Seance

Three years was a long time to be away from one's home, longer still when you lived a waking sleep and could no more understand the language of your surroundings than you could speak it.
Sometimes he felt like a ghost and wondered if he had died that afternoon at St Bartholomew's, then Mycroft would text, two or three words, and he'd remember that he was human, living, that he should eat and remember to sleep, and that one day, he'd get to go home.
Mycroft failed to tell him that he no longer had a home to go to.
Maybe Mycroft hadn't heard the old saying; what was it? A house is more than bricks and mortar and clay. Or the other, Home is where the heart is, though Sherlock hadn't got a heart, had he? Then of course Christian Morganstern once said that Home is not where you live, but where they understand you, and in that respect, perhaps Sherlock had never had a home, not once.
Three years away from London was enough however. Three years away from familiarity.
Knowing that everything around one remained perpetually unchanging meant that one could concentrate on the small things that were different, the things that were important. In new places, with new languages, new soundscapes, landscapes, cityscapes and new skies; everything needed to be examined in turn, and the noise often became deafening.  
Sherlock had learnt to sleep with one eye open. The men he was hunting were also hunting him. It was a game of draughts, the King had been the first piece taken yet every piece on the board wanted desperately to take the crown.
Moriarty was dead. His kingdom had not been. Not until now.
Thirty eight months and twelve days, fifteen countries, fourteen dead men, three arrested and one Sherlock Holmes with eight new scars and a longing that he'd not felt before in his life time. A longing for home.
Sherlock sometimes forgot what language he actually spoke, he passed country boarders often. He could go days without saying a word and wondered occasionally if he might have dropped his voice on a foreign road somewhere, and had it blown away by the breeze- and he wondered where  it might land. Perhaps, just perhaps he would return to England and sit in his chair in 221B Baker Street and find that someone had retrieved his art of conversation, as small as it had been, and it was waiting there for him in an envelope addressed to The Ghost of Sherlock Holmes on the mantle.
He never imagined that when he returned to London it would seem just as alien as each of the other countries he had visited.
Despite his intellect, despite the information given, he couldn't have deduced that going home would be nothing at all like waking from a dream to find yourself safe and warm in bed.
Sherlock looked at himself in the familiar mirror over the fireplace at 221B, and for the first time studied the silvery additions to his face; the first running perfectly across the line of his right cheekbone, and the other curling a tiny smile like gesture on the left side of his lip. His hair was longer he noted, and his frame thinner. He had changed. He had not intended to do so. London must change too, he supposed. Three years was a great deal of time for someone to mourn.
He recalled a conversation with Mycroft about the futility of mourning, and the sheer nonsense of its nature. Despite his previous hatred of the notion, he had hoped that John Watson would have mourned him, would still be mourning. Sherlock found instead that on returning, that that word too had no meaning. No sense.
The living area and kitchen looked much the same, once he had pulled the dust sheeting from his furniture. There were some books missing, and most of the crockery. It had been John's. The house was not however as he left it. The warmth was missing.
Sherlock tried to sleep. He still slept as if expecting to be woken. He had anticipated that despite the gang members all having been dispatched, it would be his home that would sate him, and that his own bed might carry him finally into the arms of Morpheus and Queen Mab. This was not his home however. This 221B was an artist's impression. An approximation of what the flat should look like. It was a replica, a forgery:- though it looked nearly the same, it lacked all the character of the original. It was empty.
Sherlock felt empty too.
It was three days before Mrs Hudson would speak to him, and when she did it was with tears, and anger and something akin to happiness. It seemed far away, and it was tinged with a sadness that Sherlock could not place.
It took three weeks before he was able to ask about John, to push his name past his lips and work out how to form the syllables that to the shape of his mouth felt like h-o-m-e. She looked at him with sad, knowing eyes and told the truth. John was not in London any longer, he had a family, a job, a new house in the country. No, that was not the word she used. John had a new home in the country.  
Sherlock had asked her to leave.
Sherlock was as lost in London as he had been in Paris and Amsterdam and Madrid.
Mycroft text him twice, to remind him he was alive, that he should eat and try to sleep.
Lestrade text him once to tell him that he was forgiven.
John did not text him at all.
Sherlock became more and more convinced that he was nothing but a spectre.
***
It was on the third month of returning to London town and moving slowly about its streets, haunting various places that they used to visit, that Sherlock Holmes finally pulled out his telephone with shaking slender fingers, and typed a message he nearly did not send.
"Am I still alive? I cannot recall. S.H"
He wanted an answer, something. Anything. He wanted John to come and punch him until his knuckles were red with it, he wanted him to shout and scream and curse him for dying.  
Perhaps he was already cursed.
Sherlock had never before experienced loneliness. John had introduced him to the scent of a home and to a notion of safety and companionship that he had never previously considered. In committing suicide to save his friends, Sherlock had severed the connections that he had been striving to preserve. Irony was a compelling notion, and one that was not lost on him.
It was nearly a week before a reply found its way through the air to Sherlock's phone.
"It would appear that you are indeed living. J.W"
The text was not one that sifted comfort into his bones, it was a start, but John knew everything without even having to see him for himself. He was living yes, but not alive.
Sherlock was stuck in a purgatory between life and…something other. A floating world where each movement was as heavy as lead and took aeons to execute. A slow, sticky actuality that meant that one was constantly moving against a tide of black syrup and oil, vision blinded, movement stilled, limbs heavy.
It took an hour to compose his reply.
"I enjoyed your eulogy. It made me feel. S.H"
He had attempted to explain to John what it had made him feel, that despite death, the other's words were what kept him from believing he was actually gone. He had deleted the lines of text more than twice a minute, and eventually sent lacking.
"I hated your funeral, it made me feel. J.W"
Unsurprising. Predictable.
"I need to see you. I want to feel. S.H"
His thumb slipped to the send button like a death sentence. If John had wanted to see him, it would have already have come to pass, but the doctor had always put the needs of others before his own. It was a virtue Sherlock hoped he had retained.
His chest ached as the stone in his stomach grew weighted and Sherlock wondered briefly if Mycroft might send him messages every now and then to remind him how to breathe.