There is something wrong with the baby.

Mycroft is only seven years old, but he knows something is wrong with his new baby brother. Babies shouldn't scream like that.

He sees Mummy rush to the bassinet when the baby cries: those dreadful shrieks that shred the eardrums and leave the head spinning. She picks up a blanket, somehow folds and tucks it around the baby so that he's tightly wrapped in a compact package. The baby's cries dissolve into whimpers, the hot blood drains from his face, his body relaxes into its encasement and he falls asleep.

This happens more times than Mycroft can count.

The swaddling doesn't always help, but to the relief of the family, Sherlock almost completely grows out of his shrieking fits by age two.

In the next year Mummy deciphers Sherlock's preferences for certain textures and fabrics. He refuses to wear clothing made from synthetics, first pulling and plucking, then just tearing the articles off his body. This only has to occur once in public for Mummy to resolve that soft, natural fabrics are best for her fussy son. Cottons and flannels in all permutations from pants to undershirts, to bedsheets and blankets. The difference in the child's temperament is immediate.

(Years later, Sherlock can articulate the qualities of different fabrics which attract and repel him: Fine cottons are cool and substantial. He cannot abide the scratch of wool against bare skin, which makes him seethe until he wants to tear his veins out. Satin sheets drag and tug. Silk is delightful but sometimes too airy. A touch of cashmere is like being inside a cloud. Sherlock uses these perceptions to inform his clothing and linen choices for his entire adult life.)

Again the family breathes a collective sigh of reprieve, until elastic waistbands, clothing tags, and labels start to chafe and scratch. Mycroft once finds Sherlock, age three, on the bathroom floor with a pair of large scissors, busily cutting the tags out of his trousers. That is, by cutting straight through the trousers. Mummy tries to laugh when she sees the clipped holes in Sherlock's clothing, but by this time she is starting to show signs of stress. Her gentle nature is being chased away by her constant efforts to stay on top of Sherlock's demands - an impossible task, as his bodily sensitivities are evolving with the progressive brain development that occurs throughout childhood.

And that brain development is remarkably advanced; it's apparent well before Sherlock is school-age and easily recognized because of their first son's own proclivities toward genius. The parents quickly realize they have another gifted child on their hands, which would have been welcomed - they were prepared to enhance their children's gifts - if not for Sherlock's increasing difficulties with environmental stressors. Once Sherlock begins attending school, his social deficits become obvious. He is taken to specialists and put through a battery of tests. Astounding verbal and maths scores, extremely high logic abilities, excellent physical health; but a puzzling array of behaviors which indicate an underlying problem with social skills and below-normal levels of empathy.

Mycroft watches Mummy unravel when the doctors are unable to help, and they label her beloved child "temperamental; high-strung; sensitive." Father finally confesses his suspicions that Mummy created this mess by coddling Sherlock and giving in to his ridiculous demands. Mummy whirls on Father, her face livid with maternal love and defence, ready to fight to the death anyone who challenges her opinion of what's best for her children. Father begins distancing himself. He invents reasons to spend less time at home, desperate for domestic peace far from temper tantrums, altered environments, and special needs.

Despite Sherlock's sensitivity to sound, he enjoys laying at his mother's feet when she plays piano. Beneath the instrument he is surrounded by tones, enveloped in waves that press him into the floor. He begs her to play the low tones and he thrills at the vibrations that reverberate through his thin frame. This musical acuity is revealed to be true talent; he prefers the violin - poignant strains that weep his internal turmoil - but its high pitch is sometimes too much to bear. In fact, he cannot play at all on "bad days."

Mycroft is sixteen when Mummy is hospitalized. It is triggered by an incident involving one of Sherlock's "fits." It's been another bad day; he lays on his bed on top of the duvet, curled into a fetal ball, eyes shut tight against the sunlight filtered through the closed curtains. Mycroft from his bedroom hears a strange noise through their shared wall. He goes into Sherlock's room to investigate, and finds his brother clutching pillows to his head, keening and rocking.

"Make it stop," Sherlock pleads from behind a pillow. Mycroft tries to identify the current source of Sherlock's anguish. He observes nothing out of the ordinary with the bedroom. The beams of sunlight are too filtered to be disruptive. There is no discernable odor (Sherlock is sensitive to strong scents); no distasteful fabrics. Mycroft listens. His own senses are sharp and it doesn't take him long to focus on the potential offenses; observing, for Mycroft, is as natural as breathing. Observing and then deducing.

He hears the radio in Father's study down the hall. Mummy playing the piano downstairs. Melting ice dripping from the eaves outside Sherlock's window. Barely discernable electromagnetic hum. Normal traffic sounds beyond the boundaries of their home. And - oh yes, Mycroft sighs. There it is. The sounds of noisy machinery, jarring construction work three blocks away that Sherlock must hear like it's next door.

Mycroft approaches Sherlock and pries a pillow away. Sherlock opens his eyes, and Mycroft immediately detects their bloodshot condition, and the tears that are trickling from the corners. "Please, Mycroft, make it stop," Sherlock whispers from the edge of agony. He squirms on the duvet, uncomfortable in his skin. "Help me."

Mycroft just stands there holding the pillow. He can't think of anything to say.

Mycroft's lack of response seems to make Sherlock snap. He suddenly bounds off the bed with a snarl, takes three leaps to the window, and, shoving aside the curtains, begins slamming his hands on the glass. The cries coming from his throat are inhuman. Mycroft yells for help, grabs Sherlock's shoulders as he begins hitting his head on the window along with his fists. Mycroft manages to force Sherlock away from the window before he can do any real damage. Father arrives first, followed by Mummy. Father pins Sherlock to the bed. Wrists restrained above his head, Sherlock quiets, gasps for air, but continues to writhe against his father's body. Mycroft observes and is struck by inspiration. He rushes out of the room, grabs an armful of heavy blankets and afghans from the closet at the end of the hall, and returns to dump them all on Sherlock. Father stands aside impatiently while Mycroft and Mummy arrange the blankets. Mycroft also fetches a fan from another closet and sets it on the bedside table, turns it on, and aims it away from Sherlock.

"White noise," he explains. "Drowns out ambient sounds."

His father leaves the room in disgust.

Sherlock tries to remember how to breathe. The weight of the blankets compressing him is strangely soothing. He relaxes into the bed and the purr of the fan. He looks at Mycroft with gratitude and then lets his eyelids fall shut, exhausted from fighting the oppression of the environment.

Their mother is leaning against the doorway, stricken. She swipes at tears with both hands, and wonders hysterically how her beautiful, brilliant son will ever manage to lead a normal life.

Mummy quickly goes downhill. Her hands won't stop shaking. She gains a faraway look in her eyes and she becomes forgetful, distant, listless, unable to concentrate. Mycroft hears a tremor in her voice. She begins to sob behind closed doors. When she is unable to stop crying after two days, Father ushers her out the door. Mummy screams, "Don't you dare take me away from my children! They need me, I am their mother, I won't be separated from them! Do you hear me?" Mycroft and Sherlock watch from the window as Father forces Mummy into the car and they drive away.

She is hospitalized for nerves.

She comes home after two weeks with a prescription for pills. The house is a bit more peaceful now because Sherlock has been sleeping with the fan at his side, body enveloped in blankets. The improved sleeping conditions seem to help him manage during the day. School is still a trial, the roar of the playground an assault of sound and sight, but he can come home every afternoon to the oasis in his bedroom, shut out the daylight, turn on the fan, and rest.

Sherlock is put through more medical and psychological testing a decade after the first round. Mycroft convinces their mother to have Sherlock retested because research is close to defining his spectrum of symptoms. Mummy takes it upon herself to schedule the tests without consulting her husband; by now, they're practically separated, anyway. This time, the doctors explore the possibility of migraine headaches, Asperger's disorder, personality disorder, hyperacusis, tactile defensiveness. One by one they are ruled out or inconclusive. One psychiatrist offers a prescription for a specially designed weighted blanket and antianxiety medication. Sherlock likes the blanket; loves the medication.

At university, Sherlock begins frequenting clubs for amusement when he is bored. At first he is wary of the extremely loud music, but the outrage of his ears is secondary to the beneficial effect on the rest of his body. He can tolerate the screaming upper ranges because the bass is so solid. The vibrations of it in his solar plexus slow and intensify his breaths. For once the brainwork halts, and he can enjoy the paradoxical peace that comes with massive bodily sensation.

Aided by his striking appearance, Sherlock discovers during his nights out that people of both genders consider him attractive. This is an interesting revelation; he finds himself craving touch but also recoiling from the actual experience. He experiments with men and women to see for himself what the fuss is about, kisses them, lets them put their hot wet tongues in his mouth. Their trailing fingertips are cobwebs against his skin. They maul and pinch and leave bruises in the name of pleasure. Sherlock ceases each experiment in intimacy when hands begin to grope south. He cannot cope with being kissed and touched; he can only imagine what sexual intercourse would do to his overwrought brain and body. Naturally, these half-gone encounters do not end well, usually resulting in ugly scenes. He endures shouted insults, drinks thrown in his face, handbags swung at his head. Once, Sherlock is unable to deflect a huge punishing fist that connects with his jaw.

Sherlock gives up on sex and dives into drugs. These experiments are conducted in much the same way until he settles on a satisfying mix of cocaine and opiates, alternating them depending on the state of his sensory arousal. He's just chipping at first, for the sensible aim of treating the problem, but it develops into a habit.

Big brother is watching, of course. Mycroft visits Sherlock in his shabby room, finds him sprawled on the tiles of the bathroom floor, seemingly unconscious. He prods Sherlock's thigh with the tip of his umbrella. Sherlock squints up with one eye, barely registering the stern face looking down at him.

Very cold: "So, Sherlock. What is it today? Heroin? Pills, perhaps?"

This causes Sherlock to snap both eyes open. No point in hiding it. He opens his hand to reveal an empty prescription bottle. "You know."

"Oh yes, and I know all about your cocaine use, too. I know when you use and how much you use, though why you would want to overstimulate your sensitive nervous system is beyond me. And you know how upset Mummy would be if she knew."

"I can't live with the overload. But sometimes I'm so... dull, and that hurts too," Sherlock mutters, his gaze shifting to the side. "Don't you understand? I just want to feel normal. The way everyone else gets to feel!"

"Well, you don't get that," Mycroft snaps. "You don't get to feel like everyone else. Consider it the price of your genius. We're different, we're not like the rest of them."

"Don't put yourself in league with me," Sherlock sneers. "You're not like me and you know it. You don't suffer as I do. You fit in."

Mycroft sighs. "I may not have your low sensory threshold, but I know what it's like to have no control over the constant datastream. There are ways to cope -"

"I'm trying!"

"I am not talking about drugs, Sherlock." Mycroft bins the prescription bottle. "Not like this. There are ways to manage without resorting to these wild cycles of artificial stimulation and depression. Promising studies are being done on pink noise -"

"I'm done with studies." Sherlock remembers past experiences with clinical trials for this problem that has no name.

"Let's try something else, then. Something more immediate."

They go into the sitting room and Mycroft has Sherlock stretch out on the sofa. He puts his hand on Sherlock' stomach, tells him to focus on filling his lungs with air, deep full breaths followed by slow exhales. Sherlock rolls his eyes in scorn and tries to get up. "This is ridiculous -"

Mycroft says, "Humor me," and though it's spoken mildly, it's an order. Mycroft steers Sherlock back into a prone position.

Mycroft directs him to slow his rate of respiration until he feels lucid and calm. Tells Sherlock to focus on the sound of his voice and the rhythm of his own breathing. After fifteen minutes of meditative imagery, Sherlock's jaw slackens, his face relaxes, and his limbs feel heavy and sodden. Mycroft drapes the weighted blanket around Sherlock's long body. He pulls three books at random from the shelf (British Birds, Catullus, The Holy Wars) and stacks them on Sherlock's stomach for increased compression. Mycroft glances around the cluttered room, reminding himself to speak to Sherlock about the need to reduce the visual confusion for improved clarity of thought.

Sherlock doesn't completely stop using drugs (not yet, anyway; real sobriety comes a few years later) but he finds solace in the meditation. With Mycroft's assistance, he tries mantras to help him reach the other side of silence even faster. He experiments with different phrases, finally settling on the words "ground and center." Ground to remind him to plant his body into whatever surface he is lying on: bed, sofa, or floor. Center to remind him to shut out the environment and breathe from the depths of his core. It helps, but it's a treatment, not a cure.

John Watson enters Sherlock's life by way of a chance introduction. At their first meeting Sherlock assumes John is like everyone else: idiots, all of them, who can't keep up and threaten to upset his equilibrium with their banalities. He very quickly realizes that his initial assessment of John is incorrect. He adjusts his theory to fit the data, and comprehends the potentially earth-shattering impact this new friend could have on his life. If he's not pushed away by Sherlock's temperament, that is.

The day after meeting John, Sherlock becomes involved in the serial suicide case.

Later that evening, his flat is invaded, his personal belongings are searched, his sobriety is questioned. Sherlock paces. The whirlwind of chaos threatens to take his body and mind hostage. Too much commotion. He's trying to think, can't they see that? He's trying to think while their annoying voices pummel his ears with their unimportant questions and comments. Sherlock twitches beneath his clothes, prickly and defensive.

He notices for the first time that John is watching him intently with an expression that can only be identified as concern. Sherlock is accustomed to seeing expressions of offense and disgust on the faces of people around him; John's reaction is singular. Sherlock catalogs this observation. He vows to attend to it when this is over. Now, in addition to the sensory stimulation, he feels Anderson's hateful eyes drilling holes into his back. It sends him over the edge. "Shut up!" he yells with unbridled contempt. "Don't move, don't speak, don't breathe! Anderson, face the other way, you're putting me off." Tension building inside him, his heart a fist in his chest. He fights the urge to flee.

Lestrade doesn't exactly comprehend what is going on beneath the surface, but he recognizes signs that Sherlock is at his breaking point. He understands Sherlock well enough to know what he needs. Lestrade calls for quiet and orders Anderson to turn around. Anderson reluctantly obeys. Mrs. Hudson pesters and Sherlock snaps. Suddenly there is blissful silence. Stillness. Sherlock breathes. The body now quiet, the brain can take over and do its work. The puzzle is solved and, happily, we know how that one ends: with John taking cold aim down the sights of a handgun and saving Sherlock's life with one well-timed, well-placed bullet. Interesting. It seems there's more to John Watson than would appear on the surface, beyond those boring jumpers and common intellect.

John continues to exert a powerful influence on Sherlock. For the first time, Sherlock feels utterly grounded by another person. In fact, being in John's presence is like being chained to an anchor after years of floating aimlessly. John proves his infinite value by smoothing potentially difficult social interactions, by attending to Sherlock's manic input/output of information, by knowing exactly when Sherlock requires silence, or conversation, or a cup of tea, or a meal, or companionship, or solitude. John passes test after test like no one else before him. Stunned, Sherlock realizes that, despite his best efforts, he is unable to push John away. Apparently John intends to stay.

Sherlock stretches into his favorite sofa position. Grounds himself. At some point over the years he became accustomed to placing his hands together beneath his chin, as if praying. The pose comes naturally whenever he needs to concentrate and center his energy.

Meditations complete, he lifts his feet and rests them on the top of the sofa, knees bent. Eyes remain closed. He reaches out tentatively - it's like testing the temperature of bath water - listens for distractions. He finds comfort in listening to John's regular breathing, the clicks of the laptop keys as he types at the desk. He perceives the distant dull hum of the refrigerator. Fat raindrops hitting the window panes in a disjointed pattern. Mrs. Hudson hoovering downstairs. Curiously, none of this registers as noise. Sherlock exhales.

John looks up. "What is it? What's wrong?" he asks softly.

Seconds pass as Sherlock processes. His body is solid against the texture of the sofa on his back, the upholstery of the damask pillow a cradle beneath his head. The healing white aura of human warmth before him that is John's life force.

"Nothing's wrong," Sherlock whispers. "Nothing at all."

He's found his sanctuary. He's finally home.