This story will eventually contain triggers for eating disorders and self-injury.
So it is that seven years later, Mycroft is the one who piggybacks Sherlock on the way to Doctor Watson at 221B Baker Street. Mummy trails after them, her face washed out and her hair hanging tangled in her face. Daddy is in Singapore.
Sherlock thinks Mycroft is the strongest person in the universe, even if he has to put him down every half a block. He watches the passersby with wide-eyed wonder.
When they get to the subway, it's too crowded for piggyback, so he has to hold onto Mycroft's hand instead. The noises hurt his ears and the data flow makes his head ache. Sherlock buries his face in Mycroft's warm belly and listens to the watery gush of his insides. As soon as they climb back into the sunlight, Mycroft picks him up again.
Finally, as they turn onto Baker Street, Mycroft sets him down for the final time. He puts both his hands on Sherlock's shoulders. Sherlock looks at his feet. Even though it isn't raining, he's wearing his favorite galoshes.
Mycroft sighs.
"Little brother," he says, "finding a pediatrician in London isn't easy. I'm growing tired of trying. Please do be good to this one."
He gives Sherlock the same speech every time.
"I hate doctors," Sherlock says to his shoes. "I don't want to go. I'm healthy. I want to go home."
"You can't tell that for yourself."
"My heart beat is one hundred twenty-five a minute. The temperature in my timepanic cavity is 36.2. I pass stool thr-"
"Tympanic," Mycroft corrects, then takes his hand and tugs him up the steps. He rings the doorbell, then turns back. "Mummy, we're going in right now. Could you come with us, please?"
His voice always gets gentle when he talks to Mummy. This is one of their rules. Sherlock knows that Mummy is sick with something that makes her sad, like the time his pet rabbit got out and was eaten by a local cat, but worse.
An old woman opens the door. She's wearing a flowery dress. "You smell like cinnamon and ... and something chalky. Are you making cookies?"
"Denture solution," says Mycroft.
Sherlock does not care about that. "Can I have some?" he asks.
Her hands flutter at her throat. "Oh, my," she says, then leans back and calls up the stairs. "John! Your patients are here!"
There is an uneven pounding on the stairs. Sherlock squints, thinking, then yanks Mycroft's arm. Mycroft leans down and inclines an ear towards Sherlock. "A limp. He's got a cane."
He doesn't have to wait for an answer, because they can soon see the man himself proceeding down the steps. He does, indeed, have a metal cane at his side. His hair is a dusty blond.
He looks at the old woman, and pats her shoulder. "Thank you, Mrs. Hudson. I can get on from here." His gaze swings first to Mummy, who's hanging back at the door and scratching at the base of her hand, then to Mycroft, and finally to Sherlock. "You must be the Holmes."
Mycroft nods. "Yes. Mummy called earlier about the appointment."
Doctor Watson looks to Mummy again, frowning. "Right. Funny, she sounds quite a bit like you."
Mycroft's hand tightens around Sherlock's, who decides that he hates this man who makes his brother nervous.
But Doctor Watson only rubs his face, then nods. "Right," he says, "I'm sorry, that's no problem. I'm a little tired. I don't usually do ... this. Come on up, then."
He turns and limps up the stairs.
Mycroft tugs him upwards. Mummy follows.
##
When they get upstairs, Doctor Watson won't let Mycroft and Mummy come in with him. Sherlock crosses his arms over his chest and corrects his stance to make himself immobile. Even Mycroft gives the Doctor a harsh look and moves to take Sherlock away until the doctor shows him how he'll leave the door open a crack. He explains that Mycroft can come in any time he wants - he just needs to talk to Sherlock alone for a bit, please, for the sake of his privacy.
After that, Mycroft pushes him forwards. Sherlock walks into the room behind Doctor Watson.
It's an office, a stark little thing with green wallpaper and nothing on the walls. It hasn't got certificates like most of the doctors Sherlock has been to - he thinks this might be because Doctor Watson is a consulting pediatrician, whatever that is. There are two chairs in it, one a leather desk chair and the other clearly pulled from the kitchen, because it matches the ones around the table.
Doctor Watson sits in the leather chair and swivels around to face Sherlock. Sherlock looks at the kitchen chair, then crosses his arms and makes his eyes go cold and flat. It's a trick he mastered in the bathroom mirror. He uses it when kids at school try to tease him.
"I'm healthy."
The corners of Doctor Watson's mouth turns up. "Right, of course. Let's just do a few checks to be sure, shall we?"
Instead of answering, Sherlock turns and surveys the room.
There's a skull sitting on the bookshelf, its wide eyes gaping. Doctor Watson catches him looking and stands up, limping towards it. "That's, er - I call him Yorik. Do you want to see?" He turns it around and wags it at Sherlock, as if it were talking. He makes his voice go hoarse, like a dead thing. "Hello, little Sherlock."
Sherlock flattens himself against the wall and narrows his eyes. He doesn't like that voice. It makes his heart jump in his chest. "I'm not little."
"Sorry, sorry. Of course you're not." Quickly, Doctor Watson turns to put it back, but Sherlock sticks out his hands.
"But I want to see. Give it to me."
"Of course." The doctor drops it into his outstretched palms. "You've got a good set of lungs on you."
Sometimes people tell Sherlock that he talks too loud. He doesn't care. He sits down where he is and turns the skull over in his hands. It's smooth. He runs his fingers over the top of the skull, where there are thin indents.
The cane tap-tap-taps against the floor as the doctor limps over. "It's interesting, isn't it?"
Sherlock shrugs.
"Do you want to know what those are?"
"I know what they are. They're cracks in the skull. The person fell, probably from a great height, because bones are harder than concrete - you can crack them if you get a funny angle, like the time when Mycroft was climbing to reach the mugs at the top of the cupboard and he slipped and snapped his - his -" He shuts his eyes, trying to remember the word. "Lemur. He broke his lemur. But you can't get a skull at a funny angle because it's round, so you'd have to drop it from somewhere high."
For some reason, the corners of the doctor's mouth are twitching.
"That's really clever, Sherlock. It's not exactly right, though."
"Did you drop it after you got it out of a head?"
"Er - no. When you're a baby, your skull is all in pieces. The pieces get stuck together when you grow up, and they make those lines. They're called sutures."
Sherlock thinks about this. He turns the skull over in his hands. Thoughtfully, he rubs his thumb over its teeth, then puts a finger in his mouth to see if his own feel the same. He's not supposed to suck his thumb - Mummy says its dirty and childish and causes dental problems besides - but this is different. His own teeth are rougher, covered with a film that this one doesn't have.
"Is it real, then?"
"It is. Listen, Sherlock. We need to do some tests just to make sure you're completely healthy. Why don't you hold onto that while we do them?"
"What if I don't want to do them?"
"Then I'll have to take Yorik away. Sorry." He sounds so apologetic that Sherlock is sure that if he doesn't some natural law will make itself known. Reluctantly, Sherlock stands. He grips the skull tightly in both hands.
Doctor Watson asks him a bunch of questions. He makes him open his mouth so he can look down his throat. He sticks a device in Sherlock's ear - "36.2," Sherlock informs him, and Doctor Watson laughs and tells him he's brilliant, which makes him feel warm and bright.
When he stands on the scale, Doctor Watson says he must take off his galoshes and cardigan, and let go of the skull. Sherlock frowns.
"What if we put the skull and the cardigan on the galoshes on the scale and measured them without me? Then I'd be whatever is left over."
The doctor stares at him. "Where did you hear that?"
"It was on the Storyteller. On October second, Sir Boast-a-lot meets a dragon who -"
Sometimes, he gets so caught up in doing something that he looses track of the world. It's disconcerting, but he's used to it.
By the time he's done explaining, Sherlock finds himself sitting on Doctor Watson's desk chair, his hands held together and pressed against his lips.
His galoshes are on the floor.
He catches the doctor staring at his bare feet. He doesn't have any socks, and they're covered in dead skin that looks like grey scales. Sherlock pulls his legs in to his chest and glares.
"Sorry," the doctor says again, then rises. "Anyway, I think we're done here. You've been very good, Sherlock."
Sherlock climbs off the chair. "I'm going to hold the skull while you look at Mycroft."
The doctor smiles again. Sherlock decides that he sort of likes the expression after all. "I can't see why not." He passes the skull over, and Sherlock cradles it to his chest. "On you go, then."
###
Afterwards, when Sherlock and Mycroft are both done their examinations, Doctor Watson comes out to speak with Mummy. Sherlock, who's taken up residence in in an overstuffed sofa with a Union Jack pillow on it, explores the skull with his fingers. He's only half-listening. Although it's unlikely that anyone will provide him with this information later, he's long since learned that adult conversations are almost universally boring. Mycroft sits next to him, his squeezing his hands so tight that his knuckles turn white.
He hears snatches of words: 'slightly malnourished', 'clearly intelligent', and 'some concerns about hygiene.'
Once, when the doctor reaches forwards to touch Mummy's shoulder and drops his voice a register, Sherlock catches a whole sentence: 'If you're having difficulties, there's no shame in seeking help.' He says a number and Mummy writes it down.
On the way out, Mummy takes Sherlock's hand. Her fingers are cold. He looks up in surprise, then slips his hand from hers and grabs Mycroft's instead.
With surprising gentleness, Mycroft puts it back around Mummy's. He takes Sherlock's other hand, though, so that's alright.