Four years ago he jumped off a building to save the people he cared about and a lot has changed since that fateful fall. He spent three years alone with a heart full of a pain that only an array of mind numbing drugs could cure.
When he returned things were different between him and his flatmate, something lay beneath the surface of his mind that he could not quite rid himself of but which he also refused to accept. It lurked like a filthy, smog filled shadow at the back of his mind, subtly altering his actions and changing his mind, clogging it up like a blocked drain. More than ever he sunk into a drug induced stupor, rarely emerging from his room let alone 221B unless a case in which he could thoroughly immerse himself arose. He was beyond the point of return, not caring just determined not to have anything to do with the world and all its complicated matters of the heart.
For the first week he returned John did not think he was real, saw him as another cruel trick played on him by a mind he thought had finally got over the death of the great Sherlock Holmes. Then, when he realised Sherlock was real and not just a figment of his wayward imagination he had chucked him out of Baker Street in a fit of rage and had not allowed him back in for over a month. When Sherlock returned with John's permission to Baker Street it was only because Mycroft, fearing for his brother who had been lying at his house in a drug induced stupor for the past month, forced him to let Sherlock come back.
Eventually John accepted Sherlock back into his life and after forgiving him, tried to wean Sherlock off the deadly cocktail of drugs he was hooked on, burning every stash he found secreted away in various corners of the flat.
Finally after several months everything was seemingly back to the way it had always been, except is wasn't. Something lurked in the back of his mind and in the far reaches of his heart, waiting to pounce on him the moment he let his guard down. He lay awake tossing and turning each night before finally giving up on the idea of sleep altogether and immersing himself in experiment after experiment, carelessly testing new poisons and chemicals on himself before he was sure of the effects or even the antidote. On those infrequent occasions when his body finally shut down and he fell asleep to be found slumped over the kitchen table the next morning by John he was haunted by strange thoughts and haunting dreams.
He had asked her to help him, it was his fault she lay cold, dead and long buried in a graveyard next to a plot that had once belonged to him.
All you have to do is help me survive the fall he had said.
You've always counted and I've always trusted you he had told her.
And just like that she come running at the crook of his finger, only to be halted by the path of a bullet three weeks later when she came to say goodbye to him. A simple late night mugging gone wrong, that was all.
But still his fault.
If he hadn't involved her in his plan she wouldn't have come to wave him off. She would still be alive.
His fault. All his fault.
Only to late did he realise just how much she had meant to him.
How much he needed her.
Wanted her.
Now she was gone and he was alone and lost without her.
John says it's not his fault, trys to get him to go to a psychologist but what does he know.
Sherlock is alone and it's all his fault. He knows John is worried for him, sees the concern etched into his eyes, so he tries to hide how his heart is broken and shattered, ground to dust and blown away on the wind while the rest of him falls apart.
It'll be over soon.
After the funeral, two funerals for one man was really quite an achievement when you thought about it, John read over the coroner's report. It said death due to dependency on drugs but Sherlock would never OD by accident. No one else could know how Sherlock had suffered and how that roiling fog of sheer desperation, lovesick depression and mind shattering boredom had overtaken him and swallowed him up until only one escape remained and as far as John was concerned no one ever would, the remains of that note lay in ashes, scattered on the wind.