Sherlock had always thought they would grow old together.
The particulars of their "together-ness" were never clear to him, but frankly the specifics had always seemed unimportant, irrelevant details to a companionship that was rooted in knowing, not in expressing.
He had simply assumed that John knew too.
Somehow, John manages to get him to his feet, and the two men struggle to the bedroom, Sherlock nearly dead weight against John's bad shoulder. John keeps quiet about it, doesn't complain or whimper or vocalize it in any way, but Sherlock can tell from the way John trembles that the pain is quite severe.
At least they have one thing in common.
The queasy feeling from before has intensified, the pain in his joints and head now pounding in agonizing rhythm with his heart, and it takes all he has not to vomit on the carpet as John deposits him onto his bed. They sit for a moment, recovering, and Sherlock takes note of John's labored breathing, the faintest edge of a hiss on his tongue as he rotates his bad shoulder, the tang of blood as the both bite their lips to stop from crying out.
"Fuck." John mutters as he rubs at his arm, and Sherlock can feel the eyes on him as John spins full circle into doctor mode.
"Right then." John clears his throat, begins to roll up his sleeves. "Do you have anything you normally take for this sort of thing? Pain meds? Anything?"
"No."
"Nothing."
Sherlock shakes his head, a fractional shift from right to left. The scratch of cotton again his cheek sends spikes of white hot pain up his temples, yet he gasps out a response in spite of it.
"Us— us—used to have some benzodiazepine, but Mycroft—" He lets out a moan as the pain spikes, fingers strangling the sheets as he arches off the mattress. His eyes are being twisted from their sockets, his brain wrenched from his skull, bone cracking and snapping even as John tries to soothe it back together.
John can feel himself beginning to shut down as he watches, his own mind overcome with panic, rapidly clouding away his medical knowledge as he watches his best friend scream as though he is being tortured. Substance abuse is never pretty, and the detox nearly always worse- John knows this, rationally understands that it will pass, heal, that the pain is unavoidable but will ultimately dissipate, a demon that must be exercised through patience and encouragement, and yet this does nothing to soothe his own mangled nerves as Sherlock writhes on the bed, trembles from a chill John cannot feel.
The detective's lips move fractionally, face contorted in pain as he clutches John's knee through his jeans. John lets his hand slip down, covering Sherlock's hand with his own, trying not to flinch when Sherlock finally manages a word from underneath the panting.
"Hurts"
"What hurts?" John whispers.
Sherlock shakes his head slightly, whimpers into the sheets. He looks like a child. John strokes very softly at his hair, leans in close to ask again.
"What hurts, Sherlock?"
Sherlock lets out a wail, and for a moment he looks nearly hysterical. Yet when he speaks it is feeble, fragile like tissue paper.
"…. hur's so much… 's not… 's not usually this bad."
Every word is chalky, faded, lacking the precision and pressure of Sherlock's usual cutting dialogue, colors bleeding away from their normal brights and melting into Easter pastels.
John has forgotten how to use his hands, his mouth, his tongue. Everything is distant and strange, his feet too large for his shoes and the buttons on his shirt painful when he breathes. But this is not about him. It's never about him. This is about Sherlock. Sherlock needs him.
The detective's breathing has intensified, rapidly approaching hyperventilation, and John shakes himself from his shock, breaking the surface to gasp a breath of air that might just save them both from drowning.
"Hey, hey, it's alright, Sherlock, okay? You're going to be just fine, okay? Just breathe for me, hmm? Deep breath, nice deep breaths. Mm hm. Just like that. Just like that."
Sherlock stiffens, forces himself to choke down are that makes him gag, squeezes his eyes tight and focuses on breathing. In and out, just like John says.
He thinks perhaps, if he can do just this one simple thing right, maybe John will stay.
Even through the pain, even with his eyes shut tight, he can still feel John's glow in the room, a faint aura of blue and plaid and aftershave picked up from the Tesco. It's nothing special, some generic brand that's no more than a couple of pounds, but Sherlock has become quite fond of it. Despite his awareness of its chemical makeup; of the molecular components of each ingredient, the elements that bonded and reacted to create this one particular scent, one worn no doubt by thousands of blokes all across the country, Sherlock now labels this scent simply as "John".
The doorbell rings suddenly. The sound sends waves of hyperawareness down his spine, endless pools of neon yellow rings that flash before Sherlock's eyelids in sync with his pulse. He presses his hands over his ears, not caring what he looks like at the moment, because he can feel the beginnings of a migraine coming on and the thought alone makes his blood turn cold.
He doesn't realize just how warm and comforting John's presence is until it's gone, rustle of pants as he stands and goes to the door, leaving a hand-shaped oval of emptiness on Sherlock's shoulder.
The patch of cotton begins to cool almost instantly to room temperature.
Sherlock pulls his knees up to his chest and tries not to scream.
He wants to. Wants to rage and shout and shake John, punch him black and blue, kiss him drunk, fuck him into the wall until they both see stars, until John comes screaming his name and promises never to leave him again. He wants to prove himself, prove he has something that Mary does not, cannot, will never have, something profound and beautiful and poetic beyond words, something that does not require a ring to be understood.
He knows it's too late.
He would say he has been replaced, but truthfully, he has come to understand that he never occupied enough of John's heart to merit a replacement. Mary has not come to succeed him, Mary has come to provide what he could not.
His shoulder is now cold, his limbs warmed only by the heat of his own body.
The migraine has wormed its way into his brain now, and even his thoughts are becoming fuzzy, marred, as though the hard drive is being warped by a magnet, not erasing, but simply reshaping into something dark and ugly and broken. He wonders if the damage has already been done.
He's nearly forgotten about John until the warmth returns, this time at his knee, as John settles on the bed with what sounds like a bottle of pills.
"Mycroft." He says by way of explanation, nudging the pills. "I've got some anti-neauzea medication for you. Should help put you to sleep too."
He can hear John shake a few tablets into his palm, wait patiently for Sherlock to sit up. When he doesn't, John simply sighs, fingers gently brushing Sherlock's jaw.
"Open up."
Blue dissolves against pink, and Sherlock tries not to let his mouth linger on John's fingers. John gives him an awkward little pat before standing.
"I'll be in the other room if you need me. Try and get some sleep?"
"Stay" Sherlock thinks, but John doesn't, instead departs without another word, leaving nothing behind but a faintly sweet aroma of aftershave tucked into the sheets.