It's not so much a measured rhythm as a cacophony, that tick-tock-tick-tocking of the clock on his bedroom wall. It beats a staccato on his temples and, somehow, though he'd have doubted it possible an hour earlier, his nausea worsens.

He squeezes his eyes shut and tries to breath in through his nose, all in an effort to steady his rabbiting heart, to calm his roiling stomach. Instead, he manages to send more saliva and post-nasal drip down his esophagus, sliding past his gag reflex and nearly sending bile back up. His stomach cramps. Curling in on himself, he rolls onto his side and screws his head further down into his pillow.

Nothing helps, and Sherlock can't even find any self-recrimination to throw at his misery. Yes, he's had therapists, in and out of rehab, who've tried to impress on him the realities of addiction, the complexities that exculpate the addict. But he's always seen himself as well below reproach. He used to tell himself that his drug use was mind over matter, and that he could control his withdrawals if he weren't being self-indulgent.

"A load of rot," a soft voice would whisper in his ear. Still, he'd had no desire to believe the better, sentry lab-coated angel perched on his shoulder. So he'd told himself he wasn't an addict. He'd told himself that a needle in his arm was just one more tool at his disposal to make his mind work.

Now, as Sherlock's teeth chatter and the rigor chills course through him until he fears he might tear or dislocate something, he can't fight the flicker of hurt he feels when he remembers that Mary—his Mary—asked him to do this. Intellectually, he knows she was desperately afraid for John, should something happen to her. That was the only thing that could have lead to her request. But it makes the ache of her death that much more acute. If she had to die, why couldn't they have had more time? Not just to devise a way to 'save John Watson', but more time all around? More time for Sherlock appreciate her brilliance and wit, more time for John to hold his wife, more time for Rosie...

But, yes, most pressing to him right now: why couldn't they have had more time to discuss contingencies, rather than a "Dear Sherlock" video, delivered with a half-hearted Moriarty joke on its facing? If Mary knew death might meet her sooner rather than later, why hadn't she told Sherlock? They certainly spent plenty of time together without John. The good doctor would lumber off to his practice and Mary would pop around to drag Sherlock to the shops with her. They'd wander the aisles of the Tesco and she'd make him push the pram, snickering even as she scolded him when he'd pile toffee puddings, crisps, and bread on top of the sleeping baby (even though he made sure Rosie could still breathe…).

He's grateful that John is speaking to him again. He is. But this wrenching pain of withdrawal, compounded by an unmourned grief at the loss of one of his dearest friends who still managed to hurt him from the grave, might physically tear him apart. It causes a stabbing pain in his chest each time he remembers, and he nearly asks aloud, "Why?"

Most horrifying of all, he isn't sure if he'd be asking himself, a ghost, or gods he doesn't believe in.

So, here lies Sherlock Holmes. Lonely Consulting Detective. Junkie. Smackhead. Addict. And he can't escape the pain as it shudders through him two-fold.

Just as he hears the creaking floorboard by his side of the bed, cool hands brush the sweaty curls back from his forehead. He tries to hide his face in his pillow, ashamed. He's no stranger to shame where she's concerned. She is one of the few who has seen it in him one more than one occasion. The crux of it is that it would almost be easier if she, too, thought he should be embarrassed.

But, of course, Molly Hooper won't let him hide. He doubts there's place or way he could pull it off effectively, where she's concerned. He tries to play Knock Door Run where she's concerned, but she always manages to catch him as he's reaching for the knocker.

After placing a wet flannel on his forehead, she sits down on the edge of the bed and begins smoothing her hand over his back, first over his damp t-shirt, and then under it. His body assumes an even more pugilistic curve, but toward her, so he can press his face into the side of her thigh.

They remain there for a long time. The soft brushing of her callused fingers on his back offers something new for him to hone in on. He is almost able to drown out the sounds of the clock and dead friends.

He doesn't realize he's still juddering, though, until Molly gently pushes on his shoulder, urging him to roll onto his left side while she takes away the flannel and drops it back into the bowl of water she must have brought in with her.

Again, the ache in his chest starts to rear its head, but she quashes it handily when she lies down, spooning herself around him and holding him tightly.

"It hurts," he croaks, and somehow, inexorably, she knows what he's talking about. The heat of her breath reaches the damp of his t-shirt as she exhales.

"She shouldn't have asked it of you," she whispers.

Having someone else—having Molly affirm this ache doesn't make him feel better. Not nearly. It makes his eyes and sinuses burn with unshed tears. But all the same, he feels less monstrous for it.

Still, he shakes his head. "She knew what it would take to save John. I didn't die."

"Even almost killing yourself isn't some grand, noble thing, Sherlock. Mary rarely let us down, but she wasn't right about this. John would have grieved and then he either would have eventually returned to the land of the living, or his problems ran far deeper than the sudden death of his wife."

She's being pragmatic. Even as her clinical words sooth Sherlock, he can't escape the itch of discomfort that he's betraying Mary by even entertaining Molly's words.

"I had to do it, after I killed h—"

"You didn't kill her," she interrupts flatly. "Hubris is annoying, but it didn't pull a trigger and put Mary in front of the bullet. Vivian Norbury killed her."

He doesn't agree. He could argue, but the warmth of Molly at his back, the way her words are muffled because her mouth is pressed to his shoulder, are all lulling him. If not to sleep, at least into calm. His muscles are relaxing and, though he still shudders with the shock of the heroin seeping out of his every pore, it's not pulling him apart. He's almost past that torturous mark.

"I will miss Mary every day," Molly whispers. "She was my friend and I loved her. She was wonderful. But don't ask me to say what she asked you to do was acceptable, Sherlock. Because I can't and I won't."

He wets his lips. "I don't know what I could have done differently," he admits.

Her arm tightens around him again, and ridiculously, it comforts him. "You could have stayed healthy. You could have asked John to speak with you. You could have told him you were worried about him. You could have realized that, in this instance, your responsibility to keep him alive only goes as far as his mental health allows."

"I would have relapsed with or without Mary's efforts."

Molly remains quiet for a moment, but it's thoughtful, not accusatory. Finally, she says, "Maybe. You've always tied the drugs to your work, and that's an unsustainable approach to sobriety. Especially when part of you still believes they help you."

"I'm seeing the error in that logic right now," he says, in a weak attempt at dry admission. Molly doesn't join his banter, though.

"I'll try to help you remember. Because your body can't take much more of this, Sherlock."

Again, he swipes at the emotions that swamp him so much more easily these days, but he can't keep his voice from cracking as he says, as genuinely as before, "I don't want to die."

She presses a kiss to his back. "I know. And as long as you want that, you can make sure you don't."

He can't help but say, in a pathetic attempt to divert the scalding sentiment of the moment, "Science disagrees, Molly. We're all dying."

She bites his shoulder blade, a gentle nip of reproof. "You know what I mean."

He is surprised to find himself nodding, acknowledging both her words and a foreign glimmer of hope in the dregs of his heart that he can't attribute entirely to lethargy from withdrawal.

"I probably do," he agrees as he pulls her hand up to his mouth to kiss her palm. He doesn't let go after.

They stop talking after that, and the tick-tock-tick-tocking of the wall clock plays counterpoint to their quiet breathing.