the other side. "I needed you every day. If I had known you were this impacted, I never—"

"If you needed me, why didn't you tell me? Why did you lie to me?"

"I was afraid, John." His small, thin voice evaporates into the air. "I was afraid you would turn out like me. Twisted and blackened and bloodied and cold. I was afraid you would get lost. I would get lost. And I wouldn't be able to bring us out of it. The death. The darkness. You had to stay here. It was better this way for you to be here. For me to do this work for you."

"Better? For who?" John snarls. "For me? You were dead, Sherlock!" John's heat flares through the door, singeing Sherlock's nerves. "Do you know what that was like? Thinking that you were never coming back? Ever? Do you understand what that did to me? Being here, without you?"

"I know. I wanted to tell you. I didn't think you'd understand. I wanted to...please, John. I just..." Sherlock aches to link his mind to John's, transmit his bright, burning fear directly to John's neural net. "I knew you would be safe here. I thought you would be safe here. I thought I could handle it alone. If you were with me, I'd have to worry about you, and if you were killed... I know I said 'dangerous,' John, and I know you wanted it, but this was different, this was...hell. I didn't want to. I needed to. I had to keep you safe. I didn't know it would take so long.

"I did things I don't want to remember anymore. And I can't delete them no matter how hard I try. I didn't want you to see. I needed to keep you. You were the only reason I lived this long. I don't mean just while I was gone, but before. When I first met you. You were a puzzle, John. A walking paradox. Something fine, like a perfect watch or an old violin, and I knew I had to keep you. I had to keep you safe.

"I wasn't afraid of dying. If I died alone, that meant you weren't with me, so you were safe. I've always been a danger to you. Always. And this time was too much. I couldn't let you do this work for me. I couldn't let your hands get dirty for me. I did this for you. I swear I did this all for you. I know you can't forgive me...and if you don't, I understand. I can leave now if you need me to. Or you can punch me if you want. I'll tell you everything. I promise. Just...please don't go yet. I need...I need to see you. I haven't felt you. I wanted to tell you for so long. John...please...just...don't send me away yet, just one more moment and then I can leave you forever..." He sucks down a terrible sob, scraping at the bottom of his soul. The swarm of words streams from his mouth like bees, their stingers lodging in his lips. "John, it was all a lie, I couldn't do this by myself, I don't know if you'll recognize me any more, there's a black spot on my heart and it's grown so much and I don't want you to see it, I never wanted you to see it, I never wanted you to see that I was just like him, you were in the mirror and he was in the mirror and I had to choose and I always tried to choose you but I had to choose him eventually, I didn't want to, and I couldn't let you see that, John, I couldn't let you see me like him, I couldn't let you become like him, I had to leave you here, don't you understand, it was imperative and I needed you to be here and whole and safe and I need you I need you please—" His breath slows and stops, his eyes tight and wild. His hand, twisted in John's jacket, shakes, his knuckles white. "Please."

Sherlock's words tumble over John like a rockslide, the boulders and pebbles crushing the breath out of him. He blinks and shudders as the tsunami of words washes over him, almost sucking him out to sea. John clutches the urn tighter to his chest, rivulets of blood trickling over his arms from his ragged scratches. "When did you stop believing in me?"

"What?"

"When did you stop believing in me?" John says. "In us? That we could do all of this together? Because it sounds like you didn't believe in us at all."

"John. I never...I never doubted you. I doubted myself. I couldn't trust myself. I couldn't make a mistake. The web was everywhere, John, it was all around me, so many people, so many fibers, and I nearly died in the middle of it and I couldn't break free for so long and the thought of you trapped in there with me...I couldn't bear it. I couldn't let you die. Not for this. Not for me."

"You didn't have to protect me. That was my job. To protect you. From him. That was my job. To keep you safe. Even from yourself." John scrubs the tears from his eyes, something bitter twisting in his chest. "Hell...and I couldn't even do that."

"John—"

"Sherlock...I knew, from the beginning, that I'd be here. That I was staying. I knew that on the first night, when I shot the cabbie for you. Hell, I knew that when you fixed my limp for me. I made a promise to myself that I was going to look after you. I knew then I needed you. That whatever sort of madness you were selling, I wanted. I knew that right from the start. And I thought you did, too. I thought..." John's voice flutters, like a bird with a broken wing. "...you needed me, too. I thought that maybe you believed in me enough that you'd want me around when it mattered the most." He draws his knees closer to his body. "I guess I was wrong."

"John." Sherlock's voice is murky, like the pitch-black bed of the sea. "I need you more than anyone else on this planet. I needed to know you were alive and breathing somewhere on this earth. It didn't matter to me where you were, or what you were doing. I just needed to know you were alive. Because if I had brought you with me, and made a mistake, and let you die, or gotten you killed..." His voice descends further into the abyss. "I would not have survived without you."

The core of John goes very still, and very quiet, like the dark, cool depths at the bottom of a well. His words unspool like thread, flowing over their bodies, tangling around their feet. "There was a day, about two years after. It was a clear day, a beautiful day, and I was walking through Oxford Circus, where the traffic is so busy. And I thought, you're never coming back. I thought, it would be so easy. Just to see you again. All those buses going by, all those cars, so fast, like a sea of them, and I was drowning, and I thought... And then my foot started to move, and I started to lean into the street, and I just held my breath and waited for someone to catch me...and no one did. There were other people there, and no one caught me. And I thought, no one's going to miss me when I die. No one will remember me...but they'll remember you. I thought, I have to stay alive so I can remember you."

John slumps against the door, his spirit hovering at his side, waiting to slip back into his body. The sound of pittering tears fills the silence. "I'm sorry," Sherlock says.

"I know."

Sherlock's voice is smaller than an atom. "I don't know what to say."

John manages a small grin, the required muscles stiff from disuse. "That's a first. I'll have to put that on the blog."

"You're still writing?"

"No. I couldn't. Not after I left Baker Street."

"Why did you go?"

"It hurt too much. You were everywhere."

"Why come back here then?"

"It was here. And cheap. And nothing." Like me, John thinks, the room a perfect, beige echo of his spirit. The silence stretches under the door, enveloping him in the creak of wood and the sound of Sherlock's breath. "So what now?"

"I don't...I don't know," Sherlock says. "I could stay here. Or I could leave, if that's what you want. If it would make it better."

"I don't want that...I don't want you to go. Not after everything. I want..." John's heart tears in two, his anger taking one arm, his longing another, pulling at him like two vultures fighting over a carcass. "Damn it, Sherlock, I wanted you! I needed you! I've always done everything for you, and the one time I need you, you go off and die! You didn't even let me have a say in any of this. I could have come with you. We could have done this together. We didn't have to be alone, Sherlock..."

"John..."

John descends into another fit of sobs, thin, thready things punctuated with chest-choking whines. "You were everything to me. You were everything... God, Sherlock...you didn't even let me say goodbye. You didn't even...God, Sherlock, I want you, you're all I ever wanted, and you were gone—" John drops the urn to his side, spinning around onto his knees, and flings open the door, stray remnants of bone digging into his knees. Sherlock kneels before him, his pale face damp with sweat and tears, his hair mussed and wild, his eyes liquid and quivering in their sockets. "John..."

Smudged with bones and blood and tears, John totters toward Sherlock, clutching him like a tree trunk in a hurricane. Sherlock's shivering warmth curls around him as he sobs into Sherlock's chest, trembling in the morning light. "I loved you, you fucking bastard. How could you do this to me? I love you, you stupid fucking bastard, I love you, I love you, I love you..." His lips brand the words into Sherlock's body, down to his heart.

Sherlock cradles John, rocking them back and forth on their ocean of pain, making a boat of his body for him. He strokes John's hair, smoothing over his back, holding onto his shaking, fragile vertebrae. Sherlock breathes one trembling word against John's ear, over and over, pouring from his lips like a prayer: "Yes. Yes. Yes." Slowly, the black barbed wire embedded in John's heart, slicing deeper with every pulse, crumbles and collapses, falling away from his tender flesh. His heart takes a full, shuddering breath, screaming as its old scabs and scars split open, the muscle atrophied from being bound so long. His pain merges with Sherlock's into a single Möbius strip of suffering, rusted copper and dull steel forged together and edged with blood, twisted in an infinite loop, the two of them breathing in each others' sorrow until their mouths are quiet and there is nothing more to say.

Gratitude, as always, goes to my BetaGoddess, Mirith Griffin: "yes." Thanks to my official music consultant, SongstersMiscellany, and my sister across the sea, BehindTintedGlass. And thanks to you for reading, commenting, and sharing.

The title references a line in Van Morrison's "Dweller on the Threshold." The section re: Sherlock's doubt is remixed from Heart on a Shelf, co-written with BehindTintedGlass. The idea of Sherlock telling time by his heartbeats is from WhoreCouture's untitled 1m x 1m box Sherlock+John fic. The "I thought I was as trustworthy as your brother" references a line from the Granada treatment of ACD's The Empty House. The Möbius strip is a nod to an image from Mirith Griffin's Control, Alt, Delete. Visual inspiration for Sherlock and John's embrace comes from Reapersun's i held your name inside my mouth. Thanks to filledesang, marielikestodraw, and theplatonicnonyeah for their suggestions on high-traffic areas in London.