The boy is a man now.
Warning: this is more angsty than the rest of the story. So please read on your own discretion and review!
Sherlock is thirty four, a living and breathing lightning sliding over the rooftops of London, glimpses of arrogant curls flashing in dark alleys and up steep fire ladders, iron muscles lurking under creamy pale skin. Lestrade blames his being almost completely gray now on multiple nearly-heart attacks Sherlock's been giving him over years. But however much Sherlock teases Greg for being obtuse even he never doubts the DI would have made a brilliant career still without Sherlock's weaving his way in and out of the policeman's office.
On that day Mycroft has been calling Sherlock since early morning. The lanky detective ignores his brother as thoroughly as usual, running across the city after another serial murderer. When finally Lestrade has the killer in cuffs and Sherlock is done with an eloquent explanation of his deductions and earned a couple more acidic 'freak's from Donovan, he concedes to checking his phone. There is a dozen of missed calls and only one text, with one simple question, 'When did you go home last time, brother mine? - MH'.
Sherlock frowns, for all his incredible brilliance he doesn't see at once where Mycroft is going with this. Sherlock hasn't been in the old empty (since their father's death) mansion for almost two years now, since he got clean and Lestrade agreed to provide him with cases to solve again. But before that he has been going back at least once a year to see…
Sherlock's hand holding his phone suddenly trembles…
…to see John.
Sherlock whirls on the spot and dashes away, surprised and suspicious Lestrade barking something after him. Then Greg's phone chimes and he suddenly looks understanding and sorrowful. He re-reads the short text for a couple of times as if trying to find some other meaning than it actually contains. In the evening after patiently piling a heap of ready paperwork on his desk the DI goes to a pub. He gets as drunk as he possibly can, long-forgotten memories marching in a neat row in front of his dazed eyes.
The sun is setting when Sherlock is finally briskly walking across a meadow over-grown with weeds. He skipped past the gloomy mansion without a second thought. His destination is the small farm nearby that is run by some sweet old couple hired by Mycroft - now that Mrs. Hudson is a happily widowed landlady in Baker Street.
The stables were rebuilt a long time ago, to provide a more comfortable accommodation for much fewer horses. Sherlock knows only Mycroft's horses live here now, the ones he uses for organizing strategic riding parties and hunts with high-ranking guests he deems necessary to entertain. So it's half a dozen Mycroft's horses… and John.
John's stall is at the farther end of the stable and Sherlock slowly walks there in semi-darkness, absorbing familiar comforting sounds of light hoof clicks as horses shift in the stalls, crunching of hay and gentle puffs of breath. Sherlock knows what he will see in John's stable but it turns out nothing could have prepared him for this. In his mind's eye John is always shiningly golden, strong and healthy, always fast and intelligent. This John is completely white with age, lying on the ground despondently, breathing slowly and raucously. But he sees Sherlock and recognizes his boy at once. He tries to get up, but weak legs only scratch the ground jerkily. And he gives up, lays back on his side, sighing almost apologetically.
Sherlock goes down on his knees as if broken. He slides his shaking fingers through the still soft mane and struggles to say something but only chokes on dry gasps. John is gone only minutes later, last gentle neigh more a breath than a sound. It's as if he has been waiting only to see Sherlock for one last time. And when Sherlock realizes his lifetime friend has left he loses it, hugging the limp neck tightly and crying without tears, his whole body wracked by immense sobs.
Mycroft, lurking in the shadows outside John's stall, knows better than to try to comfort his little brother.
Approximately one year later Sherlock is gloomily dropping acid in a Petry dish of another atrociously dangerous liquid when Mike Stamford leads a short golden-haired man in the laboratory. Sherlock is instantly captivated by something in this man that he can't quite put his finger on yet. And his breath stalls suddenly when he hears, 'This is John Watson.' Life looks promising for once.