A/N: Sherlock POV

The room is tipped at a startling angle. Sherlock narrows his eyes, trying to sharpen his vision as he wonders with detached curiosity why the floor is suddenly inclined at approximately eight-six degrees to where it ought to be.

"Sit down."

Sherlock wonders what the result of that will be, what with the wall and the floor apparently having traded places, but he sits down where he's standing anyway. Someone's fingers close on the back of his neck and push his head downward, so that he is looking at the inseam of his trousers, and the touch lights a fire on his skin that makes him sip a rapid breath. It also snaps the room into focus, and the floor returns to its rightful place with a sickening lurch.

The hand disappears from his neck. "You should not be running up and down staircases," says the owner of the hand, and Sherlock recognises that it is John. Dutiful, practical, perfect John with his wonderfully cool fingers and calm voice.

Lifting a hand, Sherlock gestures with what is in it, slowly straightening from his doubled-over position on the bottom step. He looks up at John, who is haloed by the overhead light behind him. "Violin was upstairs," he says by way of explaining his actions. His left hand is curled around the neck of the instrument.

"Yes, I know," John says patiently. "I put it there, because you shouldn't be playing, either."

"What should I be doing? Watching telly?"

"If you like."

Slowly and carefully, Sherlock stands. He is shirtless, clad only in a pair of loose-fitting pyjama bottoms despite the chill of the flat. Even the rasp of fabric sends a spark of electric agony flowing through his skin, aggravating hypersensitive nerve endings with every movement. The only reason he's wearing clothes at all is to preserve his own dignity, and John's eyesight.

And perhaps Mrs. Hudson's, too.

Mycroft can go to hell, though, and if Sherlock thought that hanging about the flat stark naked might irritate his brother, he'd do it just for the fun of it.

Oh, that isn't nice. He did poison himself for me, as John is so fond of repeating at every available opportunity.

Sherlock spreads a hand over his chest. "Why do my ribs hurt?"

John bites his lip guiltily. He has no desire to tell Sherlock about the fact his heart stopped shortly after the first dose of Mycroft's serum-laden blood, and so up to this point he's avoided the question or lied. John hates lying, and the lie is weak – even a strong cough like the one Sherlock has right now wouldn't cause the sort of damage that sudden, efficiently-delivered, emotionally-charged CPR would. Did.

"I... dislocated one of your ribs," John says as nonchalantly and as quickly as possible, turning away from Sherlock and heading toward the sitting room. If he thinks that being in the presence of their 'guests' will deter Sherlock from having it out with him, though, he's mistaken.

With surprising speed, Sherlock alights on the floor and goes after John, grabbing his arm just before he reaches the sitting room threshold.

The detective's grey eyes narrow on John's face, which is trying very hard to be passive.

Exhausted, Sherlock reads in the dark circles under John's eyes. Physically, yes, but emotionally too. I've been ill and it was distressing, but there's something else. Thin layer of stubble and a general lack of personal care – he hasn't showered or shaved in two days. Wrinkled shirt, trousers stained with spilt tea and nigh-undetectable flecks of blood. Mycroft's, not mine. He keeps rubbing his shoulder; it's hurting him – why would it be hurting him? Physical exertion, that's why, he's been straining the muscles but not exercising. Sherlock's eyes flick toward the sitting room, scanning the pile of equipment. Portable monitors, syringes, saline, crash trolley, cases of medication, intubation kits of three different kinds.

Crash trolley. Prepared, but not used; charged and waiting in the corner.

Half-used vial of atropine.

I wouldn't have needed atropine, the toxin wouldn't have affected my breathing that badly at that stage, and the toxin causes tachycardia, not bradycardia – atropine would have only been required if my heart rate was low, or if something went wrong, something like...

Cardiac arrest.

Oh.

Sherlock's hand slides from John's arm as he realises what must have happened. He puzzles over it for a moment, wondering why John wouldn't tell him, or would lie to avoid telling him. It doesn't make sense, but then the invented images play in his head like a surveillance tape and the thing that stands out to Sherlock is the amount of stress and grief John must have experienced during that ordeal and he thinks he now has a grasp of why John would keep it to himself.

Something is poking at Sherlock's insides in a painful way and he guesses that it's probably guilt. Obviously he needn't feel guilty for his heart stopping, but he did put himself in the position to be poisoned in the first place, as Lestrade was so fond of telling them: You are not authorised to pursue suspects, either of you! And what about subduing them so that you can swoop in and make the arrest? No, not that either.

"Sherlock..." John says, and there is guilt in his eyes. Guilt. He feels bad.

The words don't come. Sherlock can only stare and stare, for once at a loss for what to say. His eyes are on John, as though the whole world has slipped away.

He stares for so long and with such a strange expression that John becomes concerned, and reaches a hand out. "Sherlock...?"

Mrs. Hudson's voice breaks the spell. "Kettle's boiled, dears, I was – oh, Sherlock. You look a bit peaky. Shall I get the bin?"

"No," Sherlock says faintly, blinking the room back into existence. "No, I'm alright." His eyes end up on John's again with that same strange expression as they turn to go and have tea together like they have done so many times in the past.

Sherlock thinks that what he's feeling now might be Admiration, but it's still vying for space next to the Guilt.

Is caring a disadvantage?

"You have to take it, Sherlock."

"It makes me ill." Sherlock's voice is precariously close to a whine as he stands in the living room. Hovering. Physical contact with the sofa is uncomfortable, so he stands rather frequently. Being that his lungs are functioning at approximately 60% of their normal capabilities, and the dizzy spells and nausea have not abated, this doesn't always work out so well.

John sighs, his patience wearing thin. "You feel worse after a seizure, you said so this morning."

Sherlock winces at the memory.

Mycroft rises from his place in Sherlock's armchair and stands between them. "Sherlock, take your medicine without whining. You are not a five-year-old."

"I don't see you taking yours," Sherlock shoots back at him, disproving the not-a-five-year-old theory.

Rarely if ever does Mycroft sink to Sherlock's level, but this time he does it. With a pointed look, he scoops the tablets off the side table and tosses them back, raising his glass to Sherlock in a silent, sarcastic toast before collapsing back down into the chair. "There," he says. "Now do as you're told."

With a petulant pout, Sherlock shifts his weight, taking on a defensive stance as though preparing himself for a fight. He probably is. Mycroft is seven years older, after all, and they were both children once. They've throttled each other before. "Make me."

John chooses this moment to re-enter the conversation. "I will," he growls, staring Sherlock down.

There is a very long, pregnant silence.

Ever so slowly, Sherlock uncurls one arm, holding out his hand for John to deposit the tablets.

Once he's taken them, John's shoulders seem to relax a little – really, though, he ought to be celebrating, he has just won victories over both Holmes boys. "At last," he sighs. "Next, you'll have a proper meal and sleep in your actual bed." It is not a question, it is not a hypothesis. It is an order.

One that Sherlock feels the need to defy. "We'll see," he grumbles.